Git clone and fetch over SSH slower in Stash 3.11.0

Summary

Git clones and fetches over SSH are slower in Stash 3.11.0 and 3.11.1 than in previous releases. In the SSH connection between the client and Stash, an approximately 2 second pause can be observed in which no data is transferred and nothing appears to be happening. No additional CPU, memory, or I/O load is added during these pauses, but under heavy load of many small SSH requests (e.g., polling from CI servers), Stash may display "Stash is queuing requests" and "Stash is reaching resource limits" (as described in https://confluence.atlassian.com/display/STASHKB/Stash+is+reaching+resource+limits) more readily than in previous releases. When Stash is queuing requests, all Git hosting operations, not just SSH clones and fetches, may take considerably (even minutes) longer, and may time out unnecessarily.

Workaround for Stash 3.11.0 and 3.11.1

1. Download stash-scm-cache-1.5.6.jar attached to this issue.
2. Log in to Stash as a system administrator, and go to Administration > Add-Ons > Manage add-ons.
3. Click Upload add-on.
4. Click the Choose file button and browse to stash-scm-cache-1.5.6.jar.
5. Click the Upload button.

Solution

Upgrade to Stash 3.11.2.