[CI] OldMappingsIT testStandardTokenFilter failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic-platform-support #6685 / sles-15_platform-support-unix
• elasticsearch-periodic-platform-support #6685 / amazonlinux-2023_platform-support-aws

Reproduction Line:

./gradlew ":x-pack:qa:repository-old-versions:javaRestTestAfterRestart#6_0_0" --tests "org.elasticsearch.oldrepos.OldMappingsIT.testStandardTokenFilter" -Dtests.seed=ECF1B51573ABF69A -Dtests.locale=ps-Arab-AF -Dtests.timezone=Pacific/Rarotonga -Druntime.java=23

Applicable branches:
8.x

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: 
Expected: a collection with size <1>
     but: collection size was <0>

Issue Reasons:

• [8.x] 2 failures in test testStandardTokenFilter (0.2% fail rate in 1000 executions)

Note:
This issue was created using new test triage automation. Please report issues or feedback to es-delivery.

[elasticsearchmachine]

Pinging @elastic/es-search-foundations (Team:Search Foundations)

[cbuescher]

Actually two test failures here, one looks like a duplicate of #120148, that's why I will look into it deeper. The other one (org.elasticsearch.oldrepos.OldMappingsIT/testStandardTokenFilter) is possibly related but the assertion looks different. I'm also not sure why these are failing out of a sudden, at least OldRepositoryAccessIT testOldRepoAccess looked muted to me on most branches but will check.

[cbuescher]

I looked into this particular failure and it occurs in parallel with the error seen in #120148. Its quite likely that the test cluster node died because of the uncaught exception we get from OldRepositoryAccessIT here. I cherry-picked a few other failures of this test from the last two months, they always look like happening in parallel with other rest test failures or cluster formation issues. I'm closing this here for now because I think its a secondary failure related to the above mentioned issues.