IndexShardIT#testStressMaybeFlushOrRollTranslogGeneration occasionally fails with an assertion error. #31629
Description
In a 6.3 build, IndexShardIT#testStressMaybeFlushOrRollTranslogGeneration failed with an assertion error around the total number of flushes. This looks similar to #25773, which was already addressed, but is likely different because of the details of the assertion failure: this build failed comparing 1 to 2 flushes, while the previous failure compared 1 with a very large number like 775331. I unfortunately wasn't able to reproduce this locally.
Link to the build: https://elasticsearch-ci.elastic.co/job/elastic+elasticsearch+6.3+multijob-unix-compatibility/os=amazon/149/console
Command to reproduce:
./gradlew :server:integTest \
-Dtests.seed=32E55CC3C4A38C89 \
-Dtests.class=org.elasticsearch.index.shard.IndexShardIT \
-Dtests.method="testStressMaybeFlushOrRollTranslogGeneration" \
-Dtests.security.manager=true \
-Dtests.locale=he \
-Dtests.timezone=Pacific/Johnston
Relevant excerpt from the logs:
FAILURE 0.15s J3 | IndexShardIT.testStressMaybeFlushOrRollTranslogGeneration <<< FAILURES!
> Throwable #1: java.lang.AssertionError:
> Expected: <1L>
> but: was <2L>
> at __randomizedtesting.SeedInfo.seed([32E55CC3C4A38C89:DFE968D623B47EAF]:0)
> at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:20)
> at org.elasticsearch.index.shard.IndexShardIT.lambda$testStressMaybeFlushOrRollTranslogGeneration$6(IndexShardIT.java:448)
> at org.elasticsearch.index.shard.IndexShardIT.testStressMaybeFlushOrRollTranslogGeneration(IndexShardIT.java:463)
> at java.lang.Thread.run(Thread.java:748)
Full log: index_shard_log.txt