[ARTEMIS-3615] Artemis CORE client create a new Netty Event Loop group for each connection

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Francesco Nigro
• Reporter: Francesco Nigro
• Created: 18/Dec/21 07:44
• Updated: 18/Dec/21 08:19

Description

Currently Artemis's Core client is creating a whole new Netty event loop group sized by default using 3*available cores, although it serves just a single transport connection, requiring no more then a single thread.

Ideally event loop group(s) (and threads) should be shared on the same connection factory, allowing many connections to be handled on them (with N:M ratio) or each connection should have its own dedicated single threaded event loop (that seems a waste really, if a client box have more connections opened then available cores).
The most relevant problem of the current approach is that is going to waste native resources while both creating useless native threads and selector(s) that won't ever be used. In addition, setting `nioRemotingThreads`just won't have any effect.

Issue Links

• Discovered while testing: ARTEMIS-3522 Implement performance tools to evaluate throughput and Response Under Load performance of Artemis