--- 1/draft-ietf-cdni-control-triggers-03.txt 2014-09-03 09:14:35.709877659 -0700 +++ 2/draft-ietf-cdni-control-triggers-04.txt 2014-09-03 09:14:35.773879230 -0700 @@ -1,27 +1,27 @@ Network Working Group R. Murray Internet-Draft B. Niven-Jenkins Intended status: Standards Track Velocix (Alcatel-Lucent) -Expires: January 3, 2015 July 2, 2014 +Expires: March 7, 2015 September 3, 2014 CDNI Control Interface / Triggers - draft-ietf-cdni-control-triggers-03 + draft-ietf-cdni-control-triggers-04 Abstract - This document describes the part of the CDN Interconnect Control + This document describes the part of the CDN Interconnection Control Interface that allows a CDN to trigger activity in an interconnected CDN that is configured to deliver content on its behalf. The upstream CDN can use this mechanism to request that the downstream - CDN pre-positions metadata or content, or that it re-validate or - purge metadata or content. The upstream CDN can monitor the status + CDN pre-positions metadata or content, or that it invalidates or + purges metadata or content. The upstream CDN can monitor the status of activity that it has triggered in the downstream CDN. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Status of This Memo @@ -31,216 +31,178 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on January 3, 2015. + This Internet-Draft will expire on March 7, 2015. Copyright Notice Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 - 2. Model for CDNI Triggers . . . . . . . . . . . . . . . . . . . 5 - 2.1. Timing of Triggered Activity . . . . . . . . . . . . . . 7 - 2.2. Trigger Results . . . . . . . . . . . . . . . . . . . . . 7 - 3. Collections of Trigger Status Resources . . . . . . . . . . . 7 - 4. CDNI Trigger interface . . . . . . . . . . . . . . . . . . . 8 - 4.1. Creating Triggers . . . . . . . . . . . . . . . . . . . . 9 - 4.2. Checking Status . . . . . . . . . . . . . . . . . . . . . 11 - 4.2.1. Polling Trigger Status Resource collections . . . . . 11 - 4.2.2. Polling Trigger Status Resources . . . . . . . . . . 11 - 4.3. Deleting Triggers . . . . . . . . . . . . . . . . . . . . 11 - 4.4. Expiry of Trigger Status Resources . . . . . . . . . . . 12 - 4.5. Error Handling . . . . . . . . . . . . . . . . . . . . . 12 - 5. Properties of Triggers . . . . . . . . . . . . . . . . . . . 13 - 5.1. Properties of Trigger Requests . . . . . . . . . . . . . 13 - 5.1.1. Content URLs . . . . . . . . . . . . . . . . . . . . 14 - 5.2. Properties of Trigger Status Resources . . . . . . . . . 15 - 5.3. Properties of ErrorDesc . . . . . . . . . . . . . . . . . 16 - 5.4. Properties of Trigger Collections . . . . . . . . . . . . 17 - 5.5. Trigger Resource Simple Data Type Descriptions . . . . . 17 - 5.5.1. TriggerType . . . . . . . . . . . . . . . . . . . . . 17 - 5.5.2. TriggerStatus . . . . . . . . . . . . . . . . . . . . 18 - 5.5.3. URLs . . . . . . . . . . . . . . . . . . . . . . . . 18 - 5.5.4. AbsoluteTime . . . . . . . . . . . . . . . . . . . . 18 - 5.5.5. ErrorCode . . . . . . . . . . . . . . . . . . . . . . 18 - 6. JSON Encoding of Objects . . . . . . . . . . . . . . . . . . 19 - 6.1. JSON Encoding of Embedded Types . . . . . . . . . . . . . 20 - 6.1.1. TriggerType . . . . . . . . . . . . . . . . . . . . . 20 - 6.1.2. TriggerStatus . . . . . . . . . . . . . . . . . . . . 20 - 6.1.3. PatternMatch . . . . . . . . . . . . . . . . . . . . 20 - 6.1.4. ErrorDesc . . . . . . . . . . . . . . . . . . . . . . 21 - 6.1.5. ErrorCode . . . . . . . . . . . . . . . . . . . . . . 22 - 6.2. MIME Media Types . . . . . . . . . . . . . . . . . . . . 22 - 7. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 22 - 7.1. Creating Triggers . . . . . . . . . . . . . . . . . . . . 23 - 7.1.1. Preposition . . . . . . . . . . . . . . . . . . . . . 23 - 7.1.2. Invalidate . . . . . . . . . . . . . . . . . . . . . 24 - 7.2. Examining Trigger Status . . . . . . . . . . . . . . . . 25 - 7.2.1. Collection of All Triggers . . . . . . . . . . . . . 25 - 7.2.2. Filtered Collections of Triggers . . . . . . . . . . 26 - 7.2.3. Trigger Status Resources . . . . . . . . . . . . . . 28 - 7.2.4. Polling for Change . . . . . . . . . . . . . . . . . 30 - 7.2.5. Cancelling or Removing a Trigger . . . . . . . . . . 33 - 7.2.6. Error Reporting . . . . . . . . . . . . . . . . . . . 35 - 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 36 - 8.1. CI/T MIME Media Types . . . . . . . . . . . . . . . . . . 36 - 9. Security Considerations . . . . . . . . . . . . . . . . . . . 36 - 9.1. Authentication, Confidentiality, Integrity Protection . . 36 - 9.2. Denial of Service . . . . . . . . . . . . . . . . . . . . 37 - 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 37 - 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 37 - 11.1. Normative References . . . . . . . . . . . . . . . . . . 37 - 11.2. Informative References . . . . . . . . . . . . . . . . . 37 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38 + 2. Model for CDNI Triggers . . . . . . . . . . . . . . . . . . . 4 + 2.1. Timing of Triggered Activity . . . . . . . . . . . . . . 6 + 2.2. Trigger Results . . . . . . . . . . . . . . . . . . . . . 6 + 3. Collections of Trigger Status Resources . . . . . . . . . . . 6 + 4. CDNI Trigger Interface . . . . . . . . . . . . . . . . . . . 7 + 4.1. Creating Triggers . . . . . . . . . . . . . . . . . . . . 8 + 4.2. Checking Status . . . . . . . . . . . . . . . . . . . . . 10 + 4.2.1. Polling Trigger Status Resource collections . . . . . 10 + 4.2.2. Polling Trigger Status Resources . . . . . . . . . . 10 + 4.3. Cancelling Triggers . . . . . . . . . . . . . . . . . . . 10 + 4.4. Deleting Triggers . . . . . . . . . . . . . . . . . . . . 11 + 4.5. Expiry of Trigger Status Resources . . . . . . . . . . . 12 + 4.6. Loop Detection and Prevention . . . . . . . . . . . . . . 12 + 4.7. Error Handling . . . . . . . . . . . . . . . . . . . . . 13 + 4.8. Content URLs . . . . . . . . . . . . . . . . . . . . . . 13 + 5. CI/T Object Properties and Encoding . . . . . . . . . . . . . 14 + 5.1. CI/T Objects . . . . . . . . . . . . . . . . . . . . . . 14 + 5.1.1. CI/T Commands . . . . . . . . . . . . . . . . . . . . 14 + 5.1.2. Trigger Status Resource . . . . . . . . . . . . . . . 15 + 5.1.3. Trigger Collection . . . . . . . . . . . . . . . . . 16 + 5.2. Properties of CI/T Objects . . . . . . . . . . . . . . . 17 + 5.2.1. Trigger Specification . . . . . . . . . . . . . . . . 18 + 5.2.2. Trigger Type . . . . . . . . . . . . . . . . . . . . 19 + 5.2.3. Trigger Status . . . . . . . . . . . . . . . . . . . 19 + 5.2.4. PatternMatch . . . . . . . . . . . . . . . . . . . . 20 + 5.2.5. Absolute Time . . . . . . . . . . . . . . . . . . . . 21 + 5.2.6. Error Description . . . . . . . . . . . . . . . . . . 21 + 5.2.7. Error Code . . . . . . . . . . . . . . . . . . . . . 22 + 6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 22 + 6.1. Creating Triggers . . . . . . . . . . . . . . . . . . . . 23 + 6.1.1. Preposition . . . . . . . . . . . . . . . . . . . . . 23 + 6.1.2. Invalidate . . . . . . . . . . . . . . . . . . . . . 24 + 6.2. Examining Trigger Status . . . . . . . . . . . . . . . . 25 + 6.2.1. Collection of All Triggers . . . . . . . . . . . . . 25 + 6.2.2. Filtered Collections of Triggers . . . . . . . . . . 26 + 6.2.3. Trigger Status Resources . . . . . . . . . . . . . . 28 + 6.2.4. Polling for Change . . . . . . . . . . . . . . . . . 30 + 6.2.5. Removing a Trigger . . . . . . . . . . . . . . . . . 33 + 6.2.6. Error Reporting . . . . . . . . . . . . . . . . . . . 35 + 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 36 + 7.1. Media type registrations . . . . . . . . . . . . . . . . 36 + 7.1.1. CI/T Commands . . . . . . . . . . . . . . . . . . . . 36 + 7.1.2. CI/T Trigger Status Resource . . . . . . . . . . . . 37 + 7.1.3. CI/T Trigger Collection . . . . . . . . . . . . . . . 38 + 8. Security Considerations . . . . . . . . . . . . . . . . . . . 39 + 8.1. Authentication, Confidentiality, Integrity Protection . . 39 + 8.2. Denial of Service . . . . . . . . . . . . . . . . . . . . 39 + 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 40 + 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 40 + 10.1. Normative References . . . . . . . . . . . . . . . . . . 40 + 10.2. Informative References . . . . . . . . . . . . . . . . . 40 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 41 1. Introduction - [RFC6707] introduces the Problem scope for CDN Interconnection (CDNI) + [RFC6707] introduces the problem scope for CDN Interconnection (CDNI) and lists the four categories of interfaces that may be used to compose a CDNI solution (Control, Metadata, Request Routing, Logging). - [I-D.ietf-cdni-framework] expands on the information provided in - [RFC6707] and describes each of the interfaces and the relationships - between them in more detail. + [RFC7336] expands on the information provided in [RFC6707] and + describes each of the interfaces and the relationships between them + in more detail. This document describes the "CI/T" interface, "CDNI Control interface / Triggers". It does not consider those parts of the control interface that relate to configuration, bootstrapping or - authentication of CDN Interconnect interfaces. Requirements for CI/T - are the "High" and "Medium" priority requirements for the CI - identified in section 4 of [I-D.ietf-cdni-requirements], reproduced - here for convenience: - - CI-1 [HIGH] The CDNI Control interface shall allow the Upstream - CDN to request that the Downstream CDN, including downstream - cascaded CDNs, delete an object or set of objects and/or its CDNI - metadata from the CDN surrogates and any storage. Only the - object(s) and CDNI metadata that pertain to the requesting - Upstream CDN are allowed to be purged. - - CI-2 [MED] The CDNI Control interface should allow for multiple - content items identified by a Content Collection ID to be purged - using a single Content Purge action. - - CI-3 [MED] The CDNI Control interface should allow the Upstream - CDN to request that the Downstream CDN, including downstream - cascaded CDNs, mark an object or set of objects and/or its CDNI - metadata as "stale" and revalidate them before they are delivered - again. - - CI-4 [HIGH] The CDNI Control interface shall allow the Downstream - CDN to report on the completion of these actions (by itself, and - including downstream cascaded CDNs, in a manner appropriate for - the action (e.g. synchronously or asynchronously). The - confirmation receipt should include a success or failure - indication. The failure indication along with the reason are used - if the Downstream CDN cannot delete the content in its storage. - - CI-5 [MED] The CDNI Control interface should support initiation - and control by the Upstream CDN of pre-positioned CDNI metadata - acquisition by the Downstream CDN. - - CI-6 [MED] The CDNI Control interface should support initiation - and control by the Upstream CDN of pre-positioned content - acquisition by the Downstream CDN. + authentication of CDN Interconnect interfaces. Section 4 of + [RFC7337] identifies the requirements specific to the CI interface, + requirements applicable to the CI/T interface are CI-1 to CI-6. o Section 2 outlines the model for the CI/T Interface at a high level. - o Section 3 describes collections of Trigger Resources. + o Section 3 describes collections of Trigger Status Resources. o Section 4 defines the web service provided by the dCDN. - o Section 5 lists properties of Trigger Requests and Status - Resources. - - o Section 6 defines a JSON encoding for Trigger Requests and Status - Resources. + o Section 5 lists properties of CI/T Commands and Status Resources. - o Section 7 contains example messages. + o Section 6 contains example messages. 1.1. Terminology This document reuses the terminology defined in [RFC6707]. 2. Model for CDNI Triggers - A trigger, sent from the uCDN to the dCDN, is a request for dCDN to - do some work relating to data originating from the uCDN. + A trigger, sent from the uCDN to the dCDN, is a request for the dCDN + to do some work relating to data originating from the uCDN. - The trigger may request action on either metadata or content, the + The trigger can request action on either metadata or content, the following actions can be requested: o preposition - used to instruct the dCDN to fetch metadata from the uCDN, or content from any origin including the uCDN. o invalidate - used to instruct the dCDN to revalidate specific metadata or content before re-using it. o purge - used to instruct the dCDN to delete specific metadata or content. + Multiple representations of an HTTP resource may share the same URL. + Requests to invalidate and purge metadata or content apply to all + resource representations with matching URLs. + The CI/T interface is a web service offered by the dCDN. It allows creation and deletion of triggers, and tracking of the triggered activity. When the dCDN accepts a trigger it creates a resource describing status of the triggered activity, a Trigger Status - Resource. The uCDN MAY poll Trigger Status Resources to monitor + Resource. The uCDN can poll Trigger Status Resources to monitor progress. - Requests to invalidate and purge metadata or content apply to all - variants of that data with a given URI. - The dCDN maintains a collection of Trigger Status Resources for each uCDN, each uCDN only has access to its own collection and the location of that collection is shared when CDN interconnection is established. - To trigger activity in the dCDN, the uCDN will POST to the collection - of Trigger Status Resources. If the dCDN accepts the trigger, it - creates a new Trigger Status Resource and returns its location to the - uCDN. To monitor progress, the uCDN MAY GET the Trigger Status - Resource. To cancel a trigger, or remove a trigger from the - collection once its activity has been completed, the uCDN MAY DELETE - the Trigger Status Resource. + To trigger activity in the dCDN, the uCDN POSTs a CI/T Command to the + collection of Trigger Status Resources. If the dCDN accepts the + trigger, it creates a new Trigger Status Resource and returns its + location to the uCDN. To monitor progress, the uCDN can GET the + Trigger Status Resource. To request cancellation of a trigger the + uCDN can POST to the collection of Trigger Status Resources, or + simply DELETE the Trigger Status Resource. - In addition to the collection of all Trigger Status Resources for - uCDN, uCDN has access to filtered views of that collection. These + In addition to the collection of all Trigger Status Resources for the + uCDN, the dCDN can maintain filtered views of that collection. These filtered views are defined in Section 3 and include collections of active and completed triggers. These collections provide a mechanism for polling the status of multiple jobs. Figure 1 is an example showing the basic message flow used by the - uCDN to trigger activity in dCDN, and for uCDN to discover the status - of that activity. Only successful triggering is shown. Examples of - the messages are given in Section 7. + uCDN to trigger activity in the dCDN, and for the uCDN to discover + the status of that activity. Only successful triggering is shown. + Examples of the messages are given in Section 6. uCDN dCDN | (1) POST http://dcdn.example.com/triggers/uCDN | [ ] --------------------------------------------------> [ ]--+ | [ ] | (2) | (3) HTTP 201 Response [ ]<-+ [ ] <-------------------------------------------------- [ ] | Loc: http://dcdn.example.com/triggers/uCDN/123 | | | . . . @@ -252,995 +214,1040 @@ | [ ] | (5) HTTP 200 Trigger Status Resource [ ] [ ] <-------------------------------------------------- [ ] | | | | Figure 1: Basic CDNI Message Flow for Triggers The steps in Figure 1 are: - 1. uCDN triggers action in the dCDN by posting to a collection of - Trigger Status Resources, "http://dcdn.example.com/triggers/ - uCDN". The URL of this was given to the uCDN when the trigger - interface was established. + 1. The uCDN triggers action in the dCDN by posting a CI/T Command to + a collection of Trigger Status Resources, + "http://dcdn.example.com/triggers/uCDN". The URL of this was + given to the uCDN when the trigger interface was established. - 2. dCDN authenticates the request, validates the trigger and if it - accepts the request, creates a new Trigger Status Resource. + 2. The dCDN authenticates the request, validates the trigger and if + it accepts the request, creates a new Trigger Status Resource. - 3. dCDN responds to the uCDN with an HTTP 201 response status, and - the location of the Trigger Status Resource. + 3. The dCDN responds to the uCDN with an HTTP 201 response status, + and the location of the Trigger Status Resource. - 4. uCDN may repeatedly poll the Trigger Status Resource in the dCDN. + 4. The uCDN can repeatedly poll the Trigger Status Resource in the + dCDN. - 5. dCDN responds with the Trigger Status Resource, describing + 5. The dCDN responds with the Trigger Status Resource, describing progress or results of the triggered activity. The remainder of this document describes the messages, Trigger Status Resources, and collections of Trigger Status Resources in more detail. 2.1. Timing of Triggered Activity - Timing of triggered activity is under the dCDN's control, including - its start-time and pacing of the activity in the network. + Timing of the execution of triggered activity is under the dCDN's + control, including its start-time and pacing of the activity in the + network. Invalidate and purge triggers MUST be applied to all data acquired - before the trigger was created in the dCDN. The dCDN may apply the + before the trigger was created in the dCDN. The dCDN MAY apply the triggers to data acquired after trigger creation. If the uCDN wishes to invalidate or purge content, then immediately pre-position replacement content at the same URLs, it SHOULD ensure the dCDN has completed the invalidate/purge before initiating the - prepositioning. Otherwise, the dCDN may pre-position the new content - then immediately invalidate or purge it (as a result of the two uCDN - requests running in parallel). + prepositioning. Otherwise, there is a risk that the dCDN pre- + positions the new content, then immediately invalidates or purges it + (as a result of the two uCDN requests running in parallel). 2.2. Trigger Results - Each Trigger Request may operate on multiple data items. The trigger - MUST NOT be reported as "complete" unless all actions can be - completed successfully, otherwise it MUST be reported as "failed" or - "processed". The reasons for failure and URLs or Patterns affected - SHOULD be enumerated in the Trigger Status Resource. For more - detail, see section Section 4.5. + Each trigger can operate on multiple metadata and content URLs. The + trigger MUST NOT be reported as "complete" until all actions have + been completed successfully. The reasons for failure, and URLs or + Patterns affected, SHOULD be enumerated in the Trigger Status + Resource. For more detail, see section Section 4.7. If a dCDN is also acting as a uCDN in a cascade, it MUST forward triggers to any downstream CDNs that may have data affected by the - trigger. The trigger MUST NOT be reported as complete in a CDN until - it is complete in all of its downstream CDNs. A trigger MAY be - reported as failed as soon as it fails in a CDN or in any of its - downstream CDNs. + trigger. The trigger MUST NOT be reported as 'complete' in a CDN + until it is 'complete' in all of its downstream CDNs. If a trigger + is reported as 'processed' in any dCDN, intermediate CDNs MUST NOT + report 'complete', instead they must also report 'processed'. A + trigger MAY be reported as 'failed' as soon as it fails in a CDN or + in any of its downstream CDNs. A cancelled trigger MUST be reported + as 'cancelling' until it has been reported as 'cancelled', + 'complete', or 'failed' by all dCDNs in a cascade. 3. Collections of Trigger Status Resources - As described in Section 2, Trigger Status Resources exist in dCDN to - report the status of activity triggered by each uCDN. + As described in Section 2, Trigger Status Resources exist in the dCDN + to report the status of activity triggered by each uCDN. A collection of Trigger Status Resources is a resource that contains a reference to each Trigger Status Resource in that collection. - To trigger activity in the dCDN, the uCDN creates a new Trigger - Status Resource by posting to the dCDN's collection of uCDN's Trigger - Status Resources. The URL of each Trigger Status Resource is - generated by the dCDN when it accepts the trigger, and returned to - the uCDN. This immediately enables the uCDN to check the status of - that trigger. - - The dCDN MUST present a different set of Trigger Status Resources to - each interconnected uCDN. Trigger Status Resources belonging to a - uCDN MUST NOT be visible to any other client. The dCDN may, for - example, achieve this by offering different collection URLs to uCDNs, - or by filtering the response based on the client uCDN. + The dCDN MUST make a collection of a uCDN's Trigger Status Resources + available to that uCDN. This collection includes all of the uCDN + triggers that have been accepted by the dCDN, and have not yet been + deleted by the uCDN, or expired and removed by the dCDN (as described + in section Section 4.4). Trigger Status Resources belonging to a + uCDN MUST NOT be visible to any other CDN. The dCDN could, for + example, achieve this by offering different collection URLs to each + uCDN, or by filtering the response based on the client uCDN. - The dCDN resource representing the collection of all the uCDN's - Trigger Status Resources is accessible to the uCDN. This collection - lists all of the uCDN triggers that have been accepted by the dCDN, - and have not yet been deleted by the uCDN, or expired and removed by - the dCDN (as described in section Section 4.3). + To trigger activity in a dCDN, or to cancel triggered activity, the + uCDN POSTs a CI/T Command to the dCDN's collection of the uCDN's + Trigger Status Resources. - In order to allow the uCDN to check status of multiple jobs in a + In order to allow the uCDN to check the status of multiple jobs in a single request, the dCDN SHOULD also maintain collections representing filtered views of the collection of all Trigger Status - Resources. The filtered collections are: + Resources. If it implements these filtered collections, the dCDN + MUST include links to them in the collection of all triggers. The + filtered collections are: o Pending - Trigger Status Resources for triggers that have been accepted, but not yet acted upon. o Active - Trigger Status Resources for triggered activity that is currently being processed in the dCDN. o Complete - Trigger Status Resources representing activity that - completed successfully, or for which no further status updates - will be made by the dCDN. + completed successfully and 'processed' triggers for which no + further status updates will be made by the dCDN. o Failed - Trigger Status Resources representing activity that - failed. + failed or was cancelled by the uCDN. -4. CDNI Trigger interface +4. CDNI Trigger Interface This section describes an interface to enable an upstream CDN to - trigger defined activities in a downstream CDN. The interface is - intended to be independent of the set of activities defined now, or - that may be defined in future. + trigger activity in a downstream CDN. - CI/T is built on the principles of RESTful web services. Requests - are made over HTTP, and the HTTP Method defines the operation the - request would like to perform. The corresponding HTTP Response - returns the status of the operation in the HTTP Status Code and - returns the current representation of the resource (if appropriate) - in the Response Body. HTTP Responses from servers implementing CI/T - that contain a response body SHOULD include an ETag to enable - validation of cached versions of returned resources. + Requests are made over HTTP, and the HTTP Method defines the + operation the request would like to perform. The corresponding HTTP + Response returns the status of the operation in the HTTP Status Code + and returns the current representation of the resource (if + appropriate) in the Response Body. HTTP Responses from dCDNs + implementing CI/T that contain a response body SHOULD include an ETag + to enable validation of cached versions of returned resources. - Servers implementing CI/T MUST support the HTTP GET, HEAD, POST and + All dCDNs implementing CI/T MUST support the HTTP GET, HEAD, POST and DELETE methods as defined in [RFC7231]. The only representation specified in this document is JSON, [RFC7159]. - The URL of the dCDN's collections of Trigger Status Resources need to - be either discovered by, or configured in, the uCDN. The mechanism - for discovery of those URLs is outside the scope of this document. + The URL of the dCDN's collection of all Trigger Status Resources + needs to be either discovered by, or configured in, the uCDN. The + mechanism for discovery of that URL is outside the scope of this + document. - Trigger Requests are POSTed to the dCDN's collection of all Trigger - Status Resources. If the trigger is accepted by the dCDN, it creates - a new Trigger Status Resource and returns its URI to the dCDN in an - HTTP 201 response. The triggered activity can then be monitored by - the uCDN using that resource and the collections described in - Section 3. + CI/T Commands are POSTed to the dCDN's collection of all Trigger + Status Resources. If a command to create a new trigger is accepted + by the dCDN, it creates a new Trigger Status Resource and returns its + URI to the dCDN in an HTTP 201 response. The triggered activity can + then be monitored by the uCDN using that resource and the collections + described in Section 3. The URI of each Trigger Status Resource is returned to the uCDN when it is created. This means all Trigger Status Resources can be - discovered, so CI/T servers are free to assign whatever structure - they desire to the URIs for CI/T resources. CI/T clients MUST NOT - make any assumptions regarding the structure of CI/T URIs or the - mapping between CI/T objects and their associated URIs. Therefore - any URIs present in the examples below are purely illustrative and - are not intended to impose a definitive structure on CI/T interface + discovered, so dCDNs are free to assign whatever structure they + desire to the URIs for CI/T resources. Therefore uCDNs MUST NOT make + any assumptions regarding the structure of CI/T URIs or the mapping + between CI/T objects and their associated URIs. URIs present in the + examples in this document are purely illustrative and are not + intended to impose a definitive structure on CI/T interface implementations. - The CI/T interface builds on top of HTTP, so CI/T servers may make - use of any HTTP feature when implementing the CI/T interface. For - example, a CI/T server may make use of HTTP's caching mechanisms to - indicate that a requested response/representation has not been - modified, reducing the processing needed to determine whether the - status of triggered activity has changed. - - This specification is neutral with regard to the transport below the - HTTP layer. + The CI/T interface builds on top of HTTP, so dCDNs may make use of + any HTTP feature when implementing the CI/T interface. For example, + a dCDN SHOULD make use of HTTP's caching mechanisms to indicate that + a requested response/representation has not been modified, reducing + the uCDN's processing needed to determine whether the status of + triggered activity has changed. The dCDN MUST ensure that activity triggered by the uCDN only affects - metadata or content originating from that uCDN. Since only one CDN - can be authoritative for a given item of metadata or content, this - requirement means there cannot be any "loops" in trigger requests - between CDNs. + metadata or content originating from that uCDN. 4.1. Creating Triggers - To create a new trigger, the uCDN makes an HTTP POST to the - unfiltered collection of its triggers. The request body of that POST - is a Trigger Request. + To create a new trigger, the uCDN makes an HTTP POST to the dCDN's + collection of all of the uCDN's Trigger Status Resources. The + request body of that POST is a CI/T Command with a "trigger", as + described in Section 5.1.1. The dCDN validates and authenticates that request, if it is malformed - or the uCDN does not have sufficient access rights it MAY reject the - request immediately. In this case, it MUST respond with an - appropriate 4xx HTTP error code and a resource MUST NOT be created on - dCDN. + or the uCDN does not have sufficient access rights it MUST either + respond with an appropriate 4xx HTTP error code and a resource MUST + NOT be created on the dCDN, or create a 'failed' Trigger Status + Resource containing an appropriate error description. If the request is accepted, the uCDN MUST create a new Trigger Status Resource. The HTTP response to the dCDN MUST have status code 201 and the URI of the Trigger Status Resource in the Location header field. The HTTP response SHOULD include the content of the newly created Trigger Status Resource, this is recommended particularly in cases where the trigger has completed immediately. Once a Trigger Status Resource has been created the dCDN MUST NOT re- use its location, even after that resource has been removed. - The "request" property of the Trigger Status Resource contains the - information posted in the body of the Trigger Request. Note that - this need not be a byte-for-byte copy. For example, in the JSON + The "trigger" property of the Trigger Status Resource contains the + Trigger Specification posted in the body of the CI/T Command. Note + that this need not be a byte-for-byte copy. For example, in the JSON representation the dCDN may re-serialise the information differently. - If the dCDN is not able to track triggered activity, it MUST indicate - that indicate that it has accepted the request but will not be + If the dCDN is not able to track the execution of triggered activity, + it MUST indicate that it has accepted the request but will not be providing further status updates. To do this, it sets the "status" of the Trigger Status Resource to "processed". In this case, CI/T processing should continue as for a "complete" request, so the Trigger Status Resource MUST be added to the dCDN's collection of Complete Triggers. The dCDN SHOULD also provide an estimated completion time for the request, by using the "etime" property of the Trigger Status Resource. This will allow the uCDN to schedule prepositioning after an earlier delete of the same URLs is expected to have finished. - If the dCDN is able to track triggered activity, the trigger is - queued by the dCDN for later action, the "status" property of the - Trigger Status Resource MUST be "pending". Once trigger processing - has started the "status" MUST be "active". Finally, once the - triggered activity is complete, the trigger status MUST be set to + If the dCDN is able to track the execution of triggered activity, the + trigger is queued by the dCDN for later action, the "status" property + of the Trigger Status Resource MUST be "pending". Once trigger + processing has started the "status" MUST be "active". Finally, once + the triggered activity is complete, the trigger status MUST be set to "complete" or "failed". A trigger may result in no activity in the dCDN if, for example, it is an invalidate or purge request for data the dCDN has not yet acquired, or a prepopulate request for data it has already acquired and which is still valid. In this case, the "status" of the Trigger Status Resource MUST be "processed" or "complete", and the Trigger Status Resource MUST be added to the dCDN's collection of Complete Triggers. - Once created, Trigger Status Resources may be deleted by the uCDN but - not modified. The dCDN MUST reject PUT and POST requests from the - uCDN to Trigger Status Resources using HTTP status code 403. + Once created, Trigger Status Resources can be cancelled or deleted by + the uCDN, but not modified. The dCDN MUST reject PUT and POST + requests from the uCDN to Trigger Status Resources by responding with + an appropriate HTTP status code. 4.2. Checking Status The uCDN has two ways to check progress of activity it has triggered - in the dCDN, described in the following sections. + in the dCDN, described in sections Section 4.2.1 and Section 4.2.2. To check for change in status of a resource or collection of resources without re-fetching the whole resource or collection, - Entity Tags SHOULD be used by the uCDN as cache validators, as - defined in [RFC7232]. + Entity Tags SHOULD be included by the dCDN for the uCDN to use as + cache validators, as defined in [RFC7232]. The dCDN SHOULD use the cache control headers for responses to GETs for Trigger Status Resources and Collections to indicate the - frequency at which it recommends uCDN should poll for change. + frequency at which it recommends the uCDN should poll for change. 4.2.1. Polling Trigger Status Resource collections The uCDN can fetch the collection of its Trigger Status Resources, or filtered views of that collection. This makes it possible to poll status of all triggered activity in a single request. If the dCDN moves a Trigger Status Resource from the - Active to the Completed collection, the uCDN may chose to fetch the - result of that activity. + Active to the Completed collection, the uCDN can fetch the result of + that activity. When polling in this way, the uCDN SHOULD use HTTP Entity Tags to monitor for change, rather than repeatedly fetching the whole collection. 4.2.2. Polling Trigger Status Resources - The uCDN has a reference (URI provided by the dCDN) for each Trigger - Status Resource it has created, it may fetch that resource at any - time. + The uCDN has a URI provided by the dCDN for each Trigger Status + Resource it has created, it may fetch that resource at any time. - This MAY be used to retrieve progress information, and to fetch the + This can be used to retrieve progress information, and to fetch the result of triggered activity. -4.3. Deleting Triggers + When polling in this way, the uCDN SHOULD use HTTP Entity Tags to + monitor for change, rather than repeatedly fetching the Trigger + Status Resource. - The uCDN MAY delete Trigger Status Resources at any time, using the - HTTP DELETE method. +4.3. Cancelling Triggers + + The uCDN can request cancellation of a trigger by POSTing a Trigger + "cancel" Command to the collection of all triggers. + + The uCDN should respond to that command appropriately, for example + with HTTP status code 200 "OK" if the cancellation has been processed + and the trigger is inactive, 202 "Accepted" if the command has been + accepted but the trigger remains active, or 403 "Forbidden" if + cancellation is not supported by the dCDN. + + If cancellation of a "pending" Trigger Status Resource is accepted by + the dCDN, the dCDN SHOULD NOT start processing of that activity. + Cancelling a "pending" trigger does not however guarantee that not + activity is started, because the uCDN cannot control the timing of + that activity. Processing could, for example, start after the POST + is sent by the uCDN but before that request is processed by the dCDN. + + If cancellation of an "active" or "processed" Trigger Status Resource + is accepted by the dCDN, the dCDN SHOULD stop processing the + triggered activity. However, as with cancellation of a "pending" + trigger, the dCDN does not guarantee this. + + If the triggered activity cannot be stopped immediately, the + trigger's status MUST be set to "cancelling" and the Trigger Status + Resource remains in the collection of active triggers. If processing + is stopped before normal completion, the trigger's status MUST be set + to "cancelled" and included in the collection of failed triggers. + + Cancellation of a "complete" or "failed" Trigger Status Resource + requires no processing in the dCDN, its status MUST NOT be changed to + "cancelled". + +4.4. Deleting Triggers + + The uCDN can delete Trigger Status Resources at any time, using the + HTTP DELETE method. The effect is similar to cancellation, but no + Trigger Status Resource remains afterwards. Once deleted, the references to a Trigger Status Resource MUST be removed from all Trigger Status Resource collections. Subsequent - requests for the resource MUST be handled as required by HTTP, and so - will receive responses with status 404 or 410. + requests to GET the deleted resource SHOULD fail. If a "pending" Trigger Status Resource is deleted, the dCDN SHOULD NOT start processing of that activity. Deleting a "pending" trigger - does not however guarantee that it is not started because the uCDN + does not however guarantee that it has not started because the uCDN cannot control the timing of that activity. Processing may, for - example, start after the DELETE is sent by the uCDN but before the - DELETE is processed by the dCDN. + example, start after the DELETE is sent by the uCDN but before that + request is processed by the dCDN. - If an "active" Trigger Status Resource is deleted, the dCDN MAY stop - processing the triggered activity. However, as with deletion of a - "pending" trigger, the dCDN does not guarantee this. + If an "active" or "processed" Trigger Status Resource is deleted, the + dCDN MAY stop processing the triggered activity. However, as with + deletion of a "pending" trigger, the dCDN does not guarantee this. - Deletion of a "complete", "processed" or "failed" Trigger Status - Resource requires no processing in the dCDN other than deletion of - the resource. + Deletion of a "complete" or "failed" Trigger Status Resource requires + no processing in the dCDN other than deletion of the resource. -4.4. Expiry of Trigger Status Resources +4.5. Expiry of Trigger Status Resources - The dCDN MAY choose to automatically delete Trigger Status Resources - some time after they become "complete", "processed" or "failed". In - this case, the dCDN will remove the resource and respond to - subsequent requests for it with HTTP status 404 or 410. + The dCDN can choose to automatically delete Trigger Status Resources + some time after they become "complete", "processed", "failed" or + "cancelled". In this case, the dCDN will remove the resource and + respond to subsequent requests for it with an HTTP error. If the dCDN performs this housekeeping, it MUST have reported the - length of time after which completed Trigger Status Resources become - stale via a property of the collection of all Trigger Status + length of time after which completed Trigger Status Resources will be + deleted via a property of the collection of all Trigger Status Resources. It is recommended that Trigger Status Resources are not automatically deleted for at least 24 hours after they become - "complete", "processed" or "failed". + "complete", "processed", "failed" or "cancelled". - To ensure it has access to the status of its completed and failed - triggers, it is recommended that the uCDN's polling interval is half - the time after which records for completed activity will be - considered stale. + To ensure it is able to get the status of its completed and failed + triggers, it is recommended that the uCDN's polling interval is less + than the time after which records for completed activity will be + deleted. -4.5. Error Handling +4.6. Loop Detection and Prevention - A CI/T server may reject a trigger request using HTTP status codes. - For example, 400 if the request is malformed, or 401 if the client - does not have permission to create triggers or it is trying to act on - another CDN's data. + Given three CDNs, A, B and C. If CDNs B and C delegate delivery of + CDN A's content to each other, CDN A's triggers could be passed + between CDNs B and C in a loop. More complex networks of CDNs could + contain similar loops involving more hops. - If any part of the trigger request fails, the trigger SHOULD be - reported as "failed" once its activity is complete or if no further - errors will be reported. The "errors" property in the Trigger Status - Resource will be used to enumerate which actions failed and the - reasons for failure, and may be present while the trigger is still - "pending" or "active", if the trigger is still running for some URLs - or Patterns in the trigger request. + In order to prevent and detect such CI/T loops, each CDN uses a CDN + Provider ID to uniquely identify itself. Each CDN MUST insert its + CDN Provider ID into the cdn-path key of every CI/T Command it + originates or cascades. When receiving CI/T commands a dCDN MUST + check the cdn-path and reject any CI/T Command which already contains + its own CDN Provider ID in the cdn-path. Transit CDNs MUST check the + cdn-path and not cascade the CI/T Command to dCDNs that are already + listed in cdn-path. - Once a request has been accepted, processing errors are reported in - the Trigger Status Resource using a list of "ErrorDesc". Each - ErrorDesc is used to report errors against one or more of the URLs or - Patterns in the trigger request. + The CDN Provider Id consists of the characters AS followed by the CDN + Provider's AS number, then a colon (':') and an additional qualifier + that is used to guarantee uniqueness in case a particular AS has + multiple independent CDNs deployed. For example "AS64496:0". - If a surrogate affected by a trigger is offline in the dCDN, or the - dCDN is unable to pass a trigger request on to any of its cascaded - dCDNs; the dCDN SHOULD report an error if the request is abandoned. - Otherwise, it SHOULD keep the trigger in state "pending" or "active" - until it's acted upon or the uCDN chooses to cancel it. Or, if the - request is queued and the dCDN will not report further status, the - dCDN MAY report the trigger as "processed", in which case it SHOULD - also provide an estimated completion time. + If the RI interface described in [I-D.ietf-cdni-redirection] is + implemented by the dCDN, the CI/T and RI interfaces SHOULD use the + same CDN Provider Id. - Note that an "invalidate" trigger may be reported as "complete" when - surrogates that may have the data are offline. In this case, - surrogates MUST NOT use the affected data without first revalidating - it when they are back online. This does not apply to "preposition" - or "purge" triggers. +4.7. Error Handling -5. Properties of Triggers + A dCDN can reject a CI/T Command using HTTP status codes. For + example, 400 if the request is malformed, or 401 if the uCDN does not + have permission to create triggers or it is trying to act on another + CDN's data. -5.1. Properties of Trigger Requests + If any part of the trigger fails, the trigger SHOULD be reported as + "failed" once its activity is complete or if no further errors will + be reported. The "errors" property in the Trigger Status Resource + will be used to enumerate which actions failed and the reasons for + failure, and can be present while the trigger is still "pending" or + "active", if the trigger is still running for some URLs or Patterns + in the Trigger Specification. - Properties of Trigger Requests are defined in the following - subsections. + Once a request has been accepted, processing errors are reported in + the Trigger Status Resource using a list of Error Descriptions. Each + Error Description is used to report errors against one or more of the + URLs or Patterns in the Trigger Specification. - Property: type + If a surrogate affected by a trigger is offline in the dCDN, or the + dCDN is unable to pass a CI/T Command on to any of its cascaded + dCDNs: - Description: This property defines the type of the trigger. + o If the request is abandoned by the dCDN, the dCDN SHOULD report an + error. - Type: TriggerType + o An "invalidate" trigger may be reported as "complete" when + surrogates that may have the data are offline. In this case, + surrogates MUST NOT use the affected data without first + revalidating it when they are back online. - Mandatory: Yes + o "preposition" and "purge" triggers can be reported as "processed" + if affected caches are offline and the activity will complete when + they return to service. - Property: metadata.urls + o Otherwise, the dCDN SHOULD keep the trigger in state "pending" or + "active" until the trigger is acted upon, or the uCDN chooses to + cancel it. - Description: The uCDN URL for the metadata the trigger applies - to. +4.8. Content URLs - Type: URLs + To refer to content in the dCDN, the uCDN MUST present URLs in the + same form as in the metadata it supplied to the dCDN. By definition, + it is always possible for the dCDN to locate content based on URLs in + this form. - Mandatory: No, but at least one of 'metadata.*' or 'content.*' - MUST be present and non-empty. + Therefore, if content URLs are transformed by an intermediate CDN in + a cascade, that intermediate CDN MUST transform URLs in CI/T commands + it passes to its dCDN. - Property: content.urls + When processing Trigger Specifications, CDNs MUST ignore the URL + scheme (http or https) in comparing URLs. For example, for an + invalidate or purge trigger, content MUST be invalidated or purged + regardless of the protocol clients use to request it. - Description: URLs of content data the trigger applies to, see - Section 5.1.1. +5. CI/T Object Properties and Encoding - Type: URLs + CI/T Commands, Trigger Status Resources and Trigger Collections and + their properties are encoded using JSON, as defined in sections + Section 5.1.1, Section 5.2.1, and Section 5.1.2. - Mandatory: No, but at least one of 'metadata.*' or 'content.*' - MUST be present and non-empty. + Names in JSON are case sensitive and therefore the names and literal + values specified here MUST always use lower-case. - Property: content.ccid + Unrecognised name/value pairs in JSON objects SHOULD NOT be treated + as an error by either the uCDN or dCDN. - Description: The Content Collection IDentifier of data the - trigger applies to. +5.1. CI/T Objects - Type: List of strings + The top-level objects defined by the CI/T interface are described in + this section. Each has an associated MIME Media Type. The encoding + of values used by these objects is described in Section 5.2. - Mandatory: No, but at least one of 'metadata.*' or 'content.*' - MUST be present and non-empty. +5.1.1. CI/T Commands - Property: metadata.patterns + CI/T Commands SHOULD use a MIME Media Type of application/ + cdni.ci.TriggerCommand+json. - Description: The metadata the trigger applies to. + A CI/T Command is encoded as a JSON object containing the following + name/value pairs. - Type: List of PatternMatch + Name: trigger - Mandatory: No, but at least one of 'metadata.*' or 'content.*' - MUST be present and non-empty, and metadata.patterns MUST NOT - be present if the TriggerType is Preposition. + Description: A specification of the trigger type, and a set of + data to act upon. - Property: content.patterns + Value: A Trigger Specification, as defined in Section 5.2.1. - Description: The content data the trigger applies to. + Mandatory: No, but exactly one of "trigger" or "cancel" MUST be + present in a CI/T Command. - Type: List of PatternMatch + Name: cancel + Description: The URLs of Trigger Status Resources for triggers + that the uCDN wants to cancel. - Mandatory: No, but at least one of 'metadata.*' or 'content.*' - MUST be present and non-empty, and content.patterns MUST NOT be - present if the TriggerType is Preposition. + Value: A JSON array of URLs represented as JSON strings. -5.1.1. Content URLs + Mandatory: No, but exactly one of "trigger" or "cancel" MUST be + present in a CI/T Command. - To refer to content in the dCDN, the uCDN MUST present URLs in the - same form clients will use to access content in that dCDN, after - transformation to remove any surrogate-specific parts of a - 302-redirect URL form. By definition, it is always possible to - locate content based on URLs in this form. + Name: cdn-path - If content URLs are transformed by an intermediate CDN in a cascade, - that intermediate CDN MUST transform URLs in trigger requests it - passes to its dCDN. + Description: The CDN Provider Identifiers of CDNs that have + already accepted the CI/T Command. - When processing trigger requests, CDNs MUST ignore the URL scheme - (http or https) in comparing URLs. For example, for an invalidate or - purge trigger, content MUST invalidated or purged regardless of the - protocol clients use to request it. + Value: A JSON array of JSON strings, where each string is a CDN + Provider Identifier as defined in Section 4.6. -5.2. Properties of Trigger Status Resources + Mandatory: Yes. - Property: trigger +5.1.2. Trigger Status Resource - Description: The properties of trigger request that created - this record. + Trigger Status Resources SHOULD use a MIME Media Type of application/ + cdni.ci.TriggerStatus+json. - Type: TriggerRequest + A Trigger Status Resource is encoded as a JSON object containing the + following name/value pairs. + + Name: trigger + + Description: The Trigger Specification that was used to create + this Trigger Status Resource. + + Value: A Trigger Specification, as defined in Section 5.2.1. Mandatory: Yes - Property: ctime + Name: ctime - Description: Time at which the request was received by the + Description: Time at which the CI/T Command was received by the dCDN. Time is determined by the dCDN, there is no requirement to synchronise clocks between interconnected CDNs. - Type: AbsoluteTime + Value: Absolute Time, as defined in Section 5.2.5. Mandatory: Yes - Property: mtime - - Description: Time at which the resource was last modified. - Time is determined by the dCDN, there is no requirement to - synchronise clocks between interconnected CDNs. + Name: mtime + Description: Time at which the Trigger Status Resource was last + modified. Time is determined by the dCDN, there is no + requirement to synchronise clocks between interconnected CDNs. - Type: AbsoluteTime + Value: Absolute Time, as defined in Section 5.2.5. Mandatory: Yes - Property: etime + Name: etime Description: Estimate of the time at which the dCDN expects to complete the activity. Time is determined by the dCDN, there is no requirement to synchronise clocks between interconnected CDNs. - Type: AbsoluteTime + Value: Absolute Time, as defined in Section 5.2.5. + Mandatory: No - Property: status + Name: status Description: Current status of the triggered activity. - Type: TriggerStatus + Value: Trigger Status, as defined in Section 5.2.3. Mandatory: Yes - Property: errors - - Description: List of ErrorDesc. - - Mandatory: No. - -5.3. Properties of ErrorDesc - - An ErrorDesc object is used to report failure for URLs and patterns - in a trigger request. - - Property: error - - Type: ErrorCode. - - Mandatory: Yes. - - Property: metadata.urls, content.urls, metadata.patterns, - content.patterns - - Description: Metadata and content references copied from the - trigger request. Only those URLs and patterns to which the - error applies shall be included in each property, but those - URLs and patterns MUST be exactly as they appear in the - request, the dCDN must not generalise the URLs. (For example, - if the uCDN requests prepositioning of URLs - "http://ucdn.example.com/a" and "http://ucdn.example.com/b", - the dCDN must not generalise its error report to Pattern - "http://ucdn.example.com/*"). - - Mandatory: At least one of these properties is mandatory in - each ErrorDesc. + Name: errors - Property: description + Description: Descriptions of errors that have occurred while + processing a Trigger Command. - Description: A String containing a human-readable description - of the error. + Value: A list of Error Descriptions, as defined in + Section 5.2.6. Mandatory: No. -5.4. Properties of Trigger Collections +5.1.3. Trigger Collection - Property: triggers + Trigger Collections SHOULD use a MIME Media Type of application/ + cdni.ci.TriggerCollection+json. + + A Trigger Collection is encoded as a JSON object containing the + following name/value pairs. + Name: triggers Description: Links to Trigger Status Resources in the collection. - Type: URLs. + Value: A JSON array of URLs represented as JSON strings. Mandatory: Yes - Property: staleresourcetime + Name: staleresourcetime Description: The length of time for which the dCDN guarantees to keep a completed Trigger Status Resource. After this time, - the dCDN MAY delete the resource and all references to it from - collections. + the dCDN SHOULD delete the resource and all references to it + from collections. - Type: Integer, time in seconds. + Value: A JSON number, integer time in seconds. Mandatory: Yes, in the collection of all Trigger Status Resources if the dCDN deletes stale entries. If the property is present in the filtered collections, it MUST have the same value as in the collection of all Trigger Status Resources. -5.5. Trigger Resource Simple Data Type Descriptions - - This section describes the simpler data types that are used for - properties of Trigger Status resources. - -5.5.1. TriggerType - - This type defines the type of action being triggered, permitted - actions are: - - o Preposition - a request for the dCDN to acquire metadata or - content. - - o Invalidate - a request for the dCDN to invalidate metadata or - content. After servicing this request the dCDN will not use the - specified data without first re-validating it using, for example, - an "If-None-Match" HTTP request. The dCDN need not erase the - associated data. - - o Purge - a request for the dCDN to erase metadata or content. - After servicing the request, the specified data MUST NOT be held - on dCDN. + Names: coll-all, coll-pending, coll-active, coll-complete, coll- + failed -5.5.2. TriggerStatus + Description: Link to a Trigger Collection. - This type describes the current status of a Trigger, possible values - are: + Value: A URL represented as a JSON string. - o Pending - the trigger has not yet been acted upon. + Mandatory: Links to filtered collections are mandatory in the + collection of all Trigger Status Resources, if the dCDN + implements the filtered collections. Otherwise, optional. - o Active - the trigger is currently being acted upon. + Name: cdn-id - o Complete - the triggered activity completed successfully. + Description: The CDN Provider Identifier of the dCDN. - o Processed - the trigger has been accepted and no further status - update will be made (may be used in cases where completion cannot - be confirmed). + Value: A JSON string, the dCDN's CDN Provider Identifier, as + defined in Section 4.6. - o Failed - the triggered activity could not be completed. + Mandatory: Only in the collection of all Trigger Status + Resources, if the dCDN implements the filtered collections. + Optional in the filtered collections. -5.5.3. URLs +5.2. Properties of CI/T Objects - This type describes a set of references to metadata or content, it is - simply a list of absolute URLs. + This section defines the values that can appear in the top level + objects described in Section 5.1, and their encodings. -5.5.4. AbsoluteTime +5.2.1. Trigger Specification - Times are expressed in seconds since the UNIX epoch. + A Trigger Collection is encoded as a JSON object containing the + following name/value pairs. -5.5.5. ErrorCode + An unrecognised name/value pair in the Trigger Specification object + contained in a CI/T Command SHOULD be preserved in the Trigger + Specification of any Trigger Status Resource it creates. - This type is used by dCDN to report failures in trigger processing. + Name: type - o EMETA - the dCDN was unable to acquire metadata required to fulfil - the request. + Description: This property defines the type of the trigger. - o ECONTENT - the dCDN was unable to acquire content (preposition - triggers only). + Value: Trigger Type, as defined in Section 5.2.2. - o EPERM - the uCDN does not have permission to trigger the requested - activity (for example, the data is owned by another CDN). + Mandatory: Yes - o EREJECT - the dCDN is not willing to fulfil the request (for - example, a preposition request for content at a time when dCDN - would not accept Request Routing requests from uCDN). + Name: metadata.urls - o ECDN - An internal error in the dCDN or one of its downstream - CDNs. + Description: The uCDN URLs of the metadata the trigger applies + to. -6. JSON Encoding of Objects + Value: A JSON array of URLs represented as JSON strings. - The encoding for a CI/T object is a JSON object containing a - dictionary of (key,value) pairs where the keys are the property - names, and the values are the associated property values. + Mandatory: No, but at least one of 'metadata.*' or 'content.*' + MUST be present and non-empty. - The keys of the dictionary are the names of the properties associated - with the object and are therefore dependent on the specific object - being encoded (i.e. dependent on the MIME Media Type of the returned - resource). Likewise, the values associated with each key are - dependent on the specific object being encoded (i.e. dependent on the - MIME Media Type of the returned resource). + Name: content.urls - The "trigger" property of the top level JSON object lists the - requested action. + Description: URLs of content the trigger applies to, see + Section 4.8. - Key: trigger + Value: A JSON array of URLs represented as JSON strings. - Description: An object specifying the trigger type and a set of - data to act upon. + Mandatory: No, but at least one of 'metadata.*' or 'content.*' + MUST be present and non-empty. - Type: A JSON object. + Name: content.ccid - Mandatory: Yes. + Description: The Content Collection Identifier of content the + trigger applies to. The 'ccid' is a grouping of content, as + defined by [I-D.ietf-cdni-metadata]. - Object keys in JSON are case sensitive and therefore any dictionary - key defined by this document (for example the names of CI/T object - properties) MUST always be represented in lowercase. + Value: A JSON array of strings, where each string is a Content + Collection Identifier. - In addition to the properties of an object, the following additional - keys MAY be present. + Mandatory: No, but at least one of 'metadata.*' or 'content.*' + MUST be present and non-empty. - Key: base + Name: metadata.patterns - Description: Provides a prefix for any relative URLs in the - object. This is similar to the XML base tag [XML-BASE]. If - absent, all URLs in the remainder of the document MUST be - absolute URLs. + Description: The metadata the trigger applies to. - Type: URI + Value: A JSON array of Pattern Match, as defined in + Section 5.2.4. - Mandatory: No + Mandatory: No, but at least one of 'metadata.*' or 'content.*' + MUST be present and non-empty, and metadata.patterns MUST NOT + be present if the TriggerType is Preposition. - Key: _links - Description: The relationships of this object to other - addressable objects. + Name: content.patterns - Type: Array of Relationships. + Description: The content data the trigger applies to. - Mandatory: Yes + Value: A JSON array of Pattern Match, as defined in + Section 5.2.4. -6.1. JSON Encoding of Embedded Types + Mandatory: No, but at least one of 'metadata.*' or 'content.*' + MUST be present and non-empty, and content.patterns MUST NOT be + present if the TriggerType is Preposition. -6.1.1. TriggerType +5.2.2. Trigger Type - Key: type + Trigger Type is used in a Trigger Specification to describe trigger + action. It MUST be one of the JSON strings in the following table: - Description: One of "preposition", "invalidate" or "purge". + +-------------+-----------------------------------------------------+ + | JSON String | Description | + +-------------+-----------------------------------------------------+ + | preposition | A request for the dCDN to acquire metadata or | + | | content. | + | invalidate | A request for the dCDN to invalidate metadata or | + | | content. After servicing this request the dCDN will | + | | not use the specified data without first re- | + | | validating it using, for example, an "If-None- | + | | Match" HTTP request. The dCDN need not erase the | + | | associated data. | + | purge | A request for the dCDN to erase metadata or | + | | content. After servicing the request, the specified | + | | data MUST NOT be held on the dCDN. | + +-------------+-----------------------------------------------------+ - Type: string +5.2.3. Trigger Status -6.1.2. TriggerStatus + This describes the current status of a Trigger. It MUST be one of + the JSON strings in the following table: - Key: status + +------------+------------------------------------------------------+ + | JSON | Description | + | String | | + +------------+------------------------------------------------------+ + | pending | The trigger has not yet been acted upon. | + | active | The trigger is currently being acted upon. | + | complete | The triggered activity completed successfully. | + | processed | The trigger has been accepted and no further status | + | | update will be made (can be used in cases where | + | | completion cannot be confirmed). | + | failed | The triggered activity could not be completed. | + | cancelling | The triggered activity is still in progress, but the | + | | trigger has been cancelled by the uCDN. | + | cancelled | The triggered activity was cancelled by the uCDN. | + +------------+------------------------------------------------------+ - Description: One of "pending", "active", "failed", "complete" +5.2.4. PatternMatch - Type: string + A Pattern Match consists of a string pattern to match, and flags + describing the type of match. -6.1.3. PatternMatch + It is encoded as a JSON object with the following name/value pairs: - A PatternMatch is encoded as a JSON Object containing a string to - match and flags describing the type of match. + Name: pattern - Key: pattern + Description: A pattern for string matching. - Description: A pattern for string matching. The pattern may + Value: A JSON string representing the pattern. The pattern may contain the wildcards * and ?, where * matches any sequence of characters (including the empty string) and ? matches exactly - one character. The three literals \ , * and ? MUST be escaped - as \\, \* and \? - - Type: String + one character. The three literals "\" , "*" and "?" MUST be + escaped as "\\", "\*" and "\?". - Mandatory: Yes + Mandatory: Yes. - Key: case-sensitive + Name: case-sensitive Description: Flag indicating whether or not case-sensitive matching should be used. - Type: Boolean + Value: One of the JSON values 'true' or 'false'. + Mandatory: No, default is case-insensitive match. - Key: match-query-string + Name: match-query-string Description: Flag indicating whether or not the query string should be included in the pattern match. - Type: Boolean + Value: One of the JSON values 'true' or 'false'. - Mandatory: No, default is not to include query. + Mandatory: No, default is not to include the query string in + the pattern match. Example of case-sensitive prefix match against "http://www.example.com/trailers/": { "pattern": "http://www.example.com/trailers/*", "case-sensitive": true } -6.1.4. ErrorDesc - - ErrorDesc is encoded as a JSON object with the following keys: - - Key: error +5.2.5. Absolute Time - Type: ErrorCode + A JSON number, seconds since the UNIX epoch. - Mandatory: Yes +5.2.6. Error Description - Keys: metadata.urls, content.urls + An Error Description is used to report failure of a Trigger Command, + or in the activity it triggered. - Type: Array of strings + Name: error - Mandatory: At least one of metadata.* or content.* MUST be - present. + Value: Error Code, as defined in Section 5.2.7. - Keys: metadata.patterns, content.patterns + Mandatory: Yes. - Type: Array of PatternMatch + Names: metadata.urls, content.urls, metadata.patterns, + content.patterns - Mandatory: At least one of metadata.* or content.* MUST be - present. + Description: Metadata and content references copied from the + Trigger Specification. Only those URLs and patterns to which + the error applies are included in each property, but those URLs + and patterns MUST be exactly as they appear in the request, the + dCDN MUST NOT generalise the URLs. (For example, if the uCDN + requests prepositioning of URLs "http://content.example.com/a" + and "http://content.example.com/b", the dCDN must not + generalise its error report to Pattern + "http://content.example.com/*".) - Key: description + Value: A JSON array of JSON strings, where each string is + copied from a 'content.*' or 'metadata.*' value in the + corresponding Trigger Specification. - Type: String + Mandatory: At least one of these name/value pairs is mandatory + in each Error Description object. - Mandatory: No. + Name: description -6.1.5. ErrorCode + Description: A human-readable description of the error. - One of the strings "EMETA", "ECONTENT", "EPERM", "EREJECT" or "ECDN". + Value: A JSON string, the human-readable description. -6.2. MIME Media Types + Mandatory: No. - Table 1 lists the MIME Media Type for the trigger request, and each - trigger object (resource) that is retrievable through the CI/T - interface. +5.2.7. Error Code - +-------------------+--------------------------------------------+ - | Data Object | MIME Media Type | - +-------------------+--------------------------------------------+ - | TriggerRequest | application/cdni.ci.TriggerRequest+json | - | TriggerStatus | application/cdni.ci.TriggerStatus+json | - | TriggerCollection | application/cdni.ci.TriggerCollection+json | - +-------------------+--------------------------------------------+ + This type is used by the dCDN to report failures in trigger + processing. - Table 1: MIME Media Types for CDNI Trigger resources + +------------+------------------------------------------------------+ + | Error Code | Description | + +------------+------------------------------------------------------+ + | emeta | The dCDN was unable to acquire metadata required to | + | | fulfil the request. | + | econtent | The dCDN was unable to acquire content (preposition | + | | triggers only). | + | eperm | The uCDN does not have permission to trigger the | + | | requested activity (for example, the data is owned | + | | by another CDN). | + | ereject | The dCDN is not willing to fulfil the request (for | + | | example, a preposition request for content at a time | + | | when the dCDN would not accept Request Routing | + | | requests from the uCDN). | + | ecdn | An internal error in the dCDN or one of its | + | | downstream CDNs. | + | ecancelled | The uCDN cancelled the request. | + +------------+------------------------------------------------------+ -7. Examples +6. Examples The following sections provide examples of different CI/T objects encoded as JSON. - No authentication is shown in the following illustrative examples, it - is anticipated that authentication mechanisms will be aligned with - other CDNI Interfaces as and when those mechanisms are defined. - Discovery of the triggers interface is out of scope of this document. - In an implementation, all URLs are under the control of the dCDN. - The uCDN MUST NOT attempt to ascribe any meaning to individual - elements of the path. In examples in this section, the following - URLs are used as the location of the collections of triggers: - - o Collection of all Triggers belonging to one uCDN: - - http://dcdn.example.com/triggers - - o Filtered collections: - - Pending: http://dcdn.example.com/triggers/pending - - Active: http://dcdn.example.com/triggers/active - - Complete: http://dcdn.example.com/triggers/complete + In an implementation, all CI/T URLs are under the control of the + dCDN. The uCDN MUST NOT attempt to ascribe any meaning to individual + elements of the path. - Failed: http://dcdn.example.com/triggers/failed + In examples in this section, the URL 'http://dcdn.example.com/ + triggers' is used as the location of the collection of all triggers, + and the CDN Provider Id of uCDN is "AS64496:1". -7.1. Creating Triggers +6.1. Creating Triggers - Examples of uCDN triggering activity in dCDN: + Examples of the uCDN triggering activity in the dCDN: -7.1.1. Preposition +6.1.1. Preposition An example of a preposition request, a POST to the "AllTriggers" collection. Note that "metadata.patterns" and "content.patterns" are not allowed - in a preposition trigger request. + in a preposition Trigger Specification. REQUEST: POST /triggers HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* - Content-Type: application/cdni.ci.TriggerRequest+json - Content-Length: 315 + Content-Type: application/cdni.ci.TriggerCommand+json + Content-Length: 347 { "trigger" : { "type": "preposition", "metadata.urls" : [ "http://metadata.example.com/a/b/c" ], "content.urls" : [ "http://www.example.com/a/b/c/1", "http://www.example.com/a/b/c/2", "http://www.example.com/a/b/c/3", "http://www.example.com/a/b/c/4" ] - } + }, + "cdn-path" : [ "AS64496:1" ] } RESPONSE: HTTP/1.1 201 Created - Date: Wed, 02 Jul 2014 18:57:19 GMT + Date: Sun, 31 Aug 2014 09:53:18 GMT Content-Length: 472 Content-Type: application/cdni.ci.TriggerStatus+json Location: http://dcdn.example.com/triggers/0 Server: example-server/0.1 { - "ctime": 1404327439, - "etime": 1404327447, - "mtime": 1404327439, + "ctime": 1409478798, + "etime": 1409478806, + "mtime": 1409478798, "status": "pending", "trigger": { "content.urls": [ "http://www.example.com/a/b/c/1", "http://www.example.com/a/b/c/2", "http://www.example.com/a/b/c/3", "http://www.example.com/a/b/c/4" ], "metadata.urls": [ "http://metadata.example.com/a/b/c" ], "type": "preposition" } } -7.1.2. Invalidate +6.1.2. Invalidate An example of an invalidate request, another POST to the "AllTriggers" collection. This instructs the dCDN to re-validate the content at "http://www.example.com/a/index.html", as well as any metadata and content whose URLs are prefixed by "http://metadata.example.com/a/b/" and "http://www.example.com/a/b/" respectively, using case-insensitive matching. REQUEST: POST /triggers HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* - Content-Type: application/cdni.ci.TriggerRequest+json - Content-Length: 352 + Content-Type: application/cdni.ci.TriggerCommand+json + Content-Length: 384 { "trigger" : { "type": "invalidate", "metadata.patterns" : [ { "pattern" : "http://metadata.example.com/a/b/*" } ], "content.urls" : [ "http://www.example.com/a/index.html" ], "content.patterns" : [ { "pattern" : "http://www.example.com/a/b/*", "case-sensitive" : true } ] - } + }, + "cdn-path" : [ "AS64496:1" ] } RESPONSE: HTTP/1.1 201 Created - Date: Wed, 02 Jul 2014 18:57:20 GMT + Date: Sun, 31 Aug 2014 09:53:19 GMT Content-Length: 551 Content-Type: application/cdni.ci.TriggerStatus+json Location: http://dcdn.example.com/triggers/1 Server: example-server/0.1 { - "ctime": 1404327440, - "etime": 1404327448, - "mtime": 1404327440, + "ctime": 1409478799, + "etime": 1409478807, + "mtime": 1409478799, "status": "pending", "trigger": { "content.patterns": [ { "case-sensitive": true, "pattern": "http://www.example.com/a/b/*" } ], "content.urls": [ "http://www.example.com/a/index.html" ], "metadata.patterns": [ { "pattern": "http://metadata.example.com/a/b/*" } ], "type": "invalidate" } } -7.2. Examining Trigger Status +6.2. Examining Trigger Status Once triggers have been created, the uCDN can check their status as shown in these examples. -7.2.1. Collection of All Triggers +6.2.1. Collection of All Triggers The uCDN can fetch the set of all the triggers it has created and which have not yet been deleted or removed as expired. After creation of the "preposition" and "invalidate" triggers shown above, this collection might look as follows: REQUEST: GET /triggers HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* RESPONSE: HTTP/1.1 200 OK - Content-Length: 153 - Expires: Wed, 02 Jul 2014 18:58:20 GMT + Content-Length: 347 + Expires: Sun, 31 Aug 2014 09:54:19 GMT Server: example-server/0.1 - Etag: "9179988753593038498" + Etag: "-6516741166528256414" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 18:57:20 GMT + Date: Sun, 31 Aug 2014 09:53:19 GMT Content-Type: application/cdni.ci.TriggerCollection+json { + "cdn-id": "AS64496:0", + "coll-active": "/triggers/active", + "coll-complete": "/triggers/complete", + "coll-failed": "/triggers/failed", + "coll-pending": "/triggers/pending", "staleresourcetime": 86400, "triggers": [ "http://dcdn.example.com/triggers/0", "http://dcdn.example.com/triggers/1" ] } -7.2.2. Filtered Collections of Triggers +6.2.2. Filtered Collections of Triggers - The filtered collections are also available to uCDN. Before the dCDN - starts processing the two triggers shown above, both will appear in - the collection of Pending Triggers, for example: + The filtered collections are also available to the uCDN. Before the + dCDN starts processing the two triggers shown above, both will appear + in the collection of Pending Triggers, for example: - RREQUEST: + REQUEST: GET /triggers/pending HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* RESPONSE: HTTP/1.1 200 OK Content-Length: 153 - Expires: Wed, 02 Jul 2014 18:58:20 GMT + Expires: Sun, 31 Aug 2014 09:54:19 GMT Server: example-server/0.1 Etag: "5012053611544832286" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 18:57:20 GMT + Date: Sun, 31 Aug 2014 09:53:19 GMT Content-Type: application/cdni.ci.TriggerCollection+json { "staleresourcetime": 86400, "triggers": [ "http://dcdn.example.com/triggers/0", "http://dcdn.example.com/triggers/1" ] } @@ -1251,60 +1258,60 @@ GET /triggers/complete HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* RESPONSE: HTTP/1.1 200 OK Content-Length: 56 - Expires: Wed, 02 Jul 2014 18:58:20 GMT + Expires: Sun, 31 Aug 2014 09:54:19 GMT Server: example-server/0.1 Etag: "2986340333785000363" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 18:57:20 GMT + Date: Sun, 31 Aug 2014 09:53:19 GMT Content-Type: application/cdni.ci.TriggerCollection+json { "staleresourcetime": 86400, "triggers": [] } -7.2.3. Trigger Status Resources +6.2.3. Trigger Status Resources The Trigger Status Resources can also be examined for detail about individual triggers. For example, for the "preposition" and "invalidate" triggers from previous examples: REQUEST: GET /triggers/0 HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* RESPONSE: HTTP/1.1 200 OK Content-Length: 472 - Expires: Wed, 02 Jul 2014 18:58:20 GMT + Expires: Sun, 31 Aug 2014 09:54:19 GMT Server: example-server/0.1 - Etag: "-3651695664007658154" + Etag: "-4765587034697674779" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 18:57:20 GMT + Date: Sun, 31 Aug 2014 09:53:19 GMT Content-Type: application/cdni.ci.TriggerStatus+json { - "ctime": 1404327439, - "etime": 1404327447, - "mtime": 1404327439, + "ctime": 1409478798, + "etime": 1409478806, + "mtime": 1409478798, "status": "pending", "trigger": { "content.urls": [ "http://www.example.com/a/b/c/1", "http://www.example.com/a/b/c/2", "http://www.example.com/a/b/c/3", "http://www.example.com/a/b/c/4" ], "metadata.urls": [ "http://metadata.example.com/a/b/c" @@ -1317,365 +1324,493 @@ GET /triggers/1 HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* RESPONSE: HTTP/1.1 200 OK Content-Length: 551 - Expires: Wed, 02 Jul 2014 18:58:20 GMT + Expires: Sun, 31 Aug 2014 09:54:19 GMT Server: example-server/0.1 - Etag: "-7664987687828084413" + Etag: "-7657333837290433420" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 18:57:20 GMT + Date: Sun, 31 Aug 2014 09:53:19 GMT Content-Type: application/cdni.ci.TriggerStatus+json { - "ctime": 1404327440, - "etime": 1404327448, - "mtime": 1404327440, + "ctime": 1409478799, + "etime": 1409478807, + "mtime": 1409478799, "status": "pending", "trigger": { "content.patterns": [ { "case-sensitive": true, "pattern": "http://www.example.com/a/b/*" } ], "content.urls": [ "http://www.example.com/a/index.html" ], "metadata.patterns": [ { "pattern": "http://metadata.example.com/a/b/*" } ], "type": "invalidate" } } -7.2.4. Polling for Change +6.2.4. Polling for Change - The uCDN may use the Entity Tags of collections or resources when + The uCDN SHOULD use the Entity Tags of collections or resources when polling for change in status, as shown in the following examples: REQUEST: GET /triggers/pending HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* If-None-Match: "5012053611544832286" RESPONSE: HTTP/1.1 304 Not Modified Content-Length: 0 - Expires: Wed, 02 Jul 2014 18:58:20 GMT + Expires: Sun, 31 Aug 2014 09:54:19 GMT Server: example-server/0.1 Etag: "5012053611544832286" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 18:57:20 GMT + Date: Sun, 31 Aug 2014 09:53:19 GMT Content-Type: application/cdni.ci.TriggerCollection+json REQUEST: GET /triggers/0 HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* - If-None-Match: "-3651695664007658154" + If-None-Match: "-4765587034697674779" RESPONSE: HTTP/1.1 304 Not Modified Content-Length: 0 - Expires: Wed, 02 Jul 2014 18:58:20 GMT + Expires: Sun, 31 Aug 2014 09:54:19 GMT Server: example-server/0.1 - Etag: "-3651695664007658154" + Etag: "-4765587034697674779" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 18:57:20 GMT + Date: Sun, 31 Aug 2014 09:53:19 GMT Content-Type: application/cdni.ci.TriggerStatus+json When the triggered activity is complete, the contents of the filtered collections will be updated, along with their Entity Tags. For example, when the two example triggers are complete, the collections - of pending and complete triggers may look like: + of pending and complete triggers might look like: REQUEST: GET /triggers/pending HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* RESPONSE: HTTP/1.1 200 OK Content-Length: 56 - Expires: Wed, 02 Jul 2014 18:58:24 GMT + Expires: Sun, 31 Aug 2014 09:54:29 GMT Server: example-server/0.1 Etag: "-4471185573414616962" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 18:57:24 GMT + Date: Sun, 31 Aug 2014 09:53:29 GMT Content-Type: application/cdni.ci.TriggerCollection+json { "staleresourcetime": 86400, "triggers": [] } REQUEST: GET /triggers/complete HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* RESPONSE: HTTP/1.1 200 OK Content-Length: 153 - Expires: Wed, 02 Jul 2014 18:58:31 GMT + Expires: Sun, 31 Aug 2014 09:54:30 GMT Server: example-server/0.1 Etag: "-1508172875796647067" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 18:57:31 GMT + Date: Sun, 31 Aug 2014 09:53:30 GMT Content-Type: application/cdni.ci.TriggerCollection+json { "staleresourcetime": 86400, "triggers": [ "http://dcdn.example.com/triggers/0", "http://dcdn.example.com/triggers/1" ] } -7.2.5. Cancelling or Removing a Trigger +6.2.5. Removing a Trigger - To request the dCDN to cancel a Trigger, the uCDN may delete the - Trigger Resource. It may also delete completed and failed triggers + To request the dCDN to cancel a Trigger, the uCDN can delete the + Trigger Resource. It can also delete completed and failed triggers to reduce the size of the collections. For example, to remove the "preposition" request from earlier examples: REQUEST: DELETE /triggers/0 HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* RESPONSE: HTTP/1.1 204 No Content - Date: Wed, 02 Jul 2014 18:57:31 GMT + Date: Sun, 31 Aug 2014 09:53:30 GMT Content-Length: 0 Content-Type: text/html; charset=UTF-8 Server: example-server/0.1 This would, for example, cause the collection of completed triggers shown in the example above to be updated to: REQUEST: GET /triggers/complete HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* RESPONSE: HTTP/1.1 200 OK Content-Length: 106 - Expires: Wed, 02 Jul 2014 18:58:31 GMT + Expires: Sun, 31 Aug 2014 09:54:30 GMT Server: example-server/0.1 Etag: "-1842390246836476263" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 18:57:31 GMT + Date: Sun, 31 Aug 2014 09:53:30 GMT Content-Type: application/cdni.ci.TriggerCollection+json { "staleresourcetime": 86400, "triggers": [ "http://dcdn.example.com/triggers/1" ] } -7.2.6. Error Reporting +6.2.6. Error Reporting In this example the uCDN has requested prepositioning of "http://newsite.example.com/index.html", but the dCDN was unable to locate metadata for that site: REQUEST: GET /triggers/2 HTTP/1.1 User-Agent: example-user-agent/0.1 Host: dcdn.example.com Accept: */* RESPONSE: HTTP/1.1 200 OK Content-Length: 505 - Expires: Wed, 02 Jul 2014 19:16:48 GMT + Expires: Sun, 31 Aug 2014 09:54:38 GMT Server: example-server/0.1 - Etag: "-6310233270471598826" + Etag: "-3893590191073700822" Cache-Control: max-age=60 - Date: Wed, 02 Jul 2014 19:15:48 GMT + Date: Sun, 31 Aug 2014 09:53:38 GMT Content-Type: application/cdni.ci.TriggerStatus+json { - "ctime": 1404328544, + "ctime": 1409478810, "errors": [ { "content.urls": [ "http://newsite.example.com/index.html" ], "description": "No HostIndex entry found for newsite.example.com", - "error": "EMETA" + "error": "emeta" } ], - "etime": 1404328552, - "mtime": 1404328548, + "etime": 1409478818, + "mtime": 1409478814, "status": "active", "trigger": { "content.urls": [ "http://newsite.example.com/index.html" ], "type": "preposition" } } -8. IANA Considerations +7. IANA Considerations -8.1. CI/T MIME Media Types +7.1. Media type registrations - The IANA is requested to allocate the following MIME Media Types in - the MIME Media Types registry: +7.1.1. CI/T Commands - o application/cdni.ci.TriggerRequest + The MIME media type for CI/T Commands is application/ + cdni.ci.TriggerCommand+json. - o application/cdni.ci.TriggerStatus + Type Name: application - o application/cdni.ci.TriggerCollection + Subtype name: cdni.ci.TriggerCommand+json - Use of these types is specified in Section 6.2 of the present - document. + Required parameters: N/A -9. Security Considerations + Optional parameters: N/A -9.1. Authentication, Confidentiality, Integrity Protection + Encoding considerations: binary + + Security Considerations: See [RFCthis], Section 8 + + Interoperability Considerations: Described in [RFCthis] + + Published Specification: [RFCthis] + + Applications that use this media type: No known applications + currently use this media type. + + Additional Information: + + Deprecated alias names for this type: N/A + + Magic number(s): N/A + + File Extensions: N/A + + Macintosh file type code(s): TEXT + + Person & email address to contact for further information: IESG + + + Intended Usage: COMMON + + Restrictions on usage: None + + Author: Rob Murray + + Change controller: IESG + Note: No "charset" parameter is defined for this registration because + a charset parameter is not defined for application/json [RFC7159]. + +7.1.2. CI/T Trigger Status Resource + + The MIME media type for CI/T Trigger Status Resources is application/ + cdni.ci.TriggerStatus+json. + + Type Name: application + + Subtype name: cdni.ci.TriggerStatus+json + + Required parameters: N/A + + Optional parameters: N/A + + Encoding considerations: binary + + Security Considerations: See [RFCthis], Section 8 + + Interoperability Considerations: Described in [RFCthis] + + Published Specification: [RFCthis] + + Applications that use this media type: No known applications + currently use this media type. + + Additional Information: + + Deprecated alias names for this type: N/A + + Magic number(s): N/A + + File Extensions: N/A + + Macintosh file type code(s): TEXT + + Person & email address to contact for further information: IESG + + + Intended Usage: COMMON + + Restrictions on usage: None + + Author: Rob Murray + + Change controller: IESG + Note: No "charset" parameter is defined for this registration because + a charset parameter is not defined for application/json [RFC7159]. + +7.1.3. CI/T Trigger Collection + + The MIME media type for CI/T Trigger Collections is application/ + cdni.ci.TriggerCollection+json. + + Type Name: application + + Subtype name: cdni.ci.TriggerCollection+json + + Required parameters: N/A + + Optional parameters: N/A + + Encoding considerations: binary + + Security Considerations: See [RFCthis], Section 8 + + Interoperability Considerations: Described in [RFCthis] + + Published Specification: [RFCthis] + + Applications that use this media type: No known applications + currently use this media type. + + Additional Information: + + Deprecated alias names for this type: N/A + + Magic number(s): N/A + + File Extensions: N/A + + Macintosh file type code(s): TEXT + + Person & email address to contact for further information: IESG + + + Intended Usage: COMMON + + Restrictions on usage: None + + Author: Rob Murray + + Change controller: IESG + Note: No "charset" parameter is defined for this registration because + a charset parameter is not defined for application/json [RFC7159]. + +8. Security Considerations + +8.1. Authentication, Confidentiality, Integrity Protection A CI/T dCDN server implementation MUST support TLS transport for HTTP (https) as per [RFC2818]. The use of TLS for transport of the CI/T interface allows the dCDN and the uCDN to authenticate each other (to - ensure they are receiving trigger requests from, or reporting status - to, an authenticated CDN). - - HTTP requests that attempt to access or operate on CI/T data - belonging to another CDN MUST be rejected using either HTTP "403 - Forbidden" or "404 Not Found". (Note that in a "diamond" - configuration, where one uCDN's content can be acquired via more than - one directly-connected uCDN, it may not be possible for the dCDN to - determine from which uCDN it acquired content. In this case, it MUST - allow each upstream that may have been responsible for acquisition of - that content to act upon it using trigger requests.) - - Trigger creation requests that attempt to operate on metadata or - content not acquired from the uCDN making the request MUST be - rejected. The rejection can either be signalled to dCDN using HTTP - "403 Forbidden" or "404 Not Found", or a Trigger Status Resource can - be created with an ErrorDesc value of EPERM for any affected URLs. + ensure they are receiving CI/T Commands from, or reporting status to, + an authenticated CDN). In an environment where any such protection is required, TLS SHOULD be used for transport of the CI/T requests and responses, unless alternate methods are used for ensuring that only authorised clients are able to access their own data (such as setting up an IPsec tunnel between the two CDNs, or using a physically secured internal network between two CDNs that are owned by the same corporate entity). Both parties of the transaction (the uCDN and the dCDN) SHOULD use mutual authentication. - A CI/T implementation MUST support the + A TLS implementation of CI/T MUST support the TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 cipher suite ([RFC5288]). An implementation of the CI/T Interface SHOULD prefer cipher suites which support perfect forward secrecy over cipher suites that don't. -9.2. Denial of Service + HTTP requests that attempt to access or operate on CI/T data + belonging to another CDN MUST be rejected using, for example, HTTP + "403 Forbidden" or "404 Not Found". + + Note that in a "diamond" configuration, where one uCDN's content can + be acquired via more than one directly-connected uCDN, it may not be + possible for the dCDN to determine from which uCDN it acquired + content. In this case, the dCDN MUST allow each uCDN from which the + content could have been acquired to act upon that content using CI/T + Commands. + +8.2. Denial of Service This document does not define a specific mechanism to protect against Denial of Service (DoS) attacks on the CI/T. However, CI/T endpoints can be protected against DoS attacks through the use of TLS transport and/or via mechanisms outside the scope of the CI/T interface, such as firewalling or use of Virtual Private Networks (VPNs). -10. Acknowledgements + Depending on the implementation, triggered activity may consume + significant processing and bandwidth in the dCDN. A malicious or + faulty uCDN could use this to generate unnecessary load in the dCDN. + The dCDN should consider mechanisms to avoid overload, for example by + rate-limiting acceptance or processing of CI/T Commands, or batching + up its processing. - The authors thank Kevin Ma for his ongoing input. +9. Acknowledgements -11. References + The authors thank Kevin Ma for his input. -11.1. Normative References +10. References + +10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifier (URI): Generic Syntax", STD 66, RFC 3986, January 2005. [RFC7159] Bray, T., "The JavaScript Object Notation (JSON) Data Interchange Format", RFC 7159, March 2014. [RFC7231] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content", RFC 7231, June 2014. [RFC7232] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests", RFC 7232, June 2014. -11.2. Informative References - - [I-D.ietf-cdni-framework] - Peterson, L., Davie, B., and R. Brandenburg, "Framework - for CDN Interconnection", draft-ietf-cdni-framework-14 - (work in progress), June 2014. +10.2. Informative References [I-D.ietf-cdni-metadata] - Niven-Jenkins, B., Murray, R., Watson, G., Caulfield, M., - Leung, K., and K. Ma, "CDN Interconnect Metadata", draft- - ietf-cdni-metadata-06 (work in progress), February 2014. + Niven-Jenkins, B., Murray, R., Caulfield, M., Leung, K., + and K. Ma, "CDN Interconnection Metadata", draft-ietf- + cdni-metadata-07 (work in progress), July 2014. - [I-D.ietf-cdni-requirements] - Leung, K. and Y. Lee, "Content Distribution Network - Interconnection (CDNI) Requirements", draft-ietf-cdni- - requirements-17 (work in progress), January 2014. + [I-D.ietf-cdni-redirection] + Niven-Jenkins, B. and R. Brandenburg, "Request Routing + Redirection Interface for CDN Interconnection", draft- + ietf-cdni-redirection-03 (work in progress), August 2014. [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. - [RFC4287] Nottingham, M., Ed. and R. Sayre, Ed., "The Atom - Syndication Format", RFC 4287, December 2005. - [RFC5288] Salowey, J., Choudhury, A., and D. McGrew, "AES Galois Counter Mode (GCM) Cipher Suites for TLS", RFC 5288, August 2008. [RFC6707] Niven-Jenkins, B., Le Faucheur, F., and N. Bitar, "Content Distribution Network Interconnection (CDNI) Problem Statement", RFC 6707, September 2012. - [XML-BASE] - Marsh, J., Ed. and R. Tobin, Ed., "XML Base (Second - Edition) - http://www.w3.org/TR/xmlbase/", January 2009. + [RFC7336] Peterson, L., Davie, B., and R. van Brandenburg, + "Framework for Content Distribution Network + Interconnection (CDNI)", RFC 7336, August 2014. + + [RFC7337] Leung, K. and Y. Lee, "Content Distribution Network + Interconnection (CDNI) Requirements", RFC 7337, August + 2014. Authors' Addresses Rob Murray Velocix (Alcatel-Lucent) 3 Ely Road Milton, Cambridge CB24 6DD UK Email: rmurray@velocix.com