Shard subscription-tree-regression-consumer to speed up Multi-Cluster IT

[JackieTien97]

Summary

• Splits the subscription-tree-regression-consumer job in pipe-it.yml into 3 parallel matrix shards. Expected: ~30–45 min → ~12–18 min per shard, removing it as the Multi-Cluster IT pipeline's long pole.
• Reuses the \$RUNNER_TEMP/it-shard.txt + -Dfailsafe.includesFile pattern from PR Shard Windows IT jobs to speed up 1C1D and Table 1C1D CI #17692 (the 1C1D Windows sharding work).
• Emits paths relative to src/test/java/ (e.g. org/apache/iotdb/.../IoTDBFooIT.java) rather than bare class names — needed because this suite has 6 pairs of duplicate simple names across pushconsumer/multi/ and pullconsumer/multi/ that would otherwise run twice across shards.

Why this job specifically

The Multi-Cluster IT pipeline currently runs 11 parallel jobs. All others finish in 10–20 min; subscription-tree-regression-consumer runs 72 IT classes serially in a single forkCount=1 JVM, each restarting a 2-cluster environment. That single job dictates the whole pipeline's wall clock on every PR.

Other subscription/dual-cluster jobs in pipe-it.yml are not sharded:

• subscription-tree-regression-misc (13 classes) — borderline; defer to follow-up
• arch-verification jobs (1–4 classes each) — sharding overhead would exceed savings
• dual-tree/dual-table jobs (9–13 classes) — already under the new shard wall clock

Local verification

$ grep -rlE --include='*IT.java' '\bMultiClusterIT2SubscriptionTreeRegressionConsumer\b' integration-test/src/test/java | wc -l
72
$ for s in 0 1 2; do
    grep -rlE --include='*IT.java' '\bMultiClusterIT2SubscriptionTreeRegressionConsumer\b' integration-test/src/test/java \
      | sed 's|.*/src/test/java/||' | sort | awk -v s=\$s -v t=3 'NR%t==s' | wc -l
  done
24
24
24
$ # And unique-paths == total (i.e. no collisions after disambiguation):
$ grep -rlE --include='*IT.java' '\bMultiClusterIT2SubscriptionTreeRegressionConsumer\b' integration-test/src/test/java | sed 's|.*/src/test/java/||' | sort -u | wc -l
72

Test plan

• CI: 3 parallel subscription-tree-regression-consumer (…, 0/1/2) jobs appear under Multi-Cluster IT and all go green.
• Each shard finishes in ~12–18 min (down from ~30–45 min for the single un-sharded job).
• No `Files with unapproved licenses` warning referencing `it-shard.txt` in any shard's log.
• Union of executed test classes across the 3 shards == 72 (no class missing, no class run twice — verify via surefire-reports artifacts).

Tracker

This is item #2 from Remaining bottlenecks in the CI optimization status doc. The other two (AINode cold build and broader Subscription/daily-it sharding) will be addressed separately.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[JackieTien97]

Closing — this PR optimized the wrong target.

After looking at actual durations from 3 recent successful Multi-Cluster IT runs, subscription-tree-regression-consumer was already finishing in ~5 minutes unsharded; my pre-PR estimate of 30-45 min was wrong. The real long poles are the dual-* jobs:

Job	Duration	Classes
dual-table-manual-basic	~63 min	13
dual-table-manual-enhanced	~62 min	11
dual-tree-auto-enhanced	~51 min	9
dual-tree-auto-basic	~42 min	12
dual-tree-manual	~27 min	11
subscription-tree-regression-consumer	~5 min	72

Sharding subscription added ~10 runner-min per CI run for zero wall-clock benefit. A follow-up PR will shard the dual-* jobs above instead — that should cut Multi-Cluster IT wall clock from ~63 min to ~22 min.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 40.39%. Comparing base (2f57fd6) to head (b996d09).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #17694      +/-   ##
============================================
- Coverage     40.39%   40.39%   -0.01%     
  Complexity     2574     2574              
============================================
  Files          5179     5179              
  Lines        349628   349628              
  Branches      44683    44683              
============================================
- Hits         141243   141215      -28     
- Misses       208385   208413      +28     

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