HTTP/3 and QPACK qlog event definitions

Internet-Draft	HTTP/3 and QPACK qlog event definitions	July 2023
Marx, et al.	Expires 11 January 2024	[Page]

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].¶

Table 1: HTTP/3 and QPACK Events
Name value	Importance	Definition
h3:parameters_set	Base	Section 4.1
h3:parameters_restored	Base	Section 4.2
h3:stream_type_set	Base	Section 4.3
h3:priority_updated	Base	Section 4.4
h3:frame_created	Core	Section 4.5
h3:frame_parsed	Core	Section 4.6
h3:datagram_created	Base	Section 4.7
h3:datagram_parsed	Base	Section 4.8
h3:push_resolved	Extra	Section 4.9
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

4. HTTP/3 Events

HTTP/3 events extend the $ProtocolEventBody extension point defined in [QLOG-MAIN].¶

H3Events = H3ParametersSet /
           H3ParametersRestored /
           H3StreamTypeSet /
           H3PriorityUpdated /
           H3FrameCreated /
           H3FrameParsed /
           H3DatagramCreated /
           H3DatagramParsed /
           H3PushResolved

$ProtocolEventBody /= H3Events

Figure 1: H3Events definition and ProtocolEventBody extension

HTTP events are logged when a certain condition happens at the application layer, and there isn't always a one to one mapping between HTTP and QUIC events. The exchange of data between the HTTP and QUIC layer is logged via the "stream_data_moved" and "datagram_data_moved" events in [QLOG-QUIC].¶

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.¶

The "owner" field reflects how Settings are exchanged on a connection. Sent settings have the value "local" and received settings have the value "received". A qlog can have multiple instances of this event.¶

As a reminder the CDDL unwrap operator (~), see [RFC8610]), copies the fields from the referenced type (H3Parameters) into the target type directly, extending the target with the unwrapped fields.¶

Definition:¶

H3ParametersSet = {
    ? owner: Owner
    ~H3Parameters

    ; qlog-specific
    ; indicates whether this implementation waits for a SETTINGS
    ; frame before processing requests
    ? waits_for_settings: bool
}

H3Parameters = {
    ; RFC9114
    ? max_field_section_size: uint64

    ; RFC9204
    ? max_table_capacity: uint64
    ? blocked_streams_count: uint64

    ; RFC9220 (SETTINGS_ENABLE_CONNECT_PROTOCOL)
    ? extended_connect: uint16

    ; RFC9297 (SETTINGS_H3_DATAGRAM)
    ? h3_datagram: uint16

    ; additional settings for grease and extensions
    * text => uint64
}

Figure 2: H3ParametersSet definition

This event can contain any number of unspecified fields. This allows for representation of reserved settings (aka GREASE) or ad-hoc support for extension settings that do not have a related qlog schema definition.¶

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:¶

H3ParametersRestored = {
    ~H3Parameters
}

Figure 3: H3ParametersRestored definition

Similar to H3ParametersSet this event can contain any number of unspecified fields to allow for reserved or extension 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.¶

The stream_type_value field is the numerical value without VLIE encoding.¶

Definition:¶

H3StreamTypeSet = {
    ? owner: Owner
    stream_id: uint64
    stream_type: H3StreamType

    ; only when stream_type === "unknown"
    ? stream_type_value: uint64

    ; only when stream_type === "push"
    ? associated_push_id: uint64
}

H3StreamType =  "request" /
                  "control" /
                  "push" /
                  "reserved" /
                  "unknown" /
                  "qpack_encode" /
                  "qpack_decode"

Figure 4: H3StreamTypeSet definition

4.4. priority_updated

Importance: Base¶

Emitted when the priority of a request stream or push stream is initialized or updated through mechanisms defined in [RFC9218]. For example, the priority can be updated through signals received from client and/or server (e.g., in HTTP/3 HEADERS or PRIORITY_UPDATE frames) or it can be changed or overridden due to local policies.¶

Definition:¶

H3PriorityUpdated = {
    ; if the prioritized element is a request stream
    ? stream_id: uint64

    ; if the prioritized element is a push stream
    ? push_id: uint64

    ? old: H3Priority
    new: H3Priority
}

Figure 5: H3PriorityUpdated definition

4.5. frame_created

Importance: Core¶

This event is emitted when the HTTP/3 framing actually happens. This does not necessarily coincide with HTTP/3 data getting passed to the QUIC layer. For that, see the "stream_data_moved" event in [QLOG-QUIC].¶

Definition:¶

H3FrameCreated = {
    stream_id: uint64
    ? length: uint64
    frame: $H3Frame
    ? raw: RawInfo
}

Figure 6: H3FrameCreated definition

4.6. frame_parsed

Importance: Core¶

This event is emitted when the HTTP/3 frame is parsed. This is not necessarily the same as when the HTTP/3 data is actually received on the QUIC layer. For that, see the "stream_data_moved" event in [QLOG-QUIC].¶

Definition:¶

H3FrameParsed = {
    stream_id: uint64
    ? length: uint64
    frame: $H3Frame
    ? raw: RawInfo
}

Figure 7: H3FrameParsed definition

HTTP/3 DATA frames can have arbitrarily large lengths to reduce frame header overhead. As such, DATA frames can span multiple QUIC packets. In this case, the frame_parsed event is emitted once for the frame header, and further streamed data is indicated using the stream_data_moved event.¶

4.7. datagram_created

Importance: Base¶

This event is emitted when an HTTP/3 Datagram is created (see [RFC9297]). This does not necessarily coincide with the HTTP/3 Datagram getting passed to the QUIC layer. For that, see the "datagram_data_moved" event in [QLOG-QUIC].¶

Definition:¶

H3DatagramCreated = {
    quarter_stream_id: uint64
    ? datagram: $H3Datagram
    ? raw: RawInfo
}

Figure 8: H3DatagramCreated definition

4.8. datagram_parsed

Importance: Base¶

This event is emitted when the HTTP/3 Datagram is parsed (see [RFC9297]). This is not necessarily the same as when the HTTP/3 Datagram is actually received on the QUIC layer. For that, see the "datagram_data_moved" event in [QLOG-QUIC].¶

Definition:¶

H3DatagramParsed = {
    quarter_stream_id: uint64
    ? datagram: $H3Datagram
    ? raw: RawInfo
}

Figure 9: H3DatagramParsed definition

4.9. 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:¶

H3PushResolved = {
    ? push_id: uint64

    ; in case this is logged from a place that does not have access
    ; to the push_id
    ? stream_id: uint64
    decision: H3PushDecision
}

H3PushDecision = "claimed" /
                   "abandoned"

Figure 10: H3PushResolved 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 11: Owner definition

5.2. H3Frame

The generic $H3Frame is defined here as a CDDL extension point (a "socket" or "plug"). It can be extended to support additional HTTP/3 frame types.¶

; The H3Frame is any key-value map (e.g., JSON object)
$H3Frame /= {
    * text => any
}

Figure 12: H3Frame plug definition

The HTTP/3 frame types defined in this document are as follows:¶

H3BaseFrames = H3DataFrame /
               H3HeadersFrame /
               H3CancelPushFrame /
               H3SettingsFrame /
               H3PushPromiseFrame /
               H3GoawayFrame /
               H3MaxPushIDFrame /
               H3ReservedFrame /
               H3UnknownFrame

$H3Frame /= H3BaseFrames

Figure 13: H3BaseFrames definition

5.3. H3Datagram

The generic $H3Datagram is defined here as a CDDL extension point (a "socket" or "plug"). It can be extended to support additional HTTP/3 datagram types. This document intentionally does not define any specific HTTP/3 Datagram types.¶

; The H3Datagram is any key-value map (e.g., JSON object)
$H3Datagram /= {
    * text => any
}

Figure 14: H3Datagram plug definition

5.3.1. H3DataFrame

H3DataFrame = {
    frame_type: "data"
    ? raw: RawInfo
}

Figure 15: H3DataFrame definition

5.3.2. H3HeadersFrame

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"
  }
]

Figure 16: H3HeadersFrame example

H3HeadersFrame = {
    frame_type: "headers"
    headers: [* H3HTTPField]
}

Figure 17: H3HeadersFrame definition

H3HTTPField = {
    name: text
    ? value: text
}

Figure 18: H3HTTPField definition

5.3.3. H3CancelPushFrame

H3CancelPushFrame = {
    frame_type: "cancel_push"
    push_id: uint64
}

Figure 19: H3CancelPushFrame definition

5.3.4. H3SettingsFrame

H3SettingsFrame = {
    frame_type: "settings"
    settings: [* H3Setting]
}

H3Setting = {
    name: text
    value: uint64
}

Figure 20: H3SettingsFrame definition

5.3.5. H3PushPromiseFrame

H3PushPromiseFrame = {
    frame_type: "push_promise"
    push_id: uint64
    headers: [* H3HTTPField]
}

Figure 21: H3PushPromiseFrame definition

5.3.6. H3GoAwayFrame

H3GoawayFrame = {
    frame_type: "goaway"

    ; Either stream_id or push_id.
    ; This is implicit from the sender of the frame
    id: uint64
}

Figure 22: H3GoawayFrame definition

5.3.7. H3MaxPushIDFrame

H3MaxPushIDFrame = {
    frame_type: "max_push_id"
    push_id: uint64
}

Figure 23: H3MaxPushIDFrame definition

5.3.8. H3PriorityUpdateFrame

The PRIORITY_UPDATE frame is defined in [RFC9218].¶

H3PriorityUpdateFrame = {
    frame_type: "priority_update"

    ; if the prioritized element is a request stream
    ? stream_id: uint64

    ; if the prioritized element is a push stream
    ? push_id: uint64

    priority_field_value: H3Priority
}

; The priority value in ASCII text, encoded using Structured Fields
; Example: u=5, i
H3Priority = text

Figure 24: h3priorityupdateframe definition

5.3.9. H3ReservedFrame

H3ReservedFrame = {
    frame_type: "reserved"
    ? length: uint64
}

Figure 25: H3ReservedFrame definition

5.3.10. H3UnknownFrame

The frame_type_value field is the numerical value without VLIE encoding.¶

H3UnknownFrame = {
    frame_type: "unknown"
    frame_type_value: uint64
    ? raw: RawInfo
}

Figure 26: UnknownFrame definition

5.3.11. H3ApplicationError

H3ApplicationError = "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 27: H3ApplicationError definition

The H3ApplicationError 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 /= H3ApplicationError

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 28: 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).¶

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 29: 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.¶

This event is of "Core" importance, as it might have a large impact on HTTP/3's observed performance.¶

Definition:¶

QPACKStreamStateUpdate = {
    stream_id: uint64

    ; streams are assumed to start "unblocked"
    ; until they become "blocked"
    state: QPACKStreamState
}

QPACKStreamState = "blocked" /
                   "unblocked"

Figure 30: 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 31: QPACKDynamicTableUpdate definition

6.4. headers_encoded

Importance: Base¶

This event is emitted when an uncompressed header block is encoded successfully.¶

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: [+ H3HTTPField]
    block_prefix: QPACKHeaderBlockPrefix
    header_block: [+ QPACKHeaderBlockRepresentation]
    ? raw: RawInfo
}

Figure 32: QPACKHeadersEncoded definition

6.5. headers_decoded

Importance: Base¶

This event is emitted when a compressed header block is decoded successfully.¶

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: [+ H3HTTPField]
    block_prefix: QPACKHeaderBlockPrefix
    header_block: [+ QPACKHeaderBlockRepresentation]
    ? raw: RawInfo
}

Figure 33: QPACKHeadersDecoded definition

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
    ? raw: RawInfo
}

Figure 34: QPACKInstructionCreated definition

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
    ? raw: RawInfo
}

Figure 35: QPACKInstructionParsed definition

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)¶

7. QPACK Data Field Definitions

The following data field definitions can be used in QPACK events.¶

7.1. QPACKInstruction

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 36: QPACKInstruction definition

7.1.1. SetDynamicTableCapacityInstruction

SetDynamicTableCapacityInstruction = {
    instruction_type: "set_dynamic_table_capacity"
    capacity: uint32
}

Figure 37: 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 38: InsertWithNameReferenceInstruction definition

7.1.3. InsertWithoutNameReferenceInstruction

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 39: InsertWithoutNameReferenceInstruction definition

7.1.4. DuplicateInstruction

DuplicateInstruction = {
    instruction_type: "duplicate"
    index: uint32
}

Figure 40: DuplicateInstruction definition

7.1.5. SectionAcknowledgementInstruction

SectionAcknowledgementInstruction = {
    instruction_type: "section_acknowledgement"
    stream_id: uint64
}

Figure 41: SectionAcknowledgementInstruction definition

7.1.6. StreamCancellationInstruction

StreamCancellationInstruction = {
    instruction_type: "stream_cancellation"
    stream_id: uint64
}

Figure 42: StreamCancellationInstruction definition

7.1.7. InsertCountIncrementInstruction

InsertCountIncrementInstruction = {
    instruction_type: "insert_count_increment"
    increment: uint32
}

Figure 43: InsertCountIncrementInstruction definition

7.2. QPACKHeaderBlockRepresentation

QPACKHeaderBlockRepresentation = IndexedHeaderField /
                                 LiteralHeaderFieldWithName /
                                 LiteralHeaderFieldWithoutName

Figure 44: QPACKHeaderBlockRepresentation definition

7.2.1. IndexedHeaderField

This is 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 45: IndexedHeaderField definition

7.2.2. LiteralHeaderFieldWithName

This is 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
}

Figure 46: 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 47: LiteralHeaderFieldWithoutName definition

7.3. QPACKHeaderBlockPrefix

QPACKHeaderBlockPrefix = {
    required_insert_count: uint32
    sign_bit: bool
    delta_base: uint32
}

Figure 48: QPACKHeaderBlockPrefix definition

7.4. QPACKTableType

QPACKTableType = "static" /
                 "dynamic"

Figure 49: QPACKTableType definition

10. References

10.1. Normative References

[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>.
[EXTENDED-CONNECT]: Hamilton, R., "Bootstrapping WebSockets with HTTP/3", RFC 9220, DOI 10.17487/RFC9220, June 2022, <https://www.rfc-editor.org/rfc/rfc9220>.
[H3-DATAGRAM]: Schinazi, D. and L. Pardue, "HTTP Datagrams and the Capsule Protocol", RFC 9297, DOI 10.17487/RFC9297, August 2022, <https://www.rfc-editor.org/rfc/rfc9297>.
[H3_PRIORITIZATION]: Oku, K. and L. Pardue, "Extensible Prioritization Scheme for HTTP", RFC 9218, DOI 10.17487/RFC9218, June 2022, <https://www.rfc-editor.org/rfc/rfc9218>.
[HTTP/3]: Bishop, M., Ed., "HTTP/3", RFC 9114, DOI 10.17487/RFC9114, June 2022, <https://www.rfc-editor.org/rfc/rfc9114>.
[HTTP3]: 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., Seemann, M., and L. Pardue, "Main logging schema for qlog", Work in Progress, Internet-Draft, draft-ietf-quic-qlog-main-schema-05, 13 February 2023, <https://datatracker.ietf.org/doc/html/draft-ietf-quic-qlog-main-schema-05>.
[QLOG-QUIC]: Marx, R., Niccolini, L., Seemann, M., and L. Pardue, "QUIC event definitions for qlog", Work in Progress, Internet-Draft, draft-ietf-quic-qlog-quic-events-04, 13 February 2023, <https://datatracker.ietf.org/doc/html/draft-ietf-quic-qlog-quic-events-04>.
[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>.
[RFC9218]: Oku, K. and L. Pardue, "Extensible Prioritization Scheme for HTTP", RFC 9218, DOI 10.17487/RFC9218, June 2022, <https://www.rfc-editor.org/rfc/rfc9218>.
[RFC9297]: Schinazi, D. and L. Pardue, "HTTP Datagrams and the Capsule Protocol", RFC 9297, DOI 10.17487/RFC9297, August 2022, <https://www.rfc-editor.org/rfc/rfc9297>.

10.2. Informative References

[RFC8610]: 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>.

Appendix A. Change Log

A.1. Since draft-ietf-quic-qlog-h3-events-04:

Renamed 'http' category to 'h3' (#300)¶
H3HTTPField.value is now optional (#296)¶
Added definitions for RFC9297 (HTTP/3 Datagram extension) (#310)¶
Added definitions for RFC9218 (HTTP Extensible Prioritizations extension) (#312)¶
Added definitions for RFC9220 (Extended Connect extension) (#325)¶
Editorial and formatting changes (#298, #258, #299, #304, #327)¶

A.2. Since draft-ietf-quic-qlog-h3-events-03:

Ensured consistent use of RawInfo to indicate raw wire bytes (#243)¶
Changed HTTPStreamTypeSet:raw_stream_type to stream_type_value (#54)¶
Changed HTTPUnknownFrame:raw_frame_type to frame_type_value (#54)¶
Renamed max_header_list_size to max_field_section_size (#282)¶

A.3. Since draft-ietf-quic-qlog-h3-events-02:

Renamed HTTPStreamType data to request (#222)¶
Added HTTPStreamType value unknown (#227)¶
Added HTTPUnknownFrame (#224)¶
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.4. Since draft-ietf-quic-qlog-h3-events-01:

No changes - new draft to prevent expiration¶

A.5. Since draft-ietf-quic-qlog-h3-events-00:

Change the data definition language from TypeScript to CDDL (#143)¶

A.6. 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.7. 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)¶
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)¶
Extended connection_state_updated with more fine-grained states (#49)¶

A.8. 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)¶