[KAFKA-13558] NioEchoServer fails to close resources

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0
• Fix Version/s: 3.2.0
• Assignee: Kirk True
• Reporter: Kirk True
• Created: 20/Dec/21 18:44
• Updated: 08/Feb/22 21:44
• Resolved: 08/Feb/22 21:44

Description

NioEchoServer does not close the selectors that it opens. The result of this can be manifested in flaky tests because the JVM/OS can run out of available file descriptors if the NioEchoServer is used in a lot of tests. Each test then leaks a handful of descriptors, and eventually the 'too many open files' error is thrown.

This was compounded because the NioEchoServer intentionally doesn't output stack traces, so the underlying issue was hidden and was manifest in odd (flaky) ways in tests.

Issue Links

• links to: GitHub Pull Request #11618