HA: Limit max open database connections to 1

yhabteab · yhabteab · commit 4062f86e704f · 2024-10-24T09:27:59.000+02:00
Previously, the HA feature was allowed to open `max_connections`
database connection in parallel to other Icinga DB components. Meaning,
Icinga DB wasn't limited to the configured `max_connections`, but
effectively to `2 * max_connections`. Additionally, this masked a
serious bug in the `HA#realize()` method, where we start a new
transaction after each retry without rolling back in case of an error,
leading to connections not being released before exceeding the ctx
deadline.
diff --git a/cmd/icingadb/main.go b/cmd/icingadb/main.go
@@ -113,6 +113,7 @@ func run() int {
 			logger.Fatalf("%+v", errors.Wrap(err, "can't create database connection pool from config"))
 		}
 		defer func() { _ = db.Close() }()
+		db.SetMaxOpenConns(1)
 		ha = icingadb.NewHA(ctx, db, heartbeat, logs.GetChildLogger("high-availability"))
 
 		telemetryLogger := logs.GetChildLogger("telemetry")

Original file line number	Diff line number	Diff line change
`@@ -113,6 +113,7 @@ func run() int {`
`113`	`113`	`logger.Fatalf("%+v", errors.Wrap(err, "can't create database connection pool from config"))`
`114`	`114`	`}`
`115`	`115`	`defer func() { _ = db.Close() }()`
	`116`	`+ db.SetMaxOpenConns(1)`
`116`	`117`	`ha = icingadb.NewHA(ctx, db, heartbeat, logs.GetChildLogger("high-availability"))`
`117`	`118`
`118`	`119`	`telemetryLogger := logs.GetChildLogger("telemetry")`