From 7d7b3810e7080cceeb58d39a193f06ac4585c8e7 Mon Sep 17 00:00:00 2001
From: antirez <antirez@gmail.com>
Date: Thu, 20 Feb 2014 12:13:52 +0100
Subject: [PATCH] Sentinel: report instances role switch events.

This is useful mostly for debugging of issues.
---
 src/sentinel.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/sentinel.c b/src/sentinel.c
index 9fbd43de..5de6afea 100644
--- a/src/sentinel.c
+++ b/src/sentinel.c
@@ -1770,6 +1770,14 @@ void sentinelRefreshInstanceInfo(sentinelRedisInstance *ri, const char *info) {
         ri->role_reported_time = mstime();
         ri->role_reported = role;
         if (role == SRI_SLAVE) ri->slave_conf_change_time = mstime();
+        /* Log the event with +role-change if the new role is coherent or
+         * with -role-change if there is a mismatch with the current config. */
+        sentinelEvent(REDIS_VERBOSE,
+            ((ri->flags & (SRI_MASTER|SRI_SLAVE)) == role) ?
+            "+role-change" : "-role-change",
+            ri, "%@ new reported role is %s",
+            role == SRI_MASTER ? "master" : "slave",
+            ri->flags & SRI_MASTER ? "master" : "slave");
     }
 
     /* Handle master -> slave role switch. */