initialize pool from scratch after TableGC.Close

Signed-off-by: Mohamed Hamza <[email protected]>

Author: mhamza15

go/vt/vttablet/tabletserver/gc/tablegc.go

@@ -141,12 +141,9 @@ func NewTableGC(env tabletenv.Env, ts *topo.Server, lagThrottler *throttle.Throt
 		throttlerClient: throttle.NewBackgroundClient(lagThrottler, throttlerapp.TableGCName, throttle.ThrottleCheckPrimaryWrite),
 		isOpen:          0,
 
-		env: env,
-		ts:  ts,
-		pool: connpool.NewPool(env, "TableGCPool", tabletenv.ConnPoolConfig{
-			Size:        2,
-			IdleTimeout: env.Config().OltpReadPool.IdleTimeout,
-		}),
+		env:  env,
+		ts:   ts,
+		pool: newPool(env),
 
 		purgingTables:    map[string]bool{},
 		checkRequestChan: make(chan bool),
@@ -175,6 +172,11 @@ func (collector *TableGC) Open() (err error) {
 		return nil
 	}
 
+	// Reinitialize the pool if it was closed
+	if collector.pool == nil {
+		collector.pool = newPool(collector.env)
+	}
+
 	collector.lifecycleStates, err = schema.ParseGCLifecycle(gcLifecycle)
 	if err != nil {
 		return fmt.Errorf("Error parsing --table_gc_lifecycle flag: %+v", err)
@@ -227,7 +229,12 @@ func (collector *TableGC) Close() {
 		collector.cancelOperation()
 	}
 	log.Infof("TableGC - closing pool")
-	collector.pool.Close()
+
+	if collector.pool != nil {
+		collector.pool.Close()
+		collector.pool = nil
+	}
+
 	atomic.StoreInt64(&collector.isOpen, 0)
 	log.Infof("TableGC - finished execution of Close")
 }
@@ -705,3 +712,10 @@ func (collector *TableGC) Status() *Status {
 
 	return status
 }
+
+func newPool(env tabletenv.Env) *connpool.Pool {
+	return connpool.NewPool(env, "TableGCPool", tabletenv.ConnPoolConfig{
+		Size:        2,
+		IdleTimeout: env.Config().OltpReadPool.IdleTimeout,
+	})
+}