Cluster: basic data structures for nodes black list.

src/cluster.c

@@ -260,6 +260,8 @@ void clusterInit(void) {
     server.cluster->state = REDIS_CLUSTER_FAIL;
     server.cluster->size = 1;
     server.cluster->nodes = dictCreate(&clusterNodesDictType,NULL);
+    server.cluster->nodes_black_list =
+        dictCreate(&clusterNodesBlackListDictType,NULL);
     server.cluster->failover_auth_time = 0;
     server.cluster->failover_auth_count = 0;
     server.cluster->failover_auth_epoch = 0;

src/cluster.h

@@ -78,6 +78,7 @@ typedef struct clusterState {
     int state;            /* REDIS_CLUSTER_OK, REDIS_CLUSTER_FAIL, ... */
     int size;             /* Num of master nodes with at least one slot */
     dict *nodes;          /* Hash table of name -> clusterNode structures */
+    dict *nodes_black_list; /* Nodes we don't re-add for a few seconds. */
     clusterNode *migrating_slots_to[REDIS_CLUSTER_SLOTS];
     clusterNode *importing_slots_from[REDIS_CLUSTER_SLOTS];
     clusterNode *slots[REDIS_CLUSTER_SLOTS];

src/redis.c

@@ -583,6 +583,18 @@ dictType clusterNodesDictType = {
     NULL                        /* val destructor */
 };
 
+/* Cluster re-addition blacklist. This maps node IDs to the time
+ * we can re-add this node. The goal is to avoid readding a removed
+ * node for some time. */
+dictType clusterNodesBlackListDictType = {
+    dictSdsCaseHash,            /* hash function */
+    NULL,                       /* key dup */
+    NULL,                       /* val dup */
+    dictSdsKeyCaseCompare,      /* key compare */
+    dictSdsDestructor,          /* key destructor */
+    NULL                        /* val destructor */
+};
+
 /* Migrate cache dict type. */
 dictType migrateCacheDictType = {
     dictSdsHash,                /* hash function */

src/redis.h

@@ -884,6 +884,7 @@ extern struct sharedObjectsStruct shared;
 extern dictType setDictType;
 extern dictType zsetDictType;
 extern dictType clusterNodesDictType;
+extern dictType clusterNodesBlackListDictType;
 extern dictType dbDictType;
 extern dictType shaScriptObjectDictType;
 extern double R_Zero, R_PosInf, R_NegInf, R_Nan;