redispool: Wait SRC_REDIS_WAIT_FOR before quitting sysreq check
Created by: tsenart
This commit makes our redispool
sysreq check wait for 90s
by
default instead of 5s
and allows admins to set a SRC_REDIS_WAIT_FOR
environment variable to control this timeout if it turns out the new
default isn't enough.
Addresses part of #2904. The next step is make Redis start-up faster by ensuring it maintains a small AOF file that is short to process on startup (#3300).
Additionally, repo-updater also uses redis, but doesn't currently integrate with the sysreq package. I'll be reviewing whether we still need to use redis at all in it (it's currently used for caching GitHub API responses). If we still need it, I'll run sysreq checks in repo-updater, otherwise, I'll get rid of the redis dependency there.