MySQL enable MaxOpenCon and MaxIdleCon regards how constring is configured.

[dfredell]

Please include this information:

• What Grafana version are you using?
  grafana:4.6.0-beta3 I can't use anything newer because I need alerts fixed in "tsdb.HandleRequest() error invalid value type" #9777
• What datasource are you using?
  prometheus 2.0.0-rc.2
• What OS are you running grafana on?
  docker
• What did you do?
  loading the Home page
• What was the expected result?
  take under 5 seconds
• What happened instead?
  took 20 seconds
• If related to metric query / data viz:
  • Include raw network request & response: get by opening Chrome Dev Tools (F12, Ctrl+Shift+I on windows, Cmd+Opt+I on Mac), go the network tab.
    
• config
  Using env variable to point to a remote mysql db via GF_DATABASE_URL

I tried restarting the mysql and the grafana, with no change. I ran grafana from my development box with GF_DATABASE_URL and the home page loaded fast which made me think it was an issue with the docker.

Then I enabled SQL debugging in Grafana for the database and found queries against the user table were taking 5 secs. I only have 2 users in grafana.

"[SQL] SELECT
u.id as user_id,
u.is_admin as is_grafana_admin,
u.email as email,
u.login as login,
u.name as name,
u.help_flags1 as help_flags1,
u.last_seen_at as last_seen_at,
org.name as org_name,
org_user.role as org_role,
org.id as org_id
FROM user as u
LEFT OUTER JOIN org_user on org_user.org_id = 1 and org_user.user_id = u.id
LEFT OUTER JOIN org on org.id = org_user.org_id WHERE u.id=? [1] - took: 5.020826667s" logger=sqlstore.xorm

Then I tried using GF_DATABASE_TYPE, GF_DATABASE_HOST, GF_DATABASE_NAME, GF_DATABASE_USER, GF_DATABASE_PASSWORD variables instead of GF_DATABASE_URL and the docker was blazing fast. So I kept digging and found that when using the GF_DATABASE_URL config var grafana doesn't set the MaxOpenConn and MaxIdleConn like it does when the DATABASE configs are separate.

grafana/pkg/services/sqlstore/sqlstore.go

Line 193 in c5400ff

DbCfg.MaxOpenConn = sec.Key("max_open_conn").MustInt(0)

So I tried adding the MaxOpenConn and MaxIdleConn options to the GF_DATABASE_URL section and sure enough the home page loads fast again.

Now it is taking under a second to load in the docker, when running with GF_DATABASE_URL and my change to add MaxOpenConn and MaxIdleConn