fix(shutdown): Force exit if CTRL-C is caught before initialization (#…

…6359) (#6408)

Forcefully kill alpha if CTRL-C is caught before node initialization completes.

Fixes DGRAPH-2377

Co-authored-by: Manish R Jain <[email protected]>
(cherry picked from commit 41c2052)

dgraph/cmd/alpha/run.go

@@ -30,6 +30,7 @@ import (
 	"os/signal"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"syscall"
 	"time"
 
@@ -74,7 +75,8 @@ var (
 	startTime = time.Now()
 
 	// Alpha is the sub-command invoked when running "dgraph alpha".
-	Alpha x.SubCommand
+	Alpha    x.SubCommand
+	initDone uint32
 )
 
 func init() {
@@ -516,6 +518,7 @@ func setupServer() {
 
 	glog.Infoln("gRPC server started.  Listening on port", grpcPort())
 	glog.Infoln("HTTP server started.  Listening on port", httpPort())
+	atomic.AddUint32(&initDone, 1)
 	wg.Wait()
 }
 
@@ -691,7 +694,13 @@ func run() {
 			}
 			numShutDownSig++
 			glog.Infoln("Caught Ctrl-C. Terminating now (this may take a few seconds)...")
-			if numShutDownSig == 3 {
+
+			switch {
+			case atomic.LoadUint32(&initDone) < 2:
+				// Forcefully kill alpha if we haven't finish server initialization.
+				glog.Infoln("Stopped before initialization completed")
+				os.Exit(1)
+			case numShutDownSig == 3:
 				glog.Infoln("Signaled thrice. Aborting!")
 				os.Exit(1)
 			}
@@ -702,6 +711,8 @@ func run() {
 	aclCloser := z.NewCloser(1)
 	go func() {
 		worker.StartRaftNodes(worker.State.WALstore, bindall)
+		atomic.AddUint32(&initDone, 1)
+
 		// initialization of the admin account can only be done after raft nodes are running
 		// and health check passes
 		edgraph.ResetAcl()