#include "redis.h"
+#include "endianconv.h"
#include <arpa/inet.h>
#include <fcntl.h>
#include <unistd.h>
+#include <sys/socket.h>
void clusterAcceptHandler(aeEventLoop *el, int fd, void *privdata, int mask);
void clusterReadHandler(aeEventLoop *el, int fd, void *privdata, int mask);
* Initialization
* -------------------------------------------------------------------------- */
-void clusterGetRandomName(char *p) {
- FILE *fp = fopen("/dev/urandom","r");
- char *charset = "0123456789abcdef";
- int j;
-
- if (fp == NULL || fread(p,REDIS_CLUSTER_NAMELEN,1,fp) == 0) {
- for (j = 0; j < REDIS_CLUSTER_NAMELEN; j++)
- p[j] = rand();
- }
- for (j = 0; j < REDIS_CLUSTER_NAMELEN; j++)
- p[j] = charset[p[j] & 0x0F];
- fclose(fp);
-}
-
int clusterLoadConfig(char *filename) {
FILE *fp = fopen(filename,"r");
char *line;
exit(1);
}
if (aeCreateFileEvent(server.el, server.cfd, AE_READABLE,
- clusterAcceptHandler, NULL) == AE_ERR) oom("creating file event");
+ clusterAcceptHandler, NULL) == AE_ERR) redisPanic("Unrecoverable error creating Redis Cluster file event.");
server.cluster.slots_to_keys = zslCreate();
}
if (nodename)
memcpy(node->name, nodename, REDIS_CLUSTER_NAMELEN);
else
- clusterGetRandomName(node->name);
+ getRandomHexChars(node->name, REDIS_CLUSTER_NAMELEN);
node->flags = flags;
memset(node->slots,0,sizeof(node->slots));
node->numslaves = 0;
de = dictFind(server.cluster.nodes,s);
sdsfree(s);
if (de == NULL) return NULL;
- return dictGetEntryVal(de);
+ return dictGetVal(de);
}
/* This is only used after the handshake. When we connect a given IP/PORT
* 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);
}
/* 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
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 ||
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) {
int update_config = 0;
}
}
/* Update our info about the node */
- link->node->pong_received = time(NULL);
+ if (link->node) link->node->pong_received = time(NULL);
/* Update master/slave info */
if (sender) {
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 {
- redisLog(REDIS_NOTICE,"Received unknown packet type: %d", type);
+ redisLog(REDIS_WARNING,"Received unknown packet type: %d", type);
}
return 1;
}
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 = dictGetVal(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;
+ int totlen = 0;
memset(hdr,0,sizeof(*hdr));
hdr->type = htons(type);
/* Populate the gossip fields */
while(freshnodes > 0 && gossipcount < 3) {
struct dictEntry *de = dictGetRandomKey(server.cluster.nodes);
- clusterNode *this = dictGetEntryVal(de);
+ clusterNode *this = dictGetVal(de);
clusterMsgDataGossip *gossip;
int j;
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.
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
* -------------------------------------------------------------------------- */
/* Check if we have disconnected nodes and reestablish the connection. */
di = dictGetIterator(server.cluster.nodes);
while((de = dictNext(di)) != NULL) {
- clusterNode *node = dictGetEntryVal(de);
+ clusterNode *node = dictGetVal(de);
if (node->flags & (REDIS_NODE_MYSELF|REDIS_NODE_NOADDR)) continue;
if (node->link == NULL) {
* the oldest ping_sent time */
for (j = 0; j < 5; j++) {
de = dictGetRandomKey(server.cluster.nodes);
- clusterNode *this = dictGetEntryVal(de);
+ clusterNode *this = dictGetVal(de);
if (this->link == NULL) continue;
if (this->flags & (REDIS_NODE_MYSELF|REDIS_NODE_HANDSHAKE)) continue;
/* Iterate nodes to check if we need to flag something as failing */
di = dictGetIterator(server.cluster.nodes);
while((de = dictNext(di)) != NULL) {
- clusterNode *node = dictGetEntryVal(de);
+ clusterNode *node = dictGetVal(de);
int delay;
if (node->flags &
di = dictGetIterator(server.cluster.nodes);
while((de = dictNext(di)) != NULL) {
- clusterNode *node = dictGetEntryVal(de);
+ clusterNode *node = dictGetVal(de);
/* Node coordinates */
ci = sdscatprintf(ci,"%.40s %s:%d ",
addReplyBulk(c,o);
decrRefCount(o);
} else if ((!strcasecmp(c->argv[1]->ptr,"addslots") ||
- !strcasecmp(c->argv[1]->ptr,"delslots")) && c->argc >= 3) {
+ !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);
int del = !strcasecmp(c->argv[1]->ptr,"delslots");
retval = del ? clusterDelSlot(j) :
clusterAddSlot(server.cluster.myself,j);
- redisAssert(retval == REDIS_OK);
+ redisAssertWithInfo(c,NULL,retval == REDIS_OK);
}
}
zfree(slots);
clusterSaveConfigOrDie();
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[1]->ptr,"setslot") && c->argc >= 4) {
- /* SETSLOT 10 MIGRATING <instance ID> */
- /* SETSLOT 10 IMPORTING <instance ID> */
+ /* SETSLOT 10 MIGRATING <node ID> */
+ /* SETSLOT 10 IMPORTING <node ID> */
/* SETSLOT 10 STABLE */
+ /* SETSLOT 10 NODE <node ID> */
int slot;
clusterNode *n;
/* 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 == 4) {
+ } else if (!strcasecmp(c->argv[3]->ptr,"node") && c->argc == 5) {
/* CLUSTER SETSLOT <SLOT> NODE <NODE ID> */
clusterNode *n = clusterLookupNode(c->argv[4]->ptr);
keys = zmalloc(sizeof(robj*)*1);
numkeys = GetKeysInSlot(slot, keys, 1);
zfree(keys);
- if (numkeys == 0) {
+ 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;
}
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 {
}
/* -----------------------------------------------------------------------------
- * RESTORE and MIGRATE commands
+ * DUMP, RESTORE and MIGRATE commands
* -------------------------------------------------------------------------- */
+/* Generates a DUMP-format representation of the object 'o', adding it to the
+ * io stream pointed by 'rio'. This function can't fail. */
+void createDumpPayload(rio *payload, robj *o) {
+ unsigned char buf[2];
+ uint64_t crc;
+
+ /* 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());
+ redisAssert(rdbSaveObjectType(payload,o));
+ redisAssert(rdbSaveObject(payload,o));
+
+ /* Write the footer, this is how it looks like:
+ * ----------------+---------------------+---------------+
+ * ... RDB payload | 2 bytes RDB version | 8 bytes CRC64 |
+ * ----------------+---------------------+---------------+
+ * RDB version and CRC are both in little endian.
+ */
+
+ /* RDB version */
+ buf[0] = REDIS_RDB_VERSION & 0xff;
+ buf[1] = (REDIS_RDB_VERSION >> 8) & 0xff;
+ payload->io.buffer.ptr = sdscatlen(payload->io.buffer.ptr,buf,2);
+
+ /* CRC64 */
+ crc = crc64(0,(unsigned char*)payload->io.buffer.ptr,
+ sdslen(payload->io.buffer.ptr));
+ memrev64ifbe(&crc);
+ payload->io.buffer.ptr = sdscatlen(payload->io.buffer.ptr,&crc,8);
+}
+
+/* Verify that the RDB version of the dump payload matches the one of this Redis
+ * instance and that the checksum is ok.
+ * If the DUMP payload looks valid REDIS_OK is returned, otherwise REDIS_ERR
+ * is returned. */
+int verifyDumpPayload(unsigned char *p, size_t len) {
+ unsigned char *footer;
+ uint16_t rdbver;
+ uint64_t crc;
+
+ /* At least 2 bytes of RDB version and 8 of CRC64 should be present. */
+ if (len < 10) return REDIS_ERR;
+ footer = p+(len-10);
+
+ /* Verify RDB version */
+ rdbver = (footer[1] << 8) | footer[0];
+ if (rdbver != REDIS_RDB_VERSION) return REDIS_ERR;
+
+ /* Verify CRC64 */
+ crc = crc64(0,p,len-8);
+ memrev64ifbe(&crc);
+ return (memcmp(&crc,footer+2,8) == 0) ? REDIS_OK : REDIS_ERR;
+}
+
+/* DUMP keyname
+ * 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) {
+ robj *o, *dumpobj;
+ rio payload;
+
+ /* Check if the key is here. */
+ if ((o = lookupKeyRead(c->db,c->argv[1])) == NULL) {
+ addReply(c,shared.nullbulk);
+ return;
+ }
+
+ /* Create the DUMP encoded representation. */
+ createDumpPayload(&payload,o);
+
+ /* Transfer to the client */
+ dumpobj = createObject(REDIS_STRING,payload.io.buffer.ptr);
+ addReplyBulk(c,dumpobj);
+ decrRefCount(dumpobj);
+ return;
+}
+
/* RESTORE key ttl serialized-value */
void restoreCommand(redisClient *c) {
long ttl;
return;
}
+ /* Verify RDB version and data checksum. */
+ if (verifyDumpPayload(c->argv[3]->ptr,sdslen(c->argv[3]->ptr)) == REDIS_ERR) {
+ addReplyError(c,"DUMP payload version or checksum are wrong");
+ return;
+ }
+
rioInitWithBuffer(&payload,c->argv[3]->ptr);
if (((type = rdbLoadObjectType(&payload)) == -1) ||
((obj = rdbLoadObject(type,&payload)) == NULL))
/* Create the key and set the TTL if any */
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],mstime()+ttl);
+ signalModifiedKey(c->db,c->argv[1]);
addReply(c,shared.ok);
+ server.dirty++;
}
/* MIGRATE host port key dbid timeout */
int fd;
long timeout;
long dbid;
- time_t ttl;
+ long long ttl = 0, expireat;
robj *o;
rio cmd, payload;
* 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;
}
if ((aeWait(fd,AE_WRITABLE,timeout*1000) & AE_WRITABLE) == 0) {
- addReplyError(c,"Timeout connecting to the client");
+ addReplySds(c,sdsnew("-IOERR error or timeout connecting to the client\r\n"));
return;
}
+ /* Create RESTORE payload and generate the protocol to call the command. */
rioInitWithBuffer(&cmd,sdsempty());
- redisAssert(rioWriteBulkCount(&cmd,'*',2));
- redisAssert(rioWriteBulkString(&cmd,"SELECT",6));
- redisAssert(rioWriteBulkLongLong(&cmd,dbid));
-
- ttl = getExpire(c->db,c->argv[3]);
- redisAssert(rioWriteBulkCount(&cmd,'*',4));
- redisAssert(rioWriteBulkString(&cmd,"RESTORE",7));
- redisAssert(c->argv[3]->encoding == REDIS_ENCODING_RAW);
- redisAssert(rioWriteBulkString(&cmd,c->argv[3]->ptr,sdslen(c->argv[3]->ptr)));
- redisAssert(rioWriteBulkLongLong(&cmd,(ttl == -1) ? 0 : ttl));
+ redisAssertWithInfo(c,NULL,rioWriteBulkCount(&cmd,'*',2));
+ redisAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,"SELECT",6));
+ redisAssertWithInfo(c,NULL,rioWriteBulkLongLong(&cmd,dbid));
+
+ expireat = getExpire(c->db,c->argv[3]);
+ if (expireat != -1) {
+ ttl = expireat-mstime();
+ if (ttl < 1) ttl = 1;
+ }
+ 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));
/* Finally the last argument that is the serailized object payload
- * in the form: <type><rdb-serialized-object>. */
- rioInitWithBuffer(&payload,sdsempty());
- redisAssert(rdbSaveObjectType(&payload,o));
- redisAssert(rdbSaveObject(&payload,o) != -1);
- redisAssert(rioWriteBulkString(&cmd,payload.io.buffer.ptr,sdslen(payload.io.buffer.ptr)));
+ * in the DUMP format. */
+ createDumpPayload(&payload,o);
+ 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. */
while ((towrite = sdslen(buf)-pos) > 0) {
towrite = (towrite > (64*1024) ? (64*1024) : towrite);
- nwritten = syncWrite(fd,buf+nwritten,towrite,timeout);
+ nwritten = syncWrite(fd,buf+pos,towrite,timeout);
if (nwritten != (signed)towrite) goto socket_wr_err;
pos += nwritten;
}
addReplyErrorFormat(c,"Target instance replied with error: %s",
(buf1[0] == '-') ? buf1+1 : buf2+1);
} else {
+ robj *aux;
+
dbDelete(c->db,c->argv[3]);
+ signalModifiedKey(c->db,c->argv[3]);
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);
}
}
return;
socket_wr_err:
- redisLog(REDIS_NOTICE,"Can't write to target node for MIGRATE: %s",
- strerror(errno));
- addReplyErrorFormat(c,"MIGRATE failed, writing to target node: %s.",
- strerror(errno));
+ addReplySds(c,sdsnew("-IOERR error or timeout writing to target instance\r\n"));
sdsfree(cmd.io.buffer.ptr);
close(fd);
return;
socket_rd_err:
- redisLog(REDIS_NOTICE,"Can't read from target node for MIGRATE: %s",
- strerror(errno));
- addReplyErrorFormat(c,"MIGRATE failed, reading from target node: %s.",
- strerror(errno));
+ addReplySds(c,sdsnew("-IOERR error or timeout reading from target node\r\n"));
sdsfree(cmd.io.buffer.ptr);
close(fd);
return;
}
-/* DUMP keyname
- * 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) {
- robj *o, *dumpobj;
- rio payload;
-
- /* Check if the key is here. */
- if ((o = lookupKeyRead(c->db,c->argv[1])) == NULL) {
- addReply(c,shared.nullbulk);
+/* 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;
}
-
- /* 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());
- redisAssert(rdbSaveObjectType(&payload,o));
- redisAssert(rdbSaveObject(&payload,o));
-
- /* Transfer to the client */
- dumpobj = createObject(REDIS_STRING,payload.io.buffer.ptr);
- addReplyBulk(c,dumpobj);
- decrRefCount(dumpobj);
- return;
+ c->flags |= REDIS_ASKING;
+ addReply(c,shared.ok);
}
/* -----------------------------------------------------------------------------
slot = keyHashSlot((char*)firstkey->ptr, sdslen(firstkey->ptr));
n = server.cluster.slots[slot];
- redisAssert(n != NULL);
+ redisAssertWithInfo(c,firstkey,n != NULL);
} else {
/* If it is not the first key, make sure it is exactly
* the same key as the first we saw. */
}
/* 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. */
- if (server.cluster.importing_slots_from[slot] != NULL)
+ * 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;
}