From ac8c4ed5fe5a2be21b06677ce826021d64ebd188 Mon Sep 17 00:00:00 2001
From: Matt Jaffee <matthew.jaffee@gmail.com>
Date: Mon, 23 Sep 2019 07:51:04 -0500
Subject: [PATCH 1/2] add concurrent field creation test

---
 server/server_test.go | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/server/server_test.go b/server/server_test.go
index 11a026dea..d968792ff 100644
--- a/server/server_test.go
+++ b/server/server_test.go
@@ -318,6 +318,30 @@ func TestConfig_Parse_DataDir(t *testing.T) {
 	}
 }
 
+func TestConcurrentFieldCreation(t *testing.T) {
+	cluster := test.MustRunCluster(t, 3)
+	defer cluster.Close()
+
+	api0 := cluster[0].API
+	if _, err := api0.CreateIndex(context.Background(), "i", pilosa.IndexOptions{}); err != nil {
+		t.Fatalf("creating index: %v", err)
+	}
+	eg := errgroup.Group{}
+	for i := 0; i < 100; i++ {
+		i := i
+		eg.Go(func() error {
+			if _, err := api0.CreateField(context.Background(), "i", fmt.Sprintf("f%d", i)); err != nil {
+				return err
+			}
+			return nil
+		})
+	}
+	err := eg.Wait()
+	if err != nil {
+		t.Fatalf("creating concurrent field: %v", err)
+	}
+}
+
 func TestMain_RecalculateHashes(t *testing.T) {
 	const clusterSize = 5
 	cluster := test.MustRunCluster(t, clusterSize)

From 07f8f5b8e07b17efee82619ca4ce14842b10233b Mon Sep 17 00:00:00 2001
From: Matt Jaffee <matthew.jaffee@gmail.com>
Date: Mon, 23 Sep 2019 07:54:01 -0500
Subject: [PATCH 2/2] fix concurrent field creation race condition

---
 server.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server.go b/server.go
index 10de7fc91..c2b9d7970 100644
--- a/server.go
+++ b/server.go
@@ -601,7 +601,7 @@ func (s *Server) receiveMessage(m Message) error {
 			return fmt.Errorf("local index not found: %s", obj.Index)
 		}
 		opt := obj.Meta
-		_, err := idx.createField(obj.Field, *opt)
+		_, err := idx.createFieldIfNotExists(obj.Field, *opt)
 		if err != nil {
 			return err
 		}