YARN-11975. Docs: comma-separated username syntax in CapacityScheduler.md

[myloginid]

Summary

Document comma-separated username syntax for Capacity Scheduler placement rules in CapacityScheduler.md.

Changes

• Legacy yarn.scheduler.capacity.queue-mappings — document comma-separated user lists within one mapping (e.g. u:alice,bob:queue1)
• JSON matches field — document comma-separated usernames for type=user rules

Dependencies

• Describes behavior implemented in YARN-11973

Related

• Parent: YARN-11972
• Engine PR: YARN-11973. RM engine: comma-separated username matching in placement rules #8656
• CS UI PR: YARN-11974. CS UI: comma-separated usernames in placement rule form #8657

Sub-task of YARN-11972.
Fixes: https://issues.apache.org/jira/browse/YARN-11975

[myloginid]

Please add labels: trunk, YARN

[hadoop-yetus]

🎊 +1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	19m 35s		Docker mode activated.
			_ Prechecks _
+1 💚	dupname	0m 0s		No case conflicting files found.
+0 🆗	codespell	0m 0s		codespell was not available.
+0 🆗	detsecrets	0m 0s		detect-secrets was not available.
+0 🆗	markdownlint	0m 0s		markdownlint was not available.
+1 💚	@author	0m 0s		The patch does not contain any @author tags.
			_ trunk Compile Tests _
+1 💚	mvninstall	49m 0s		trunk passed
+1 💚	mvnsite	0m 50s		trunk passed
+1 💚	shadedclient	84m 47s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+1 💚	mvninstall	0m 15s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
+1 💚	mvnsite	0m 20s		the patch passed
+1 💚	shadedclient	33m 17s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
+1 💚	asflicense	0m 35s		The patch does not generate ASF License warnings.
		140m 26s

Subsystem	Report/Notes
Docker	ClientAPI=1.55 ServerAPI=1.55 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8658/1/artifact/out/Dockerfile
GITHUB PR	#8658
Optional Tests	dupname asflicense mvnsite codespell detsecrets markdownlint
uname	Linux 7d4e1eb4ed61 5.15.0-181-generic #191-Ubuntu SMP Fri May 22 19:09:02 UTC 2026 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / 226398d
Max. process+thread count	581 (vs. ulimit of 10000)
modules	C: hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site U: hadoop-yarn-project/hadoop-yarn/hadoop-yarn-site
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-8658/1/console
versions	git=2.43.0 maven=3.9.15
Powered by	Apache Yetus 0.14.1 https://yetus.apache.org

This message was automatically generated.