Merge branch 'bugfix1' into 'master' (merge request !374)

[bugfix] do cluster failover don't break client connections. #79
### MR描述
<!--- 详细描述MR的细节 -->
cluster failover的时候，主节点切了从，不应该断开客户端连接，应该返回moved错误。

### 修改动机和上下文背景
<!--- 为什么需要此修改, 解决了什么问题 -->
<!---如果解决了相关的#issue, 在此处进行关联(#issue, close #issue) -->

### 此MR如何进行测试 ?
<!--- 请描述测试MR的细节 -->
<!--- 包括测试的环境以及执行的测试用例 -->
<!--- 说明 change 如何影响其他部分的代码 etc. -->
```
predixy下面挂tendis集群。
往predixy压测：
redis-benchmark -h 127.0.0.1 -p 51000 -a tendis+test -t set -n 10000000 -c 50 -r 30000000 -d 256 -R -e
执行failover：
redis-cli -p 54003 -a tendis+test cluster failover
此时redis-benchmark客户端不应该报错：
Error from server: ERR server connection close
```
### change 类型
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- [ ] Bug fix (修复了issue的非侵入式修改)
- [ ] New feature (增加功能的非侵入式修改)
- [ ] Breaking change (修复或者增加特性, 但是会造成现有行为的非预期行为)

### 清单
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- [ ] 遵循项目的Code-Style
- [ ] Change 需要文档的修改
- [ ] 我已经进行相关文档的修改
- [ ] 我的MR已经通过的相关流水线测试

src/tendisplus/commands/command.cpp

@@ -278,7 +278,7 @@ Expected<std::string> Command::runSessionCmd(Session* sess) {
       sess->getServerEntry()->setTsEp(sess->getCtx()->getTsEP());
     }
   } else {
-    if (sess->getCtx()->isReplOnly()) {
+    if (sess->getCtx()->isReplOnly() && sess->getCtx()->isMaster()) {
       // NOTE(vinchen): If it's a slave, the connection should be closed
       // when there is an error. And the error should be log
       ServerEntry::logError(v.status().toString(), sess);

src/tendisplus/integrate_test/clustertestFailover.go

@@ -6,6 +6,7 @@ package main
 
 import (
     "flag"
+    "fmt"
     "github.com/ngaut/log"
     "tendisplus/integrate_test/util"
     "os/exec"
@@ -125,6 +126,23 @@ func testCluster(clusterIp string, clusterPortStart int, clusterNodeNum int) {
     <-channel
     log.Infof("cluster adddata end")
 
+    // when do cluster failover, old master change to slave, it shouldn't close the clients connection
+    // so redis-benchmark shouldn't print log: "Error from server: ERR server connection close"
+    logFilePath := fmt.Sprintf("benchmark_%d.log", predixy.RedisServer.Port)
+    log.Infof("check redis-benchmark log file: %s", logFilePath)
+    logcontent := "Error from server: ERR server connection close"
+    cmd := fmt.Sprintf("grep \"%s\" %s|wc -l", logcontent, logFilePath)
+    out, err := exec.Command("sh", "-c", cmd).CombinedOutput()
+    if err != nil {
+        log.Fatalf("grep %s failed %v", logFilePath, err)
+        return
+    }
+    log.Infof("logcontent: %s", string(out))
+    if string(out) != "0\n" {
+        log.Fatalf("%s logcontent: %s", logFilePath, string(out))
+        return
+    }
+
     // wait predixy add data end
     time.Sleep(30 * time.Second)
 

src/tendisplus/integrate_test/common.go

@@ -136,7 +136,7 @@ func addData(m *util.RedisServer, num int, prefixkey string) {
 	  }*/
 	logFilePath := fmt.Sprintf("benchmark_%d.log", m.Port)
 	var cmd string
-	cmd = fmt.Sprintf("../../../bin/redis-benchmark -h %s -p %d -c 20 -n %d -r 8 -i -f %s -t %s -a %s > %s 2>&1",
+	cmd = fmt.Sprintf("../../../bin/redis-benchmark -h %s -p %d -c 20 -n %d -r 8 -i -f %s -t %s -a %s -e > %s 2>&1",
 		m.Ip, m.Port, num, prefixkey, *benchtype, *auth, logFilePath)
 	log.Infof("addData cmd:%s", cmd)
 	args := []string{}