From 8e094c0e55ea9ee0e286481d75508358b4f46ba7 Mon Sep 17 00:00:00 2001
From: dongxu <i@huangdx.net>
Date: Mon, 16 Nov 2015 10:26:23 +0800
Subject: [PATCH 1/2] hbase-store: use rand instead of timestamp for selecing
 connection randomly

---
 store/hbase/kv.go | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/store/hbase/kv.go b/store/hbase/kv.go
index c796214248..a91c9830f2 100644
--- a/store/hbase/kv.go
+++ b/store/hbase/kv.go
@@ -14,6 +14,7 @@
 package hbasekv
 
 import (
+	"math/rand"
 	"strings"
 	"sync"
 	"time"
@@ -59,6 +60,7 @@ var mc storeCache
 
 func init() {
 	mc.cache = make(map[string]*hbaseStore)
+	rand.Seed(time.Now().UnixNano())
 }
 
 type hbaseStore struct {
@@ -72,7 +74,7 @@ func (s *hbaseStore) Begin() (kv.Transaction, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	// get random conn
-	hbaseCli := s.conns[time.Now().UnixNano()%hbaseConnPoolSize]
+	hbaseCli := s.conns[rand.Intn(hbaseConnPoolSize)]
 	t := themis.NewTxn(hbaseCli)
 	txn := newHbaseTxn(t, s.storeName)
 	txn.UnionStore = kv.NewUnionStore(newHbaseSnapshot(t, s.storeName))
@@ -81,7 +83,7 @@ func (s *hbaseStore) Begin() (kv.Transaction, error) {
 
 func (s *hbaseStore) GetSnapshot(ver kv.Version) (kv.MvccSnapshot, error) {
 	// get random conn
-	hbaseCli := s.conns[time.Now().UnixNano()%hbaseConnPoolSize]
+	hbaseCli := s.conns[rand.Intn(hbaseConnPoolSize)]
 	t := themis.NewTxn(hbaseCli)
 	return newHbaseSnapshot(t, s.storeName), nil
 }
@@ -108,7 +110,7 @@ func (s *hbaseStore) UUID() string {
 }
 
 func (s *hbaseStore) CurrentVersion() (kv.Version, error) {
-	hbaseCli := s.conns[time.Now().UnixNano()%hbaseConnPoolSize]
+	hbaseCli := s.conns[rand.Intn(hbaseConnPoolSize)]
 	t := themis.NewTxn(hbaseCli)
 	defer t.Release()
 

From 4960a63b81e04d5297c07b4a5b65e9bcfa8a5fd8 Mon Sep 17 00:00:00 2001
From: dongxu <i@huangdx.net>
Date: Mon, 16 Nov 2015 10:47:25 +0800
Subject: [PATCH 2/2] hbase-store: address review comments

---
 store/hbase/kv.go | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/store/hbase/kv.go b/store/hbase/kv.go
index a91c9830f2..9f29023aaa 100644
--- a/store/hbase/kv.go
+++ b/store/hbase/kv.go
@@ -70,11 +70,15 @@ type hbaseStore struct {
 	conns     []hbase.HBaseClient
 }
 
+func (s *hbaseStore) getHBaseClient() hbase.HBaseClient {
+	// return hbase connection randomly
+	return s.conns[rand.Intn(hbaseConnPoolSize)]
+}
+
 func (s *hbaseStore) Begin() (kv.Transaction, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	// get random conn
-	hbaseCli := s.conns[rand.Intn(hbaseConnPoolSize)]
+	hbaseCli := s.getHBaseClient()
 	t := themis.NewTxn(hbaseCli)
 	txn := newHbaseTxn(t, s.storeName)
 	txn.UnionStore = kv.NewUnionStore(newHbaseSnapshot(t, s.storeName))
@@ -82,8 +86,7 @@ func (s *hbaseStore) Begin() (kv.Transaction, error) {
 }
 
 func (s *hbaseStore) GetSnapshot(ver kv.Version) (kv.MvccSnapshot, error) {
-	// get random conn
-	hbaseCli := s.conns[rand.Intn(hbaseConnPoolSize)]
+	hbaseCli := s.getHBaseClient()
 	t := themis.NewTxn(hbaseCli)
 	return newHbaseSnapshot(t, s.storeName), nil
 }
@@ -110,7 +113,7 @@ func (s *hbaseStore) UUID() string {
 }
 
 func (s *hbaseStore) CurrentVersion() (kv.Version, error) {
-	hbaseCli := s.conns[rand.Intn(hbaseConnPoolSize)]
+	hbaseCli := s.getHBaseClient()
 	t := themis.NewTxn(hbaseCli)
 	defer t.Release()