Network Working Group F. Le Faucheur
Internet-Draft M. Viveganandhan
Intended status: Informational K. Leung
Expires: January 14, 2013 Cisco
July 13, 2012
CDNI Logging Formats for HTTP and HTTP Adaptive Streaming Deliveries
draft-lefaucheur-cdni-logging-delivery-01
Abstract
The interconnection of Content Distribution Networks (CDNs) is
motivated by several use cases. CDN Interconnection can be achieved
through four CDNI interfaces, one of which is the CDNI Logging
interface. This document discusses CDNI logging formats for content
deliveries performed using HTTP or HTTP adaptive streaming.
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
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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 14, 2013.
Copyright Notice
Copyright (c) 2012 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
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(http://trustee.ietf.org/license-info) in effect on the date of
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. CDNI Logging for regular HTTP Delivery . . . . . . . . . . . . 4
2.1. Regular HTTP Log Triggers . . . . . . . . . . . . . . . . 4
2.2. Regular HTTP Log Fields . . . . . . . . . . . . . . . . . 4
3. CDNI Logging for HTTP Adaptive Streaming . . . . . . . . . . . 6
3.1. HAS Chunk-Based Log Triggers . . . . . . . . . . . . . . . 6
3.2. HAS Chunk-Based Log fields . . . . . . . . . . . . . . . . 6
4. Performance Monitoring . . . . . . . . . . . . . . . . . . . . 7
5. CDNI Log Encoding and Transport . . . . . . . . . . . . . . . 7
5.1. CDNI Log Header Information . . . . . . . . . . . . . . . 8
5.2. CDNI per-Log-Record Information . . . . . . . . . . . . . 8
5.3. CDNI Log Footer Information . . . . . . . . . . . . . . . 9
5.4. CDNI Customized Log Format . . . . . . . . . . . . . . . . 9
6. Impact on CDNI Metadata Requirements . . . . . . . . . . . . . 9
7. Impact on CDNI Footprint and Capabilities Advertisement . . . 10
8. Generation of CDNI Logs . . . . . . . . . . . . . . . . . . . 10
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
10. Security Considerations . . . . . . . . . . . . . . . . . . . 11
11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
12.1. Normative References . . . . . . . . . . . . . . . . . . . 11
12.2. Informative References . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12
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1. Introduction
The interconnection of Content Distribution Networks (CDNs) is
motivated by several use cases, such as those described in
[I-D.ietf-cdni-use-cases]. The overall problem space for CDN
Interconnection (CDNI) is described in
[I-D.ietf-cdni-problem-statement]. The CDN Interconnection framework
is defined in [I-D.ietf-cdni-framework] and the requirements for the
CDN Interconnection solution are specified in
[I-D.ietf-cdni-requirements].
One of the CDNI interfaces defined in these documents is the CDNI
Logging interface whose description is quoted here:
"o CDNI Logging interface: This interface allows the Logging system
in interconnected CDNs to communicate the relevant activity logs in
order to allow log consuming applications to operate in a multi-CDN
environments. For example, an upstream CDN may collect delivery logs
from a downstream CDN in order to perform consolidated charging of
the CSP or for settlement purposes across CDNs. Similarly, an
upstream CDN may collect delivery logs from a downstream CDN in order
to provide consolidated reporting and monitoring to the CSP."
The logging interface is discussed in details in
[I-D.bertrand-cdni-logging]. The present document identifies a
number of additional considerations regarding logging for content
delivery performed using HTTP.
[I-D.brandenburg-cdni-has] discusses the interactions of HTTP
Adaptive Streaming with CDNI Logging and provides recommendations on
how to specifically perform CDNI Logging for delievry performed using
HTTP Adaptive Streaming. The present document discusses in more
details how these recommendations woudl impact the CDNI Logging
interface.
Section 2 discusses the aspect of CDNI Logging that are specific to
content delivery performed via regular HTTP. Section 3 discusses the
aspect of CDNI Logging that are specific to content delivery
performed via HTTP adaptive streaming. Section 5 discusses the
aspect of CDNI Logging that are generic to all the CDNI Logs for
delivery.
CDNI Logging for other events than content delivery (e.g. failures,
request routing, service monitoring,...) are not discussed in the
present document.
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1.1. Terminology
This document uses all terminology defined in
[I-D.brandenburg-cdni-has].
2. CDNI Logging for regular HTTP Delivery
This section discusses the triggers on which a CDNI log is generated
for delivery of content using regular HTTP delivery, as well as the
fields contained in the corresponding log.
2.1. Regular HTTP Log Triggers
A CDNI Log is generated for a regular HTTP delivery on the following
triggers:
+-----------------+-------------------------------------------------+
| Event | Description |
+-----------------+-------------------------------------------------+
| content Request | Reception and processing of a request for a |
| | content |
+-----------------+-------------------------------------------------+
2.2. Regular HTTP Log Fields
A CDNI Log for regular HTTP delivery contains the following fields
(or a subset therefof as discused in Section 5.4):
+------------------+------------+-----------------------------------+
| Field | Descriptio | Examples |
| | n | |
+------------------+------------+-----------------------------------+
| Current-Time | Time, in | [20/Feb/2012:00:29.510+0200] |
| | millisecon | |
| | ds, at | |
| | which the | |
| | request | |
| | was | |
| | received. | |
| Time-to-Serve | Time, in | 952195 |
| | microsecon | |
| | ds, taken | |
| | to | |
| | complete | |
| | the | |
| | request. | |
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| Client-IP | IP address | 203.0.113.2 |
| | of the | |
| | requesting | |
| | client. | |
| Action | Squid | TCP_HIT, TCP_MISS, ... |
| | action | |
| | describing | |
| | how the | |
| | request | |
| | was | |
| | treated | |
| | locally | |
| | descriptio | |
| | n(e.g., | |
| | cache | |
| | hit/miss) | |
| | . | |
| Status-Returned | HTTP | 200, 404, ... |
| | response | |
| | code. | |
| Bytes-Transferre | Bytes sent | 23567992 |
| d | to the | |
| | client, | |
| | including | |
| | the | |
| | headers. | |
| Method | HTTP | GET |
| | request | |
| | method. | |
| URI | URI of | http://cache3.cdn1.com/movie/ice/ |
| | requested | icemovie.mpg |
| | content. | |
| Content-Type | MIME-Type | video/mpeg |
| | from the | |
| | reply | |
| | header. | |
| User-Agent (and | content of | Mozilla/5.0 (X11; Linux x86_64; |
| possibly some | the | rv:12.0) Gecko/20100101 |
| other HTTP | User-Agent | Firefox/12.0 |
| headers) | HTTP | |
| | Header | |
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| URI-Signing-Vali | Flag | 0/1 |
| dation | indicating | |
| | whether | |
| | URI | |
| | signature | |
| | validation | |
| | was | |
| | perfomed | |
+------------------+------------+-----------------------------------+
3. CDNI Logging for HTTP Adaptive Streaming
This section discusses the CDNI logs for delivery of content using
HTTP adaptive streaming. In line with the recommendations of
[I-D.brandenburg-cdni-has], this document proposes that a log record
be generated for delivery of each chunk or manifest file.
3.1. HAS Chunk-Based Log Triggers
A chunk-based Log record is generated for HAS delivery on the
following triggers:
+--------------------+----------------------------------------------+
| Event | Description |
+--------------------+----------------------------------------------+
| Chunk/Manifest | Reception of a request for a Segment (or |
| Request | Manifest File) |
+--------------------+----------------------------------------------+
3.2. HAS Chunk-Based Log fields
A chunk-based Log record for HTTP adaptive streaming may contain all
the same fields as a CDNI Log for a regular HTTP request, as well as
the following additional fields:
+------------+-------------------+----------------------------------+
| Field | Description | Examples |
+------------+-------------------+----------------------------------+
| Content | Identifier for | format and scope of unicity are |
| Collection | Content | TBD |
| ID | Collection | |
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| Session-id | a string | 6141F5795BE774691D234A0465B9667A |
| | generated by the | |
| | delivering CDN | |
| | and unique (to | |
| | the delivering | |
| | CDN) to identify | |
| | the Session. (*) | |
+------------+-------------------+----------------------------------+
(*) The Session-ID value to be included in a log record by the
delivering CDN is such that:
o different per-chunk log records with the same Session-ID value
must correspond to the same user session (.i.e delivery of same
content to same enduser at a given point in time)
o log records for different chunks of the same user session (.i.e
delivery of same content to same enduser at a given point in time)
should be provided with the same session-ID value. While
undesirable, there may be situations where the delivering CDN uses
more than one session-ID value for different per-chunk log records
of a given session, for example in scenarios of fail-over or load-
balancing across multiple Surrogates and where the delivering CDN
does not implement mechanism to synchronize session-IDs across
Surrogates.
4. Performance Monitoring
The CDNI Log fields listed in the previous sections allow monitoring
of essential delivery performance indicators across the CDN Mesh.
For example, for a regular HTTP delivery, these fields allow tracking
of the time taken to serve the requested content, tracking of content
delivery failures, tracking of partial deliveries and tracking of
cache hit ratios. As another example, for HTTP adaptive streaming,
these fields allow tracking of the presentation (and its fluctuation
over time) served to the End-User as well as the End-User random
content access (e.g. Play/Stop/Seek).
Subsequent versions of this document may discuss potential additional
log fields for enhanced performance monitoring.
5. CDNI Log Encoding and Transport
Details for CDNI Log encoding and transport will be specified in
subsequent versions. WE observe that this is expected to allow
optional use of common compression techniques (e.g. gzip). However,
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Section 5.1 identifies the information that is to be included in the
header of CDNI Logs, Section 5.2 identifies information that is to be
attached to every CDNI Log record and Section 5.3 identifies the
information that is to be included in the footer of CDNI Logs.
Finally, Section 5.4 discusses the notion of customized Logging.
5.1. CDNI Log Header Information
The header of CDNI Logs contains the following fields:
+----------------+-------------------+------------------------------+
| Field | Description | Examples |
+----------------+-------------------+------------------------------+
| Format-Version | Version of the | v1.0 |
| | CDNI Log format. | |
| Log-Field-List | The list of the | time cs-method cs-uri |
| | fields provided | |
| | in the log | |
| | records | |
| Log-ID | Unique identifier | |
| | for the CDNI Log | |
| | (facilitates | |
| | detection of | |
| | duplicate Logs | |
| | and tracking in | |
| | case of | |
| | aggregation). | |
| Log-Timestamp | Time, in | [20/Feb/2012:00:29.510+0200] |
| | milliseconds, the | |
| | CDNI Log was | |
| | generated. | |
+----------------+-------------------+------------------------------+
5.2. CDNI per-Log-Record Information
In addition to the log fields discussed in previous sections, each
CDNI log record contains the following fields:
+----------+---------------------------------------------+----------+
| Field | Description | Examples |
+----------+---------------------------------------------+----------+
| Log | Digest of the Log records (facilitates | |
| Record | recovery of uncorrupted Log records inside | |
| Digest | a corrupted CDNI Log) | |
+----------+---------------------------------------------+----------+
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5.3. CDNI Log Footer Information
The footer of CDNI Logs contains the following fields:
+---------+----------------------------------------------+----------+
| Field | Description | Examples |
+---------+----------------------------------------------+----------+
| Log | Digest of the complete Log (facilitates | |
| Digest | detection of Log corruption) | |
+---------+----------------------------------------------+----------+
5.4. CDNI Customized Log Format
This document proposes that customized logs be supported by CDNI in
the following manner:
o the uCDN uses the CDNI Metadata interface to indicate to the dCDN
which subset of the CDNI logging fields are to be provided in a
log record for corresponding to a request for a given content
o the dCDN provides, via the CDNI Logging interface, log records
containing the subset of CDNI logging fields requested by the
uCDN.
o The dCDN explicitly lists in the CDNI Log Header the fields
actually provided (as discussed in Section 5.1).
6. Impact on CDNI Metadata Requirements
We request that the following requirements be added in section 6 of
[I-D.ietf-cdni-requirements]:
"
META-X [HIGH] The CDNI Metadata Distribution interface shall support
an OPTIONAL mechanism allowing the Upstream CDN to indicate to the
Downstream CDN which CDNI Log fields are to be provided for all, for
specific sets of, or for specific content items delivered using HTTP.
A CDNI implementation that does not support this optional CDNI
Metadata Distribution Interface mechanism MUST ignore this log format
indication and generate CDNI logging format for adaptive streaming
using the default set of CDNI Logging fields. [Editor's note: A
default set of logging fields need to be defined]
META-X [MID] The CDNI Metadata Distribution interface shall allow the
uCDN to signal to the dCDN the Content Collection ID value for all,
for specific sets of, or for specific content items delivered using
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HTTP. Whenever the dCDN is instructed by the uCDN (using the
customized logging mechanism described in Section 5.4) to report the
Content Collection ID field in the log records, the dCDN is to use
the value provided through the CDNI Metadata interface for the
corresponding content.
"
7. Impact on CDNI Footprint and Capabilities Advertisement
We request that the following requirement be added in section 5 of
[I-D.ietf-cdni-requirements]:
"
REQ-X [MID] The CDNI Request Routing/Footprint and Advertisement
Interface shall support advertisement of the following capabilities:
o support for customized CDNI Logging
o support of Content Collection ID logging
o support for Session-ID logging
"
8. Generation of CDNI Logs
Like other CDNI interfaces, the CDNI Logging interface specifies
operations across CDNs and not inside a CDN. Therefore, the log
formats specified in this document apply to CDNI logging information
exchanged across CDNs and does not constrain the process for
generating such inter-CDN logs within a given CDN. The format of the
logs generated by a given CDN Surrogate is beyond the scope of the
present document. We observe that a given CDN could elect to have
its Surrogates natively generate logs in the same format as the one
to be used for exchange with another CDN, or that the CDN could elect
to have its Surrogates generate logs in any other format (as long as
they include the necessary information) and have these logs then
reformatted prior to exchange with another CDN.
9. IANA Considerations
[This will be specified in subsequent versions].
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10. Security Considerations
CDNI Logs exchanged over the CDNI Logging interface can be consumed
by very sensitive applications including inter-CDN accounting and
billing. The associated security concerns are discussed in
[I-D.ietf-cdni-framework]. At this stage, we observe that the CDNI
Logging interface can leverage the existing security mechanisms
supported by the underlying transport protocol that will be selected
for transport of CDNI Logs (e.g. to support authentication of the
entities exchanging CDNI Logs through the CDNI Logging interface, to
support privacy and protection against spoofing). This will be
further discussed in subsequent versions of this document.
11. Acknowledgements
The authors want to thank Gene Halbrooks for his input into this
document.
12. References
12.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
12.2. Informative References
[I-D.bertrand-cdni-logging]
Bertrand, G. and S. Emile, "CDNI Logging Interface",
draft-bertrand-cdni-logging-00 (work in progress),
February 2012.
[I-D.brandenburg-cdni-has]
Brandenburg, R., Deventer, O., Faucheur, F., and K. Leung,
"Models for adaptive-streaming-aware CDN Interconnection",
draft-brandenburg-cdni-has-03 (work in progress),
July 2012.
[I-D.ietf-cdni-framework]
Peterson, L. and B. Davie, "Framework for CDN
Interconnection", draft-ietf-cdni-framework-00 (work in
progress), April 2012.
[I-D.ietf-cdni-problem-statement]
Niven-Jenkins, B., Faucheur, F., and N. Bitar, "Content
Distribution Network Interconnection (CDNI) Problem
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Statement", draft-ietf-cdni-problem-statement-08 (work in
progress), June 2012.
[I-D.ietf-cdni-requirements]
Leung, K. and Y. Lee, "Content Distribution Network
Interconnection (CDNI) Requirements",
draft-ietf-cdni-requirements-03 (work in progress),
June 2012.
[I-D.ietf-cdni-use-cases]
Bertrand, G., Emile, S., Burbridge, T., Eardley, P., Ma,
K., and G. Watson, "Use Cases for Content Delivery Network
Interconnection", draft-ietf-cdni-use-cases-09 (work in
progress), July 2012.
Authors' Addresses
Francois Le Faucheur
Cisco Systems
Greenside, 400 Avenue de Roumanille
Sophia Antipolis 06410
France
Phone: +33 4 97 23 26 19
Email: flefauch@cisco.com
Mahesh Viveganandhan
Cisco Systems
375 East Tasman Drive
San Jose 95134
USA
Email: mvittal@cisco.com
Kent Leung
Cisco Systems
3625 Cisco Way
San Jose 95134
USA
Phone: +1 408 526 5030
Email: kleung@cisco.com
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