1 files changed, 35 insertions, 1 deletions

diff --git a/src/sentinel.c b/src/sentinel.c
index ae447e172..7f81443bb 100644
--- a/src/sentinel.c
+++ b/src/sentinel.c
@@ -336,6 +336,7 @@ char *sentinelVoteLeader(sentinelRedisInstance *master, uint64_t req_epoch, char
 void sentinelFlushConfig(void);
 void sentinelGenerateInitialMonitorEvents(void);
 int sentinelSendPing(sentinelRedisInstance *ri);
+int sentinelForceHelloUpdateForMaster(sentinelRedisInstance *master);
 
 /* ========================= Dictionary types =============================== */
 
@@ -1921,6 +1922,7 @@ void sentinelRefreshInstanceInfo(sentinelRedisInstance *ri, const char *info) {
                 ri->master,"%@");
             sentinelCallClientReconfScript(ri->master,SENTINEL_LEADER,
                 "start",ri->master->addr,ri->addr);
+            sentinelForceHelloUpdateForMaster(ri->master);
         } else {
             /* A slave turned into a master. We want to force our view and
              * reconfigure as slave. Wait some time after the change before
@@ -2059,7 +2061,7 @@ void sentinelPublishReplyCallback(redisAsyncContext *c, void *reply, void *privd
     r = reply;
 
     /* Only update pub_time if we actually published our message. Otherwise
-     * we'll retry against in 100 milliseconds. */
+     * we'll retry again in 100 milliseconds. */
     if (r->type != REDIS_REPLY_ERROR)
         ri->last_pub_time = mstime();
 }
@@ -2225,6 +2227,38 @@ int sentinelSendHello(sentinelRedisInstance *ri) {
     return REDIS_OK;
 }
 
+/* Reset last_pub_time in all the instances in the specified dictionary
+ * in order to force the delivery of an Hello update ASAP. */
+void sentinelForceHelloUpdateDictOfRedisInstances(dict *instances) {
+    dictIterator *di;
+    dictEntry *de;
+
+    di = dictGetSafeIterator(instances);
+    while((de = dictNext(di)) != NULL) {
+        sentinelRedisInstance *ri = dictGetVal(de);
+        if (ri->last_pub_time >= (SENTINEL_PUBLISH_PERIOD+1))
+            ri->last_pub_time -= (SENTINEL_PUBLISH_PERIOD+1);
+    }
+    dictReleaseIterator(di);
+}
+
+/* This function forces the delivery of an "Hello" message (see
+ * sentinelSendHello() top comment for further information) to all the Redis
+ * and Sentinel instances related to the specified 'master'.
+ *
+ * It is technically not needed since we send an update to every instance
+ * with a period of SENTINEL_PUBLISH_PERIOD milliseconds, however when a
+ * Sentinel upgrades a configuration it is a good idea to deliever an update
+ * to the other Sentinels ASAP. */
+int sentinelForceHelloUpdateForMaster(sentinelRedisInstance *master) {
+    if (!(master->flags & SRI_MASTER)) return REDIS_ERR;
+    if (master->last_pub_time >= (SENTINEL_PUBLISH_PERIOD+1))
+        master->last_pub_time -= (SENTINEL_PUBLISH_PERIOD+1);
+    sentinelForceHelloUpdateDictOfRedisInstances(master->sentinels);
+    sentinelForceHelloUpdateDictOfRedisInstances(master->slaves);
+    return REDIS_OK;
+}
+
 /* Send a PING to the specified instance and refresh the last_ping_time
  * if it is zero (that is, if we received a pong for the previous ping).
  *