RATIS-2074. Intermittent fork timeout in TestRaftWithNetty#testBasicAppendEntriesKillLeader.

[szetszwo]

See RATIS-2074

[szetszwo]

@adoroszlai , could you test if this could fix the problem?

[adoroszlai]

Thanks @szetszwo for the patch.

Tried 100 runs with it:

• RATIS-2074 did not happen
• RATIS-2076 happened in 6 runs (about the same rate as previously)

Failed to close channel localhost:... in 10s appears in 2 runs:

• split 7 iteration 5
• split 9 iteration 1

It may have appeared in successful runs, too, but those logs are not kept.

testBasicAppendEntriesKillLeader is successful even if channel cannot be closed.

So the patch fixes the fork timeout.

[szetszwo]

Failed to close channel localhost:... in 10s appears in 2 runs:

Both cases seem okay

• split 7 iteration 5: Interrupted
• split 9 iteration 1: Connection refused: localhost/127.0.0.1:15052 (network problem?)

[szetszwo]

RATIS-2076 happened in 6 runs (about the same rate as previously)

There were 300 threads running. I suspect the failures was due to slowness. Let's try increasing the timeout.

[adoroszlai]

Let's try increasing the timeout.

Only 1/100 runs failed with 63490ea:
https://github.com/adoroszlai/ratis/actions/runs/8989894896/job/24693966187#step:6:7592

[szetszwo]

@adoroszlai , thanks for testing and reviewing this! Let's merge this PR first. We can continue fixing the remaining problem on RATIS-2076.