SCRIPT command for introspection and control of the scripting environment.

[redis.git] / src / cluster.c

diff --git a/src/cluster.c b/src/cluster.c
index 46350cc221f4f5301bde8e96140c8c2fe60d62c2..fadce42eacdb9a8adf082b2ecf8029801e63e762 100644 (file)
--- a/src/cluster.c
+++ b/src/cluster.c
@@ -11,6 +11,9 @@ void clusterSendFail(char *nodename);
 void clusterUpdateState(void);
 int clusterNodeGetSlotBit(clusterNode *n, int slot);
 sds clusterGenNodesDescription(void);
 void clusterUpdateState(void);
 int clusterNodeGetSlotBit(clusterNode *n, int slot);
 sds clusterGenNodesDescription(void);

+clusterNode *clusterLookupNode(char *name);
+int clusterNodeAddSlave(clusterNode *master, clusterNode *slave);
+int clusterAddSlot(clusterNode *n, int slot);

 
 /* -----------------------------------------------------------------------------
  * Initialization
 
 /* -----------------------------------------------------------------------------
  * Initialization


@@ -21,12 +24,10 @@ void clusterGetRandomName(char *p) {
     char *charset = "0123456789abcdef";
     int j;
 
     char *charset = "0123456789abcdef";
     int j;
 

-    if (!fp) {
-        redisLog(REDIS_WARNING,
-            "Unrecovarable error: can't open /dev/urandom:%s" ,strerror(errno));
-        exit(1);
+    if (fp == NULL || fread(p,REDIS_CLUSTER_NAMELEN,1,fp) == 0) {
+        for (j = 0; j < REDIS_CLUSTER_NAMELEN; j++)
+            p[j] = rand();

     }
     }

-    fread(p,REDIS_CLUSTER_NAMELEN,1,fp);

     for (j = 0; j < REDIS_CLUSTER_NAMELEN; j++)
         p[j] = charset[p[j] & 0x0F];
     fclose(fp);
     for (j = 0; j < REDIS_CLUSTER_NAMELEN; j++)
         p[j] = charset[p[j] & 0x0F];
     fclose(fp);


@@ -35,7 +36,7 @@ void clusterGetRandomName(char *p) {
 int clusterLoadConfig(char *filename) {
     FILE *fp = fopen(filename,"r");
     char *line;
 int clusterLoadConfig(char *filename) {
     FILE *fp = fopen(filename,"r");
     char *line;

-    int maxline;
+    int maxline, j;

    
     if (fp == NULL) return REDIS_ERR;
 
    
     if (fp == NULL) return REDIS_ERR;
 


@@ -48,8 +49,102 @@ int clusterLoadConfig(char *filename) {
     while(fgets(line,maxline,fp) != NULL) {
         int argc;
         sds *argv = sdssplitargs(line,&argc);
     while(fgets(line,maxline,fp) != NULL) {
         int argc;
         sds *argv = sdssplitargs(line,&argc);

+        clusterNode *n, *master;
+        char *p, *s;
+
+        /* Create this node if it does not exist */
+        n = clusterLookupNode(argv[0]);
+        if (!n) {
+            n = createClusterNode(argv[0],0);
+            clusterAddNode(n);
+        }
+        /* Address and port */
+        if ((p = strchr(argv[1],':')) == NULL) goto fmterr;
+        *p = '\0';
+        memcpy(n->ip,argv[1],strlen(argv[1])+1);
+        n->port = atoi(p+1);
+
+        /* Parse flags */
+        p = s = argv[2];
+        while(p) {
+            p = strchr(s,',');
+            if (p) *p = '\0';
+            if (!strcasecmp(s,"myself")) {
+                redisAssert(server.cluster.myself == NULL);
+                server.cluster.myself = n;
+                n->flags |= REDIS_NODE_MYSELF;
+            } else if (!strcasecmp(s,"master")) {
+                n->flags |= REDIS_NODE_MASTER;
+            } else if (!strcasecmp(s,"slave")) {
+                n->flags |= REDIS_NODE_SLAVE;
+            } else if (!strcasecmp(s,"fail?")) {
+                n->flags |= REDIS_NODE_PFAIL;
+            } else if (!strcasecmp(s,"fail")) {
+                n->flags |= REDIS_NODE_FAIL;
+            } else if (!strcasecmp(s,"handshake")) {
+                n->flags |= REDIS_NODE_HANDSHAKE;
+            } else if (!strcasecmp(s,"noaddr")) {
+                n->flags |= REDIS_NODE_NOADDR;
+            } else if (!strcasecmp(s,"noflags")) {
+                /* nothing to do */
+            } else {
+                redisPanic("Unknown flag in redis cluster config file");
+            }
+            if (p) s = p+1;
+        }
+
+        /* Get master if any. Set the master and populate master's
+         * slave list. */
+        if (argv[3][0] != '-') {
+            master = clusterLookupNode(argv[3]);
+            if (!master) {
+                master = createClusterNode(argv[3],0);
+                clusterAddNode(master);
+            }
+            n->slaveof = master;
+            clusterNodeAddSlave(master,n);
+        }

 
 

-        printf("Node: %s\n", argv[0]);
+        /* Set ping sent / pong received timestamps */
+        if (atoi(argv[4])) n->ping_sent = time(NULL);
+        if (atoi(argv[5])) n->pong_received = time(NULL);
+
+        /* Populate hash slots served by this instance. */
+        for (j = 7; j < argc; j++) {
+            int start, stop;
+
+            if (argv[j][0] == '[') {
+                /* Here we handle migrating / importing slots */
+                int slot;
+                char direction;
+                clusterNode *cn;
+
+                p = strchr(argv[j],'-');
+                redisAssert(p != NULL);
+                *p = '\0';
+                direction = p[1]; /* Either '>' or '<' */
+                slot = atoi(argv[j]+1);
+                p += 3;
+                cn = clusterLookupNode(p);
+                if (!cn) {
+                    cn = createClusterNode(p,0);
+                    clusterAddNode(cn);
+                }
+                if (direction == '>') {
+                    server.cluster.migrating_slots_to[slot] = cn;
+                } else {
+                    server.cluster.importing_slots_from[slot] = cn;
+                }
+                continue;
+            } else if ((p = strchr(argv[j],'-')) != NULL) {
+                *p = '\0';
+                start = atoi(argv[j]);
+                stop = atoi(p+1);
+            } else {
+                start = stop = atoi(argv[j]);
+            }
+            while(start <= stop) clusterAddSlot(n, start++);
+        }

 
         sdssplitargs_free(argv,argc);
     }
 
         sdssplitargs_free(argv,argc);
     }


@@ -57,11 +152,10 @@ int clusterLoadConfig(char *filename) {
     fclose(fp);
 
     /* Config sanity check */
     fclose(fp);
 
     /* Config sanity check */

-    /* TODO: check that myself is set. */
-    return REDIS_ERR;
-
+    redisAssert(server.cluster.myself != NULL);

     redisLog(REDIS_NOTICE,"Node configuration loaded, I'm %.40s",
         server.cluster.myself->name);
     redisLog(REDIS_NOTICE,"Node configuration loaded, I'm %.40s",
         server.cluster.myself->name);

+    clusterUpdateState();

     return REDIS_OK;
 
 fmterr:
     return REDIS_OK;
 
 fmterr:


@@ -100,7 +194,7 @@ void clusterSaveConfigOrDie(void) {
 void clusterInit(void) {
     int saveconf = 0;
 
 void clusterInit(void) {
     int saveconf = 0;
 

-    server.cluster.myself = createClusterNode(NULL,REDIS_NODE_MYSELF);
+    server.cluster.myself = NULL;

     server.cluster.state = REDIS_CLUSTER_FAIL;
     server.cluster.nodes = dictCreate(&clusterNodesDictType,NULL);
     server.cluster.node_timeout = 15;
     server.cluster.state = REDIS_CLUSTER_FAIL;
     server.cluster.nodes = dictCreate(&clusterNodesDictType,NULL);
     server.cluster.node_timeout = 15;


@@ -113,6 +207,7 @@ void clusterInit(void) {
     if (clusterLoadConfig(server.cluster.configfile) == REDIS_ERR) {
         /* No configuration found. We will just use the random name provided
          * by the createClusterNode() function. */
     if (clusterLoadConfig(server.cluster.configfile) == REDIS_ERR) {
         /* No configuration found. We will just use the random name provided
          * by the createClusterNode() function. */

+        server.cluster.myself = createClusterNode(NULL,REDIS_NODE_MYSELF);

         redisLog(REDIS_NOTICE,"No cluster configuration found, I'm %.40s",
             server.cluster.myself->name);
         clusterAddNode(server.cluster.myself);
         redisLog(REDIS_NOTICE,"No cluster configuration found, I'm %.40s",
             server.cluster.myself->name);
         clusterAddNode(server.cluster.myself);


@@ -128,6 +223,7 @@ void clusterInit(void) {
     }
     if (aeCreateFileEvent(server.el, server.cfd, AE_READABLE,
         clusterAcceptHandler, NULL) == AE_ERR) oom("creating file event");
     }
     if (aeCreateFileEvent(server.el, server.cfd, AE_READABLE,
         clusterAcceptHandler, NULL) == AE_ERR) oom("creating file event");

+    server.cluster.slots_to_keys = zslCreate();

 }
 
 /* -----------------------------------------------------------------------------
 }
 
 /* -----------------------------------------------------------------------------


@@ -343,7 +439,7 @@ void clusterProcessGossipSection(clusterMsg *hdr, clusterLink *link) {
              * time PONG figure if it is newer than our figure.
              * Note that it's not a problem if we have a PING already 
              * in progress against this node. */
              * time PONG figure if it is newer than our figure.
              * Note that it's not a problem if we have a PING already 
              * in progress against this node. */

-            if (node->pong_received < ntohl(g->pong_received)) {
+            if (node->pong_received < (signed) ntohl(g->pong_received)) {

                  redisLog(REDIS_DEBUG,"Node pong_received updated by gossip");
                 node->pong_received = ntohl(g->pong_received);
             }
                  redisLog(REDIS_DEBUG,"Node pong_received updated by gossip");
                 node->pong_received = ntohl(g->pong_received);
             }


@@ -397,6 +493,7 @@ void nodeIp2String(char *buf, clusterLink *link) {
 /* Update the node address to the IP address that can be extracted
  * from link->fd, and at the specified port. */
 void nodeUpdateAddress(clusterNode *node, clusterLink *link, int port) {
 /* Update the node address to the IP address that can be extracted
  * from link->fd, and at the specified port. */
 void nodeUpdateAddress(clusterNode *node, clusterLink *link, int port) {

+    /* TODO */

 }
 
 /* When this function is called, there is a packet to process starting
 }
 
 /* When this function is called, there is a packet to process starting


@@ -414,8 +511,10 @@ int clusterProcessPacket(clusterLink *link) {
     uint16_t type = ntohs(hdr->type);
     clusterNode *sender;
 
     uint16_t type = ntohs(hdr->type);
     clusterNode *sender;
 

-    redisLog(REDIS_DEBUG,"--- packet to process %lu bytes (%lu) ---",
-        (unsigned long) totlen, sdslen(link->rcvbuf));
+    redisLog(REDIS_DEBUG,"--- Processing packet of type %d, %lu bytes",
+        type, (unsigned long) totlen);
+
+    /* Perform sanity checks */

     if (totlen < 8) return 1;
     if (totlen > sdslen(link->rcvbuf)) return 1;
     if (type == CLUSTERMSG_TYPE_PING || type == CLUSTERMSG_TYPE_PONG ||
     if (totlen < 8) return 1;
     if (totlen > sdslen(link->rcvbuf)) return 1;
     if (type == CLUSTERMSG_TYPE_PING || type == CLUSTERMSG_TYPE_PONG ||


@@ -434,9 +533,19 @@ int clusterProcessPacket(clusterLink *link) {
         explen += sizeof(clusterMsgDataFail);
         if (totlen != explen) return 1;
     }
         explen += sizeof(clusterMsgDataFail);
         if (totlen != explen) return 1;
     }

+    if (type == CLUSTERMSG_TYPE_PUBLISH) {
+        uint32_t explen = sizeof(clusterMsg)-sizeof(union clusterMsgData);
+
+        explen += sizeof(clusterMsgDataPublish) +
+                ntohl(hdr->data.publish.msg.channel_len) +
+                ntohl(hdr->data.publish.msg.message_len);
+        if (totlen != explen) return 1;
+    }

 
 

+    /* Ready to process the packet. Dispatch by type. */

     sender = clusterLookupNode(hdr->sender);
     if (type == CLUSTERMSG_TYPE_PING || type == CLUSTERMSG_TYPE_MEET) {
     sender = clusterLookupNode(hdr->sender);
     if (type == CLUSTERMSG_TYPE_PING || type == CLUSTERMSG_TYPE_MEET) {

+        int update_config = 0;

         redisLog(REDIS_DEBUG,"Ping packet received: %p", link->node);
 
         /* Add this node if it is new for us and the msg type is MEET.
         redisLog(REDIS_DEBUG,"Ping packet received: %p", link->node);
 
         /* Add this node if it is new for us and the msg type is MEET.


@@ -450,6 +559,7 @@ int clusterProcessPacket(clusterLink *link) {
             nodeIp2String(node->ip,link);
             node->port = ntohs(hdr->port);
             clusterAddNode(node);
             nodeIp2String(node->ip,link);
             node->port = ntohs(hdr->port);
             clusterAddNode(node);

+            update_config = 1;

         }
 
         /* Get info from the gossip section */
         }
 
         /* Get info from the gossip section */


@@ -457,8 +567,12 @@ int clusterProcessPacket(clusterLink *link) {
 
         /* Anyway reply with a PONG */
         clusterSendPing(link,CLUSTERMSG_TYPE_PONG);
 
         /* Anyway reply with a PONG */
         clusterSendPing(link,CLUSTERMSG_TYPE_PONG);

+
+        /* Update config if needed */
+        if (update_config) clusterSaveConfigOrDie();

     } else if (type == CLUSTERMSG_TYPE_PONG) {
     } else if (type == CLUSTERMSG_TYPE_PONG) {

-        int update = 0;
+        int update_state = 0;
+        int update_config = 0;

 
         redisLog(REDIS_DEBUG,"Pong packet received: %p", link->node);
         if (link->node) {
 
         redisLog(REDIS_DEBUG,"Pong packet received: %p", link->node);
         if (link->node) {


@@ -479,6 +593,7 @@ int clusterProcessPacket(clusterLink *link) {
                 redisLog(REDIS_DEBUG,"Handshake with node %.40s completed.",
                     link->node->name);
                 link->node->flags &= ~REDIS_NODE_HANDSHAKE;
                 redisLog(REDIS_DEBUG,"Handshake with node %.40s completed.",
                     link->node->name);
                 link->node->flags &= ~REDIS_NODE_HANDSHAKE;

+                update_config = 1;

             } else if (memcmp(link->node->name,hdr->sender,
                         REDIS_CLUSTER_NAMELEN) != 0)
             {
             } else if (memcmp(link->node->name,hdr->sender,
                         REDIS_CLUSTER_NAMELEN) != 0)
             {


@@ -488,6 +603,7 @@ int clusterProcessPacket(clusterLink *link) {
                 redisLog(REDIS_DEBUG,"PONG contains mismatching sender ID");
                 link->node->flags |= REDIS_NODE_NOADDR;
                 freeClusterLink(link);
                 redisLog(REDIS_DEBUG,"PONG contains mismatching sender ID");
                 link->node->flags |= REDIS_NODE_NOADDR;
                 freeClusterLink(link);

+                update_config = 1;

                 /* FIXME: remove this node if we already have it.
                  *
                  * If we already have it but the IP is different, use
                 /* FIXME: remove this node if we already have it.
                  *
                  * If we already have it but the IP is different, use


@@ -533,7 +649,7 @@ int clusterProcessPacket(clusterLink *link) {
                             server.cluster.slots[j]->flags & REDIS_NODE_FAIL)
                         {
                             server.cluster.slots[j] = sender;
                             server.cluster.slots[j]->flags & REDIS_NODE_FAIL)
                         {
                             server.cluster.slots[j] = sender;

-                            update = 1;
+                            update_state = update_config = 1;

                         }
                     }
                 }
                         }
                     }
                 }


@@ -544,15 +660,14 @@ int clusterProcessPacket(clusterLink *link) {
         clusterProcessGossipSection(hdr,link);
 
         /* Update the cluster state if needed */
         clusterProcessGossipSection(hdr,link);
 
         /* Update the cluster state if needed */

-        if (update) {
-            clusterUpdateState();
-            clusterSaveConfigOrDie();
-        }
+        if (update_state) clusterUpdateState();
+        if (update_config) clusterSaveConfigOrDie();

     } else if (type == CLUSTERMSG_TYPE_FAIL && sender) {
         clusterNode *failing;
 
         failing = clusterLookupNode(hdr->data.fail.about.nodename);
     } else if (type == CLUSTERMSG_TYPE_FAIL && sender) {
         clusterNode *failing;
 
         failing = clusterLookupNode(hdr->data.fail.about.nodename);

-        if (failing && !(failing->flags & REDIS_NODE_FAIL)) {
+        if (failing && !(failing->flags & (REDIS_NODE_FAIL|REDIS_NODE_MYSELF)))
+        {

             redisLog(REDIS_NOTICE,
                 "FAIL message received from %.40s about %.40s",
                 hdr->sender, hdr->data.fail.about.nodename);
             redisLog(REDIS_NOTICE,
                 "FAIL message received from %.40s about %.40s",
                 hdr->sender, hdr->data.fail.about.nodename);


@@ -561,8 +676,24 @@ int clusterProcessPacket(clusterLink *link) {
             clusterUpdateState();
             clusterSaveConfigOrDie();
         }
             clusterUpdateState();
             clusterSaveConfigOrDie();
         }

+    } else if (type == CLUSTERMSG_TYPE_PUBLISH) {
+        robj *channel, *message;
+        uint32_t channel_len, message_len;
+
+        /* Don't bother creating useless objects if there are no Pub/Sub subscribers. */
+        if (dictSize(server.pubsub_channels) || listLength(server.pubsub_patterns)) {
+            channel_len = ntohl(hdr->data.publish.msg.channel_len);
+            message_len = ntohl(hdr->data.publish.msg.message_len);
+            channel = createStringObject(
+                        (char*)hdr->data.publish.msg.bulk_data,channel_len);
+            message = createStringObject(
+                        (char*)hdr->data.publish.msg.bulk_data+channel_len, message_len);
+            pubsubPublishMessage(channel,message);
+            decrRefCount(channel);
+            decrRefCount(message);
+        }

     } else {
     } else {

-        redisLog(REDIS_NOTICE,"Received unknown packet type: %d", type);
+        redisLog(REDIS_WARNING,"Received unknown packet type: %d", type);

     }
     return 1;
 }
     }
     return 1;
 }


@@ -655,6 +786,22 @@ void clusterSendMessage(clusterLink *link, unsigned char *msg, size_t msglen) {
     link->sndbuf = sdscatlen(link->sndbuf, msg, msglen);
 }
 
     link->sndbuf = sdscatlen(link->sndbuf, msg, msglen);
 }
 

+/* Send a message to all the nodes with a reliable link */
+void clusterBroadcastMessage(void *buf, size_t len) {
+    dictIterator *di;
+    dictEntry *de;
+
+    di = dictGetIterator(server.cluster.nodes);
+    while((de = dictNext(di)) != NULL) {
+        clusterNode *node = dictGetEntryVal(de);
+
+        if (!node->link) continue;
+        if (node->flags & (REDIS_NODE_MYSELF|REDIS_NODE_NOADDR)) continue;
+        clusterSendMessage(node->link,buf,len);
+    }
+    dictReleaseIterator(di);
+}
+

 /* Build the message header */
 void clusterBuildMessageHdr(clusterMsg *hdr, int type) {
     int totlen;
 /* Build the message header */
 void clusterBuildMessageHdr(clusterMsg *hdr, int type) {
     int totlen;


@@ -739,20 +886,48 @@ void clusterSendPing(clusterLink *link, int type) {
     clusterSendMessage(link,buf,totlen);
 }
 
     clusterSendMessage(link,buf,totlen);
 }
 

-/* Send a message to all the nodes with a reliable link */
-void clusterBroadcastMessage(void *buf, size_t len) {
-    dictIterator *di;
-    dictEntry *de;
+/* Send a PUBLISH message.
+ *
+ * If link is NULL, then the message is broadcasted to the whole cluster. */
+void clusterSendPublish(clusterLink *link, robj *channel, robj *message) {
+    unsigned char buf[4096], *payload;
+    clusterMsg *hdr = (clusterMsg*) buf;
+    uint32_t totlen;
+    uint32_t channel_len, message_len;

 
 

-    di = dictGetIterator(server.cluster.nodes);
-    while((de = dictNext(di)) != NULL) {
-        clusterNode *node = dictGetEntryVal(de);
+    channel = getDecodedObject(channel);
+    message = getDecodedObject(message);
+    channel_len = sdslen(channel->ptr);
+    message_len = sdslen(message->ptr);

 
 

-        if (!node->link) continue;
-        if (node->flags & (REDIS_NODE_MYSELF|REDIS_NODE_NOADDR)) continue;
-        clusterSendMessage(node->link,buf,len);
+    clusterBuildMessageHdr(hdr,CLUSTERMSG_TYPE_PUBLISH);
+    totlen = sizeof(clusterMsg)-sizeof(union clusterMsgData);
+    totlen += sizeof(clusterMsgDataPublish) + channel_len + message_len;
+
+    hdr->data.publish.msg.channel_len = htonl(channel_len);
+    hdr->data.publish.msg.message_len = htonl(message_len);
+    hdr->totlen = htonl(totlen);
+
+    /* Try to use the local buffer if possible */
+    if (totlen < sizeof(buf)) {
+        payload = buf;
+    } else {
+        payload = zmalloc(totlen);
+        hdr = (clusterMsg*) payload;
+        memcpy(payload,hdr,sizeof(hdr));

     }
     }

-    dictReleaseIterator(di);
+    memcpy(hdr->data.publish.msg.bulk_data,channel->ptr,sdslen(channel->ptr));
+    memcpy(hdr->data.publish.msg.bulk_data+sdslen(channel->ptr),
+        message->ptr,sdslen(message->ptr));
+
+    if (link)
+        clusterSendMessage(link,payload,totlen);
+    else
+        clusterBroadcastMessage(payload,totlen);
+
+    decrRefCount(channel);
+    decrRefCount(message);
+    if (payload != buf) zfree(payload);

 }
 
 /* Send a FAIL message to all the nodes we are able to contact.
 }
 
 /* Send a FAIL message to all the nodes we are able to contact.


@@ -769,6 +944,17 @@ void clusterSendFail(char *nodename) {
     clusterBroadcastMessage(buf,ntohl(hdr->totlen));
 }
 
     clusterBroadcastMessage(buf,ntohl(hdr->totlen));
 }
 

+/* -----------------------------------------------------------------------------
+ * CLUSTER Pub/Sub support
+ *
+ * For now we do very little, just propagating PUBLISH messages across the whole
+ * cluster. In the future we'll try to get smarter and avoiding propagating those
+ * messages to hosts without receives for a given channel.
+ * -------------------------------------------------------------------------- */
+void clusterPropagatePublish(robj *channel, robj *message) {
+    clusterSendPublish(NULL, channel, message);
+}
+

 /* -----------------------------------------------------------------------------
  * CLUSTER cron job
  * -------------------------------------------------------------------------- */
 /* -----------------------------------------------------------------------------
  * CLUSTER cron job
  * -------------------------------------------------------------------------- */


@@ -810,7 +996,7 @@ void clusterCron(void) {
              * normal PING packets. */
             node->flags &= ~REDIS_NODE_MEET;
 
              * normal PING packets. */
             node->flags &= ~REDIS_NODE_MEET;
 

-            redisLog(REDIS_NOTICE,"Connecting with Node %.40s at %s:%d\n", node->name, node->ip, node->port+REDIS_CLUSTER_PORT_INCR);
+            redisLog(REDIS_NOTICE,"Connecting with Node %.40s at %s:%d", node->name, node->ip, node->port+REDIS_CLUSTER_PORT_INCR);

         }
     }
     dictReleaseIterator(di);
         }
     }
     dictReleaseIterator(di);


@@ -840,22 +1026,34 @@ void clusterCron(void) {
         int delay;
 
         if (node->flags &
         int delay;
 
         if (node->flags &

-            (REDIS_NODE_MYSELF|REDIS_NODE_NOADDR|REDIS_NODE_HANDSHAKE|
-             REDIS_NODE_FAIL)) continue;
+            (REDIS_NODE_MYSELF|REDIS_NODE_NOADDR|REDIS_NODE_HANDSHAKE))
+                continue;

         /* Check only if we already sent a ping and did not received
          * a reply yet. */
         if (node->ping_sent == 0 ||
             node->ping_sent <= node->pong_received) continue;
 
         delay = time(NULL) - node->pong_received;
         /* Check only if we already sent a ping and did not received
          * a reply yet. */
         if (node->ping_sent == 0 ||
             node->ping_sent <= node->pong_received) continue;
 
         delay = time(NULL) - node->pong_received;

-        if (node->flags & REDIS_NODE_PFAIL) {
+        if (delay < server.cluster.node_timeout) {

             /* The PFAIL condition can be reversed without external
              * help if it is not transitive (that is, if it does not
             /* The PFAIL condition can be reversed without external
              * help if it is not transitive (that is, if it does not

-             * turn into a FAIL state). */
-            if (delay < server.cluster.node_timeout)
+             * turn into a FAIL state).
+             *
+             * The FAIL condition is also reversible if there are no slaves
+             * for this host, so no slave election should be in progress.
+             *
+             * TODO: consider all the implications of resurrecting a
+             * FAIL node. */
+            if (node->flags & REDIS_NODE_PFAIL) {

                 node->flags &= ~REDIS_NODE_PFAIL;
                 node->flags &= ~REDIS_NODE_PFAIL;

+            } else if (node->flags & REDIS_NODE_FAIL && !node->numslaves) {
+                node->flags &= ~REDIS_NODE_FAIL;
+                clusterUpdateState();
+            }

         } else {
         } else {

-            if (delay >= server.cluster.node_timeout) {
+            /* Timeout reached. Set the noad se possibly failing if it is
+             * not already in this state. */
+            if (!(node->flags & (REDIS_NODE_PFAIL|REDIS_NODE_FAIL))) {

                 redisLog(REDIS_DEBUG,"*** NODE %.40s possibly failing",
                     node->name);
                 node->flags |= REDIS_NODE_PFAIL;
                 redisLog(REDIS_DEBUG,"*** NODE %.40s possibly failing",
                     node->name);
                 node->flags |= REDIS_NODE_PFAIL;


@@ -899,9 +1097,21 @@ int clusterNodeGetSlotBit(clusterNode *n, int slot) {
  * If the slot is already assigned to another instance this is considered
  * an error and REDIS_ERR is returned. */
 int clusterAddSlot(clusterNode *n, int slot) {
  * If the slot is already assigned to another instance this is considered
  * an error and REDIS_ERR is returned. */
 int clusterAddSlot(clusterNode *n, int slot) {

-    redisAssert(clusterNodeSetSlotBit(n,slot) == 0);
-    server.cluster.slots[slot] = server.cluster.myself;
-    printf("SLOT %d added to %.40s\n", slot, n->name);
+    if (clusterNodeSetSlotBit(n,slot) != 0)
+        return REDIS_ERR;
+    server.cluster.slots[slot] = n;
+    return REDIS_OK;
+}
+
+/* Delete the specified slot marking it as unassigned.
+ * Returns REDIS_OK if the slot was assigned, otherwise if the slot was
+ * already unassigned REDIS_ERR is returned. */
+int clusterDelSlot(int slot) {
+    clusterNode *n = server.cluster.slots[slot];
+
+    if (!n) return REDIS_ERR;
+    redisAssert(clusterNodeClearSlotBit(n,slot) == 1);
+    server.cluster.slots[slot] = NULL;

     return REDIS_OK;
 }
 
     return REDIS_OK;
 }
 


@@ -972,7 +1182,8 @@ sds clusterGenNodesDescription(void) {
         ci = sdscatprintf(ci,"%ld %ld %s",
             (long) node->ping_sent,
             (long) node->pong_received,
         ci = sdscatprintf(ci,"%ld %ld %s",
             (long) node->ping_sent,
             (long) node->pong_received,

-            node->link ? "connected" : "disconnected");
+            (node->link || node->flags & REDIS_NODE_MYSELF) ?
+                        "connected" : "disconnected");

 
         /* Slots served by this instance */
         start = -1;
 
         /* Slots served by this instance */
         start = -1;


@@ -993,12 +1204,39 @@ sds clusterGenNodesDescription(void) {
                 start = -1;
             }
         }
                 start = -1;
             }
         }

+
+        /* Just for MYSELF node we also dump info about slots that
+         * we are migrating to other instances or importing from other
+         * instances. */
+        if (node->flags & REDIS_NODE_MYSELF) {
+            for (j = 0; j < REDIS_CLUSTER_SLOTS; j++) {
+                if (server.cluster.migrating_slots_to[j]) {
+                    ci = sdscatprintf(ci," [%d->-%.40s]",j,
+                        server.cluster.migrating_slots_to[j]->name);
+                } else if (server.cluster.importing_slots_from[j]) {
+                    ci = sdscatprintf(ci," [%d-<-%.40s]",j,
+                        server.cluster.importing_slots_from[j]->name);
+                }
+            }
+        }
+        ci = sdscatlen(ci,"\n",1);

     }
     }

-    ci = sdscatlen(ci,"\n",1);

     dictReleaseIterator(di);
     return ci;
 }
 
     dictReleaseIterator(di);
     return ci;
 }
 

+int getSlotOrReply(redisClient *c, robj *o) {
+    long long slot;
+
+    if (getLongLongFromObject(o,&slot) != REDIS_OK ||
+        slot < 0 || slot > REDIS_CLUSTER_SLOTS)
+    {
+        addReplyError(c,"Invalid or out of range slot");
+        return -1;
+    }
+    return (int) slot;
+}
+

 void clusterCommand(redisClient *c) {
     if (server.cluster_enabled == 0) {
         addReplyError(c,"This instance has cluster support disabled");
 void clusterCommand(redisClient *c) {
     if (server.cluster_enabled == 0) {
         addReplyError(c,"This instance has cluster support disabled");


@@ -1036,24 +1274,29 @@ void clusterCommand(redisClient *c) {
         o = createObject(REDIS_STRING,ci);
         addReplyBulk(c,o);
         decrRefCount(o);
         o = createObject(REDIS_STRING,ci);
         addReplyBulk(c,o);
         decrRefCount(o);

-    } else if (!strcasecmp(c->argv[1]->ptr,"addslots") && c->argc >= 3) {
-        int j;
-        long long slot;
+    } else if ((!strcasecmp(c->argv[1]->ptr,"addslots") ||
+               !strcasecmp(c->argv[1]->ptr,"delslots")) && c->argc >= 3)
+    {
+        /* CLUSTER ADDSLOTS <slot> [slot] ... */
+        /* CLUSTER DELSLOTS <slot> [slot] ... */
+        int j, slot;

         unsigned char *slots = zmalloc(REDIS_CLUSTER_SLOTS);
         unsigned char *slots = zmalloc(REDIS_CLUSTER_SLOTS);

+        int del = !strcasecmp(c->argv[1]->ptr,"delslots");

 
         memset(slots,0,REDIS_CLUSTER_SLOTS);
         /* Check that all the arguments are parsable and that all the
          * slots are not already busy. */
         for (j = 2; j < c->argc; j++) {
 
         memset(slots,0,REDIS_CLUSTER_SLOTS);
         /* Check that all the arguments are parsable and that all the
          * slots are not already busy. */
         for (j = 2; j < c->argc; j++) {

-            if (getLongLongFromObject(c->argv[j],&slot) != REDIS_OK ||
-                slot < 0 || slot > REDIS_CLUSTER_SLOTS)
-            {
-                addReplyError(c,"Invalid or out of range slot index");
+            if ((slot = getSlotOrReply(c,c->argv[j])) == -1) {

                 zfree(slots);
                 return;
             }
                 zfree(slots);
                 return;
             }

-            if (server.cluster.slots[slot]) {
-                addReplyErrorFormat(c,"Slot %lld is already busy", slot);
+            if (del && server.cluster.slots[slot] == NULL) {
+                addReplyErrorFormat(c,"Slot %d is already unassigned", slot);
+                zfree(slots);
+                return;
+            } else if (!del && server.cluster.slots[slot]) {
+                addReplyErrorFormat(c,"Slot %d is already busy", slot);

                 zfree(slots);
                 return;
             }
                 zfree(slots);
                 return;
             }


@@ -1066,15 +1309,101 @@ void clusterCommand(redisClient *c) {
         }
         for (j = 0; j < REDIS_CLUSTER_SLOTS; j++) {
             if (slots[j]) {
         }
         for (j = 0; j < REDIS_CLUSTER_SLOTS; j++) {
             if (slots[j]) {

-                int retval = clusterAddSlot(server.cluster.myself,j);
-                
-                redisAssert(retval == REDIS_OK);
+                int retval;
+
+                /* If this slot was set as importing we can clear this 
+                 * state as now we are the real owner of the slot. */
+                if (server.cluster.importing_slots_from[j])
+                    server.cluster.importing_slots_from[j] = NULL;
+
+                retval = del ? clusterDelSlot(j) :
+                               clusterAddSlot(server.cluster.myself,j);
+                redisAssertWithInfo(c,NULL,retval == REDIS_OK);

             }
         }
         zfree(slots);
         clusterUpdateState();
         clusterSaveConfigOrDie();
         addReply(c,shared.ok);
             }
         }
         zfree(slots);
         clusterUpdateState();
         clusterSaveConfigOrDie();
         addReply(c,shared.ok);

+    } else if (!strcasecmp(c->argv[1]->ptr,"setslot") && c->argc >= 4) {
+        /* SETSLOT 10 MIGRATING <node ID> */
+        /* SETSLOT 10 IMPORTING <node ID> */
+        /* SETSLOT 10 STABLE */
+        /* SETSLOT 10 NODE <node ID> */
+        int slot;
+        clusterNode *n;
+
+        if ((slot = getSlotOrReply(c,c->argv[2])) == -1) return;
+
+        if (!strcasecmp(c->argv[3]->ptr,"migrating") && c->argc == 5) {
+            if (server.cluster.slots[slot] != server.cluster.myself) {
+                addReplyErrorFormat(c,"I'm not the owner of hash slot %u",slot);
+                return;
+            }
+            if ((n = clusterLookupNode(c->argv[4]->ptr)) == NULL) {
+                addReplyErrorFormat(c,"I don't know about node %s",
+                    (char*)c->argv[4]->ptr);
+                return;
+            }
+            server.cluster.migrating_slots_to[slot] = n;
+        } else if (!strcasecmp(c->argv[3]->ptr,"importing") && c->argc == 5) {
+            if (server.cluster.slots[slot] == server.cluster.myself) {
+                addReplyErrorFormat(c,
+                    "I'm already the owner of hash slot %u",slot);
+                return;
+            }
+            if ((n = clusterLookupNode(c->argv[4]->ptr)) == NULL) {
+                addReplyErrorFormat(c,"I don't know about node %s",
+                    (char*)c->argv[3]->ptr);
+                return;
+            }
+            server.cluster.importing_slots_from[slot] = n;
+        } else if (!strcasecmp(c->argv[3]->ptr,"stable") && c->argc == 4) {
+            /* CLUSTER SETSLOT <SLOT> STABLE */
+            server.cluster.importing_slots_from[slot] = NULL;
+            server.cluster.migrating_slots_to[slot] = NULL;
+        } else if (!strcasecmp(c->argv[3]->ptr,"node") && c->argc == 5) {
+            /* CLUSTER SETSLOT <SLOT> NODE <NODE ID> */
+            clusterNode *n = clusterLookupNode(c->argv[4]->ptr);
+
+            if (!n) addReplyErrorFormat(c,"Unknown node %s",
+                (char*)c->argv[4]->ptr);
+            /* If this hash slot was served by 'myself' before to switch
+             * make sure there are no longer local keys for this hash slot. */
+            if (server.cluster.slots[slot] == server.cluster.myself &&
+                n != server.cluster.myself)
+            {
+                int numkeys;
+                robj **keys;
+
+                keys = zmalloc(sizeof(robj*)*1);
+                numkeys = GetKeysInSlot(slot, keys, 1);
+                zfree(keys);
+                if (numkeys != 0) {
+                    addReplyErrorFormat(c, "Can't assign hashslot %d to a different node while I still hold keys for this hash slot.", slot);
+                    return;
+                }
+            }
+            /* If this node was the slot owner and the slot was marked as
+             * migrating, assigning the slot to another node will clear
+             * the migratig status. */
+            if (server.cluster.slots[slot] == server.cluster.myself &&
+                server.cluster.migrating_slots_to[slot])
+                server.cluster.migrating_slots_to[slot] = NULL;
+
+            /* If this node was importing this slot, assigning the slot to
+             * itself also clears the importing status. */
+            if (n == server.cluster.myself && server.cluster.importing_slots_from[slot])
+                server.cluster.importing_slots_from[slot] = NULL;
+
+            clusterDelSlot(slot);
+            clusterAddSlot(n,slot);
+        } else {
+            addReplyError(c,"Invalid CLUSTER SETSLOT action or number of arguments");
+            return;
+        }
+        clusterSaveConfigOrDie();
+        addReply(c,shared.ok);

     } else if (!strcasecmp(c->argv[1]->ptr,"info") && c->argc == 2) {
         char *statestr[] = {"ok","fail","needhelp"};
         int slots_assigned = 0, slots_ok = 0, slots_pfail = 0, slots_fail = 0;
     } else if (!strcasecmp(c->argv[1]->ptr,"info") && c->argc == 2) {
         char *statestr[] = {"ok","fail","needhelp"};
         int slots_assigned = 0, slots_ok = 0, slots_pfail = 0, slots_fail = 0;


@@ -1100,16 +1429,42 @@ void clusterCommand(redisClient *c) {
             "cluster_slots_ok:%d\r\n"
             "cluster_slots_pfail:%d\r\n"
             "cluster_slots_fail:%d\r\n"
             "cluster_slots_ok:%d\r\n"
             "cluster_slots_pfail:%d\r\n"
             "cluster_slots_fail:%d\r\n"

+            "cluster_known_nodes:%lu\r\n"

             , statestr[server.cluster.state],
             slots_assigned,
             slots_ok,
             slots_pfail,
             , statestr[server.cluster.state],
             slots_assigned,
             slots_ok,
             slots_pfail,

-            slots_fail
+            slots_fail,
+            dictSize(server.cluster.nodes)

         );
         addReplySds(c,sdscatprintf(sdsempty(),"$%lu\r\n",
             (unsigned long)sdslen(info)));
         addReplySds(c,info);
         addReply(c,shared.crlf);
         );
         addReplySds(c,sdscatprintf(sdsempty(),"$%lu\r\n",
             (unsigned long)sdslen(info)));
         addReplySds(c,info);
         addReply(c,shared.crlf);

+    } else if (!strcasecmp(c->argv[1]->ptr,"keyslot") && c->argc == 3) {
+        sds key = c->argv[2]->ptr;
+
+        addReplyLongLong(c,keyHashSlot(key,sdslen(key)));
+    } else if (!strcasecmp(c->argv[1]->ptr,"getkeysinslot") && c->argc == 4) {
+        long long maxkeys, slot;
+        unsigned int numkeys, j;
+        robj **keys;
+
+        if (getLongLongFromObjectOrReply(c,c->argv[2],&slot,NULL) != REDIS_OK)
+            return;
+        if (getLongLongFromObjectOrReply(c,c->argv[3],&maxkeys,NULL) != REDIS_OK)
+            return;
+        if (slot < 0 || slot >= REDIS_CLUSTER_SLOTS || maxkeys < 0 ||
+            maxkeys > 1024*1024) {
+            addReplyError(c,"Invalid slot or number of keys");
+            return;
+        }
+
+        keys = zmalloc(sizeof(robj*)*maxkeys);
+        numkeys = GetKeysInSlot(slot, keys, maxkeys);
+        addReplyMultiBulkLen(c,numkeys);
+        for (j = 0; j < numkeys; j++) addReplyBulk(c,keys[j]);
+        zfree(keys);

     } else {
         addReplyError(c,"Wrong CLUSTER subcommand or number of arguments");
     }
     } else {
         addReplyError(c,"Wrong CLUSTER subcommand or number of arguments");
     }


@@ -1121,14 +1476,13 @@ void clusterCommand(redisClient *c) {
 
 /* RESTORE key ttl serialized-value */
 void restoreCommand(redisClient *c) {
 
 /* RESTORE key ttl serialized-value */
 void restoreCommand(redisClient *c) {

-    FILE *fp;
-    char buf[64];
-    robj *o;
-    unsigned char *data;

     long ttl;
     long ttl;

+    rio payload;
+    int type;
+    robj *obj;

 
     /* Make sure this key does not already exist here... */
 
     /* Make sure this key does not already exist here... */

-    if (dbExists(c->db,c->argv[1])) {
+    if (lookupKeyWrite(c->db,c->argv[1]) != NULL) {

         addReplyError(c,"Target key name is busy.");
         return;
     }
         addReplyError(c,"Target key name is busy.");
         return;
     }


@@ -1141,46 +1495,20 @@ void restoreCommand(redisClient *c) {
         return;
     }
 
         return;
     }
 

-    /* rdbLoadObject() only works against file descriptors so we need to
-     * dump the serialized object into a file and reload. */
-    snprintf(buf,sizeof(buf),"redis-restore-%d.tmp",getpid());
-    fp = fopen(buf,"w+");
-    if (!fp) {
-        redisLog(REDIS_WARNING,"Can't open tmp file for RESTORE: %s",
-            strerror(errno));
-        addReplyErrorFormat(c,"RESTORE failed, tmp file creation error: %s",
-            strerror(errno));
-        return;
-    }
-    unlink(buf);
-
-    /* Write the actual data and rewind the file */
-    data = (unsigned char*) c->argv[3]->ptr;
-    if (fwrite(data+1,sdslen((sds)data)-1,1,fp) != 1) {
-        redisLog(REDIS_WARNING,"Can't write against tmp file for RESTORE: %s",
-            strerror(errno));
-        addReplyError(c,"RESTORE failed, tmp file I/O error.");
-        fclose(fp);
-        return;
-    }
-    rewind(fp);
-
-    /* Finally create the object from the serialized dump and
-     * store it at the specified key. */
-    if ((data[0] > 4 && data[0] < 9) ||
-         data[0] > 11 ||
-        (o = rdbLoadObject(data[0],fp)) == NULL)
+    rioInitWithBuffer(&payload,c->argv[3]->ptr);
+    if (((type = rdbLoadObjectType(&payload)) == -1) ||
+        ((obj = rdbLoadObject(type,&payload)) == NULL))

     {
     {

-        addReplyError(c,"Bad data format.");
-        fclose(fp);
+        addReplyError(c,"Bad data format");

         return;
     }
         return;
     }

-    fclose(fp);

 
     /* Create the key and set the TTL if any */
 
     /* Create the key and set the TTL if any */

-    dbAdd(c->db,c->argv[1],o);
+    dbAdd(c->db,c->argv[1],obj);

     if (ttl) setExpire(c->db,c->argv[1],time(NULL)+ttl);
     if (ttl) setExpire(c->db,c->argv[1],time(NULL)+ttl);

+    signalModifiedKey(c->db,c->argv[1]);

     addReply(c,shared.ok);
     addReply(c,shared.ok);

+    server.dirty++;

 }
 
 /* MIGRATE host port key dbid timeout */
 }
 
 /* MIGRATE host port key dbid timeout */


@@ -1188,12 +1516,9 @@ void migrateCommand(redisClient *c) {
     int fd;
     long timeout;
     long dbid;
     int fd;
     long timeout;
     long dbid;

-    char buf[64];
-    FILE *fp;

     time_t ttl;
     robj *o;
     time_t ttl;
     robj *o;

-    unsigned char type;
-    off_t payload_len;
+    rio cmd, payload;

 
     /* Sanity check */
     if (getLongFromObjectOrReply(c,c->argv[5],&timeout,NULL) != REDIS_OK)
 
     /* Sanity check */
     if (getLongFromObjectOrReply(c,c->argv[5],&timeout,NULL) != REDIS_OK)


@@ -1206,7 +1531,7 @@ void migrateCommand(redisClient *c) {
      * nothing to migrate (for instance the key expired in the meantime), but
      * we include such information in the reply string. */
     if ((o = lookupKeyRead(c->db,c->argv[3])) == NULL) {
      * nothing to migrate (for instance the key expired in the meantime), but
      * we include such information in the reply string. */
     if ((o = lookupKeyRead(c->db,c->argv[3])) == NULL) {

-        addReplySds(c,sdsnew("+NOKEY"));
+        addReplySds(c,sdsnew("+NOKEY\r\n"));

         return;
     }
     
         return;
     }
     


@@ -1223,54 +1548,41 @@ void migrateCommand(redisClient *c) {
         return;
     }
 
         return;
     }
 

-    /* Create temp file */
-    snprintf(buf,sizeof(buf),"redis-migrate-%d.tmp",getpid());
-    fp = fopen(buf,"w+");
-    if (!fp) {
-        redisLog(REDIS_WARNING,"Can't open tmp file for MIGRATE: %s",
-            strerror(errno));
-        addReplyErrorFormat(c,"MIGRATE failed, tmp file creation error: %s.",
-            strerror(errno));
-        return;
-    }
-    unlink(buf);
-
-    /* Build the SELECT + RESTORE query writing it in our temp file. */
-    if (fwriteBulkCount(fp,'*',2) == 0) goto file_wr_err;
-    if (fwriteBulkString(fp,"SELECT",6) == 0) goto file_wr_err;
-    if (fwriteBulkLongLong(fp,dbid) == 0) goto file_wr_err;
+    rioInitWithBuffer(&cmd,sdsempty());
+    redisAssertWithInfo(c,NULL,rioWriteBulkCount(&cmd,'*',2));
+    redisAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,"SELECT",6));
+    redisAssertWithInfo(c,NULL,rioWriteBulkLongLong(&cmd,dbid));

 
     ttl = getExpire(c->db,c->argv[3]);
 
     ttl = getExpire(c->db,c->argv[3]);

-    type = o->type;
-    if (fwriteBulkCount(fp,'*',4) == 0) goto file_wr_err;
-    if (fwriteBulkString(fp,"RESTORE",7) == 0) goto file_wr_err;
-    if (fwriteBulkObject(fp,c->argv[3]) == 0) goto file_wr_err;
-    if (fwriteBulkLongLong(fp, (ttl == -1) ? 0 : ttl) == 0) goto file_wr_err;
+    redisAssertWithInfo(c,NULL,rioWriteBulkCount(&cmd,'*',4));
+    redisAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,"RESTORE",7));
+    redisAssertWithInfo(c,NULL,c->argv[3]->encoding == REDIS_ENCODING_RAW);
+    redisAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,c->argv[3]->ptr,sdslen(c->argv[3]->ptr)));
+    redisAssertWithInfo(c,NULL,rioWriteBulkLongLong(&cmd,(ttl == -1) ? 0 : ttl));

 
     /* Finally the last argument that is the serailized object payload
 
     /* Finally the last argument that is the serailized object payload

-     * in the form: <type><rdb-serailized-object>. */
-    payload_len = rdbSavedObjectLen(o);
-    if (fwriteBulkCount(fp,'$',payload_len+1) == 0) goto file_wr_err;
-    if (fwrite(&type,1,1,fp) == 0) goto file_wr_err;
-    if (rdbSaveObject(fp,o) == -1) goto file_wr_err;
-    if (fwrite("\r\n",2,1,fp) == 0) goto file_wr_err;
-
-    /* Tranfer the query to the other node */
-    rewind(fp);
+     * in the form: <type><rdb-serialized-object>. */
+    rioInitWithBuffer(&payload,sdsempty());
+    redisAssertWithInfo(c,NULL,rdbSaveObjectType(&payload,o));
+    redisAssertWithInfo(c,NULL,rdbSaveObject(&payload,o) != -1);
+    redisAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,payload.io.buffer.ptr,sdslen(payload.io.buffer.ptr)));
+    sdsfree(payload.io.buffer.ptr);
+
+    /* Tranfer the query to the other node in 64K chunks. */

     {
     {

-        char buf[4096];
-        size_t nread;
-
-        while ((nread = fread(buf,1,sizeof(buf),fp)) != 0) {
-            int nwritten;
-
-            nwritten = syncWrite(fd,buf,nread,timeout);
-            if (nwritten != (signed)nread) goto socket_wr_err;
+        sds buf = cmd.io.buffer.ptr;
+        size_t pos = 0, towrite;
+        int nwritten = 0;
+
+        while ((towrite = sdslen(buf)-pos) > 0) {
+            towrite = (towrite > (64*1024) ? (64*1024) : towrite);
+            nwritten = syncWrite(fd,buf+nwritten,towrite,timeout);
+            if (nwritten != (signed)towrite) goto socket_wr_err;
+            pos += nwritten;

         }
         }

-        if (ferror(fp)) goto file_rd_err;

     }
 
     }
 

-    /* Read back the reply */
+    /* Read back the reply. */

     {
         char buf1[1024];
         char buf2[1024];
     {
         char buf1[1024];
         char buf2[1024];


@@ -1279,34 +1591,26 @@ void migrateCommand(redisClient *c) {
         if (syncReadLine(fd, buf1, sizeof(buf1), timeout) <= 0)
             goto socket_rd_err;
         if (syncReadLine(fd, buf2, sizeof(buf2), timeout) <= 0)
         if (syncReadLine(fd, buf1, sizeof(buf1), timeout) <= 0)
             goto socket_rd_err;
         if (syncReadLine(fd, buf2, sizeof(buf2), timeout) <= 0)

-                goto socket_rd_err;
+            goto socket_rd_err;

         if (buf1[0] == '-' || buf2[0] == '-') {
             addReplyErrorFormat(c,"Target instance replied with error: %s",
                 (buf1[0] == '-') ? buf1+1 : buf2+1);
         } else {
         if (buf1[0] == '-' || buf2[0] == '-') {
             addReplyErrorFormat(c,"Target instance replied with error: %s",
                 (buf1[0] == '-') ? buf1+1 : buf2+1);
         } else {

+            robj *aux;
+

             dbDelete(c->db,c->argv[3]);
             dbDelete(c->db,c->argv[3]);

+            signalModifiedKey(c->db,c->argv[3]);

             addReply(c,shared.ok);
             addReply(c,shared.ok);

+            server.dirty++;
+
+            /* Translate MIGRATE as DEL for replication/AOF. */
+            aux = createStringObject("DEL",3);
+            rewriteClientCommandVector(c,2,aux,c->argv[3]);
+            decrRefCount(aux);

         }
     }
         }
     }

-    fclose(fp);
-    close(fd);
-    return;

 
 

-file_wr_err:
-    redisLog(REDIS_WARNING,"Can't write on tmp file for MIGRATE: %s",
-        strerror(errno));
-    addReplyErrorFormat(c,"MIGRATE failed, tmp file write error: %s.",
-        strerror(errno));
-    fclose(fp);
-    close(fd);
-    return;
-
-file_rd_err:
-    redisLog(REDIS_WARNING,"Can't read from tmp file for MIGRATE: %s",
-        strerror(errno));
-    addReplyErrorFormat(c,"MIGRATE failed, tmp file read error: %s.",
-        strerror(errno));
-    fclose(fp);
+    sdsfree(cmd.io.buffer.ptr);

     close(fd);
     return;
 
     close(fd);
     return;
 


@@ -1315,7 +1619,7 @@ socket_wr_err:
         strerror(errno));
     addReplyErrorFormat(c,"MIGRATE failed, writing to target node: %s.",
         strerror(errno));
         strerror(errno));
     addReplyErrorFormat(c,"MIGRATE failed, writing to target node: %s.",
         strerror(errno));

-    fclose(fp);
+    sdsfree(cmd.io.buffer.ptr);

     close(fd);
     return;
 
     close(fd);
     return;
 


@@ -1324,7 +1628,7 @@ socket_rd_err:
         strerror(errno));
     addReplyErrorFormat(c,"MIGRATE failed, reading from target node: %s.",
         strerror(errno));
         strerror(errno));
     addReplyErrorFormat(c,"MIGRATE failed, reading from target node: %s.",
         strerror(errno));

-    fclose(fp);
+    sdsfree(cmd.io.buffer.ptr);

     close(fd);
     return;
 }
     close(fd);
     return;
 }


@@ -1333,74 +1637,39 @@ socket_rd_err:
  * DUMP is actually not used by Redis Cluster but it is the obvious
  * complement of RESTORE and can be useful for different applications. */
 void dumpCommand(redisClient *c) {
  * DUMP is actually not used by Redis Cluster but it is the obvious
  * complement of RESTORE and can be useful for different applications. */
 void dumpCommand(redisClient *c) {

-    char buf[64];
-    FILE *fp;

     robj *o, *dumpobj;
     robj *o, *dumpobj;

-    sds dump = NULL;
-    off_t payload_len;
-    unsigned int type;
+    rio payload;

 
     /* Check if the key is here. */
     if ((o = lookupKeyRead(c->db,c->argv[1])) == NULL) {
         addReply(c,shared.nullbulk);
         return;
     }
 
     /* Check if the key is here. */
     if ((o = lookupKeyRead(c->db,c->argv[1])) == NULL) {
         addReply(c,shared.nullbulk);
         return;
     }

-    
-    /* Create temp file */
-    snprintf(buf,sizeof(buf),"redis-dump-%d.tmp",getpid());
-    fp = fopen(buf,"w+");
-    if (!fp) {
-        redisLog(REDIS_WARNING,"Can't open tmp file for MIGRATE: %s",
-            strerror(errno));
-        addReplyErrorFormat(c,"DUMP failed, tmp file creation error: %s.",
-            strerror(errno));
-        return;
-    }
-    unlink(buf);
-
-    /* Dump the serailized object and read it back in memory.
-     * We prefix it with a one byte containing the type ID.
-     * This is the serialization format understood by RESTORE. */
-    if (rdbSaveObject(fp,o) == -1) goto file_wr_err;
-    payload_len = ftello(fp);
-    if (fseeko(fp,0,SEEK_SET) == -1) goto file_rd_err;
-    dump = sdsnewlen(NULL,payload_len+1);
-    if (payload_len && fread(dump+1,payload_len,1,fp) != 1) goto file_rd_err;
-    fclose(fp);
-    type = o->type;
-    if (type == REDIS_LIST && o->encoding == REDIS_ENCODING_ZIPLIST)
-        type = REDIS_LIST_ZIPLIST;
-    else if (type == REDIS_HASH && o->encoding == REDIS_ENCODING_ZIPMAP)
-        type = REDIS_HASH_ZIPMAP;
-    else if (type == REDIS_SET && o->encoding == REDIS_ENCODING_INTSET)
-        type = REDIS_SET_INTSET;
-    else
-        type = o->type;
-    dump[0] = type;
+
+    /* Serialize the object in a RDB-like format. It consist of an object type
+     * byte followed by the serialized object. This is understood by RESTORE. */
+    rioInitWithBuffer(&payload,sdsempty());
+    redisAssertWithInfo(c,NULL,rdbSaveObjectType(&payload,o));
+    redisAssertWithInfo(c,NULL,rdbSaveObject(&payload,o));

 
     /* Transfer to the client */
 
     /* Transfer to the client */

-    dumpobj = createObject(REDIS_STRING,dump);
+    dumpobj = createObject(REDIS_STRING,payload.io.buffer.ptr);

     addReplyBulk(c,dumpobj);
     decrRefCount(dumpobj);
     return;
     addReplyBulk(c,dumpobj);
     decrRefCount(dumpobj);
     return;

+}

 
 

-file_wr_err:
-    redisLog(REDIS_WARNING,"Can't write on tmp file for DUMP: %s",
-        strerror(errno));
-    addReplyErrorFormat(c,"DUMP failed, tmp file write error: %s.",
-        strerror(errno));
-    sdsfree(dump);
-    fclose(fp);
-    return;
-
-file_rd_err:
-    redisLog(REDIS_WARNING,"Can't read from tmp file for DUMP: %s",
-        strerror(errno));
-    addReplyErrorFormat(c,"DUMP failed, tmp file read error: %s.",
-        strerror(errno));
-    sdsfree(dump);
-    fclose(fp);
-    return;
+/* The ASKING command is required after a -ASK redirection.
+ * The client should issue ASKING before to actualy send the command to
+ * the target instance. See the Redis Cluster specification for more
+ * information. */
+void askingCommand(redisClient *c) {
+    if (server.cluster_enabled == 0) {
+        addReplyError(c,"This instance has cluster support disabled");
+        return;
+    }
+    c->flags |= REDIS_ASKING;
+    addReply(c,shared.ok);

 }
 
 /* -----------------------------------------------------------------------------
 }
 
 /* -----------------------------------------------------------------------------


@@ -1410,12 +1679,19 @@ file_rd_err:
 /* Return the pointer to the cluster node that is able to serve the query
  * as all the keys belong to hash slots for which the node is in charge.
  *
 /* Return the pointer to the cluster node that is able to serve the query
  * as all the keys belong to hash slots for which the node is in charge.
  *

- * If keys in query spawn multiple nodes NULL is returned. */
-clusterNode *getNodeByQuery(redisClient *c, struct redisCommand *cmd, robj **argv, int argc, int *hashslot) {
+ * If the returned node should be used only for this request, the *ask
+ * integer is set to '1', otherwise to '0'. This is used in order to
+ * let the caller know if we should reply with -MOVED or with -ASK.
+ *
+ * If the request contains more than a single key NULL is returned,
+ * however a request with more then a key argument where the key is always
+ * the same is valid, like in: RPOPLPUSH mylist mylist.*/
+clusterNode *getNodeByQuery(redisClient *c, struct redisCommand *cmd, robj **argv, int argc, int *hashslot, int *ask) {

     clusterNode *n = NULL;
     clusterNode *n = NULL;

+    robj *firstkey = NULL;

     multiState *ms, _ms;
     multiCmd mc;
     multiState *ms, _ms;
     multiCmd mc;

-    int i;
+    int i, slot = 0;

 
     /* We handle all the cases as if they were EXEC commands, so we have
      * a common code path for everything */
 
     /* We handle all the cases as if they were EXEC commands, so we have
      * a common code path for everything */


@@ -1425,7 +1701,9 @@ clusterNode *getNodeByQuery(redisClient *c, struct redisCommand *cmd, robj **arg
         if (!(c->flags & REDIS_MULTI)) return server.cluster.myself;
         ms = &c->mstate;
     } else {
         if (!(c->flags & REDIS_MULTI)) return server.cluster.myself;
         ms = &c->mstate;
     } else {

-        /* Create a fake Multi State structure, with just one command */
+        /* In order to have a single codepath create a fake Multi State
+         * structure if the client is not in MULTI/EXEC state, this way
+         * we have a single codepath below. */

         ms = &_ms;
         _ms.commands = &mc;
         _ms.count = 1;
         ms = &_ms;
         _ms.commands = &mc;
         _ms.count = 1;


@@ -1434,6 +1712,8 @@ clusterNode *getNodeByQuery(redisClient *c, struct redisCommand *cmd, robj **arg
         mc.cmd = cmd;
     }
 
         mc.cmd = cmd;
     }
 

+    /* Check that all the keys are the same key, and get the slot and
+     * node for this key. */

     for (i = 0; i < ms->count; i++) {
         struct redisCommand *mcmd;
         robj **margv;
     for (i = 0; i < ms->count; i++) {
         struct redisCommand *mcmd;
         robj **margv;


@@ -1444,26 +1724,53 @@ clusterNode *getNodeByQuery(redisClient *c, struct redisCommand *cmd, robj **arg
         margv = ms->commands[i].argv;
 
         keyindex = getKeysFromCommand(mcmd,margv,margc,&numkeys,
         margv = ms->commands[i].argv;
 
         keyindex = getKeysFromCommand(mcmd,margv,margc,&numkeys,

-                                      REDIS_GETKEYS_PRELOAD);
+                                      REDIS_GETKEYS_ALL);

         for (j = 0; j < numkeys; j++) {
         for (j = 0; j < numkeys; j++) {

-            int slot = keyHashSlot((char*)margv[keyindex[j]]->ptr,
-                sdslen(margv[keyindex[j]]->ptr));
-            struct clusterNode *slotnode;
-
-            slotnode = server.cluster.slots[slot];
-            if (hashslot) *hashslot = slot;
-            /* Node not assigned? (Should never happen actually
-             * if we reached this function).
-             * Different node than the previous one?
-             * Return NULL, the cluster can't serve multi-node requests */
-            if (slotnode == NULL || (n && slotnode != n)) {
-                getKeysFreeResult(keyindex);
-                return NULL;
+            if (firstkey == NULL) {
+                /* This is the first key we see. Check what is the slot
+                 * and node. */
+                firstkey = margv[keyindex[j]];
+
+                slot = keyHashSlot((char*)firstkey->ptr, sdslen(firstkey->ptr));
+                n = server.cluster.slots[slot];
+                redisAssertWithInfo(c,firstkey,n != NULL);

             } else {
             } else {

-                n = slotnode;
+                /* If it is not the first key, make sure it is exactly
+                 * the same key as the first we saw. */
+                if (!equalStringObjects(firstkey,margv[keyindex[j]])) {
+                    decrRefCount(firstkey);
+                    getKeysFreeResult(keyindex);
+                    return NULL;
+                }

             }
         }
         getKeysFreeResult(keyindex);
     }
             }
         }
         getKeysFreeResult(keyindex);
     }

-    return (n == NULL) ? server.cluster.myself : n;
+    if (ask) *ask = 0; /* This is the default. Set to 1 if needed later. */
+    /* No key at all in command? then we can serve the request
+     * without redirections. */
+    if (n == NULL) return server.cluster.myself;
+    if (hashslot) *hashslot = slot;
+    /* This request is about a slot we are migrating into another instance?
+     * Then we need to check if we have the key. If we have it we can reply.
+     * If instead is a new key, we pass the request to the node that is
+     * receiving the slot. */
+    if (n == server.cluster.myself &&
+        server.cluster.migrating_slots_to[slot] != NULL)
+    {
+        if (lookupKeyRead(&server.db[0],firstkey) == NULL) {
+            if (ask) *ask = 1;
+            return server.cluster.migrating_slots_to[slot];
+        }
+    }
+    /* Handle the case in which we are receiving this hash slot from
+     * another instance, so we'll accept the query even if in the table
+     * it is assigned to a different node, but only if the client
+     * issued an ASKING command before. */
+    if (server.cluster.importing_slots_from[slot] != NULL &&
+        c->flags & REDIS_ASKING) {
+        return server.cluster.myself;
+    }
+    /* It's not a -ASK case. Base case: just return the right node. */
+    return n;

 }
 }