Cannot create merge request on newly pushed branch (REDIS cache)

Hi, Yesterday we updated from 8.8.5 to 8.10.2. Everything works like a charm except one thing: We are unable to do merge request on new branches because of redis cache.

Tests done:

  • When i go to branch list the merge request button doesn't appear. Capture_d_écran_de_2016-07-28_18-43-18
  • If i go to merge request tab i don't have the new branch in the dropdown. Capture_d_écran_de_2016-07-28_18-43-49
  • If i cheat with the URL i'm able to do the merge request but merge isn't available because he said the source branch doesn't exists but the diff and the commit list works Capture_d_écran_de_2016-07-28_18-44-27

If i do some investigation on the redis instance i see this in the cache for this branch & repo:

redis /var/opt/gitlab/redis/redis.socket> GET "cache:gitlab:branch_names:production/ansible:115" "\x04\bo: ActiveSupport::Cache::Entry\b:\x0b@value[\bI\"\x0bmaster\x06:\x06ETI\"\ttest\x06;\aTI\"\ntest3\x06;\aT:\x10@created_atf\x171469723615.6927593:\x10@expires_inf\r1.2096e6" redis /var/opt/gitlab/redis/redis.socket> TTL "cache:gitlab:branch_names:production/ansible:115" (integer) 1209333 redis /var/opt/gitlab/redis/redis.socket> GET "cache:gitlab:diverging_commit_counts_test4:production/ansible:115" "\x04\bo: ActiveSupport::Cache::Entry\b:\x0b@value{\a:\x0bbehindi\x00:\naheadi\x06:\x10@created_atf\x171469723813.3710964:\x10@expires_inf\r1.2096e6"

The branch name is not in the redis cache. If i do the following action this solve the issue: redis /var/opt/gitlab/redis/redis.socket> DEL "cache:gitlab:branch_names:production/ansible:115"

I have the following output: Capture_d_écran_de_2016-07-28_18-48-02

It seems the branching name cache doesn't work as expected.