diff options
Diffstat (limited to 'examples/redis-unstable/src/cluster.c')
| -rw-r--r-- | examples/redis-unstable/src/cluster.c | 2263 |
1 files changed, 2263 insertions, 0 deletions
diff --git a/examples/redis-unstable/src/cluster.c b/examples/redis-unstable/src/cluster.c new file mode 100644 index 0000000..d07c31c --- /dev/null +++ b/examples/redis-unstable/src/cluster.c @@ -0,0 +1,2263 @@ +/* + * Copyright (c) 2009-Present, Redis Ltd. + * All rights reserved. + * + * Copyright (c) 2024-present, Valkey contributors. + * All rights reserved. + * + * Licensed under your choice of (a) the Redis Source Available License 2.0 + * (RSALv2); or (b) the Server Side Public License v1 (SSPLv1); or (c) the + * GNU Affero General Public License v3 (AGPLv3). + * + * Portions of this file are available under BSD3 terms; see REDISCONTRIBUTIONS for more information. + */ + +/* + * cluster.c contains the common parts of a clustering + * implementation, the parts that are shared between + * any implementation of Redis clustering. + */ + +#include "server.h" +#include "cluster.h" +#include "cluster_asm.h" +#include "cluster_slot_stats.h" + +#include <ctype.h> + +/* ----------------------------------------------------------------------------- + * Key space handling + * -------------------------------------------------------------------------- */ + +/* If it can be inferred that the given glob-style pattern, as implemented in + * stringmatchlen() in util.c, only can match keys belonging to a single slot, + * that slot is returned. Otherwise -1 is returned. */ +int patternHashSlot(char *pattern, int length) { + int s = -1; /* index of the first '{' */ + + for (int i = 0; i < length; i++) { + if (pattern[i] == '*' || pattern[i] == '?' || pattern[i] == '[') { + /* Wildcard or character class found. Keys can be in any slot. */ + return -1; + } else if (pattern[i] == '\\') { + /* Escaped character. Computing slot in this case is not + * implemented. We would need a temp buffer. */ + return -1; + } else if (s == -1 && pattern[i] == '{') { + /* Opening brace '{' found. */ + s = i; + } else if (s >= 0 && pattern[i] == '}' && i == s + 1) { + /* Empty tag '{}' found. The whole key is hashed. Ignore braces. */ + s = -2; + } else if (s >= 0 && pattern[i] == '}') { + /* Non-empty tag '{...}' found. Hash what's between braces. */ + return crc16(pattern + s + 1, i - s - 1) & 0x3FFF; + } + } + + /* The pattern matches a single key. Hash the whole pattern. */ + return crc16(pattern, length) & 0x3FFF; +} + +int getSlotOrReply(client *c, robj *o) { + long long slot; + + if (getLongLongFromObject(o,&slot) != C_OK || + slot < 0 || slot >= CLUSTER_SLOTS) + { + addReplyError(c,"Invalid or out of range slot"); + return -1; + } + return (int) slot; +} + +ConnectionType *connTypeOfCluster(void) { + if (server.tls_cluster) { + return connectionTypeTls(); + } + + return connectionTypeTcp(); +} + +/* ----------------------------------------------------------------------------- + * 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, robj *key, int dbid, int skip_checksum) { + unsigned char buf[2]; + uint64_t crc = 0; + + /* Serialize the object in an RDB-like format. It consist of an object type + * byte followed by the serialized object. This is understood by RESTORE. */ + rioInitWithBuffer(payload,sdsempty()); + + /* Save key metadata if present without (handles TTL separately via command args) */ + if (getModuleMetaBits(o->metabits)) + serverAssert(rdbSaveKeyMetadata(payload, key, o, dbid) != -1); + serverAssert(rdbSaveObjectType(payload,o)); + serverAssert(rdbSaveObject(payload,o,key,dbid)); + + /* 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] = RDB_VERSION & 0xff; + buf[1] = (RDB_VERSION >> 8) & 0xff; + payload->io.buffer.ptr = sdscatlen(payload->io.buffer.ptr,buf,2); + + /* If crc checksum is disabled, crc is set to 0 and no checksum validation + * will be performed on RESTORE. */ + if (!skip_checksum) { + /* 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 C_OK is returned, otherwise C_ERR + * is returned. If rdbver_ptr is not NULL, its populated with the value read + * from the input buffer. */ +int verifyDumpPayload(unsigned char *p, size_t len, uint16_t *rdbver_ptr) { + 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 C_ERR; + footer = p+(len-10); + + /* Set and verify RDB version. */ + rdbver = (footer[1] << 8) | footer[0]; + if (rdbver_ptr) { + *rdbver_ptr = rdbver; + } + if (rdbver > RDB_VERSION) return C_ERR; + + if (server.skip_checksum_validation) + return C_OK; + + uint64_t crc_payload; + memcpy(&crc_payload, footer+2, 8); + if (crc_payload == 0) /* No checksum. */ + return C_OK; + + /* Verify CRC64 */ + crc = crc64(0,p,len-8); + memrev64ifbe(&crc); + return crc == crc_payload ? C_OK : C_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(client *c) { + kvobj *o; + rio payload; + + /* Check if the key is here. */ + if ((o = lookupKeyRead(c->db,c->argv[1])) == NULL) { + addReplyNull(c); + return; + } + + /* Create the DUMP encoded representation. */ + createDumpPayload(&payload,o,c->argv[1],c->db->id,0); + + /* Transfer to the client */ + addReplyBulkSds(c,payload.io.buffer.ptr); + return; +} + +/* RESTORE key ttl serialized-value [REPLACE] [ABSTTL] [IDLETIME seconds] [FREQ frequency] */ +void restoreCommand(client *c) { + long long ttl, lfu_freq = -1, lru_idle = -1, lru_clock = -1; + rio payload; + int j, type, replace = 0, absttl = 0; + robj *obj; + + /* Parse additional options */ + for (j = 4; j < c->argc; j++) { + int additional = c->argc-j-1; + if (!strcasecmp(c->argv[j]->ptr,"replace")) { + replace = 1; + } else if (!strcasecmp(c->argv[j]->ptr,"absttl")) { + absttl = 1; + } else if (!strcasecmp(c->argv[j]->ptr,"idletime") && additional >= 1 && + lfu_freq == -1) + { + if (getLongLongFromObjectOrReply(c,c->argv[j+1],&lru_idle,NULL) + != C_OK) return; + if (lru_idle < 0) { + addReplyError(c,"Invalid IDLETIME value, must be >= 0"); + return; + } + lru_clock = LRU_CLOCK(); + j++; /* Consume additional arg. */ + } else if (!strcasecmp(c->argv[j]->ptr,"freq") && additional >= 1 && + lru_idle == -1) + { + if (getLongLongFromObjectOrReply(c,c->argv[j+1],&lfu_freq,NULL) + != C_OK) return; + if (lfu_freq < 0 || lfu_freq > 255) { + addReplyError(c,"Invalid FREQ value, must be >= 0 and <= 255"); + return; + } + j++; /* Consume additional arg. */ + } else { + addReplyErrorObject(c,shared.syntaxerr); + return; + } + } + + /* Make sure this key does not already exist here... */ + robj *key = c->argv[1]; + kvobj *oldval = lookupKeyWrite(c->db,key); + int oldtype = oldval ? oldval->type : -1; + if (!replace && oldval) { + addReplyErrorObject(c,shared.busykeyerr); + return; + } + + /* Check if the TTL value makes sense */ + if (getLongLongFromObjectOrReply(c,c->argv[2],&ttl,NULL) != C_OK) { + return; + } else if (ttl < 0) { + addReplyError(c,"Invalid TTL value, must be >= 0"); + return; + } + + /* Verify RDB version and data checksum. */ + if (verifyDumpPayload(c->argv[3]->ptr,sdslen(c->argv[3]->ptr),NULL) == C_ERR) + { + addReplyError(c,"DUMP payload version or checksum are wrong"); + return; + } + + rioInitWithBuffer(&payload,c->argv[3]->ptr); + + /* Initialize metadata spec to collect metadata+expiry from payload. */ + KeyMetaSpec keymeta; + keyMetaSpecInit(&keymeta); + + /* Compute TTL early so we can add it to metadata spec in correct order */ + if (ttl) { + if (!absttl) ttl+=commandTimeSnapshot(); + keyMetaSpecAdd(&keymeta, KEY_META_ID_EXPIRE, ttl); + } + + /* With metadata, type = RDB_OPCODE_KEY_META. Layout: [<META>,]<TYPE>,<KEY>,<VALUE> */ + type = rdbLoadType(&payload); + if (rdbResolveKeyType(&payload, &type, c->db->id, &keymeta) == -1) { + addReplyError(c,"Bad data format"); + return; + } + + /* Load the object */ + if ((obj = rdbLoadObject(type,&payload,key->ptr,c->db->id,NULL)) == NULL) + { + keyMetaSpecCleanup(&keymeta); + addReplyError(c,"Bad data format"); + return; + } + + /* Remove the old key if needed. */ + int deleted = 0; + if (replace) + deleted = dbDelete(c->db,key); + + if (ttl && checkAlreadyExpired(ttl)) { + if (deleted) { + robj *aux = server.lazyfree_lazy_server_del ? shared.unlink : shared.del; + rewriteClientCommandVector(c, 2, aux, key); + keyModified(c,c->db,key,NULL,1); + notifyKeyspaceEvent(NOTIFY_GENERIC,"del",key,c->db->id); + server.dirty++; + } + keyMetaSpecCleanup(&keymeta); + decrRefCount(obj); + addReply(c, shared.ok); + return; + } + + /* Create the key and set the TTL if any */ + kvobj *kv = dbAddInternal(c->db, key, &obj, NULL, &keymeta); + + /* If minExpiredField was set, then the object is hash with expiration + * on fields and need to register it in global HFE DS */ + if (kv->type == OBJ_HASH) { + uint64_t minExpiredField = hashTypeGetMinExpire(kv, 1); + if (minExpiredField != EB_EXPIRE_TIME_INVALID) + estoreAdd(c->db->subexpires, getKeySlot(key->ptr), kv, minExpiredField); + } + + if (ttl) { + if (!absttl) { + /* Propagate TTL as absolute timestamp */ + robj *ttl_obj = createStringObjectFromLongLong(ttl); + rewriteClientCommandArgument(c,2,ttl_obj); + decrRefCount(ttl_obj); + rewriteClientCommandArgument(c,c->argc,shared.absttl); + } + } + objectSetLRUOrLFU(kv, lfu_freq, lru_idle, lru_clock, 1000); + keyModified(c,c->db,key,NULL,1); + notifyKeyspaceEvent(NOTIFY_GENERIC,"restore",key,c->db->id); + + /* If we deleted a key that means REPLACE parameter was passed and the + * destination key existed. */ + if (deleted) { + notifyKeyspaceEvent(NOTIFY_OVERWRITTEN, "overwritten", key, c->db->id); + if (oldtype != kv->type) { + notifyKeyspaceEvent(NOTIFY_TYPE_CHANGED, "type_changed", key, c->db->id); + } + } + addReply(c,shared.ok); + server.dirty++; +} +/* MIGRATE socket cache implementation. + * + * We take a map between host:ip and a TCP socket that we used to connect + * to this instance in recent time. + * This sockets are closed when the max number we cache is reached, and also + * in serverCron() when they are around for more than a few seconds. */ +#define MIGRATE_SOCKET_CACHE_ITEMS 64 /* max num of items in the cache. */ +#define MIGRATE_SOCKET_CACHE_TTL 10 /* close cached sockets after 10 sec. */ + +typedef struct migrateCachedSocket { + connection *conn; + long last_dbid; + time_t last_use_time; +} migrateCachedSocket; + +/* Return a migrateCachedSocket containing a TCP socket connected with the + * target instance, possibly returning a cached one. + * + * This function is responsible of sending errors to the client if a + * connection can't be established. In this case -1 is returned. + * Otherwise on success the socket is returned, and the caller should not + * attempt to free it after usage. + * + * If the caller detects an error while using the socket, migrateCloseSocket() + * should be called so that the connection will be created from scratch + * the next time. */ +migrateCachedSocket* migrateGetSocket(client *c, robj *host, robj *port, long timeout) { + connection *conn; + sds name = sdsempty(); + migrateCachedSocket *cs; + + /* Check if we have an already cached socket for this ip:port pair. */ + name = sdscatlen(name,host->ptr,sdslen(host->ptr)); + name = sdscatlen(name,":",1); + name = sdscatlen(name,port->ptr,sdslen(port->ptr)); + cs = dictFetchValue(server.migrate_cached_sockets,name); + if (cs) { + sdsfree(name); + cs->last_use_time = server.unixtime; + return cs; + } + + /* No cached socket, create one. */ + if (dictSize(server.migrate_cached_sockets) == MIGRATE_SOCKET_CACHE_ITEMS) { + /* Too many items, drop one at random. */ + dictEntry *de = dictGetRandomKey(server.migrate_cached_sockets); + cs = dictGetVal(de); + connClose(cs->conn); + zfree(cs); + dictDelete(server.migrate_cached_sockets,dictGetKey(de)); + } + + /* Create the connection */ + conn = connCreate(server.el, connTypeOfCluster()); + if (connBlockingConnect(conn, host->ptr, atoi(port->ptr), timeout) + != C_OK) { + addReplyError(c,"-IOERR error or timeout connecting to the client"); + connClose(conn); + sdsfree(name); + return NULL; + } + connEnableTcpNoDelay(conn); + + /* Add to the cache and return it to the caller. */ + cs = zmalloc(sizeof(*cs)); + cs->conn = conn; + + cs->last_dbid = -1; + cs->last_use_time = server.unixtime; + dictAdd(server.migrate_cached_sockets,name,cs); + return cs; +} + +/* Free a migrate cached connection. */ +void migrateCloseSocket(robj *host, robj *port) { + sds name = sdsempty(); + migrateCachedSocket *cs; + + name = sdscatlen(name,host->ptr,sdslen(host->ptr)); + name = sdscatlen(name,":",1); + name = sdscatlen(name,port->ptr,sdslen(port->ptr)); + cs = dictFetchValue(server.migrate_cached_sockets,name); + if (!cs) { + sdsfree(name); + return; + } + + connClose(cs->conn); + zfree(cs); + dictDelete(server.migrate_cached_sockets,name); + sdsfree(name); +} + +void migrateCloseTimedoutSockets(void) { + dictIterator di; + dictEntry *de; + + dictInitSafeIterator(&di, server.migrate_cached_sockets); + while((de = dictNext(&di)) != NULL) { + migrateCachedSocket *cs = dictGetVal(de); + + if ((server.unixtime - cs->last_use_time) > MIGRATE_SOCKET_CACHE_TTL) { + connClose(cs->conn); + zfree(cs); + dictDelete(server.migrate_cached_sockets,dictGetKey(de)); + } + } + dictResetIterator(&di); +} + +/* MIGRATE host port key dbid timeout [COPY | REPLACE | AUTH password | + * AUTH2 username password] + * + * On in the multiple keys form: + * + * MIGRATE host port "" dbid timeout [COPY | REPLACE | AUTH password | + * AUTH2 username password] KEYS key1 key2 ... keyN */ +void migrateCommand(client *c) { + migrateCachedSocket *cs; + int copy = 0, replace = 0, j; + char *username = NULL; + char *password = NULL; + long timeout; + long dbid; + robj **kvArray = NULL; /* Objects to migrate. */ + robj **keyArray = NULL; /* Key names. */ + robj **newargv = NULL; /* Used to rewrite the command as DEL ... keys ... */ + rio cmd, payload; + int may_retry = 1; + int write_error = 0; + int argv_rewritten = 0; + + /* To support the KEYS option we need the following additional state. */ + int first_key = 3; /* Argument index of the first key. */ + int num_keys = 1; /* By default only migrate the 'key' argument. */ + + /* Parse additional options */ + for (j = 6; j < c->argc; j++) { + int moreargs = (c->argc-1) - j; + if (!strcasecmp(c->argv[j]->ptr,"copy")) { + copy = 1; + } else if (!strcasecmp(c->argv[j]->ptr,"replace")) { + replace = 1; + } else if (!strcasecmp(c->argv[j]->ptr,"auth")) { + if (!moreargs) { + addReplyErrorObject(c,shared.syntaxerr); + return; + } + j++; + password = c->argv[j]->ptr; + redactClientCommandArgument(c,j); + } else if (!strcasecmp(c->argv[j]->ptr,"auth2")) { + if (moreargs < 2) { + addReplyErrorObject(c,shared.syntaxerr); + return; + } + username = c->argv[++j]->ptr; + redactClientCommandArgument(c,j); + password = c->argv[++j]->ptr; + redactClientCommandArgument(c,j); + } else if (!strcasecmp(c->argv[j]->ptr,"keys")) { + if (sdslen(c->argv[3]->ptr) != 0) { + addReplyError(c, + "When using MIGRATE KEYS option, the key argument" + " must be set to the empty string"); + return; + } + first_key = j+1; + num_keys = c->argc - j - 1; + break; /* All the remaining args are keys. */ + } else { + addReplyErrorObject(c,shared.syntaxerr); + return; + } + } + + /* Sanity check */ + if (getLongFromObjectOrReply(c,c->argv[5],&timeout,NULL) != C_OK || + getLongFromObjectOrReply(c,c->argv[4],&dbid,NULL) != C_OK) + { + return; + } + if (timeout <= 0) timeout = 1000; + + /* Check if the keys are here. If at least one key is to migrate, do it + * otherwise if all the keys are missing reply with "NOKEY" to signal + * the caller there was nothing to migrate. We don't return an error in + * this case, since often this is due to a normal condition like the key + * expiring in the meantime. */ + kvArray = zrealloc(kvArray,sizeof(kvobj*)*num_keys); + keyArray = zrealloc(keyArray,sizeof(robj*)*num_keys); + int num_exists = 0; + + for (j = 0; j < num_keys; j++) { + if ((kvArray[num_exists] = lookupKeyRead(c->db,c->argv[first_key+j])) != NULL) { + keyArray[num_exists] = c->argv[first_key+j]; + num_exists++; + } + } + num_keys = num_exists; + if (num_keys == 0) { + zfree(kvArray); zfree(keyArray); + addReplySds(c,sdsnew("+NOKEY\r\n")); + return; + } + + try_again: + write_error = 0; + + /* Connect */ + cs = migrateGetSocket(c,c->argv[1],c->argv[2],timeout); + if (cs == NULL) { + zfree(kvArray); zfree(keyArray); + return; /* error sent to the client by migrateGetSocket() */ + } + + rioInitWithBuffer(&cmd,sdsempty()); + + /* Authentication */ + if (password) { + int arity = username ? 3 : 2; + serverAssertWithInfo(c,NULL,rioWriteBulkCount(&cmd,'*',arity)); + serverAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,"AUTH",4)); + if (username) { + serverAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,username, + sdslen(username))); + } + serverAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,password, + sdslen(password))); + } + + /* Send the SELECT command if the current DB is not already selected. */ + int select = cs->last_dbid != dbid; /* Should we emit SELECT? */ + if (select) { + serverAssertWithInfo(c,NULL,rioWriteBulkCount(&cmd,'*',2)); + serverAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,"SELECT",6)); + serverAssertWithInfo(c,NULL,rioWriteBulkLongLong(&cmd,dbid)); + } + + int non_expired = 0; /* Number of keys that we'll find non expired. + Note that serializing large keys may take some time + so certain keys that were found non expired by the + lookupKey() function, may be expired later. */ + + /* Create RESTORE payload and generate the protocol to call the command. */ + for (j = 0; j < num_keys; j++) { + long long ttl = 0; + long long expireat = kvobjGetExpire(kvArray[j]); + + if (expireat != -1) { + ttl = expireat-commandTimeSnapshot(); + if (ttl < 0) { + continue; + } + if (ttl < 1) ttl = 1; + } + + /* Relocate valid (non expired) keys and values into the array in successive + * positions to remove holes created by the keys that were present + * in the first lookup but are now expired after the second lookup. */ + kvArray[non_expired] = kvArray[j]; + keyArray[non_expired++] = keyArray[j]; + + serverAssertWithInfo(c,NULL, + rioWriteBulkCount(&cmd,'*',replace ? 5 : 4)); + + if (server.cluster_enabled) + serverAssertWithInfo(c,NULL, + rioWriteBulkString(&cmd,"RESTORE-ASKING",14)); + else + serverAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,"RESTORE",7)); + serverAssertWithInfo(c,NULL,sdsEncodedObject(keyArray[j])); + serverAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,keyArray[j]->ptr, + sdslen(keyArray[j]->ptr))); + serverAssertWithInfo(c,NULL,rioWriteBulkLongLong(&cmd,ttl)); + + /* Emit the payload argument, that is the serialized object using + * the DUMP format. */ + createDumpPayload(&payload,kvArray[j],keyArray[j],dbid,0); + serverAssertWithInfo(c,NULL, + rioWriteBulkString(&cmd,payload.io.buffer.ptr, + sdslen(payload.io.buffer.ptr))); + sdsfree(payload.io.buffer.ptr); + + /* Add the REPLACE option to the RESTORE command if it was specified + * as a MIGRATE option. */ + if (replace) + serverAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,"REPLACE",7)); + } + + /* Fix the actual number of keys we are migrating. */ + num_keys = non_expired; + + /* Transfer the query to the other node in 64K chunks. */ + errno = 0; + { + 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 = connSyncWrite(cs->conn,buf+pos,towrite,timeout); + if (nwritten != (signed)towrite) { + write_error = 1; + goto socket_err; + } + pos += nwritten; + } + } + + char buf0[1024]; /* Auth reply. */ + char buf1[1024]; /* Select reply. */ + char buf2[1024]; /* Restore reply. */ + + /* Read the AUTH reply if needed. */ + if (password && connSyncReadLine(cs->conn, buf0, sizeof(buf0), timeout) <= 0) + goto socket_err; + + /* Read the SELECT reply if needed. */ + if (select && connSyncReadLine(cs->conn, buf1, sizeof(buf1), timeout) <= 0) + goto socket_err; + + /* Read the RESTORE replies. */ + int error_from_target = 0; + int socket_error = 0; + int del_idx = 1; /* Index of the key argument for the replicated DEL op. */ + + /* Allocate the new argument vector that will replace the current command, + * to propagate the MIGRATE as a DEL command (if no COPY option was given). + * We allocate num_keys+1 because the additional argument is for "DEL" + * command name itself. */ + if (!copy) newargv = zmalloc(sizeof(robj*)*(num_keys+1)); + + for (j = 0; j < num_keys; j++) { + if (connSyncReadLine(cs->conn, buf2, sizeof(buf2), timeout) <= 0) { + socket_error = 1; + break; + } + if ((password && buf0[0] == '-') || + (select && buf1[0] == '-') || + buf2[0] == '-') + { + /* On error assume that last_dbid is no longer valid. */ + if (!error_from_target) { + cs->last_dbid = -1; + char *errbuf; + if (password && buf0[0] == '-') errbuf = buf0; + else if (select && buf1[0] == '-') errbuf = buf1; + else errbuf = buf2; + + error_from_target = 1; + addReplyErrorFormat(c,"Target instance replied with error: %s", + errbuf+1); + } + } else { + if (!copy) { + /* No COPY option: remove the local key, signal the change. */ + dbDelete(c->db,keyArray[j]); + keyModified(c,c->db,keyArray[j],NULL,1); + notifyKeyspaceEvent(NOTIFY_GENERIC,"del",keyArray[j],c->db->id); + server.dirty++; + + /* Populate the argument vector to replace the old one. */ + newargv[del_idx++] = keyArray[j]; + incrRefCount(keyArray[j]); + } + } + } + + /* On socket error, if we want to retry, do it now before rewriting the + * command vector. We only retry if we are sure nothing was processed + * and we failed to read the first reply (j == 0 test). */ + if (!error_from_target && socket_error && j == 0 && may_retry && + errno != ETIMEDOUT) + { + goto socket_err; /* A retry is guaranteed because of tested conditions.*/ + } + + /* On socket errors, close the migration socket now that we still have + * the original host/port in the ARGV. Later the original command may be + * rewritten to DEL and will be too later. */ + if (socket_error) migrateCloseSocket(c->argv[1],c->argv[2]); + + if (!copy) { + /* Translate MIGRATE as DEL for replication/AOF. Note that we do + * this only for the keys for which we received an acknowledgement + * from the receiving Redis server, by using the del_idx index. */ + if (del_idx > 1) { + newargv[0] = createStringObject("DEL",3); + /* Note that the following call takes ownership of newargv. */ + replaceClientCommandVector(c,del_idx,newargv); + argv_rewritten = 1; + } else { + /* No key transfer acknowledged, no need to rewrite as DEL. */ + zfree(newargv); + } + newargv = NULL; /* Make it safe to call zfree() on it in the future. */ + } + + /* If we are here and a socket error happened, we don't want to retry. + * Just signal the problem to the client, but only do it if we did not + * already queue a different error reported by the destination server. */ + if (!error_from_target && socket_error) { + may_retry = 0; + goto socket_err; + } + + if (!error_from_target) { + /* Success! Update the last_dbid in migrateCachedSocket, so that we can + * avoid SELECT the next time if the target DB is the same. Reply +OK. + * + * Note: If we reached this point, even if socket_error is true + * still the SELECT command succeeded (otherwise the code jumps to + * socket_err label. */ + cs->last_dbid = dbid; + addReply(c,shared.ok); + } else { + /* On error we already sent it in the for loop above, and set + * the currently selected socket to -1 to force SELECT the next time. */ + } + + sdsfree(cmd.io.buffer.ptr); + zfree(kvArray); zfree(keyArray); zfree(newargv); + return; + +/* On socket errors we try to close the cached socket and try again. + * It is very common for the cached socket to get closed, if just reopening + * it works it's a shame to notify the error to the caller. */ + socket_err: + /* Cleanup we want to perform in both the retry and no retry case. + * Note: Closing the migrate socket will also force SELECT next time. */ + sdsfree(cmd.io.buffer.ptr); + + /* If the command was rewritten as DEL and there was a socket error, + * we already closed the socket earlier. While migrateCloseSocket() + * is idempotent, the host/port arguments are now gone, so don't do it + * again. */ + if (!argv_rewritten) migrateCloseSocket(c->argv[1],c->argv[2]); + zfree(newargv); + newargv = NULL; /* This will get reallocated on retry. */ + + /* Retry only if it's not a timeout and we never attempted a retry + * (or the code jumping here did not set may_retry to zero). */ + if (errno != ETIMEDOUT && may_retry) { + may_retry = 0; + goto try_again; + } + + /* Cleanup we want to do if no retry is attempted. */ + zfree(kvArray); zfree(keyArray); + addReplyErrorSds(c, sdscatprintf(sdsempty(), + "-IOERR error or timeout %s to target instance", + write_error ? "writing" : "reading")); + return; +} + +/* Cluster node sanity check. Returns C_OK if the node id + * is valid an C_ERR otherwise. */ +int verifyClusterNodeId(const char *name, int length) { + if (length != CLUSTER_NAMELEN) return C_ERR; + for (int i = 0; i < length; i++) { + if (name[i] >= 'a' && name[i] <= 'z') continue; + if (name[i] >= '0' && name[i] <= '9') continue; + return C_ERR; + } + return C_OK; +} + +int isValidAuxChar(int c) { + return isalnum(c) || (strchr("!#$%&()*+:;<>?@[]^{|}~", c) == NULL); +} + +int isValidAuxString(char *s, unsigned int length) { + for (unsigned i = 0; i < length; i++) { + if (!isValidAuxChar(s[i])) return 0; + } + return 1; +} + +void clusterCommandMyId(client *c) { + char *name = clusterNodeGetName(getMyClusterNode()); + if (name) { + addReplyBulkCBuffer(c,name, CLUSTER_NAMELEN); + } else { + addReplyError(c, "No ID yet"); + } +} + +char* getMyClusterId(void) { + return clusterNodeGetName(getMyClusterNode()); +} + +void clusterCommandMyShardId(client *c) { + char *sid = clusterNodeGetShardId(getMyClusterNode()); + if (sid) { + addReplyBulkCBuffer(c,sid, CLUSTER_NAMELEN); + } else { + addReplyError(c, "No shard ID yet"); + } +} + +/* When a cluster command is called, we need to decide whether to return TLS info or + * non-TLS info by the client's connection type. However if the command is called by + * a Lua script or RM_call, there is no connection in the fake client, so we use + * server.current_client here to get the real client if available. And if it is not + * available (modules may call commands without a real client), we return the default + * info, which is determined by server.tls_cluster. */ +static int shouldReturnTlsInfo(void) { + if (server.current_client && server.current_client->conn) { + return connIsTLS(server.current_client->conn); + } else { + return server.tls_cluster; + } +} + +unsigned int countKeysInSlot(unsigned int slot) { + return kvstoreDictSize(server.db->keys, slot); +} + +/* Add detailed information of a node to the output buffer of the given client. */ +void addNodeDetailsToShardReply(client *c, clusterNode *node) { + + int reply_count = 0; + char *hostname; + void *node_replylen = addReplyDeferredLen(c); + + addReplyBulkCString(c, "id"); + addReplyBulkCBuffer(c, clusterNodeGetName(node), CLUSTER_NAMELEN); + reply_count++; + + if (clusterNodeTcpPort(node)) { + addReplyBulkCString(c, "port"); + addReplyLongLong(c, clusterNodeTcpPort(node)); + reply_count++; + } + + if (clusterNodeTlsPort(node)) { + addReplyBulkCString(c, "tls-port"); + addReplyLongLong(c, clusterNodeTlsPort(node)); + reply_count++; + } + + addReplyBulkCString(c, "ip"); + addReplyBulkCString(c, clusterNodeIp(node)); + reply_count++; + + addReplyBulkCString(c, "endpoint"); + addReplyBulkCString(c, clusterNodePreferredEndpoint(node)); + reply_count++; + + hostname = clusterNodeHostname(node); + if (hostname != NULL && *hostname != '\0') { + addReplyBulkCString(c, "hostname"); + addReplyBulkCString(c, hostname); + reply_count++; + } + + long long node_offset; + if (clusterNodeIsMyself(node)) { + node_offset = clusterNodeIsSlave(node) ? replicationGetSlaveOffset() : server.master_repl_offset; + } else { + node_offset = clusterNodeReplOffset(node); + } + + addReplyBulkCString(c, "role"); + addReplyBulkCString(c, clusterNodeIsSlave(node) ? "replica" : "master"); + reply_count++; + + addReplyBulkCString(c, "replication-offset"); + addReplyLongLong(c, node_offset); + reply_count++; + + addReplyBulkCString(c, "health"); + const char *health_msg = NULL; + if (clusterNodeIsFailing(node)) { + health_msg = "fail"; + } else if (clusterNodeIsSlave(node) && node_offset == 0) { + health_msg = "loading"; + } else { + health_msg = "online"; + } + addReplyBulkCString(c, health_msg); + reply_count++; + + setDeferredMapLen(c, node_replylen, reply_count); +} + +static clusterNode *clusterGetMasterFromShard(void *shard_handle) { + clusterNode *n = NULL; + void *node_it = clusterShardHandleGetNodeIterator(shard_handle); + while((n = clusterShardNodeIteratorNext(node_it)) != NULL) { + if (!clusterNodeIsFailing(n)) { + break; + } + } + clusterShardNodeIteratorFree(node_it); + if (!n) return NULL; + return clusterNodeGetMaster(n); +} + +/* Add the shard reply of a single shard based off the given primary node. */ +void addShardReplyForClusterShards(client *c, void *shard_handle) { + serverAssert(clusterGetShardNodeCount(shard_handle) > 0); + addReplyMapLen(c, 2); + addReplyBulkCString(c, "slots"); + + /* Use slot_info_pairs from the primary only */ + clusterNode *master_node = clusterGetMasterFromShard(shard_handle); + + if (master_node && clusterNodeHasSlotInfo(master_node)) { + serverAssert((clusterNodeSlotInfoCount(master_node) % 2) == 0); + addReplyArrayLen(c, clusterNodeSlotInfoCount(master_node)); + for (int i = 0; i < clusterNodeSlotInfoCount(master_node); i++) + addReplyLongLong(c, (unsigned long)clusterNodeSlotInfoEntry(master_node, i)); + } else { + /* If no slot info pair is provided, the node owns no slots */ + addReplyArrayLen(c, 0); + } + + addReplyBulkCString(c, "nodes"); + addReplyArrayLen(c, clusterGetShardNodeCount(shard_handle)); + void *node_it = clusterShardHandleGetNodeIterator(shard_handle); + for (clusterNode *n = clusterShardNodeIteratorNext(node_it); n != NULL; n = clusterShardNodeIteratorNext(node_it)) { + addNodeDetailsToShardReply(c, n); + clusterFreeNodesSlotsInfo(n); + } + clusterShardNodeIteratorFree(node_it); +} + +/* Add to the output buffer of the given client, an array of slot (start, end) + * pair owned by the shard, also the primary and set of replica(s) along with + * information about each node. */ +void clusterCommandShards(client *c) { + addReplyArrayLen(c, clusterGetShardCount()); + /* This call will add slot_info_pairs to all nodes */ + clusterGenNodesSlotsInfo(0); + dictIterator *shard_it = clusterGetShardIterator(); + for(void *shard_handle = clusterNextShardHandle(shard_it); shard_handle != NULL; shard_handle = clusterNextShardHandle(shard_it)) { + addShardReplyForClusterShards(c, shard_handle); + } + clusterFreeShardIterator(shard_it); +} + +void clusterCommandHelp(client *c) { + const char *help[] = { + "COUNTKEYSINSLOT <slot>", + " Return the number of keys in <slot>.", + "GETKEYSINSLOT <slot> <count>", + " Return key names stored by current node in a slot.", + "INFO", + " Return information about the cluster.", + "KEYSLOT <key>", + " Return the hash slot for <key>.", + "MYID", + " Return the node id.", + "MYSHARDID", + " Return the node's shard id.", + "NODES", + " Return cluster configuration seen by node. Output format:", + " <id> <ip:port@bus-port[,hostname]> <flags> <master> <pings> <pongs> <epoch> <link> <slot> ...", + "REPLICAS <node-id>", + " Return <node-id> replicas.", + "SLOTS", + " Return information about slots range mappings. Each range is made of:", + " start, end, master and replicas IP addresses, ports and ids", + "SLOT-STATS", + " Return an array of slot usage statistics for slots assigned to the current node.", + "SHARDS", + " Return information about slot range mappings and the nodes associated with them.", + NULL + }; + + addExtendedReplyHelp(c, help, clusterCommandExtendedHelp()); +} + +void clusterCommand(client *c) { + if (server.cluster_enabled == 0) { + addReplyError(c,"This instance has cluster support disabled"); + return; + } + + if (c->argc == 2 && !strcasecmp(c->argv[1]->ptr,"help")) { + clusterCommandHelp(c); + } else if (!strcasecmp(c->argv[1]->ptr,"nodes") && c->argc == 2) { + /* CLUSTER NODES */ + /* Report TLS ports to TLS client, and report non-TLS port to non-TLS client. */ + sds nodes = clusterGenNodesDescription(c, 0, shouldReturnTlsInfo()); + addReplyVerbatim(c,nodes,sdslen(nodes),"txt"); + sdsfree(nodes); + } else if (!strcasecmp(c->argv[1]->ptr,"myid") && c->argc == 2) { + /* CLUSTER MYID */ + clusterCommandMyId(c); + } else if (!strcasecmp(c->argv[1]->ptr,"myshardid") && c->argc == 2) { + /* CLUSTER MYSHARDID */ + clusterCommandMyShardId(c); + } else if (!strcasecmp(c->argv[1]->ptr,"slots") && c->argc == 2) { + /* CLUSTER SLOTS */ + clusterCommandSlots(c); + } else if (!strcasecmp(c->argv[1]->ptr,"shards") && c->argc == 2) { + /* CLUSTER SHARDS */ + clusterCommandShards(c); + } else if (!strcasecmp(c->argv[1]->ptr,"info") && c->argc == 2) { + /* CLUSTER INFO */ + + sds info = genClusterInfoString(); + + /* Produce the reply protocol. */ + addReplyVerbatim(c,info,sdslen(info),"txt"); + sdsfree(info); + } else if (!strcasecmp(c->argv[1]->ptr,"keyslot") && c->argc == 3) { + /* CLUSTER KEYSLOT <key> */ + sds key = c->argv[2]->ptr; + + addReplyLongLong(c,keyHashSlot(key,sdslen(key))); + } else if (!strcasecmp(c->argv[1]->ptr,"countkeysinslot") && c->argc == 3) { + /* CLUSTER COUNTKEYSINSLOT <slot> */ + long long slot; + + if (getLongLongFromObjectOrReply(c,c->argv[2],&slot,NULL) != C_OK) + return; + if (slot < 0 || slot >= CLUSTER_SLOTS) { + addReplyError(c,"Invalid slot"); + return; + } + + if (!clusterCanAccessKeysInSlot(slot)) { + addReplyLongLong(c, 0); + return; + } + addReplyLongLong(c,countKeysInSlot(slot)); + } else if (!strcasecmp(c->argv[1]->ptr,"getkeysinslot") && c->argc == 4) { + /* CLUSTER GETKEYSINSLOT <slot> <count> */ + long long maxkeys, slot; + + if (getLongLongFromObjectOrReply(c,c->argv[2],&slot,NULL) != C_OK) + return; + if (getLongLongFromObjectOrReply(c,c->argv[3],&maxkeys,NULL) + != C_OK) + return; + if (slot < 0 || slot >= CLUSTER_SLOTS || maxkeys < 0) { + addReplyError(c,"Invalid slot or number of keys"); + return; + } + + if (!clusterCanAccessKeysInSlot(slot)) { + addReplyArrayLen(c, 0); + return; + } + + unsigned int keys_in_slot = countKeysInSlot(slot); + unsigned int numkeys = maxkeys > keys_in_slot ? keys_in_slot : maxkeys; + addReplyArrayLen(c,numkeys); + kvstoreDictIterator kvs_di; + dictEntry *de = NULL; + kvstoreInitDictIterator(&kvs_di, server.db->keys, slot); + for (unsigned int i = 0; i < numkeys; i++) { + de = kvstoreDictIteratorNext(&kvs_di); + serverAssert(de != NULL); + sds sdskey = kvobjGetKey(dictGetKV(de)); + addReplyBulkCBuffer(c, sdskey, sdslen(sdskey)); + } + kvstoreResetDictIterator(&kvs_di); + } else if ((!strcasecmp(c->argv[1]->ptr,"slaves") || + !strcasecmp(c->argv[1]->ptr,"replicas")) && c->argc == 3) { + /* CLUSTER SLAVES <NODE ID> */ + /* CLUSTER REPLICAS <NODE ID> */ + clusterNode *n = clusterLookupNode(c->argv[2]->ptr, sdslen(c->argv[2]->ptr)); + int j; + + /* Lookup the specified node in our table. */ + if (!n) { + addReplyErrorFormat(c,"Unknown node %s", (char*)c->argv[2]->ptr); + return; + } + + if (clusterNodeIsSlave(n)) { + addReplyError(c,"The specified node is not a master"); + return; + } + + /* Report TLS ports to TLS client, and report non-TLS port to non-TLS client. */ + addReplyArrayLen(c, clusterNodeNumSlaves(n)); + for (j = 0; j < clusterNodeNumSlaves(n); j++) { + sds ni = clusterGenNodeDescription(c, clusterNodeGetSlave(n, j), shouldReturnTlsInfo()); + addReplyBulkCString(c,ni); + sdsfree(ni); + } + } else if (!strcasecmp(c->argv[1]->ptr, "migration")) { + clusterMigrationCommand(c); + } else if (!strcasecmp(c->argv[1]->ptr,"syncslots") && c->argc >= 3) { + clusterSyncSlotsCommand(c); + } else if(!clusterCommandSpecial(c)) { + addReplySubcommandSyntaxError(c); + return; + } +} + +/* Extract slot number from keys in a keys_result structure and return to caller. + * Returns: + * - The slot number if all keys belong to the same slot + * - INVALID_CLUSTER_SLOT if there are no keys or cluster is disabled + * - CLUSTER_CROSSSLOT if keys belong to different slots (cross-slot error) */ +int extractSlotFromKeysResult(robj **argv, getKeysResult *keys_result) { + if (keys_result->numkeys == 0 || !server.cluster_enabled) + return INVALID_CLUSTER_SLOT; + + int first_slot = INVALID_CLUSTER_SLOT; + for (int j = 0; j < keys_result->numkeys; j++) { + robj *this_key = argv[keys_result->keys[j].pos]; + int this_slot = (int)keyHashSlot((char*)this_key->ptr, sdslen(this_key->ptr)); + + if (first_slot == INVALID_CLUSTER_SLOT) + first_slot = this_slot; + else if (first_slot != this_slot) { + return CLUSTER_CROSSSLOT; + } + } + return first_slot; +} + +/* Return the pointer to the cluster node that is able to serve the command. + * For the function to succeed the command should only target either: + * + * 1) A single key (even multiple times like RPOPLPUSH mylist mylist). + * 2) Multiple keys in the same hash slot, while the slot is stable (no + * resharding in progress). + * + * On success the function returns the node that is able to serve the request. + * If the node is not 'myself' a redirection must be performed. The kind of + * redirection is specified setting the integer passed by reference + * 'error_code', which will be set to CLUSTER_REDIR_ASK or + * CLUSTER_REDIR_MOVED. + * + * When the node is 'myself' 'error_code' is set to CLUSTER_REDIR_NONE. + * + * If the command fails NULL is returned, and the reason of the failure is + * provided via 'error_code', which will be set to: + * + * CLUSTER_REDIR_CROSS_SLOT if the request contains multiple keys that + * don't belong to the same hash slot. + * + * CLUSTER_REDIR_UNSTABLE if the request contains multiple keys + * belonging to the same slot, but the slot is not stable (in migration or + * importing state, likely because a resharding is in progress). + * + * CLUSTER_REDIR_DOWN_UNBOUND if the request addresses a slot which is + * not bound to any node. In this case the cluster global state should be + * already "down" but it is fragile to rely on the update of the global state, + * so we also handle it here. + * + * CLUSTER_REDIR_DOWN_STATE and CLUSTER_REDIR_DOWN_RO_STATE if the cluster is + * down but the user attempts to execute a command that addresses one or more keys. */ +clusterNode *getNodeByQuery(client *c, struct redisCommand *cmd, robj **argv, int argc, int *hashslot, + getKeysResult *keys_result, uint8_t read_error, uint64_t cmd_flags, int *error_code) +{ + clusterNode *myself = getMyClusterNode(); + clusterNode *n = NULL; + robj *firstkey = NULL; + int multiple_keys = 0; + multiState *ms, _ms; + pendingCommand mc; + pendingCommand *mcp = &mc; + int i, slot = 0, migrating_slot = 0, importing_slot = 0, missing_keys = 0, + existing_keys = 0; + int pubsubshard_included = 0; /* Flag to indicate if a pubsub shard cmd is included. */ + + /* Allow any key to be set if a module disabled cluster redirections. */ + if (server.cluster_module_flags & CLUSTER_MODULE_FLAG_NO_REDIRECTION) + return myself; + + /* Set error code optimistically for the base case. */ + if (error_code) *error_code = CLUSTER_REDIR_NONE; + + /* Modules can turn off Redis Cluster redirection: this is useful + * when writing a module that implements a completely different + * distributed system. */ + + /* We handle all the cases as if they were EXEC commands, so we have + * a common code path for everything */ + if (cmd->proc == execCommand) { + /* If CLIENT_MULTI flag is not set EXEC is just going to return an + * error. */ + if (!(c->flags & CLIENT_MULTI)) return myself; + ms = &c->mstate; + } else { + /* 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 = &mcp; + _ms.count = 1; + + /* Properly initialize the fake pendingCommand */ + initPendingCommand(&mc); + mc.argv = argv; + mc.argc = argc; + mc.cmd = cmd; + mc.slot = hashslot ? *hashslot : INVALID_CLUSTER_SLOT; + mc.read_error = read_error; + if (keys_result) { + mc.keys_result = *keys_result; + mc.flags |= PENDING_CMD_KEYS_RESULT_VALID; + } + } + + /* Check that all the keys are in the same hash slot, and obtain this + * slot and the node associated. */ + for (i = 0; i < ms->count; i++) { + struct redisCommand *mcmd; + robj **margv; + int margc, j; + keyReference *keyindex; + + pendingCommand *pcmd = ms->commands[i]; + + mcmd = pcmd->cmd; + margc = pcmd->argc; + margv = pcmd->argv; + + /* Only valid for sharded pubsub as regular pubsub can operate on any node and bypasses this layer. */ + if (!pubsubshard_included && + doesCommandHaveChannelsWithFlags(mcmd, CMD_CHANNEL_PUBLISH | CMD_CHANNEL_SUBSCRIBE)) + { + pubsubshard_included = 1; + } + + /* If we have a cached keys result from preprocessCommand(), use it. + * Otherwise, extract keys result. */ + int use_cache_keys_result = pcmd->flags & PENDING_CMD_KEYS_RESULT_VALID; + getKeysResult result = GETKEYS_RESULT_INIT; + if (use_cache_keys_result) + result = pcmd->keys_result; + else + getKeysFromCommand(mcmd,margv,margc,&result); + keyindex = result.keys; + + for (j = 0; j < result.numkeys; j++) { + /* The command has keys and was checked for cross-slot between its keys in preprocessCommand() */ + if (pcmd->read_error == CLIENT_READ_CROSS_SLOT) { + /* Error: multiple keys from different slots. */ + if (error_code) + *error_code = CLUSTER_REDIR_CROSS_SLOT; + return NULL; + } + + robj *thiskey = margv[keyindex[j].pos]; + int thisslot = pcmd->slot; + if (thisslot == INVALID_CLUSTER_SLOT) + thisslot = keyHashSlot((char*)thiskey->ptr, sdslen(thiskey->ptr)); + + if (firstkey == NULL) { + /* This is the first key we see. Check what is the slot + * and node. */ + firstkey = thiskey; + slot = thisslot; + n = getNodeBySlot(slot); + + /* Error: If a slot is not served, we are in "cluster down" + * state. However the state is yet to be updated, so this was + * not trapped earlier in processCommand(). Report the same + * error to the client. */ + if (n == NULL) { + if (!use_cache_keys_result) getKeysFreeResult(&result); + if (error_code) + *error_code = CLUSTER_REDIR_DOWN_UNBOUND; + return NULL; + } + + /* If we are migrating or importing this slot, we need to check + * if we have all the keys in the request (the only way we + * can safely serve the request, otherwise we return a TRYAGAIN + * error). To do so we set the importing/migrating state and + * increment a counter for every missing key. */ + if (n == myself && + getMigratingSlotDest(slot) != NULL) + { + migrating_slot = 1; + } else if (getImportingSlotSource(slot) != NULL) { + importing_slot = 1; + } + } else { + /* If it is not the first key/channel, make sure it is exactly + * the same key/channel as the first we saw. */ + if (slot != thisslot) { + /* Error: multiple keys from different slots. */ + if (!use_cache_keys_result) getKeysFreeResult(&result); + if (error_code) + *error_code = CLUSTER_REDIR_CROSS_SLOT; + return NULL; + } + if (importing_slot && !multiple_keys && !equalStringObjects(firstkey,thiskey)) { + /* Flag this request as one with multiple different + * keys/channels when the slot is in importing state. */ + multiple_keys = 1; + } + } + + /* Migrating / Importing slot? Count keys we don't have. + * If it is pubsubshard command, it isn't required to check + * the channel being present or not in the node during the + * slot migration, the channel will be served from the source + * node until the migration completes with CLUSTER SETSLOT <slot> + * NODE <node-id>. */ + int flags = LOOKUP_NOTOUCH | LOOKUP_NOSTATS | LOOKUP_NONOTIFY | LOOKUP_NOEXPIRE; + if ((migrating_slot || importing_slot) && !pubsubshard_included) + { + if (lookupKeyReadWithFlags(&server.db[0], thiskey, flags) == NULL) missing_keys++; + else existing_keys++; + } + } + if (!use_cache_keys_result) getKeysFreeResult(&result); + } + + /* No key at all in command? then we can serve the request + * without redirections or errors in all the cases. */ + if (n == NULL) return myself; + + /* Cluster is globally down but we got keys? We only serve the request + * if it is a read command and when allow_reads_when_down is enabled. */ + if (!isClusterHealthy()) { + if (pubsubshard_included) { + if (!server.cluster_allow_pubsubshard_when_down) { + if (error_code) *error_code = CLUSTER_REDIR_DOWN_STATE; + return NULL; + } + } else if (!server.cluster_allow_reads_when_down) { + /* The cluster is configured to block commands when the + * cluster is down. */ + if (error_code) *error_code = CLUSTER_REDIR_DOWN_STATE; + return NULL; + } else if (cmd_flags & CMD_WRITE) { + /* The cluster is configured to allow read only commands */ + if (error_code) *error_code = CLUSTER_REDIR_DOWN_RO_STATE; + return NULL; + } else { + /* Fall through and allow the command to be executed: + * this happens when server.cluster_allow_reads_when_down is + * true and the command is not a write command */ + } + } + + /* Return the hashslot by reference. */ + if (hashslot) *hashslot = slot; + + /* MIGRATE always works in the context of the local node if the slot + * is open (migrating or importing state). We need to be able to freely + * move keys among instances in this case. */ + if ((migrating_slot || importing_slot) && cmd->proc == migrateCommand) + return myself; + + /* If we don't have all the keys and we are migrating the slot, send + * an ASK redirection or TRYAGAIN. */ + if (migrating_slot && missing_keys) { + /* If we have keys but we don't have all keys, we return TRYAGAIN */ + if (existing_keys) { + if (error_code) *error_code = CLUSTER_REDIR_UNSTABLE; + return NULL; + } else { + if (error_code) *error_code = CLUSTER_REDIR_ASK; + return getMigratingSlotDest(slot); + } + } + + /* If we are receiving the slot, and the client correctly flagged the + * request as "ASKING", we can serve the request. However if the request + * involves multiple keys and we don't have them all, the only option is + * to send a TRYAGAIN error. */ + if (importing_slot && + (c->flags & CLIENT_ASKING || cmd_flags & CMD_ASKING)) + { + if (multiple_keys && missing_keys) { + if (error_code) *error_code = CLUSTER_REDIR_UNSTABLE; + return NULL; + } else { + return myself; + } + } + + /* Handle the read-only client case reading from a slave: if this + * node is a slave and the request is about a hash slot our master + * is serving, we can reply without redirection. */ + int is_write_command = (cmd_flags & CMD_WRITE) || + (c->cmd->proc == execCommand && (c->mstate.cmd_flags & CMD_WRITE)); + if (((c->flags & CLIENT_READONLY) || pubsubshard_included) && + !is_write_command && + clusterNodeIsSlave(myself) && + clusterNodeGetSlaveof(myself) == n) + { + return myself; + } + + /* Base case: just return the right node. However, if this node is not + * myself, set error_code to MOVED since we need to issue a redirection. */ + if (n != myself && error_code) *error_code = CLUSTER_REDIR_MOVED; + return n; +} + +/* Send the client the right redirection code, according to error_code + * that should be set to one of CLUSTER_REDIR_* macros. + * + * If CLUSTER_REDIR_ASK or CLUSTER_REDIR_MOVED error codes + * are used, then the node 'n' should not be NULL, but should be the + * node we want to mention in the redirection. Moreover hashslot should + * be set to the hash slot that caused the redirection. */ +void clusterRedirectClient(client *c, clusterNode *n, int hashslot, int error_code) { + if (error_code == CLUSTER_REDIR_CROSS_SLOT) { + addReplyError(c,"-CROSSSLOT Keys in request don't hash to the same slot"); + } else if (error_code == CLUSTER_REDIR_UNSTABLE) { + /* The request spawns multiple keys in the same slot, + * but the slot is not "stable" currently as there is + * a migration or import in progress. */ + addReplyError(c,"-TRYAGAIN Multiple keys request during rehashing of slot"); + } else if (error_code == CLUSTER_REDIR_DOWN_STATE) { + addReplyError(c,"-CLUSTERDOWN The cluster is down"); + } else if (error_code == CLUSTER_REDIR_DOWN_RO_STATE) { + addReplyError(c,"-CLUSTERDOWN The cluster is down and only accepts read commands"); + } else if (error_code == CLUSTER_REDIR_DOWN_UNBOUND) { + addReplyError(c,"-CLUSTERDOWN Hash slot not served"); + } else if (error_code == CLUSTER_REDIR_MOVED || + error_code == CLUSTER_REDIR_ASK) + { + /* Report TLS ports to TLS client, and report non-TLS port to non-TLS client. */ + int port = clusterNodeClientPort(n, shouldReturnTlsInfo()); + addReplyErrorSds(c,sdscatprintf(sdsempty(), + "-%s %d %s:%d", + (error_code == CLUSTER_REDIR_ASK) ? "ASK" : "MOVED", + hashslot, clusterNodePreferredEndpoint(n), port)); + } else { + serverPanic("getNodeByQuery() unknown error."); + } +} + +/* This function is called by the function processing clients incrementally + * to detect timeouts, in order to handle the following case: + * + * 1) A client blocks with BLPOP or similar blocking operation. + * 2) The master migrates the hash slot elsewhere or turns into a slave. + * 3) The client may remain blocked forever (or up to the max timeout time) + * waiting for a key change that will never happen. + * + * If the client is found to be blocked into a hash slot this node no + * longer handles, the client is sent a redirection error, and the function + * returns 1. Otherwise 0 is returned and no operation is performed. */ +int clusterRedirectBlockedClientIfNeeded(client *c) { + clusterNode *myself = getMyClusterNode(); + if (c->flags & CLIENT_BLOCKED && + (c->bstate.btype == BLOCKED_LIST || + c->bstate.btype == BLOCKED_ZSET || + c->bstate.btype == BLOCKED_STREAM || + c->bstate.btype == BLOCKED_MODULE)) + { + dictEntry *de; + dictIterator di; + + /* If the cluster is down, unblock the client with the right error. + * If the cluster is configured to allow reads on cluster down, we + * still want to emit this error since a write will be required + * to unblock them which may never come. */ + if (!isClusterHealthy()) { + clusterRedirectClient(c,NULL,0,CLUSTER_REDIR_DOWN_STATE); + return 1; + } + + /* If the client is blocked on module, but not on a specific key, + * don't unblock it (except for the CLUSTER_FAIL case above). */ + if (c->bstate.btype == BLOCKED_MODULE && !moduleClientIsBlockedOnKeys(c)) + return 0; + + /* All keys must belong to the same slot, so check first key only. */ + dictInitIterator(&di, c->bstate.keys); + if ((de = dictNext(&di)) != NULL) { + robj *key = dictGetKey(de); + int slot = keyHashSlot((char*)key->ptr, sdslen(key->ptr)); + clusterNode *node = getNodeBySlot(slot); + + /* if the client is read-only and attempting to access key that our + * replica can handle, allow it. */ + if ((c->flags & CLIENT_READONLY) && + !(c->lastcmd->flags & CMD_WRITE) && + clusterNodeIsSlave(myself) && clusterNodeGetSlaveof(myself) == node) + { + node = myself; + } + + /* We send an error and unblock the client if: + * 1) The slot is unassigned, emitting a cluster down error. + * 2) The slot is not handled by this node, nor being imported. */ + if (node != myself && getImportingSlotSource(slot) == NULL) + { + if (node == NULL) { + clusterRedirectClient(c,NULL,0, + CLUSTER_REDIR_DOWN_UNBOUND); + } else { + clusterRedirectClient(c,node,slot, + CLUSTER_REDIR_MOVED); + } + dictResetIterator(&di); + return 1; + } + } + dictResetIterator(&di); + } + return 0; +} + +/* Returns an indication if the replica node is fully available + * and should be listed in CLUSTER SLOTS response. + * Returns 1 for available nodes, 0 for nodes that have + * not finished their initial sync, in failed state, or are + * otherwise considered not available to serve read commands. */ +static int isReplicaAvailable(clusterNode *node) { + if (clusterNodeIsFailing(node)) { + return 0; + } + long long repl_offset = clusterNodeReplOffset(node); + if (clusterNodeIsMyself(node)) { + /* Nodes do not update their own information + * in the cluster node list. */ + repl_offset = replicationGetSlaveOffset(); + } + return (repl_offset != 0); +} + +void addNodeToNodeReply(client *c, clusterNode *node) { + char* hostname = clusterNodeHostname(node); + addReplyArrayLen(c, 4); + if (server.cluster_preferred_endpoint_type == CLUSTER_ENDPOINT_TYPE_IP) { + addReplyBulkCString(c, clusterNodeIp(node)); + } else if (server.cluster_preferred_endpoint_type == CLUSTER_ENDPOINT_TYPE_HOSTNAME) { + if (hostname != NULL && hostname[0] != '\0') { + addReplyBulkCString(c, hostname); + } else { + addReplyBulkCString(c, "?"); + } + } else if (server.cluster_preferred_endpoint_type == CLUSTER_ENDPOINT_TYPE_UNKNOWN_ENDPOINT) { + addReplyNull(c); + } else { + serverPanic("Unrecognized preferred endpoint type"); + } + + /* Report TLS ports to TLS client, and report non-TLS port to non-TLS client. */ + addReplyLongLong(c, clusterNodeClientPort(node, shouldReturnTlsInfo())); + addReplyBulkCBuffer(c, clusterNodeGetName(node), CLUSTER_NAMELEN); + + /* Add the additional endpoint information, this is all the known networking information + * that is not the preferred endpoint. Note the logic is evaluated twice so we can + * correctly report the number of additional network arguments without using a deferred + * map, an assertion is made at the end to check we set the right length. */ + int length = 0; + if (server.cluster_preferred_endpoint_type != CLUSTER_ENDPOINT_TYPE_IP) { + length++; + } + if (server.cluster_preferred_endpoint_type != CLUSTER_ENDPOINT_TYPE_HOSTNAME + && hostname != NULL && hostname[0] != '\0') + { + length++; + } + addReplyMapLen(c, length); + + if (server.cluster_preferred_endpoint_type != CLUSTER_ENDPOINT_TYPE_IP) { + addReplyBulkCString(c, "ip"); + addReplyBulkCString(c, clusterNodeIp(node)); + length--; + } + if (server.cluster_preferred_endpoint_type != CLUSTER_ENDPOINT_TYPE_HOSTNAME + && hostname != NULL && hostname[0] != '\0') + { + addReplyBulkCString(c, "hostname"); + addReplyBulkCString(c, hostname); + length--; + } + serverAssert(length == 0); +} + +void addNodeReplyForClusterSlot(client *c, clusterNode *node, int start_slot, int end_slot) { + int i, nested_elements = 3; /* slots (2) + master addr (1) */ + for (i = 0; i < clusterNodeNumSlaves(node); i++) { + if (!isReplicaAvailable(clusterNodeGetSlave(node, i))) continue; + nested_elements++; + } + addReplyArrayLen(c, nested_elements); + addReplyLongLong(c, start_slot); + addReplyLongLong(c, end_slot); + addNodeToNodeReply(c, node); + + /* Remaining nodes in reply are replicas for slot range */ + for (i = 0; i < clusterNodeNumSlaves(node); i++) { + /* This loop is copy/pasted from clusterGenNodeDescription() + * with modifications for per-slot node aggregation. */ + if (!isReplicaAvailable(clusterNodeGetSlave(node, i))) continue; + addNodeToNodeReply(c, clusterNodeGetSlave(node, i)); + nested_elements--; + } + serverAssert(nested_elements == 3); /* Original 3 elements */ +} + +void clusterCommandSlots(client * c) { + /* Format: 1) 1) start slot + * 2) end slot + * 3) 1) master IP + * 2) master port + * 3) node ID + * 4) 1) replica IP + * 2) replica port + * 3) node ID + * ... continued until done + */ + clusterNode *n = NULL; + int num_masters = 0, start = -1; + void *slot_replylen = addReplyDeferredLen(c); + + for (int i = 0; i <= CLUSTER_SLOTS; i++) { + /* Find start node and slot id. */ + if (n == NULL) { + if (i == CLUSTER_SLOTS) break; + n = getNodeBySlot(i); + start = i; + continue; + } + + /* Add cluster slots info when occur different node with start + * or end of slot. */ + if (i == CLUSTER_SLOTS || n != getNodeBySlot(i)) { + addNodeReplyForClusterSlot(c, n, start, i-1); + num_masters++; + if (i == CLUSTER_SLOTS) break; + n = getNodeBySlot(i); + start = i; + } + } + setDeferredArrayLen(c, slot_replylen, num_masters); +} + +/* ----------------------------------------------------------------------------- + * Cluster functions related to serving / redirecting clients + * -------------------------------------------------------------------------- */ + +/* The ASKING command is required after a -ASK redirection. + * The client should issue ASKING before to actually send the command to + * the target instance. See the Redis Cluster specification for more + * information. */ +void askingCommand(client *c) { + if (server.cluster_enabled == 0) { + addReplyError(c,"This instance has cluster support disabled"); + return; + } + c->flags |= CLIENT_ASKING; + addReply(c,shared.ok); +} + +/* The READONLY command is used by clients to enter the read-only mode. + * In this mode slaves will not redirect clients as long as clients access + * with read-only commands to keys that are served by the slave's master. */ +void readonlyCommand(client *c) { + if (server.cluster_enabled == 0) { + addReplyError(c,"This instance has cluster support disabled"); + return; + } + c->flags |= CLIENT_READONLY; + addReply(c,shared.ok); +} + +/* Remove all the keys in the specified hash slot. + * The number of removed items is returned. */ +unsigned int clusterDelKeysInSlot(unsigned int hashslot, int by_command) { + unsigned int j = 0; + + if (!kvstoreDictSize(server.db->keys, (int) hashslot)) + return 0; + + kvstoreDictIterator kvs_di; + dictEntry *de = NULL; + kvstoreInitDictSafeIterator(&kvs_di, server.db->keys, (int) hashslot); + while((de = kvstoreDictIteratorNext(&kvs_di)) != NULL) { + enterExecutionUnit(1, 0); + sds sdskey = kvobjGetKey(dictGetKV(de)); + robj *key = createStringObject(sdskey, sdslen(sdskey)); + dbDelete(&server.db[0], key); + + keyModified(NULL, &server.db[0], key, NULL, 1); + if (by_command) { + /* Keys are deleted by a command (trimslots), we need to notify the + * keyspace event. Though, we don't need to propagate the DEL + * command, as the command (trimslots) will be propagated. */ + notifyKeyspaceEvent(NOTIFY_GENERIC, "del", key, server.db[0].id); + } else { + /* Propagate the DEL command */ + propagateDeletion(&server.db[0], key, server.lazyfree_lazy_server_del); + /* The keys are not actually logically deleted from the database, + * just moved to another node. The modules needs to know that these + * keys are no longer available locally, so just send the keyspace + * notification to the modules, but not to clients. */ + moduleNotifyKeyspaceEvent(NOTIFY_GENERIC, "del", key, server.db[0].id); + } + exitExecutionUnit(); + postExecutionUnitOperations(); + decrRefCount(key); + j++; + server.dirty++; + } + kvstoreResetDictIterator(&kvs_di); + return j; +} + +/* Delete the keys in the slot ranges. Returns the number of deleted items */ +unsigned int clusterDelKeysInSlotRangeArray(slotRangeArray *slots, int by_command) { + unsigned int j = 0; + for (int i = 0; i < slots->num_ranges; i++) { + for (int slot = slots->ranges[i].start; slot <= slots->ranges[i].end; slot++) { + j += clusterDelKeysInSlot(slot, by_command); + } + } + return j; +} + +int clusterIsMySlot(int slot) { + return getMyClusterNode() == getNodeBySlot(slot); +} + +void replySlotsFlushAndFree(client *c, slotRangeArray *slots) { + addReplyArrayLen(c, slots->num_ranges); + for (int i = 0 ; i < slots->num_ranges ; i++) { + addReplyArrayLen(c, 2); + addReplyLongLong(c, slots->ranges[i].start); + addReplyLongLong(c, slots->ranges[i].end); + } + slotRangeArrayFree(slots); +} + +/* Normalizes (sorts and merges adjacent ranges), checks that slot ranges are + * well-formed and non-overlapping. */ +int slotRangeArrayNormalizeAndValidate(slotRangeArray *slots, sds *err) { + unsigned char used_slots[CLUSTER_SLOTS] = {0}; + + if (slots->num_ranges <= 0 || slots->num_ranges >= CLUSTER_SLOTS) { + *err = sdscatprintf(sdsempty(), "invalid number of slot ranges: %d", slots->num_ranges); + return C_ERR; + } + + /* Sort and merge adjacent slot ranges. */ + slotRangeArraySortAndMerge(slots); + + for (int i = 0; i < slots->num_ranges; i++) { + if (slots->ranges[i].start >= CLUSTER_SLOTS || + slots->ranges[i].end >= CLUSTER_SLOTS) + { + *err = sdscatprintf(sdsempty(), "slot range is out of range: %d-%d", + slots->ranges[i].start, slots->ranges[i].end); + return C_ERR; + } + + if (slots->ranges[i].start > slots->ranges[i].end) { + *err = sdscatprintf(sdsempty(), "start slot number %d is greater than end slot number %d", + slots->ranges[i].start, slots->ranges[i].end); + return C_ERR; + } + + for (int j = slots->ranges[i].start; j <= slots->ranges[i].end; j++) { + if (used_slots[j]) { + *err = sdscatprintf(sdsempty(), "Slot %d specified multiple times", j); + return C_ERR; + } + used_slots[j]++; + } + } + return C_OK; +} + +/* Create a slot range array with the specified number of ranges. */ +slotRangeArray *slotRangeArrayCreate(int num_ranges) { + slotRangeArray *slots = zcalloc(sizeof(slotRangeArray) + num_ranges * sizeof(slotRange)); + slots->num_ranges = num_ranges; + return slots; +} + +/* Duplicate the slot range array. */ +slotRangeArray *slotRangeArrayDup(slotRangeArray *slots) { + slotRangeArray *dup = slotRangeArrayCreate(slots->num_ranges); + memcpy(dup->ranges, slots->ranges, sizeof(slotRange) * slots->num_ranges); + return dup; +} + +/* Set the slot range at the specified index. */ +void slotRangeArraySet(slotRangeArray *slots, int idx, int start, int end) { + slots->ranges[idx].start = start; + slots->ranges[idx].end = end; +} + +/* Create a slot range string in the format of: "1000-2000 3000-4000 ..." */ +sds slotRangeArrayToString(slotRangeArray *slots) { + sds s = sdsempty(); + if (slots == NULL || slots->num_ranges == 0) return s; + + for (int i = 0; i < slots->num_ranges; i++) { + slotRange *sr = &slots->ranges[i]; + s = sdscatprintf(s, "%d-%d ", sr->start, sr->end); + } + sdssetlen(s, sdslen(s) - 1); + s[sdslen(s)] = '\0'; + + return s; +} + +/* Parse a slot range string in the format "1000-2000 3000-4000 ..." into a slotRangeArray. + * Returns a new slotRangeArray on success, NULL on failure. */ +slotRangeArray *slotRangeArrayFromString(sds data) { + int num_ranges; + long long start, end; + slotRangeArray *slots = NULL; + if (!data || sdslen(data) == 0) return NULL; + + sds *parts = sdssplitlen(data, sdslen(data), " ", 1, &num_ranges); + if (num_ranges <= 0) goto err; + + slots = slotRangeArrayCreate(num_ranges); + + /* Parse each slot range */ + for (int i = 0; i < num_ranges; i++) { + char *dash = strchr(parts[i], '-'); + if (!dash) goto err; + + if (string2ll(parts[i], dash - parts[i], &start) == 0 || + string2ll(dash + 1, sdslen(parts[i]) - (dash - parts[i]) - 1, &end) == 0) + goto err; + slotRangeArraySet(slots, i, start, end); + } + + /* Validate all ranges */ + sds err_msg = NULL; + if (slotRangeArrayNormalizeAndValidate(slots, &err_msg) != C_OK) { + if (err_msg) sdsfree(err_msg); + goto err; + } + sdsfreesplitres(parts, num_ranges); + return slots; + +err: + if (slots) slotRangeArrayFree(slots); + sdsfreesplitres(parts, num_ranges); + return NULL; +} + +static int compareSlotRange(const void *a, const void *b) { + const slotRange *sa = a; + const slotRange *sb = b; + if (sa->start < sb->start) return -1; + if (sa->start > sb->start) return 1; + return 0; +} + +/* Sort slot ranges by start slot and merge adjacent ranges. + * Adjacent means: prev.end + 1 == next.start. + * e.g. 1000-2000 2001-3000 0-100 => 0-100 1000-3000 + * + * Note: Overlapping ranges are not merged.*/ +void slotRangeArraySortAndMerge(slotRangeArray *slots) { + if (!slots || slots->num_ranges <= 1) return; + + qsort(slots->ranges, slots->num_ranges, sizeof(slotRange), compareSlotRange); + + int idx = 0; + for (int i = 1; i < slots->num_ranges; i++) { + if (slots->ranges[idx].end + 1 == slots->ranges[i].start) + slots->ranges[idx].end = slots->ranges[i].end; + else + slots->ranges[++idx] = slots->ranges[i]; + } + slots->num_ranges = idx + 1; +} + +/* Compare two slot range arrays, return 1 if equal, 0 otherwise */ +int slotRangeArrayIsEqual(slotRangeArray *slots1, slotRangeArray *slots2) { + slotRangeArraySortAndMerge(slots1); + slotRangeArraySortAndMerge(slots2); + + if (slots1->num_ranges != slots2->num_ranges) return 0; + + for (int i = 0; i < slots1->num_ranges; i++) { + if (slots1->ranges[i].start != slots2->ranges[i].start || + slots1->ranges[i].end != slots2->ranges[i].end) { + return 0; + } + } + return 1; +} + +/* Add a slot to the slot range array. + * Usage: + * slotRangeArray *slots = NULL + * slots = slotRangeArrayAppend(slots, 1000); + * slots = slotRangeArrayAppend(slots, 1001); + * slots = slotRangeArrayAppend(slots, 1003); + * slots = slotRangeArrayAppend(slots, 1004); + * slots = slotRangeArrayAppend(slots, 1005); + * + * Result: 1000-1001, 1003-1005 + * Note: `slot` must be greater than the previous slot. + * */ +slotRangeArray *slotRangeArrayAppend(slotRangeArray *slots, int slot) { + if (slots == NULL) { + slots = slotRangeArrayCreate(4); + slots->ranges[0].start = slot; + slots->ranges[0].end = slot; + slots->num_ranges = 1; + return slots; + } + + serverAssert(slots->num_ranges >= 0 && slots->num_ranges <= CLUSTER_SLOTS); + serverAssert(slot > slots->ranges[slots->num_ranges - 1].end); + + /* Check if we can extend the last range */ + slotRange *last = &slots->ranges[slots->num_ranges - 1]; + if (slot == last->end + 1) { + last->end = slot; + return slots; + } + + /* Calculate current capacity and reallocate if needed */ + int cap = (int) ((zmalloc_size(slots) - sizeof(slotRangeArray)) / sizeof(slotRange)); + if (slots->num_ranges >= cap) + slots = zrealloc(slots, sizeof(slotRangeArray) + sizeof(slotRange) * cap * 2); + + /* Add new single-slot range */ + slots->ranges[slots->num_ranges].start = slot; + slots->ranges[slots->num_ranges].end = slot; + slots->num_ranges++; + + return slots; +} + +/* Returns 1 if the slot range array contains the given slot, 0 otherwise. */ +int slotRangeArrayContains(slotRangeArray *slots, unsigned int slot) { + for (int i = 0; i < slots->num_ranges; i++) + if (slots->ranges[i].start <= slot && slots->ranges[i].end >= slot) + return 1; + return 0; +} + +/* Free the slot range array. */ +void slotRangeArrayFree(slotRangeArray *slots) { + zfree(slots); +} + +/* Generic version of slotRangeArrayFree(). */ +void slotRangeArrayFreeGeneric(void *slots) { + slotRangeArrayFree(slots); +} + +/* Slot range array iterator */ +slotRangeArrayIter *slotRangeArrayGetIterator(slotRangeArray *slots) { + slotRangeArrayIter *it = zmalloc(sizeof(*it)); + it->slots = slots; + it->range_index = 0; + it->cur_slot = slots->num_ranges > 0 ? slots->ranges[0].start : -1; + return it; +} + +/* Returns the next slot in the array, or -1 if there are no more slots. */ +int slotRangeArrayNext(slotRangeArrayIter *it) { + if (it->range_index >= it->slots->num_ranges) return -1; + + if (it->cur_slot < it->slots->ranges[it->range_index].end) { + it->cur_slot++; + } else { + it->range_index++; + if (it->range_index < it->slots->num_ranges) + it->cur_slot = it->slots->ranges[it->range_index].start; + else + it->cur_slot = -1; /* finished */ + } + return it->cur_slot; +} + +int slotRangeArrayGetCurrentSlot(slotRangeArrayIter *it) { + return it->cur_slot; +} + +void slotRangeArrayIteratorFree(slotRangeArrayIter *it) { + zfree(it); +} + +/* Parse slot range pairs from argv starting at `pos`. + * `argc` is the argument count, `pos` is the first slot argument index. + * Returns a slotRangeArray or NULL on error. */ +slotRangeArray *parseSlotRangesOrReply(client *c, int argc, int pos) { + int start, end, count; + slotRangeArray *slots; + + /* Ensure there is at least one (start,end) slot range pairs. */ + if (argc < 0 || pos < 0 || pos >= argc || (argc - pos) < 2 || ((argc - pos) % 2) != 0) { + addReplyErrorArity(c); + return NULL; + } + + count = (argc - pos) / 2; + slots = slotRangeArrayCreate(count); + slots->num_ranges = 0; + + for (int j = pos; j < argc; j += 2) { + if ((start = getSlotOrReply(c, c->argv[j])) == -1 || + (end = getSlotOrReply(c, c->argv[j + 1])) == -1) + { + slotRangeArrayFree(slots); + return NULL; + } + slotRangeArraySet(slots, slots->num_ranges, start, end); + slots->num_ranges++; + } + + sds err = NULL; + if (slotRangeArrayNormalizeAndValidate(slots, &err) != C_OK) { + addReplyErrorSds(c, err); + slotRangeArrayFree(slots); + return NULL; + } + return slots; +} + +/* Return 1 if the keys in the slot can be accessed, 0 otherwise. */ +int clusterCanAccessKeysInSlot(int slot) { + /* If not in cluster mode, all keys are accessible */ + if (server.cluster_enabled == 0) return 1; + + /* If the slot is being imported under old slot migration approach, we should + * allow to list keys from the slot as previously. */ + if (getImportingSlotSource(slot)) return 1; + + /* If using atomic slot migration, check if the slot belongs to the current + * node or its master, return 1 if so. */ + clusterNode *myself = getMyClusterNode(); + if (clusterNodeIsSlave(myself)) { + clusterNode *master = clusterNodeGetMaster(myself); + if (master && clusterNodeCoversSlot(master, slot)) + return 1; + } else { + if (clusterNodeCoversSlot(myself, slot)) + return 1; + } + return 0; +} + +/* Return the slot ranges that belong to the current node or its master. */ +slotRangeArray *clusterGetLocalSlotRanges(void) { + slotRangeArray *slots = NULL; + + if (!server.cluster_enabled) { + slots = slotRangeArrayCreate(1); + slotRangeArraySet(slots, 0, 0, CLUSTER_SLOTS - 1); + return slots; + } + + clusterNode *master = clusterNodeGetMaster(getMyClusterNode()); + if (master) { + for (int i = 0; i < CLUSTER_SLOTS; i++) { + if (clusterNodeCoversSlot(master, i)) + slots = slotRangeArrayAppend(slots, i); + } + } + return slots ? slots : slotRangeArrayCreate(0); +} + +/* Partially flush destination DB in a cluster node, based on the slot range. + * + * Usage: SFLUSH <start-slot> <end slot> [<start-slot> <end slot>]* [SYNC|ASYNC] + * + * This is an initial implementation of SFLUSH (slots flush) which is limited to + * flushing a single shard as a whole, but in the future the same command may be + * used to partially flush a shard based on hash slots. Currently only if provided + * slots cover entirely the slots of a node, the node will be flushed and the + * return value will be pairs of slot ranges. Otherwise, a single empty set will + * be returned. If possible, SFLUSH SYNC will be run as blocking ASYNC as an + * optimization. + */ +void sflushCommand(client *c) { + int flags = EMPTYDB_NO_FLAGS, argc = c->argc; + + if (server.cluster_enabled == 0) { + addReplyError(c,"This instance has cluster support disabled"); + return; + } + + /* check if last argument is SYNC or ASYNC */ + if (!strcasecmp(c->argv[c->argc-1]->ptr,"sync")) { + flags = EMPTYDB_NO_FLAGS; + argc--; + } else if (!strcasecmp(c->argv[c->argc-1]->ptr,"async")) { + flags = EMPTYDB_ASYNC; + argc--; + } else if (server.lazyfree_lazy_user_flush) { + flags = EMPTYDB_ASYNC; + } + + /* parse the slot range */ + if (argc % 2 == 0) { + addReplyErrorArity(c); + return; + } + + /* Parse slot ranges from the command arguments. */ + slotRangeArray *slots = parseSlotRangesOrReply(c, argc, 1); + if (!slots) return; + + /* Iterate and find the slot ranges that belong to this node. Save them in + * a new slotRangeArray. It is allocated on heap since there is a chance + * that FLUSH SYNC will be running as blocking ASYNC and only later reply + * with slot ranges */ + unsigned char slots_to_flush[CLUSTER_SLOTS] = {0}; /* Requested slots to flush */ + slotRangeArray *myslots = NULL; + for (int i = 0; i < slots->num_ranges; i++) { + for (int j = slots->ranges[i].start; j <= slots->ranges[i].end; j++) { + if (clusterIsMySlot(j)) { + myslots = slotRangeArrayAppend(myslots, j); + slots_to_flush[j] = 1; + } + } + } + + /* Verify that all slots of mynode got covered. See sflushCommand() comment. */ + int all_slots_covered = 1; + for (int i = 0; i < CLUSTER_SLOTS; i++) { + if (clusterIsMySlot(i) && !slots_to_flush[i]) { + all_slots_covered = 0; + break; + } + } + if (myslots == NULL || !all_slots_covered) { + addReplyArrayLen(c, 0); + slotRangeArrayFree(slots); + slotRangeArrayFree(myslots); + return; + } + slotRangeArrayFree(slots); + + /* Flush selected slots. If not flush as blocking async, then reply immediately */ + if (flushCommandCommon(c, FLUSH_TYPE_SLOTS, flags, myslots) == 0) + replySlotsFlushAndFree(c, myslots); +} + +/* The READWRITE command just clears the READONLY command state. */ +void readwriteCommand(client *c) { + if (server.cluster_enabled == 0) { + addReplyError(c,"This instance has cluster support disabled"); + return; + } + c->flags &= ~CLIENT_READONLY; + addReply(c,shared.ok); +} + +/* Resets transient cluster stats that we expose via INFO or other means that we want + * to reset via CONFIG RESETSTAT. The function is also used in order to + * initialize these fields in clusterInit() at server startup. */ +void resetClusterStats(void) { + if (!server.cluster_enabled) return; + + clusterSlotStatResetAll(); +} + +/* This function is called at server startup in order to initialize cluster data + * structures that are shared between the different cluster implementations. */ +void clusterCommonInit(void) { + resetClusterStats(); + asmInit(); +} + +/* This function is called after the node startup in order to check if there + * are any slots that we have keys for, but are not assigned to us. If so, + * we delete the keys. */ +void clusterDeleteKeysInUnownedSlots(void) { + if (clusterNodeIsSlave(getMyClusterNode())) return; + + /* Check that all the slots we have keys for are assigned to us. Otherwise, + * delete the keys. */ + for (int i = 0; i < CLUSTER_SLOTS; i++) { + /* Skip if: no keys in the slot, it's our slot, or we are importing it. */ + if (!countKeysInSlot(i) || + clusterIsMySlot(i) || + getImportingSlotSource(i)) + { + continue; + } + + serverLog(LL_NOTICE, "I have keys for slot %d, but the slot is " + "assigned to another node. " + "Deleting keys in the slot.", i); + /* With atomic slot migration, it is safe to drop keys from slots + * that are not owned. This will not result in data loss under the + * legacy slot migration approach either, since the importing state + * has already been persisted in node.conf. */ + clusterDelKeysInSlot(i, 0); + } +} + + +/* This function is called after the node startup in order to verify that data + * loaded from disk is in agreement with the cluster configuration: + * + * 1) If we find keys about hash slots we have no responsibility for, the + * following happens: + * A) If no other node is in charge according to the current cluster + * configuration, we add these slots to our node. + * B) If according to our config other nodes are already in charge for + * this slots, we set the slots as IMPORTING from our point of view + * in order to justify we have those slots, and in order to make + * redis-cli aware of the issue, so that it can try to fix it. + * 2) If we find data in a DB different than DB0 we return C_ERR to + * signal the caller it should quit the server with an error message + * or take other actions. + * + * The function always returns C_OK even if it will try to correct + * the error described in "1". However if data is found in DB different + * from DB0, C_ERR is returned. + * + * The function also uses the logging facility in order to warn the user + * about desynchronizations between the data we have in memory and the + * cluster configuration. */ +int verifyClusterConfigWithData(void) { + /* Return ASAP if a module disabled cluster redirections. In that case + * every master can store keys about every possible hash slot. */ + if (server.cluster_module_flags & CLUSTER_MODULE_FLAG_NO_REDIRECTION) + return C_OK; + + /* If this node is a slave, don't perform the check at all as we + * completely depend on the replication stream. */ + if (clusterNodeIsSlave(getMyClusterNode())) return C_OK; + + /* Make sure we only have keys in DB0. */ + for (int i = 1; i < server.dbnum; i++) { + if (kvstoreSize(server.db[i].keys)) return C_ERR; + } + + /* Take over slots that we have keys for, but are assigned to no one. */ + clusterClaimUnassignedSlots(); + /* Delete keys in unowned slots */ + clusterDeleteKeysInUnownedSlots(); + return C_OK; +} |