Document discovery.zen.commit_timeout treats negative values like 0. Issue 36632

[cshtdd]

The scope of this PR is document the discovery.zen.commit_timeout treats negative values as 0.

A different PR will be required to update the Docs.

Supporting Research

This test proves the setting can be negative

public void testReadsNegativeCommitTimeout() {
    Settings settings = Settings.builder()
        .put(DiscoverySettings.COMMIT_TIMEOUT_SETTING.getKey(), "-10s")
        .build();

    TimeValue timeoutValue = DiscoverySettings.COMMIT_TIMEOUT_SETTING.get(settings);

    assertEquals(timeoutValue, new TimeValue(-10, TimeUnit.SECONDS));
}

However, the usage of DiscoverySettings.getCommitTimeout() leads down to this

private boolean doAcquireSharedNanos(int arg, long nanosTimeout) throws InterruptedException {
        if (nanosTimeout <= 0L)
            return false;
        ...
}

[elasticmachine]

Pinging @elastic/es-distributed

[DaveCTurner]

Since this setting is user-facing, I think the important documentation is the user-facing reference manual, i.e. docs/reference/modules/discovery/zen.asciidoc. Note that this file does not exist any more in master, reflecting that this setting will not be relevant in versions ≥7.0. You should make a PR against the 6.x branch.

[javanna]

hi @camilin87 would you mind opening a new PR against the 6.7 branch please? Like @DaveCTurner said above, this setting is not relevant anymore in master. Thanks!

[cshtdd]

No problem. I've been pretty busy for the last weeks. And I don't foresee that changing. I'll do it as soon as possible.

[javanna]

sounds good thanks @camilin87 !