hikaricp_pending_threads - what does it mean exactly?

[zvuki]

I am observing the "active connection" number is up to max connections in the pool (all connections are "active") while "hikaricp_pending_threads" is up (to a half of the pool capacity) as well.

From a database perspective (MySQL) the connections are pending (they are dropped by MySQL when wait_timeout is reached).

I am wondering what causes hikaricp_pending_threads and what it actually means.

[kirillsalykin]

Also curious about the meaning thanks!

[TimothyL96]

+1. Is it pending connections?

[amitdev]

It seems to be the number of threads waiting to get a connection from the pool (https://github.com/brettwooldridge/HikariCP/blob/dev/src/main/java/com/zaxxer/hikari/util/ConcurrentBag.java#L325). Also mentioned in the wiki.