From ec57f8c84f0fddac337d8c0580720e5e73ba5a6d Mon Sep 17 00:00:00 2001
From: Philip O'Toole <philip@influxdb.com>
Date: Mon, 20 Apr 2015 13:48:23 -0700
Subject: [PATCH] RLock shard during diagnostics

---
 CHANGELOG.md | 2 +-
 server.go    | 2 +-
 shard.go     | 8 ++++++++
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 314c1bfd18..c5ef91b4c8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,7 +17,7 @@
 - [#2300](https://github.com/influxdb/influxdb/pull/2300): Refactor integration tests.  Properly close Graphite/OpenTSDB listeners.
 - [#2338](https://github.com/influxdb/influxdb/pull/2338): Fix panic if tag key isn't double quoted when it should have been
 - [#2340](https://github.com/influxdb/influxdb/pull/2340): Fix SHOW DIAGNOSTICS panic if any shard was non-local.
-
+- [#2351](https://github.com/influxdb/influxdb/pull/2351): Fix data race by rlocking shard during diagnostics.
 
 ## v0.9.0-rc25 [2015-04-15]
 
diff --git a/server.go b/server.go
index b02acd677f..ecf668e282 100644
--- a/server.go
+++ b/server.go
@@ -3302,7 +3302,7 @@ func (s *Server) DiagnosticsAsRows() []*influxql.Row {
 		for _, n := range sh.DataNodeIDs {
 			nodes = append(nodes, strconv.FormatUint(n, 10))
 			shardsRow.Values = append(shardsRow.Values, []interface{}{now, strconv.FormatUint(sh.ID, 10),
-				strings.Join(nodes, ","), strconv.FormatUint(sh.index, 10)})
+				strings.Join(nodes, ","), strconv.FormatUint(sh.Index(), 10)})
 		}
 		// Shard may not be local to this node.
 		if sh.store != nil {
diff --git a/shard.go b/shard.go
index fd82bd78e7..baff3b1e53 100644
--- a/shard.go
+++ b/shard.go
@@ -133,6 +133,14 @@ func shardMetaIndex(tx *bolt.Tx) uint64 {
 	return index
 }
 
+// Index returns the highest Raft index processed by this shard. Shard RLock
+// held during execution.
+func (s *Shard) Index() uint64 {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return s.index
+}
+
 // close shuts down the shard's store.
 func (s *Shard) close() error {
 	// Wait for goroutines to stop.