Cluster: call clusterHandleSlaveFailover() when our master is down.

src/cluster.c

@@ -1242,6 +1242,22 @@ void clusterPropagatePublish(robj *channel, robj *message) {
     clusterSendPublish(NULL, channel, message);
 }
 
+/* -----------------------------------------------------------------------------
+ * SLAVE node specific functions
+ * -------------------------------------------------------------------------- */
+
+/* This function is called if we are a slave node and our master serving
+ * a non-zero amount of hash slots is in PFAIL state.
+ *
+ * The gaol of this function is:
+ * 1) To check if we are able to perform a failover, is our data updated?
+ * 2) Ask reachable masters the authorization to perform the failover.
+ * 3) Check if there is the majority of masters agreeing we should failover.
+ * 4) Perform the failover informing all the other nodes.
+ */
+void clusterHandleSlaveFailover(void) {
+}
+
 /* -----------------------------------------------------------------------------
  * CLUSTER cron job
  * -------------------------------------------------------------------------- */
@@ -1377,6 +1393,16 @@ void clusterCron(void) {
                              server.cluster->myself->slaveof->port);
     }
 
+    /* If we are a slave and our master is down, but is serving slots,
+     * call the function that handles the failover. */
+    if (server.cluster->myself->flags & REDIS_NODE_SLAVE &&
+        server.cluster->myself->slaveof &&
+        server.cluster->myself->slaveof->flags & REDIS_NODE_FAIL &&
+        server.cluster->myself->slaveof->numslots != 0)
+    {
+        clusterHandleSlaveFailover();
+    }
+
     if (update_state) clusterUpdateState();
 }