What's New in ATS v10.1
Metrics
- Added - proxy.process.http.total_parent_marked_down_timeout
- Added - proxy.process.http.total_client_connections_uds
- Added - proxy.process.ssl.group.user_agent.P-256
- Added - proxy.process.ssl.group.user_agent.P-384
- Added - proxy.process.ssl.group.user_agent.P-521
- Added - proxy.process.ssl.group.user_agent.X25519
- Added - proxy.process.ssl.group.user_agent.P-224
- Added - proxy.process.ssl.group.user_agent.X448
- Added - proxy.process.ssl.group.user_agent.X25519MLKEM768
Plugins
- stats_over_http: Add prometheus metrics format option 
- header_rewrite: Add - set-plugin-cntloperator
- header_rewrite: Add - LAST-CAPTUREcondition to access the last capture group of a regex
- header_rewrite: Add support for state variables that can be used in conditions and operators. 
- header_rewrite: Add support for an else clause in conditions 
- header_rewrite: Add a - GROUPcondition
- header_rewrite: Add a - HTTP-CNTLcondition to control if expensive rules are run.
- header_rewrite: Add the - set-body-fromoperator to set the response body from a URL
- header_rewrite: The - set-body-fromoperator now defers renabling the transaction until after the fetch of the URL providing the response body
- slice: Support unix domain socket paths 
- slice: Add configuration to limit slicing of some objects. 
- access_control: Generate a session cookie when - exp=0appears in a- TokenRespHdrorigin response header.
- compress: Add range request control options to adjust behavior based on the - Accept-Encodingor- Rangeheaders
- lua: Add support for millisecond sleep 
- escalate: Now handles dispatching to the failover server if the original server is down 
- ja3_fingerprint: Add the - --preserveoption to avoid modifing some existing ja* fields.
- ja4_fingerprint: Added this new plugin 
- rate_limit: Add a - --rateoption to limit by RPS
TS API
- Add - TSVConnPPInfoGetto get Proxy Protocol information.
- Add - TSContScheduleOnEntirePooland- TSContScheduleEveryOnEntirePoolto schedule continuations on every thread in a pool.
Features
- Add the - cqssglog field for TLS group name logging
- traffic_ctl: Add a new server command to show some basic internal information 
- traffic_ctl: Now displays YAML format output when the - --recordsoption is set.
- traffic_ctl: Added the - server debugcommand to enable/disable diagnostics and debug tags at runtime with a single command.
- cripts: Add some new high level convenience APIs 
- cripts: Add optional reason parameter to - Error::Status
- sni.yaml: Add - server_cipher_suiteand- server_TLSv1_3_cipher_suitesto allow overriding the setting from- records.yaml
- Add support for getting authority information from Proxy Protocol V2. with new - ppalog formatter.
- Add support for getting UDP address info from Proxy Protocol. 
- Added support for listening on a Unix Domain Socket. See - proxy.config.http.server_ports
- Added option for - proxy.config.http.auth_server_session_privateto only mark the connection private if- Proxy-Authorizationor- Www-Authenticateheaders are present
- It is now an - ERRORif a remap ACL has more than one- @actionparameter. This was an error in ATS 10.0.x
- Add a - fragment-sizeoption in volume.config to control the fragment size of the volume.
- Add an optional - avg_obj_sizeto- volume.configto control the directory entry sizing.
- The - proxy.config.http.cache.post_methodis now an overridable config.
- Defer deleting the copied plugin shared object file to startup to make it easier to debug crashes in plugins. 
Configuration
- Added - proxy.config.http.negative_revalidating_listto configure the list of status codes that apply to the negative revalidating feature
- Added - proxy.config.ssl.session_cache.modeto control TLS session caching. This is intended to replace the legacy- proxy.config.ssl.session_cache.enabledand- proxy.config.ssl.session_cache.valueconfigurations. The- proxy.config.ssl.session_cache.enabledsetting was documented but never implemented, while- proxy.config.ssl.session_cache.valuewas implemented but not documented. The new- proxy.config.ssl.session_cache.modefunctions just like the legacy- proxy.config.ssl.session_cache.valuedid in the ealier 10.0 release. The- proxy.config.ssl.session_cache.modesetting provides a clear and consistent interface going forward. For backward compatibility,- .enabledis now implemented, but both- .enabledand- .valuewill be removed in ATS 11.x.
What's New in ATS v10.0
This version of Apache Traffic Server™ includes over <x> commits, from <y> pull requests. A total of <z> contributors have participated in this development cycle.
New Features
- JSON-RPC based interface for administrative API - Traffic Server now exposes a JSON-RPC node to interact with external tools. Check JSONRPC for more details. 
- traffic_ctl has a new command - monitorto show a continuously updating list of metrics
- ip_allow.yamland- remap.confignow support named IP ranges via IP Categories. See the- ip_categorieskey definition in- ip_allow.yamlfor information about their use and definitions.
- sni.yaml- fqdn:tunnel_route, beside the already supported match group number, configuration now also supports the destination port using a variable specification either for the incoming connection port or the port that was specified by the incoming Proxy Protocol payload. Check- sni.yamlfor more information.
- The records.yaml entry - proxy.config.system_clockwas added to control the underlying system clock that ATS uses for internal timing
- OCSP requests is now be able to use GET method. See - proxy.config.ssl.ocsp.request_modefor more information.
- TSHttpSsnInfoIntGet has been added. 
New or modified Configurations
ip_allow.yaml and remap.config ACL actions
There are two new sets of actions for HTTP request method filtering introduced in Traffic Server 10.x:
- Both - ip_allow.yamland- remap.confignow support the- set_allowand- set_denyactions. These actions both behave like- allowand- denydid for- ip_allow.yamlpre Traffic Server 10.x.
- In addition, - remap.confignow supports- add_allowand- add_denyactions. These behave like- allowand- denyactions did for- remap.configACLs pre Traffic Server 10.x.
The details about the motivation and behavior of these actions are documented in ACL Filters.
Logging and Metrics
The numbers of HTTP/2 frames received have been added as metrics.
Plugins
- authproxy - - --forward-header-prefixparameter has been added
- prefetch - Cmcd-Request header support has been added 
- xdebug - - --enableoption to selectively enable features has been added
- system_stats - Stats about memory have been added 
- slice plugin - This plugin was promoted to stable. 
JSON-RPC
Remote clients, like traffic_ctl have now bi-directional access to the plugin space. For more details check Handler implementation.
Replaced autotools build system with cmake
See Installing Traffic Server for more information
Switch to C++20
Plugins are now required to be compiled as C++ code, rather than straight C.
The API is tested with C++20, so code compatible with this version is preferred.
TSDebug and related functions are removed.  Debug tracing should now be done
using cpp:func:Dbg and related functions, as in Traffic Server core code.
C++ Plugin API Deprecated
It is deprecated in this release. It will be deleted in ATS 11.
Symbols With INKUDP Prefix
In the plugin API, all types and functions starting with the prefix INKUDP are removed.
New plugin hook for request sink transformation
A new hook, TS_HTTP_REQUEST_CLIENT_HOOK, has been added. This provides the analoguas functionality of
TS_HTTP_RESPONSE_CLIENT_HOOK, for request bodies.
HTTP/2
- Support for HTTP/2 on origin server connections has been added. This is disabled by default. For more details check - proxy.config.ssl.client.alpn_protocols
- Support for CONNECT method has been added. 
- Window size control has been improved. For more details check - proxy.config.http2.flow_control.policy_in
HTTP UI Removed
The stats and cache inspector pages were unmaintained and removed in this release.