PROPOSED Distributed Tracing Working Group Charter
This document is an obsolete draft - see final charter approved
The mission of the Distributed Tracing Working Group is to define standards for interoperability between tracing tools. A tracing tool refers to a tool which is implemented as either a library or an agent to provide at least one of the following capabilities:
- Propagation of the context identifying a trace, i.e. an interaction with an application;
- Modification of trace information to indicate that additional trace information is available;
- Collection of tracing information for a specific trace.
Interoperability for tracing therefore refers to:
- A standardized way to propagate vendor-specific tracing information across tiers instrumented with different tracing tools;
- A standardized and extensible format to share trace data — full traces or fragments of traces — across tools for further interpretation.
This proposed charter is available on GitHub. Feel free to raise issues.
| Start date | [dd monthname yyyy] (date of the "Call for Participation", when the charter is approved) |
|---|---|
| End date | Start date + 2 years |
| Charter extension | See Change History. |
| Chairs | Sergey Kanzhelev (Microsoft Corporation), Daniel Khan (Dynatrace LLC), Morgan McLean (Google, Inc.) |
| Team Contacts | Philippe Le Hégaret (0.05 FTE) |
| Meeting Schedule |
Teleconferences: 1-hour team calls will be held bi-weekly.
Face-to-face: we will meet during the W3C's annual Technical Plenary week; additional face-to-face meetings may be scheduled by consent of the participants. |
Scope
Modern cloud-native applications are highly distributed and often span multiple technology and vendor boundaries. The complexity of these applications requires a detailed understanding of how individual requests are executed. This is referred to as "tracing".
Tracing tools for collecting this information have been available for quite some time. However, these tools have not been built with interoperability in mind. This leaves the developer with a number of challenges in getting an end-to-end trace of complex transactions:
- Traces are often broken, because trace context information is lost in a contributing tier or the trace is restarted
- Vendors cannot pass proprietary information across tiers instrumented with a different implementation and therefore lose relevant information (e.g. step count, server information, ...)
- End users don't have the ability to create complete end-to-end traces of application transactions which are monitored by different tools, as there is no defined data format and semantics for trace data
The scope of this working group is the definition of data formats and headers enabling the propagation and correlation of tracing data across different implementations.
Out of Scope
The following features are out of scope, and will not be addressed by this Working group.
- definition of (programming) language specific APIs for performance data collection;
- performance data analysis techniques or algorithms.
Deliverables
More detailed milestones and updated publication schedules are available on the group publication status page.
Draft state indicates the state of the deliverable at the time of the charter approval. Expected completion indicates when the deliverable is projected to become a Recommendation, or otherwise reach a stable state.
Normative Specifications
The Working Group will deliver the following W3C normative specifications:
- Trace Context (update)
-
This specification is the update of Trace Context 1 which defines headers and a value format to propagate context information that enables distributed tracing scenarios.
Draft state: Editor Draft
Expected completion: Q2 2021
- Correlation Context
-
This specification defines how correlation relevant meta data can be propagated across tiers using different tracing tools.
Draft state: Editor Draft
Expected completion: Q2 2021
- Trace Interchange Format
-
This specification defines a standardized format to exchange trace data across multiple platforms.
Draft state: Requirements Definition
- Trace Context: AMQP protocol
-
This is an extension document for the Trace Context specification. It defines the mapping of Trace Context fields to the AMQP protocol and specifics of AMQP implementation.
Draft state: Editor Draft
Expected completion: Q4 2020
- Trace Context: binary protocol
-
This is an extension document for the Trace Context specification. It defines the mapping of Trace Context fields to the binary formats.
Draft state: Editor Draft
Expected completion: Q4 2020
- Trace Context: MQTT protocol
-
This is an extension document for the Trace Context specification. It defines the mapping of Trace Context fields to the MQTT protocol.
Draft state: Editor Draft
Other Deliverables
Other non-normative documents may be created such as:
- A registry of identified formats of trace context Trace Context serialization and deserialization for protocols.
- Use case and requirement documents;
- List of recommended vendor identifiers for header values;
- Test suite and implementation report for the specification;
- Primer or Best Practice documents to support web developers when designing applications.
Success Criteria
In order to advance to Proposed Recommendation, each specification is expected to have at least two independent implementations of each of feature defined in the specification.
Each specification should contain a section detailing all known security and privacy implications for implementers, Web authors, and end users.
There should be testing plans for each specification, starting from the earliest drafts.
To promote interoperability, all changes made to specifications should have tests.
Coordination
For all specifications, this Working Group will seek horizontal review for accessibility, internationalization, performance, privacy, and security with the relevant Working and Interest Groups, and with the TAG. Invitation for review must be issued during each major standards-track document transition, including FPWD. The Working Group is encouraged to engage collaboratively with the horizontal review groups throughout development of each specification. The Working Group is advised to seek a review at least 3 months before first entering CR and is encouraged to proactively notify the horizontal review groups when major changes occur in a specification following a review.
Additional technical coordination with the following Groups will be made, per the W3C Process Document:
W3C Groups
- Web Performance Working Group
- The trace context standard relates to work around Server Timing done within the Web Performance group. Going forward it will make sense to define how trace context headers - specifically response headers - are related to the server timing header. The trace interchange format also can be used to represent server timing data.
External Organizations
- Internet Engineering Task Force
- The IETF is responsible for defining robust and secure protocols for Internet functionality, in particular HTTP. The Working Group should coordinate protocol-related work (e.g. profiles of hybi or HTTP) with the appropriate IETF WGs.
Participation
To be successful, this Working Group is expected to have 6 or more active participants for its duration, including representatives from the key implementors of this specification, and active Editors and Test Leads for each specification. The Chairs, specification Editors, and Test Leads are expected to contribute half of a working day per week towards the Working Group. There is no minimum requirement for other Participants.
The group encourages questions, comments and issues on its public mailing lists and document repositories, as described in Communication.
The group also welcomes non-Members to contribute technical submissions for consideration upon their agreement to the terms of the W3C Patent Policy.
Participants in the group are required (by the W3C Process) to follow the W3C Code of Ethics and Professional Conduct.
Communication
Technical discussions for this Working Group are conducted in public: the meeting minutes from teleconference and face-to-face meetings will be archived for public review, and technical discussions and issue tracking will be conducted in a manner that can be both read and written to by the general public. Working Drafts and Editor's Drafts of specifications will be developed on a public repository and may permit direct public contribution requests. The meetings themselves are not open to public participation, however.
Information about the group (including details about deliverables, issues, actions, status, participants, and meetings) will be available from the Distributed Tracing Working Group home page.
Most Distributed Tracing Working Group teleconferences will focus on discussion of particular specifications, and will be conducted on an as-needed basis.
This group primarily conducts its technical work on GitHub issues. The public is invited to review, discuss and contribute to this work.
The group may use a Member-confidential mailing list for administrative purposes and, at the discretion of the Chairs and members of the group, for member-only discussions in special cases when a participant requests such a discussion.
Decision Policy
This group will seek to make decisions through consensus and due process, per the W3C Process Document (section 3.3). Typically, an editor or other participant makes an initial proposal, which is then refined in discussion with members of the group and other reviewers, and consensus emerges with little formal voting being required.
However, if a decision is necessary for timely progress and consensus is not achieved after careful consideration of the range of views presented, the Chairs may call for a group vote and record a decision along with any objections.
To afford asynchronous decisions and organizational deliberation, any resolution (including publication decisions) taken in a face-to-face meeting or teleconference will be considered provisional. A call for consensus (CfC) will be issued for all resolutions (for example, via email and/or web-based survey), with a response period from 10 working days, depending on the chair's evaluation of the group consensus on the issue. If no objections are raised on the mailing list by the end of the response period, the resolution will be considered to have consensus as a resolution of the Working Group.
All decisions made by the group should be considered resolved unless and until new information becomes available or unless reopened at the discretion of the Chairs or the Director.
This charter is written in accordance with the W3C Process Document (Section 3.4, Votes) and includes no voting procedures beyond what the Process Document requires.
Patent Policy
This Working Group operates under the W3C Patent Policy (Version of 5 February 2004 updated 1 August 2017). To promote the widest adoption of Web standards, W3C seeks to issue Recommendations that can be implemented, according to this policy, on a Royalty-Free basis. For more information about disclosure obligations for this group, please see the W3C Patent Policy Implementation.
Licensing
This Working Group will use the W3C Software and Document license for all its deliverables.
About this Charter
This charter has been created according to section 5.2 of the Process Document. In the event of a conflict between this document or the provisions of any charter and the W3C Process, the W3C Process shall take precedence.
Charter History
The following table lists details of all changes from the initial charter, per the W3C Process Document (section 5.2.3):
| Charter Period | Start Date | End Date | Changes |
|---|---|---|---|
| Initial Charter | 2018-07-25 | 2020-04-30 | none |
| Proposed | [dd monthname yyyy] | [dd monthname yyyy] |
None. |