HTTP/3 and QPACK qlog event definitions
draft-ietf-quic-qlog-h3-events-03
The information below is for an old version of the document.
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| Authors | Robin Marx , Luca Niccolini , Marten Seemann , Lucas Pardue | ||
| Last updated | 2022-10-24 | ||
| Replaces | draft-marx-quic-qlog-h3-events | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
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draft-ietf-quic-qlog-h3-events-03
QUIC R. Marx, Ed.
Internet-Draft Akamai
Intended status: Standards Track L. Niccolini, Ed.
Expires: 27 April 2023 Meta
M. Seemann, Ed.
Protocol Labs
L. Pardue, Ed.
Cloudflare
24 October 2022
HTTP/3 and QPACK qlog event definitions
draft-ietf-quic-qlog-h3-events-03
Abstract
This document describes concrete qlog event definitions and their
metadata for HTTP/3 and QPACK-related events. These events can then
be embedded in the higher level schema defined in [QLOG-MAIN].
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
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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 27 April 2023.
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://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 Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Notational Conventions . . . . . . . . . . . . . . . . . 4
2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Usage with QUIC . . . . . . . . . . . . . . . . . . . . . 4
2.2. Raw packet and frame information . . . . . . . . . . . . 5
3. HTTP/3 and QPACK Event Overview . . . . . . . . . . . . . . . 5
4. HTTP/3 Events . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1. parameters_set . . . . . . . . . . . . . . . . . . . . . 7
4.2. parameters_restored . . . . . . . . . . . . . . . . . . . 8
4.3. stream_type_set . . . . . . . . . . . . . . . . . . . . . 8
4.4. frame_created . . . . . . . . . . . . . . . . . . . . . . 9
4.5. frame_parsed . . . . . . . . . . . . . . . . . . . . . . 10
4.6. push_resolved . . . . . . . . . . . . . . . . . . . . . . 10
5. HTTP/3 Data Field Definitions . . . . . . . . . . . . . . . . 11
5.1. Owner . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.2. HTTPFrame . . . . . . . . . . . . . . . . . . . . . . . . 11
5.2.1. HTTPDataFrame . . . . . . . . . . . . . . . . . . . . 12
5.2.2. HTTPHeadersFrame . . . . . . . . . . . . . . . . . . 12
5.2.3. HTTPCancelPushFrame . . . . . . . . . . . . . . . . . 13
5.2.4. HTTPSettingsFrame . . . . . . . . . . . . . . . . . . 13
5.2.5. HTTPPushPromiseFrame . . . . . . . . . . . . . . . . 13
5.2.6. HTTPGoAwayFrame . . . . . . . . . . . . . . . . . . . 14
5.2.7. HTTPMaxPushIDFrame . . . . . . . . . . . . . . . . . 14
5.2.8. HTTPReservedFrame . . . . . . . . . . . . . . . . . . 14
5.2.9. HTTPUnknownFrame . . . . . . . . . . . . . . . . . . 14
5.2.10. HTTPApplicationError . . . . . . . . . . . . . . . . 14
6. QPACK Events . . . . . . . . . . . . . . . . . . . . . . . . 15
6.1. state_updated . . . . . . . . . . . . . . . . . . . . . . 16
6.2. stream_state_updated . . . . . . . . . . . . . . . . . . 16
6.3. dynamic_table_updated . . . . . . . . . . . . . . . . . . 17
6.4. headers_encoded . . . . . . . . . . . . . . . . . . . . . 17
6.5. headers_decoded . . . . . . . . . . . . . . . . . . . . . 18
6.6. instruction_created . . . . . . . . . . . . . . . . . . . 19
6.7. instruction_parsed . . . . . . . . . . . . . . . . . . . 19
7. QPACK Data Field Definitions . . . . . . . . . . . . . . . . 20
7.1. QPACKInstruction . . . . . . . . . . . . . . . . . . . . 20
7.1.1. SetDynamicTableCapacityInstruction . . . . . . . . . 20
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7.1.2. InsertWithNameReferenceInstruction . . . . . . . . . 20
7.1.3. InsertWithoutNameReferenceInstruction . . . . . . . . 20
7.1.4. DuplicateInstruction . . . . . . . . . . . . . . . . 21
7.1.5. SectionAcknowledgementInstruction . . . . . . . . . . 21
7.1.6. StreamCancellationInstruction . . . . . . . . . . . . 21
7.1.7. InsertCountIncrementInstruction . . . . . . . . . . . 21
7.2. QPACKHeaderBlockRepresentation . . . . . . . . . . . . . 22
7.2.1. IndexedHeaderField . . . . . . . . . . . . . . . . . 22
7.2.2. LiteralHeaderFieldWithName . . . . . . . . . . . . . 22
7.2.3. LiteralHeaderFieldWithoutName . . . . . . . . . . . . 23
7.3. QPACKHeaderBlockPrefix . . . . . . . . . . . . . . . . . 23
7.4. QPACKTableType . . . . . . . . . . . . . . . . . . . . . 23
8. Security and Privacy Considerations . . . . . . . . . . . . . 23
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
10. Normative References . . . . . . . . . . . . . . . . . . . . 23
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 24
A.1. Since draft-ietf-quic-qlog-h3-events-02: . . . . . . . . 24
A.2. Since draft-ietf-quic-qlog-h3-events-01: . . . . . . . . 25
A.3. Since draft-ietf-quic-qlog-h3-events-00: . . . . . . . . 25
A.4. Since draft-marx-qlog-event-definitions-quic-h3-02: . . . 25
A.5. Since draft-marx-qlog-event-definitions-quic-h3-01: . . . 25
A.6. Since draft-marx-qlog-event-definitions-quic-h3-00: . . . 27
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 27
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27
1. Introduction
This document describes the values of the qlog name ("category" +
"event") and "data" fields and their semantics for HTTP/3 [HTTP/3]
and QPACK [QPACK].
Note to RFC editor: Please remove the follow paragraphs in this
section before publication.
Feedback and discussion are welcome at https://github.com/quicwg/qlog
(https://github.com/quicwg/qlog). Readers are advised to refer to
the "editor's draft" at that URL for an up-to-date version of this
document.
Concrete examples of integrations of this schema in various
programming languages can be found at https://github.com/quiclog/
qlog/ (https://github.com/quiclog/qlog/).
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1.1. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
The event and data structure definitions in ths document are
expressed in the Concise Data Definition Language [CDDL] and its
extensions described in [QLOG-MAIN].
The following fields from [QLOG-MAIN] are imported and used: name,
category, type, data, group_id, protocol_type, importance, RawInfo,
and time-related fields.
2. Overview
This document describes how the HTTP/3 and QPACK can be expressed in
qlog using the schema defined in [QLOG-MAIN]. HTTP/3 and QPACK
events are defined with a category, a name (the concatenation of
"category" and "event"), an "importance", an optional "trigger", and
"data" fields.
Some data fields use complex datastructures. These are represented
as enums or re-usable definitions, which are grouped together on the
bottom of this document for clarity.
When any event from this document is included in a qlog trace, the
"protocol_type" qlog array field MUST contain an entry with the value
"HTTP3".
2.1. Usage with QUIC
The events described in this document can be used with or without
logging the related QUIC events defined in [QLOG-QUIC]. If used with
QUIC events, the QUIC document takes precedence in terms of
recommended filenames and trace separation setups.
If used without QUIC events, it is recommended that the
implementation assign a globally unique identifier to each HTTP/3
connection. This ID can then be used as the value of the qlog
"group_id" field, as well as the qlog filename or file identifier,
potentially suffixed by the vantagepoint type (For example,
abcd1234_server.qlog would contain the server-side trace of the
connection with GUID abcd1234).
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2.2. Raw packet and frame information
This document re-uses the definition of the RawInfo data class from
[QLOG-MAIN].
Note: As HTTP/3 does not use trailers in frames, each HTTP/3 frame
header_length can be calculated as header_length = RawInfo:length
- RawInfo:payload_length
Note: In some cases, the length fields are also explicitly reflected
inside of frame headers. For example, all HTTP/3 frames include
their explicit payload lengths in the frame header. In these
cases, those fields are intentionally preserved in the event
definitions. Even though this can lead to duplicate data when the
full RawInfo is logged, it allows a more direct mapping of the
HTTP/3 specifications to qlog, making it easier for users to
interpret. In this case, both fields MUST have the same value.
3. HTTP/3 and QPACK Event Overview
This document defines events in two categories, written as lowercase
to follow convention: http (Section 4) and qpack (Section 6).
As described in Section 3.4.2 of [QLOG-MAIN], the qlog "name" field
is the concatenation of category and type.
Table 1 summarizes the name value of each event type that is defined
in this specification.
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+=============================+============+=============+
| Name value | Importance | Definition |
+=============================+============+=============+
| http:parameters_set | Base | Section 4.1 |
+-----------------------------+------------+-------------+
| http:parameters_restored | Base | Section 4.2 |
+-----------------------------+------------+-------------+
| http:stream_type_set | Base | Section 4.3 |
+-----------------------------+------------+-------------+
| http:frame_created | Core | Section 4.4 |
+-----------------------------+------------+-------------+
| http:frame_parsed | Core | Section 4.5 |
+-----------------------------+------------+-------------+
| http:push_resolved | Extra | Section 4.6 |
+-----------------------------+------------+-------------+
| qpack:state_updated | Base | Section 6.1 |
+-----------------------------+------------+-------------+
| qpack:stream_state_updated | Core | Section 6.2 |
+-----------------------------+------------+-------------+
| qpack:dynamic_table_updated | Extra | Section 6.3 |
+-----------------------------+------------+-------------+
| qpack:headers_encoded | Base | Section 6.4 |
+-----------------------------+------------+-------------+
| qpack:headers_decoded | Base | Section 6.5 |
+-----------------------------+------------+-------------+
| qpack:instruction_created | Base | Section 6.6 |
+-----------------------------+------------+-------------+
| qpack:instruction_parsed | Base | Section 6.7 |
+-----------------------------+------------+-------------+
Table 1: HTTP/3 and QPACK Events
4. HTTP/3 Events
HTTP/3 events extend the $ProtocolEventBody extension point defined
in [QLOG-MAIN].
HTTPEvents = HTTPParametersSet / HTTPParametersRestored /
HTTPStreamTypeSet / HTTPFrameCreated /
HTTPFrameParsed / HTTPPushResolved
$ProtocolEventBody /= HTTPEvents
Figure 1: HTTPEvents definition and ProtocolEventBody extension
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4.1. parameters_set
Importance: Base
This event contains HTTP/3 and QPACK-level settings, mostly those
received from the HTTP/3 SETTINGS frame. All these parameters are
typically set once and never change. However, they are typically set
at different times during the connection, so there can be several
instances of this event with different fields set.
Note that some settings have two variations (one set locally, one
requested by the remote peer). This is reflected in the "owner"
field. As such, this field MUST be correct for all settings included
a single event instance. If you need to log settings from two sides,
you MUST emit two separate event instances.
Note: we use the CDDL unwrap operator (~) here to make HTTPParameters
into a re-usable list of fields. The unwrap operator copies the
fields from the referenced type into the target type directly,
extending the target with the unwrapped fields. TODO: explain this
better + provide reference and maybe an example.
Definition:
HTTPParametersSet = {
? owner: Owner
~HTTPParameters
; qlog-specific
; indicates whether this implementation waits for a SETTINGS
; frame before processing requests
? waits_for_settings: bool
}
HTTPParameters = {
? max_header_list_size: uint64
? max_table_capacity: uint64
? blocked_streams_count: uint64
; additional settings for grease and extensions
* text => uint64
}
Figure 2: HTTPParametersSet definition
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Note: enabling server push is not explicitly done in HTTP/3 by use of
a setting or parameter. Instead, it is communicated by use of the
MAX_PUSH_ID frame, which should be logged using the frame_created and
frame_parsed events below.
Additionally, this event can contain any number of unspecified
fields. This is to reflect setting of for example unknown (greased)
settings or parameters of (proprietary) extensions.
4.2. parameters_restored
Importance: Base
When using QUIC 0-RTT, HTTP/3 clients are expected to remember and
reuse the server's SETTINGs from the previous connection. This event
is used to indicate which HTTP/3 settings were restored and to which
values when utilizing 0-RTT.
Definition:
HTTPParametersRestored = {
~HTTPParameters
}
Figure 3: HTTPParametersRestored definition
Note that, like for parameters_set above, this event can contain any
number of unspecified fields to allow for additional and custom
settings.
4.3. stream_type_set
Importance: Base
Emitted when a stream's type becomes known. This is typically when a
stream is opened and the stream's type indicator is sent or received.
Note: most of this information can also be inferred by looking at a
stream's id, since id's are strictly partitioned at the QUIC level.
Even so, this event has a "Base" importance because it helps a lot in
debugging to have this information clearly spelled out.
Definition:
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HTTPStreamTypeSet = {
? owner: Owner
stream_id: uint64
stream_type: HTTPStreamType
; only when stream_type === "unknown"
? raw_stream_type: uint64
; only when stream_type === "push"
? associated_push_id: uint64
}
HTTPStreamType = "request" /
"control" /
"push" /
"reserved" /
"unknown" /
"qpack_encode" /
"qpack_decode"
Figure 4: HTTPStreamTypeSet definition
4.4. frame_created
Importance: Core
HTTP equivalent to the packet_sent event. This event is emitted when
the HTTP/3 framing actually happens. Note: this is not necessarily
the same as when the HTTP/3 data is passed on to the QUIC layer. For
that, see the "data_moved" event in [QLOG-QUIC].
Definition:
HTTPFrameCreated = {
stream_id: uint64
? length: uint64
frame: $HTTPFrame
? raw: RawInfo
}
Figure 5: HTTPFrameCreated definition
Note: in HTTP/3, DATA frames can have arbitrarily large lengths to
reduce frame header overhead. As such, DATA frames can span many
QUIC packets and can be created in a streaming fashion. In this
case, the frame_created event is emitted once for the frame header,
and further streamed data is indicated using the data_moved event.
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4.5. frame_parsed
Importance: Core
HTTP equivalent to the packet_received event. This event is emitted
when we actually parse the HTTP/3 frame. Note: this is not
necessarily the same as when the HTTP/3 data is actually received on
the QUIC layer. For that, see the "data_moved" event in [QLOG-QUIC].
Definition:
HTTPFrameParsed = {
stream_id: uint64
? length: uint64
frame: $HTTPFrame
? raw: RawInfo
}
Figure 6: HTTPFrameParsed definition
Note: in HTTP/3, DATA frames can have arbitrarily large lengths to
reduce frame header overhead. As such, DATA frames can span many
QUIC packets and can be processed in a streaming fashion. In this
case, the frame_parsed event is emitted once for the frame header,
and further streamed data is indicated using the data_moved event.
4.6. push_resolved
Importance: Extra
This event is emitted when a pushed resource is successfully claimed
(used) or, conversely, abandoned (rejected) by the application on top
of HTTP/3 (e.g., the web browser). This event is added to help debug
problems with unexpected PUSH behaviour, which is commonplace with
HTTP/2.
Definition:
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HTTPPushResolved = {
? push_id: uint64
; in case this is logged from a place that does not have access
; to the push_id
? stream_id: uint64
decision: HTTPPushDecision
}
HTTPPushDecision = "claimed" / "abandoned"
Figure 7: HTTPPushResolved definition
5. HTTP/3 Data Field Definitions
The following data field definitions can be used in HTTP/3 events.
5.1. Owner
Owner = "local" / "remote"
Figure 8: Owner definition
5.2. HTTPFrame
The generic $HTTPFrame is defined here as a CDDL extension point (a
"socket" or "plug"). It can be extended to support additional HTTP/3
frame types.
; The HTTPFrame is any key-value map (e.g., JSON object)
$HTTPFrame /= {
* text => any
}
Figure 9: HTTPFrame plug definition
The HTTP/3 frame types defined in this document are as follows:
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HTTPBaseFrames = HTTPDataFrame /
HTTPHeadersFrame /
HTTPCancelPushFrame /
HTTPSettingsFrame /
HTTPPushPromiseFrame /
HTTPGoawayFrame /
HTTPMaxPushIDFrame /
HTTPReservedFrame /
HTTPUnknownFrame
$HTTPFrame /= HTTPBaseFrames
Figure 10: HTTPBaseFrames definition
5.2.1. HTTPDataFrame
HTTPDataFrame = {
frame_type: "data"
? raw: hexstring
}
Figure 11: HTTPDataFrame definition
5.2.2. HTTPHeadersFrame
This represents an _uncompressed_, plaintext HTTP Headers frame
(e.g., no QPACK compression is applied).
For example:
headers: [
{
"name": ":path",
"value": "/"
},
{
"name": ":method",
"value": "GET"
},
{
"name": ":authority",
"value": "127.0.0.1:4433"
},
{
"name": ":scheme",
"value": "https"
}
]
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Figure 12: HTTPHeadersFrame example
HTTPHeadersFrame = {
frame_type: "headers"
headers: [* HTTPField]
}
Figure 13: HTTPHeadersFrame definition
HTTPField = {
name: text
value: text
}
Figure 14: HTTPField definition
5.2.3. HTTPCancelPushFrame
HTTPCancelPushFrame = {
frame_type: "cancel_push"
push_id: uint64
}
Figure 15: HTTPCancelPushFrame definition
5.2.4. HTTPSettingsFrame
HTTPSettingsFrame = {
frame_type: "settings"
settings: [* HTTPSetting]
}
HTTPSetting = {
name: text
value: uint64
}
Figure 16: HTTPSettingsFrame definition
5.2.5. HTTPPushPromiseFrame
HTTPPushPromiseFrame = {
frame_type: "push_promise"
push_id: uint64
headers: [* HTTPField]
}
Figure 17: HTTPPushPromiseFrame definition
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5.2.6. HTTPGoAwayFrame
HTTPGoawayFrame = {
frame_type: "goaway"
; Either stream_id or push_id.
; This is implicit from the sender of the frame
id: uint64
}
Figure 18: HTTPGoawayFrame definition
5.2.7. HTTPMaxPushIDFrame
HTTPMaxPushIDFrame = {
frame_type: "max_push_id"
push_id: uint64
}
Figure 19: HTTPMaxPushIDFrame definition
5.2.8. HTTPReservedFrame
HTTPReservedFrame = {
frame_type: "reserved"
? length: uint64
}
Figure 20: HTTPReservedFrame definition
5.2.9. HTTPUnknownFrame
HTTPUnknownFrame = {
frame_type: "unknown"
raw_frame_type: uint64
? raw_length: uint32
? raw: hexstring
}
Figure 21: UnknownFrame definition
5.2.10. HTTPApplicationError
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HTTPApplicationError = "http_no_error" /
"http_general_protocol_error" /
"http_internal_error" /
"http_stream_creation_error" /
"http_closed_critical_stream" /
"http_frame_unexpected" /
"http_frame_error" /
"http_excessive_load" /
"http_id_error" /
"http_settings_error" /
"http_missing_settings" /
"http_request_rejected" /
"http_request_cancelled" /
"http_request_incomplete" /
"http_early_response" /
"http_connect_error" /
"http_version_fallback"
Figure 22: HTTPApplicationError definition
The HTTPApplicationError defines the general $ApplicationError
definition in the qlog QUIC definition, see [QLOG-QUIC].
; ensure HTTP errors are properly validate in QUIC events as well
; e.g., QUIC's ConnectionClose Frame
$ApplicationError /= HTTPApplicationError
6. QPACK Events
QPACK events extend the $ProtocolEventBody extension point defined in
[QLOG-MAIN].
QPACKEvents = QPACKStateUpdate / QPACKStreamStateUpdate /
QPACKDynamicTableUpdate / QPACKHeadersEncoded /
QPACKHeadersDecoded / QPACKInstructionCreated /
QPACKInstructionParsed
$ProtocolEventBody /= QPACKEvents
Figure 23: QPACKEvents definition and ProtocolEventBody extension
QPACK events mainly serve as an aid to debug low-level QPACK
issues.The higher-level, plaintext header values SHOULD (also) be
logged in the http.frame_created and http.frame_parsed event data
(instead).
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Note: qpack does not have its own parameters_set event. This was
merged with http.parameters_set for brevity, since qpack is a
required extension for HTTP/3 anyway. Other HTTP/3 extensions MAY
also log their SETTINGS fields in http.parameters_set or MAY define
their own events.
6.1. state_updated
Importance: Base
This event is emitted when one or more of the internal QPACK
variables changes value. Note that some variables have two
variations (one set locally, one requested by the remote peer). This
is reflected in the "owner" field. As such, this field MUST be
correct for all variables included a single event instance. If you
need to log settings from two sides, you MUST emit two separate event
instances.
Definition:
QPACKStateUpdate = {
owner: Owner
? dynamic_table_capacity: uint64
; effective current size, sum of all the entries
? dynamic_table_size: uint64
? known_received_count: uint64
? current_insert_count: uint64
}
Figure 24: QPACKStateUpdate definition
6.2. stream_state_updated
Importance: Core
This event is emitted when a stream becomes blocked or unblocked by
header decoding requests or QPACK instructions.
Note: This event is of "Core" importance, as it might have a large
impact on HTTP/3's observed performance.
Definition:
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QPACKStreamStateUpdate = {
stream_id: uint64
; streams are assumed to start "unblocked"
; until they become "blocked"
state: QPACKStreamState
}
QPACKStreamState = "blocked" / "unblocked"
Figure 25: QPACKStreamStateUpdate definition
6.3. dynamic_table_updated
Importance: Extra
This event is emitted when one or more entries are inserted or
evicted from QPACK's dynamic table.
Definition:
QPACKDynamicTableUpdate = {
; local = the encoder's dynamic table
; remote = the decoder's dynamic table
owner: Owner
update_type: QPACKDynamicTableUpdateType
entries: [+ QPACKDynamicTableEntry]
}
QPACKDynamicTableUpdateType = "inserted" / "evicted"
QPACKDynamicTableEntry = {
index: uint64
? name: text / hexstring
? value: text / hexstring
}
Figure 26: QPACKDynamicTableUpdate definition
6.4. headers_encoded
Importance: Base
This event is emitted when an uncompressed header block is encoded
successfully.
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Note: this event has overlap with http.frame_created for the
HeadersFrame type. When outputting both events, implementers MAY
omit the "headers" field in this event.
Definition:
QPACKHeadersEncoded = {
? stream_id: uint64
? headers: [+ HTTPField]
block_prefix: QPACKHeaderBlockPrefix
header_block: [+ QPACKHeaderBlockRepresentation]
? length: uint
? raw: hexstring
}
Figure 27: QPACKHeadersEncoded definition
6.5. headers_decoded
Importance: Base
This event is emitted when a compressed header block is decoded
successfully.
Note: this event has overlap with http.frame_parsed for the
HeadersFrame type. When outputting both events, implementers MAY
omit the "headers" field in this event.
Definition:
QPACKHeadersDecoded = {
? stream_id: uint64
? headers: [+ HTTPField]
block_prefix: QPACKHeaderBlockPrefix
header_block: [+ QPACKHeaderBlockRepresentation]
? length: uint32
? raw: hexstring
}
Figure 28: QPACKHeadersDecoded definition
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6.6. instruction_created
Importance: Base
This event is emitted when a QPACK instruction (both decoder and
encoder) is created and added to the encoder/decoder stream.
Definition:
QPACKInstructionCreated = {
; see definition in appendix
instruction: QPACKInstruction
? length: uint32
? raw: hexstring
}
Figure 29: QPACKInstructionCreated definition
Note: encoder/decoder semantics and stream_id's are implicit in
either the instruction types or can be logged via other events (e.g.,
http.stream_type_set)
6.7. instruction_parsed
Importance: Base
This event is emitted when a QPACK instruction (both decoder and
encoder) is read from the encoder/decoder stream.
Definition:
QPACKInstructionParsed = {
; see QPACKInstruction definition in appendix
instruction: QPACKInstruction
? length: uint32
? raw: hexstring
}
Figure 30: QPACKInstructionParsed definition
Note: encoder/decoder semantics and stream_id's are implicit in
either the instruction types or can be logged via other events (e.g.,
http.stream_type_set)
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7. QPACK Data Field Definitions
The following data field definitions can be used in QPACK events.
7.1. QPACKInstruction
Note: the instructions do not have explicit encoder/decoder types,
since there is no overlap between the instructions of both types in
neither name nor function.
QPACKInstruction = SetDynamicTableCapacityInstruction /
InsertWithNameReferenceInstruction /
InsertWithoutNameReferenceInstruction /
DuplicateInstruction /
SectionAcknowledgementInstruction /
StreamCancellationInstruction /
InsertCountIncrementInstruction
Figure 31: QPACKInstruction definition
7.1.1. SetDynamicTableCapacityInstruction
SetDynamicTableCapacityInstruction = {
instruction_type: "set_dynamic_table_capacity"
capacity: uint32
}
Figure 32: SetDynamicTableCapacityInstruction definition
7.1.2. InsertWithNameReferenceInstruction
InsertWithNameReferenceInstruction = {
instruction_type: "insert_with_name_reference"
table_type: QPACKTableType
name_index: uint32
huffman_encoded_value: bool
? value_length: uint32
? value: text
}
Figure 33: InsertWithNameReferenceInstruction definition
7.1.3. InsertWithoutNameReferenceInstruction
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InsertWithoutNameReferenceInstruction = {
instruction_type: "insert_without_name_reference"
huffman_encoded_name: bool
? name_length: uint32
? name: text
huffman_encoded_value: bool
? value_length: uint32
? value: text
}
Figure 34: InsertWithoutNameReferenceInstruction definition
7.1.4. DuplicateInstruction
DuplicateInstruction = {
instruction_type: "duplicate"
index: uint32
}
Figure 35: DuplicateInstruction definition
7.1.5. SectionAcknowledgementInstruction
SectionAcknowledgementInstruction = {
instruction_type: "section_acknowledgement"
stream_id: uint64
}
Figure 36: SectionAcknowledgementInstruction definition
7.1.6. StreamCancellationInstruction
StreamCancellationInstruction = {
instruction_type: "stream_cancellation"
stream_id: uint64
}
Figure 37: StreamCancellationInstruction definition
7.1.7. InsertCountIncrementInstruction
InsertCountIncrementInstruction = {
instruction_type: "insert_count_increment"
increment: uint32
}
Figure 38: InsertCountIncrementInstruction definition
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7.2. QPACKHeaderBlockRepresentation
QPACKHeaderBlockRepresentation = IndexedHeaderField /
LiteralHeaderFieldWithName /
LiteralHeaderFieldWithoutName
Figure 39: QPACKHeaderBlockRepresentation definition
7.2.1. IndexedHeaderField
Note: also used for "indexed header field with post-base index"
IndexedHeaderField = {
header_field_type: "indexed_header"
; MUST be "dynamic" if is_post_base is true
table_type: QPACKTableType
index: uint32
; to represent the "indexed header field with post-base index"
; header field type
is_post_base: bool .default false
}
Figure 40: IndexedHeaderField definition
7.2.2. LiteralHeaderFieldWithName
Note: also used for "Literal header field with post-base name
reference"
LiteralHeaderFieldWithName = {
header_field_type: "literal_with_name"
; the 3rd "N" bit
preserve_literal: bool
; MUST be "dynamic" if is_post_base is true
table_type: QPACKTableType
name_index: uint32
huffman_encoded_value: bool
? value_length: uint32
? value: text
; to represent the "indexed header field with post-base index"
; header field type
is_post_base: bool .default false
}
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Figure 41: LiteralHeaderFieldWithName definition
7.2.3. LiteralHeaderFieldWithoutName
LiteralHeaderFieldWithoutName = {
header_field_type: "literal_without_name"
; the 3rd "N" bit
preserve_literal: bool
huffman_encoded_name: bool
? name_length: uint32
? name: text
huffman_encoded_value: bool
? value_length: uint32
? value: text
}
Figure 42: LiteralHeaderFieldWithoutName definition
7.3. QPACKHeaderBlockPrefix
QPACKHeaderBlockPrefix = {
required_insert_count: uint32
sign_bit: bool
delta_base: uint32
}
Figure 43: QPACKHeaderBlockPrefix definition
7.4. QPACKTableType
QPACKTableType = "static" / "dynamic"
Figure 44: QPACKTableType definition
8. Security and Privacy Considerations
The security and privacy considerations discussed in [QLOG-MAIN]
apply to this document as well.
9. IANA Considerations
TBD
10. Normative References
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[CDDL] Birkholz, H., Vigano, C., and C. Bormann, "Concise Data
Definition Language (CDDL): A Notational Convention to
Express Concise Binary Object Representation (CBOR) and
JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610,
June 2019, <https://www.rfc-editor.org/rfc/rfc8610>.
[HTTP/3] Bishop, M., Ed., "HTTP/3", RFC 9114, DOI 10.17487/RFC9114,
June 2022, <https://www.rfc-editor.org/rfc/rfc9114>.
[QLOG-MAIN]
Marx, R., Niccolini, L., and M. Seemann, "Main logging
schema for qlog", Work in Progress, Internet-Draft, draft-
ietf-quic-qlog-main-schema-03, 31 August 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-quic-
qlog-main-schema-03>.
[QLOG-QUIC]
Marx, R., Niccolini, L., and M. Seemann, "QUIC event
definitions for qlog", Work in Progress, Internet-Draft,
draft-ietf-quic-qlog-quic-events-02, 31 August 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-quic-
qlog-quic-events-02>.
[QPACK] Krasic, C., Bishop, M., and A. Frindell, Ed., "QPACK:
Field Compression for HTTP/3", RFC 9204,
DOI 10.17487/RFC9204, June 2022,
<https://www.rfc-editor.org/rfc/rfc9204>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
Appendix A. Change Log
A.1. Since draft-ietf-quic-qlog-h3-events-02:
* Renamed HTTPStreamType data to request (#222)
* Added HTTPStreamType value unknown (#227)
* Added HTTPUnknownFrame (#224)
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* Replaced old and new fields with stream_type in HTTPStreamTypeSet
(#240)
* Changed HTTPFrame to a CDDL plug type (#257)
* Moved data definitions out of the appendix into separate sections
* Added overview Table of Contents
A.2. Since draft-ietf-quic-qlog-h3-events-01:
* No changes - new draft to prevent expiration
A.3. Since draft-ietf-quic-qlog-h3-events-00:
* Change the data definition language from TypeScript to CDDL (#143)
A.4. Since draft-marx-qlog-event-definitions-quic-h3-02:
* These changes were done in preparation of the adoption of the
drafts by the QUIC working group (#137)
* Split QUIC and HTTP/3 events into two separate documents
* Moved RawInfo, Importance, Generic events and Simulation events to
the main schema document.
A.5. Since draft-marx-qlog-event-definitions-quic-h3-01:
Major changes:
* Moved data_moved from http to transport. Also made the "from" and
"to" fields flexible strings instead of an enum (#111,#65)
* Moved packet_type fields to PacketHeader. Moved packet_size field
out of PacketHeader to RawInfo:length (#40)
* Made events that need to log packet_type and packet_number use a
header field instead of logging these fields individually
* Added support for logging retry, stateless reset and initial
tokens (#94,#86,#117)
* Moved separate general event categories into a single category
"generic" (#47)
* Added "transport:connection_closed" event (#43,#85,#78,#49)
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* Added version_information and alpn_information events
(#85,#75,#28)
* Added parameters_restored events to help clarify 0-RTT behaviour
(#88)
Smaller changes:
* Merged loss_timer events into one loss_timer_updated event
* Field data types are now strongly defined (#10,#39,#36,#115)
* Renamed qpack instruction_received and instruction_sent to
instruction_created and instruction_parsed (#114)
* Updated qpack:dynamic_table_updated.update_type. It now has the
value "inserted" instead of "added" (#113)
* Updated qpack:dynamic_table_updated. It now has an "owner" field
to differentiate encoder vs decoder state (#112)
* Removed push_allowed from http:parameters_set (#110)
* Removed explicit trigger field indications from events, since this
was moved to be a generic property of the "data" field (#80)
* Updated transport:connection_id_updated to be more in line with
other similar events. Also dropped importance from Core to Base
(#45)
* Added length property to PaddingFrame (#34)
* Added packet_number field to transport:frames_processed (#74)
* Added a way to generically log packet header flags (first 8 bits)
to PacketHeader
* Added additional guidance on which events to log in which
situations (#53)
* Added "simulation:scenario" event to help indicate simulation
details
* Added "packets_acked" event (#107)
* Added "datagram_ids" to the datagram_X and packet_X events to
allow tracking of coalesced QUIC packets (#91)
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* Extended connection_state_updated with more fine-grained states
(#49)
A.6. Since draft-marx-qlog-event-definitions-quic-h3-00:
* Event and category names are now all lowercase
* Added many new events and their definitions
* "type" fields have been made more specific (especially important
for PacketType fields, which are now called packet_type instead of
type)
* Events are given an importance indicator (issue #22)
* Event names are more consistent and use past tense (issue #21)
* Triggers have been redefined as properties of the "data" field and
updated for most events (issue #23)
Acknowledgements
Much of the initial work by Robin Marx was done at the Hasselt and KU
Leuven Universities.
Thanks to Jana Iyengar, Brian Trammell, Dmitri Tikhonov, Stephen
Petrides, Jari Arkko, Marcus Ihlar, Victor Vasiliev, Mirja
Kuehlewind, Jeremy Laine, Kazu Yamamoto, and Christian Huitema for
their feedback and suggestions.
Authors' Addresses
Robin Marx (editor)
Akamai
Email: rmarx@akamai.com
Luca Niccolini (editor)
Meta
Email: lniccolini@meta.com
Marten Seemann (editor)
Protocol Labs
Email: marten@protocol.ai
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Lucas Pardue (editor)
Cloudflare
Email: lucaspardue.24.7@gmail.com
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