X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/58186b9dcf88cd2132ac0ff4bd3a12304819cc4e..d310fbedabd3101505b694f5c25a2e48480a3c2b:/src/sentinel.c

diff --git a/src/sentinel.c b/src/sentinel.c
index 11df7335..70b6aa27 100644
--- a/src/sentinel.c
+++ b/src/sentinel.c
@@ -1426,7 +1426,7 @@ void sentinelRefreshInstanceInfo(sentinelRedisInstance *ri, const char *info) {
 
     /* Act if a master turned into a slave. */
     if ((ri->flags & SRI_MASTER) && role == SRI_SLAVE) {
-        if (first_runid && ri->slave_master_host) {
+        if ((first_runid || runid_changed) && ri->slave_master_host) {
             /* If it is the first time we receive INFO from it, but it's
              * a slave while it was configured as a master, we want to monitor
              * its master instead. */
@@ -1445,7 +1445,7 @@ void sentinelRefreshInstanceInfo(sentinelRedisInstance *ri, const char *info) {
         if (!(ri->master->flags & SRI_FAILOVER_IN_PROGRESS) &&
             (runid_changed || first_runid))
         {
-            /* If a slave turned into maser but:
+            /* If a slave turned into master but:
              *
              * 1) Failover not in progress.
              * 2) RunID hs changed, or its the first time we see an INFO output.
@@ -2005,6 +2005,8 @@ void sentinelCommand(redisClient *c) {
         ri = sentinelGetMasterByName(c->argv[2]->ptr);
         if (ri == NULL) {
             addReply(c,shared.nullmultibulk);
+        } else if (ri->info_refresh == 0) {
+            addReplySds(c,sdsnew("-IDONTKNOW I have not enough information to reply. Please ask another Sentinel.\r\n"));
         } else {
             sentinelAddr *addr = ri->addr;
 
@@ -2521,9 +2523,21 @@ void sentinelStartFailoverIfNeeded(sentinelRedisInstance *master) {
 int compareSlavesForPromotion(const void *a, const void *b) {
     sentinelRedisInstance **sa = (sentinelRedisInstance **)a,
                           **sb = (sentinelRedisInstance **)b;
+    char *sa_runid, *sb_runid;
+
     if ((*sa)->slave_priority != (*sb)->slave_priority)
         return (*sa)->slave_priority - (*sb)->slave_priority;
-    return strcasecmp((*sa)->runid,(*sb)->runid);
+
+    /* If priority is the same, select the slave with that has the
+     * lexicographically smaller runid. Note that we try to handle runid
+     * == NULL as there are old Redis versions that don't publish runid in
+     * INFO. A NULL runid is considered bigger than any other runid. */
+    sa_runid = (*sa)->runid;
+    sb_runid = (*sb)->runid;
+    if (sa_runid == NULL && sb_runid == NULL) return 0;
+    else if (sa_runid == NULL) return 1;  /* a > b */
+    else if (sb_runid == NULL) return -1; /* a < b */
+    return strcasecmp(sa_runid, sb_runid);
 }
 
 sentinelRedisInstance *sentinelSelectSlave(sentinelRedisInstance *master) {