Only access shard stats if shard is local

Fixes issue #2452

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Bugfixes
 - [#2446] (https://github.com/influxdb/influxdb/pull/2446): Correctly count number of queries executed. Thanks @neonstalwart
+- [#2452](https://github.com/influxdb/influxdb/issues/2452): Fix panic with shard stats on multiple clusters
 
 ## v0.9.0-rc28 [04-27-2015]
 

cmd/influxd/server_integration_test.go

@@ -1449,7 +1449,7 @@ func runTestsData(t *testing.T, testName string, nodes Cluster, database, retent
 }
 
 // Ensures that diagnostics can be written to the internal database.
-func TestSingleServerDiags(t *testing.T) {
+func TestServerDiags(t *testing.T) {
 	t.Parallel()
 	testName := "single server integration diagnostics"
 	if testing.Short() {
@@ -1461,7 +1461,7 @@ func TestSingleServerDiags(t *testing.T) {
 	config := main.NewConfig()
 	config.Monitoring.Enabled = true
 	config.Monitoring.WriteInterval = main.Duration(100 * time.Millisecond)
-	nodes := createCombinedNodeCluster(t, testName, dir, 1, config)
+	nodes := createCombinedNodeCluster(t, testName, dir, 3, config)
 	defer nodes.Close()
 
 	// Ensure some data shards also exist.

server.go

@@ -391,6 +391,10 @@ func (s *Server) StartSelfMonitoring(database, retention string, interval time.D
 			// Shard-level stats.
 			tags["shardID"] = strconv.FormatUint(s.id, 10)
 			for _, sh := range s.shards {
+				if !sh.HasDataNodeID(s.id) {
+					// No stats for non-local shards.
+					continue
+				}
 				batch = append(batch, pointsFromStats(sh.stats, tags)...)
 			}
 
@@ -3356,7 +3360,7 @@ func (s *Server) DiagnosticsAsRows() []*influxql.Row {
 			nodes = append(nodes, strconv.FormatUint(n, 10))
 		}
 		var path string
-		if sh.store != nil {
+		if sh.HasDataNodeID(s.id) {
 			path = sh.store.Path()
 		}
 		shardsRow.Values = append(shardsRow.Values, []interface{}{now, strconv.FormatUint(sh.ID, 10),

shard.go

@@ -234,7 +234,9 @@ func (s *Shard) close() error {
 	if s.store != nil {
 		_ = s.store.Close()
 	}
+	if s.stats != nil {
 		s.stats.Inc("close")
+	}
 	return nil
 }