#ifndef __CLUSTER_H #define __CLUSTER_H /*----------------------------------------------------------------------------- * Redis cluster data structures, defines, exported API. *----------------------------------------------------------------------------*/ #define CLUSTER_SLOTS 16384 #define CLUSTER_OK 0 /* Everything looks ok */ #define CLUSTER_FAIL 1 /* The cluster can't work */ #define CLUSTER_NAMELEN 40 /* sha1 hex length */ #define CLUSTER_PORT_INCR 10000 /* Cluster port = baseport + PORT_INCR */ /* The following defines are amount of time, sometimes expressed as * multiplicators of the node timeout value (when ending with MULT). */ #define CLUSTER_FAIL_REPORT_VALIDITY_MULT 2 /* Fail report validity. */ #define CLUSTER_FAIL_UNDO_TIME_MULT 2 /* Undo fail if master is back. */ #define CLUSTER_MF_TIMEOUT 5000 /* Milliseconds to do a manual failover. */ #define CLUSTER_MF_PAUSE_MULT 2 /* Master pause manual failover mult. */ #define CLUSTER_SLAVE_MIGRATION_DELAY 5000 /* Delay for slave migration. */ /* Redirection errors returned by getNodeByQuery(). */ #define CLUSTER_REDIR_NONE 0 /* Node can serve the request. */ #define CLUSTER_REDIR_CROSS_SLOT 1 /* -CROSSSLOT request. */ #define CLUSTER_REDIR_UNSTABLE 2 /* -TRYAGAIN redirection required */ #define CLUSTER_REDIR_ASK 3 /* -ASK redirection required. */ #define CLUSTER_REDIR_MOVED 4 /* -MOVED redirection required. */ #define CLUSTER_REDIR_DOWN_STATE 5 /* -CLUSTERDOWN, global state. */ #define CLUSTER_REDIR_DOWN_UNBOUND 6 /* -CLUSTERDOWN, unbound slot. */ #define CLUSTER_REDIR_DOWN_RO_STATE 7 /* -CLUSTERDOWN, allow reads. */ struct clusterNode; /* clusterLink encapsulates everything needed to talk with a remote node. */ typedef struct clusterLink { mstime_t ctime; /* Link creation time */ connection *conn; /* Connection to remote node */ sds sndbuf; /* Packet send buffer */ char *rcvbuf; /* Packet reception buffer */ size_t rcvbuf_len; /* Used size of rcvbuf */ size_t rcvbuf_alloc; /* Allocated size of rcvbuf */ struct clusterNode *node; /* Node related to this link. Initialized to NULL when unknown */ int inbound; /* 1 if this link is an inbound link accepted from the related node */ } clusterLink; /* Cluster node flags and macros. */ #define CLUSTER_NODE_MASTER 1 /* The node is a master */ #define CLUSTER_NODE_SLAVE 2 /* The node is a slave */ #define CLUSTER_NODE_PFAIL 4 /* Failure? Need acknowledge */ #define CLUSTER_NODE_FAIL 8 /* The node is believed to be malfunctioning */ #define CLUSTER_NODE_MYSELF 16 /* This node is myself */ #define CLUSTER_NODE_HANDSHAKE 32 /* We have still to exchange the first ping */ #define CLUSTER_NODE_NOADDR 64 /* We don't know the address of this node */ #define CLUSTER_NODE_MEET 128 /* Send a MEET message to this node */ #define CLUSTER_NODE_MIGRATE_TO 256 /* Master eligible for replica migration. */ #define CLUSTER_NODE_NOFAILOVER 512 /* Slave will not try to failover. */ #define CLUSTER_NODE_NULL_NAME "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000" #define nodeIsMaster(n) ((n)->flags & CLUSTER_NODE_MASTER) #define nodeIsSlave(n) ((n)->flags & CLUSTER_NODE_SLAVE) #define nodeInHandshake(n) ((n)->flags & CLUSTER_NODE_HANDSHAKE) #define nodeHasAddr(n) (!((n)->flags & CLUSTER_NODE_NOADDR)) #define nodeWithoutAddr(n) ((n)->flags & CLUSTER_NODE_NOADDR) #define nodeTimedOut(n) ((n)->flags & CLUSTER_NODE_PFAIL) #define nodeFailed(n) ((n)->flags & CLUSTER_NODE_FAIL) #define nodeCantFailover(n) ((n)->flags & CLUSTER_NODE_NOFAILOVER) /* Reasons why a slave is not able to failover. */ #define CLUSTER_CANT_FAILOVER_NONE 0 #define CLUSTER_CANT_FAILOVER_DATA_AGE 1 #define CLUSTER_CANT_FAILOVER_WAITING_DELAY 2 #define CLUSTER_CANT_FAILOVER_EXPIRED 3 #define CLUSTER_CANT_FAILOVER_WAITING_VOTES 4 #define CLUSTER_CANT_FAILOVER_RELOG_PERIOD (60*5) /* seconds. */ /* clusterState todo_before_sleep flags. */ #define CLUSTER_TODO_HANDLE_FAILOVER (1<<0) #define CLUSTER_TODO_UPDATE_STATE (1<<1) #define CLUSTER_TODO_SAVE_CONFIG (1<<2) #define CLUSTER_TODO_FSYNC_CONFIG (1<<3) #define CLUSTER_TODO_HANDLE_MANUALFAILOVER (1<<4) /* Message types. * * Note that the PING, PONG and MEET messages are actually the same exact * kind of packet. PONG is the reply to ping, in the exact format as a PING, * while MEET is a special PING that forces the receiver to add the sender * as a node (if it is not already in the list). */ #define CLUSTERMSG_TYPE_PING 0 /* Ping */ #define CLUSTERMSG_TYPE_PONG 1 /* Pong (reply to Ping) */ #define CLUSTERMSG_TYPE_MEET 2 /* Meet "let's join" message */ #define CLUSTERMSG_TYPE_FAIL 3 /* Mark node xxx as failing */ #define CLUSTERMSG_TYPE_PUBLISH 4 /* Pub/Sub Publish propagation */ #define CLUSTERMSG_TYPE_FAILOVER_AUTH_REQUEST 5 /* May I failover? */ #define CLUSTERMSG_TYPE_FAILOVER_AUTH_ACK 6 /* Yes, you have my vote */ #define CLUSTERMSG_TYPE_UPDATE 7 /* Another node slots configuration */ #define CLUSTERMSG_TYPE_MFSTART 8 /* Pause clients for manual failover */ #define CLUSTERMSG_TYPE_MODULE 9 /* Module cluster API message. */ #define CLUSTERMSG_TYPE_PUBLISHSHARD 10 /* Pub/Sub Publish shard propagation */ #define CLUSTERMSG_TYPE_COUNT 11 /* Total number of message types. */ /* Flags that a module can set in order to prevent certain Redis Cluster * features to be enabled. Useful when implementing a different distributed * system on top of Redis Cluster message bus, using modules. */ #define CLUSTER_MODULE_FLAG_NONE 0 #define CLUSTER_MODULE_FLAG_NO_FAILOVER (1<<1) #define CLUSTER_MODULE_FLAG_NO_REDIRECTION (1<<2) /* This structure represent elements of node->fail_reports. */ typedef struct clusterNodeFailReport { struct clusterNode *node; /* Node reporting the failure condition. */ mstime_t time; /* Time of the last report from this node. */ } clusterNodeFailReport; typedef struct clusterNode { mstime_t ctime; /* Node object creation time. */ char name[CLUSTER_NAMELEN]; /* Node name, hex string, sha1-size */ int flags; /* CLUSTER_NODE_... */ uint64_t configEpoch; /* Last configEpoch observed for this node */ unsigned char slots[CLUSTER_SLOTS/8]; /* slots handled by this node */ uint16_t *slot_info_pairs; /* Slots info represented as (start/end) pair (consecutive index). */ int slot_info_pairs_count; /* Used number of slots in slot_info_pairs */ int numslots; /* Number of slots handled by this node */ int numslaves; /* Number of slave nodes, if this is a master */ struct clusterNode **slaves; /* pointers to slave nodes */ struct clusterNode *slaveof; /* pointer to the master node. Note that it may be NULL even if the node is a slave if we don't have the master node in our tables. */ unsigned long long last_in_ping_gossip; /* The number of the last carried in the ping gossip section */ mstime_t ping_sent; /* Unix time we sent latest ping */ mstime_t pong_received; /* Unix time we received the pong */ mstime_t data_received; /* Unix time we received any data */ mstime_t fail_time; /* Unix time when FAIL flag was set */ mstime_t voted_time; /* Last time we voted for a slave of this master */ mstime_t repl_offset_time; /* Unix time we received offset for this node */ mstime_t orphaned_time; /* Starting time of orphaned master condition */ long long repl_offset; /* Last known repl offset for this node. */ char ip[NET_IP_STR_LEN]; /* Latest known IP address of this node */ sds hostname; /* The known hostname for this node */ int port; /* Latest known clients port (TLS or plain). */ int pport; /* Latest known clients plaintext port. Only used if the main clients port is for TLS. */ int cport; /* Latest known cluster port of this node. */ clusterLink *link; /* TCP/IP link established toward this node */ clusterLink *inbound_link; /* TCP/IP link accepted from this node */ list *fail_reports; /* List of nodes signaling this as failing */ } clusterNode; /* Slot to keys for a single slot. The keys in the same slot are linked together * using dictEntry metadata. */ typedef struct slotToKeys { uint64_t count; /* Number of keys in the slot. */ dictEntry *head; /* The first key-value entry in the slot. */ } slotToKeys; /* Slot to keys mapping for all slots, opaque outside this file. */ struct clusterSlotToKeyMapping { slotToKeys by_slot[CLUSTER_SLOTS]; }; /* Dict entry metadata for cluster mode, used for the Slot to Key API to form a * linked list of the entries belonging to the same slot. */ typedef struct clusterDictEntryMetadata { dictEntry *prev; /* Prev entry with key in the same slot */ dictEntry *next; /* Next entry with key in the same slot */ } clusterDictEntryMetadata; typedef struct clusterState { clusterNode *myself; /* This node */ uint64_t currentEpoch; int state; /* CLUSTER_OK, CLUSTER_FAIL, ... */ int size; /* Num of master nodes with at least one slot */ dict *nodes; /* Hash table of name -> clusterNode structures */ dict *nodes_black_list; /* Nodes we don't re-add for a few seconds. */ clusterNode *migrating_slots_to[CLUSTER_SLOTS]; clusterNode *importing_slots_from[CLUSTER_SLOTS]; clusterNode *slots[CLUSTER_SLOTS]; rax *slots_to_channels; /* The following fields are used to take the slave state on elections. */ mstime_t failover_auth_time; /* Time of previous or next election. */ int failover_auth_count; /* Number of votes received so far. */ int failover_auth_sent; /* True if we already asked for votes. */ int failover_auth_rank; /* This slave rank for current auth request. */ uint64_t failover_auth_epoch; /* Epoch of the current election. */ int cant_failover_reason; /* Why a slave is currently not able to failover. See the CANT_FAILOVER_* macros. */ /* Manual failover state in common. */ mstime_t mf_end; /* Manual failover time limit (ms unixtime). It is zero if there is no MF in progress. */ /* Manual failover state of master. */ clusterNode *mf_slave; /* Slave performing the manual failover. */ /* Manual failover state of slave. */ long long mf_master_offset; /* Master offset the slave needs to start MF or -1 if still not received. */ int mf_can_start; /* If non-zero signal that the manual failover can start requesting masters vote. */ /* The following fields are used by masters to take state on elections. */ uint64_t lastVoteEpoch; /* Epoch of the last vote granted. */ int todo_before_sleep; /* Things to do in clusterBeforeSleep(). */ /* Stats */ /* Messages received and sent by type. */ long long stats_bus_messages_sent[CLUSTERMSG_TYPE_COUNT]; long long stats_bus_messages_received[CLUSTERMSG_TYPE_COUNT]; long long stats_pfail_nodes; /* Number of nodes in PFAIL status, excluding nodes without address. */ unsigned long long stat_cluster_links_buffer_limit_exceeded; /* Total number of cluster links freed due to exceeding buffer limit */ /* Bit map for slots that are no longer claimed by the owner in cluster PING * messages. During slot migration, the owner will stop claiming the slot after * the ownership transfer. Set the bit corresponding to the slot when a node * stops claiming the slot. This prevents spreading incorrect information (that * source still owns the slot) using UPDATE messages. */ unsigned char owner_not_claiming_slot[CLUSTER_SLOTS / 8]; } clusterState; /* Redis cluster messages header */ /* Initially we don't know our "name", but we'll find it once we connect * to the first node, using the getsockname() function. Then we'll use this * address for all the next messages. */ typedef struct { char nodename[CLUSTER_NAMELEN]; uint32_t ping_sent; uint32_t pong_received; char ip[NET_IP_STR_LEN]; /* IP address last time it was seen */ uint16_t port; /* base port last time it was seen */ uint16_t cport; /* cluster port last time it was seen */ uint16_t flags; /* node->flags copy */ uint16_t pport; /* plaintext-port, when base port is TLS */ uint16_t notused1; } clusterMsgDataGossip; typedef struct { char nodename[CLUSTER_NAMELEN]; } clusterMsgDataFail; typedef struct { uint32_t channel_len; uint32_t message_len; unsigned char bulk_data[8]; /* 8 bytes just as placeholder. */ } clusterMsgDataPublish; typedef struct { uint64_t configEpoch; /* Config epoch of the specified instance. */ char nodename[CLUSTER_NAMELEN]; /* Name of the slots owner. */ unsigned char slots[CLUSTER_SLOTS/8]; /* Slots bitmap. */ } clusterMsgDataUpdate; typedef struct { uint64_t module_id; /* ID of the sender module. */ uint32_t len; /* ID of the sender module. */ uint8_t type; /* Type from 0 to 255. */ unsigned char bulk_data[3]; /* 3 bytes just as placeholder. */ } clusterMsgModule; /* The cluster supports optional extension messages that can be sent * along with ping/pong/meet messages to give additional info in a * consistent manner. */ typedef enum { CLUSTERMSG_EXT_TYPE_HOSTNAME, } clusterMsgPingtypes; /* Helper function for making sure extensions are eight byte aligned. */ #define EIGHT_BYTE_ALIGN(size) ((((size) + 7) / 8) * 8) typedef struct { char hostname[1]; /* The announced hostname, ends with \0. */ } clusterMsgPingExtHostname; typedef struct { uint32_t length; /* Total length of this extension message (including this header) */ uint16_t type; /* Type of this extension message (see clusterMsgPingExtTypes) */ uint16_t unused; /* 16 bits of padding to make this structure 8 byte aligned. */ union { clusterMsgPingExtHostname hostname; } ext[]; /* Actual extension information, formatted so that the data is 8 * byte aligned, regardless of its content. */ } clusterMsgPingExt; union clusterMsgData { /* PING, MEET and PONG */ struct { /* Array of N clusterMsgDataGossip structures */ clusterMsgDataGossip gossip[1]; /* Extension data that can optionally be sent for ping/meet/pong * messages. We can't explicitly define them here though, since * the gossip array isn't the real length of the gossip data. */ } ping; /* FAIL */ struct { clusterMsgDataFail about; } fail; /* PUBLISH */ struct { clusterMsgDataPublish msg; } publish; /* UPDATE */ struct { clusterMsgDataUpdate nodecfg; } update; /* MODULE */ struct { clusterMsgModule msg; } module; }; #define CLUSTER_PROTO_VER 1 /* Cluster bus protocol version. */ typedef struct { char sig[4]; /* Signature "RCmb" (Redis Cluster message bus). */ uint32_t totlen; /* Total length of this message */ uint16_t ver; /* Protocol version, currently set to 1. */ uint16_t port; /* TCP base port number. */ uint16_t type; /* Message type */ uint16_t count; /* Only used for some kind of messages. */ uint64_t currentEpoch; /* The epoch accordingly to the sending node. */ uint64_t configEpoch; /* The config epoch if it's a master, or the last epoch advertised by its master if it is a slave. */ uint64_t offset; /* Master replication offset if node is a master or processed replication offset if node is a slave. */ char sender[CLUSTER_NAMELEN]; /* Name of the sender node */ unsigned char myslots[CLUSTER_SLOTS/8]; char slaveof[CLUSTER_NAMELEN]; char myip[NET_IP_STR_LEN]; /* Sender IP, if not all zeroed. */ uint16_t extensions; /* Number of extensions sent along with this packet. */ char notused1[30]; /* 30 bytes reserved for future usage. */ uint16_t pport; /* Sender TCP plaintext port, if base port is TLS */ uint16_t cport; /* Sender TCP cluster bus port */ uint16_t flags; /* Sender node flags */ unsigned char state; /* Cluster state from the POV of the sender */ unsigned char mflags[3]; /* Message flags: CLUSTERMSG_FLAG[012]_... */ union clusterMsgData data; } clusterMsg; /* clusterMsg defines the gossip wire protocol exchanged among Redis cluster * members, which can be running different versions of redis-server bits, * especially during cluster rolling upgrades. * * Therefore, fields in this struct should remain at the same offset from * release to release. The static asserts below ensures that incompatible * changes in clusterMsg be caught at compile time. */ static_assert(offsetof(clusterMsg, sig) == 0, "unexpected field offset"); static_assert(offsetof(clusterMsg, totlen) == 4, "unexpected field offset"); static_assert(offsetof(clusterMsg, ver) == 8, "unexpected field offset"); static_assert(offsetof(clusterMsg, port) == 10, "unexpected field offset"); static_assert(offsetof(clusterMsg, type) == 12, "unexpected field offset"); static_assert(offsetof(clusterMsg, count) == 14, "unexpected field offset"); static_assert(offsetof(clusterMsg, currentEpoch) == 16, "unexpected field offset"); static_assert(offsetof(clusterMsg, configEpoch) == 24, "unexpected field offset"); static_assert(offsetof(clusterMsg, offset) == 32, "unexpected field offset"); static_assert(offsetof(clusterMsg, sender) == 40, "unexpected field offset"); static_assert(offsetof(clusterMsg, myslots) == 80, "unexpected field offset"); static_assert(offsetof(clusterMsg, slaveof) == 2128, "unexpected field offset"); static_assert(offsetof(clusterMsg, myip) == 2168, "unexpected field offset"); static_assert(offsetof(clusterMsg, extensions) == 2214, "unexpected field offset"); static_assert(offsetof(clusterMsg, notused1) == 2216, "unexpected field offset"); static_assert(offsetof(clusterMsg, pport) == 2246, "unexpected field offset"); static_assert(offsetof(clusterMsg, cport) == 2248, "unexpected field offset"); static_assert(offsetof(clusterMsg, flags) == 2250, "unexpected field offset"); static_assert(offsetof(clusterMsg, state) == 2252, "unexpected field offset"); static_assert(offsetof(clusterMsg, mflags) == 2253, "unexpected field offset"); static_assert(offsetof(clusterMsg, data) == 2256, "unexpected field offset"); #define CLUSTERMSG_MIN_LEN (sizeof(clusterMsg)-sizeof(union clusterMsgData)) /* Message flags better specify the packet content or are used to * provide some information about the node state. */ #define CLUSTERMSG_FLAG0_PAUSED (1<<0) /* Master paused for manual failover. */ #define CLUSTERMSG_FLAG0_FORCEACK (1<<1) /* Give ACK to AUTH_REQUEST even if master is up. */ #define CLUSTERMSG_FLAG0_EXT_DATA (1<<2) /* Message contains extension data */ /* ---------------------- API exported outside cluster.c -------------------- */ void clusterInit(void); void clusterCron(void); void clusterBeforeSleep(void); clusterNode *getNodeByQuery(client *c, struct redisCommand *cmd, robj **argv, int argc, int *hashslot, int *ask); int verifyClusterNodeId(const char *name, int length); clusterNode *clusterLookupNode(const char *name, int length); int clusterRedirectBlockedClientIfNeeded(client *c); void clusterRedirectClient(client *c, clusterNode *n, int hashslot, int error_code); void migrateCloseTimedoutSockets(void); int verifyClusterConfigWithData(void); unsigned long getClusterConnectionsCount(void); int clusterSendModuleMessageToTarget(const char *target, uint64_t module_id, uint8_t type, const char *payload, uint32_t len); void clusterPropagatePublish(robj *channel, robj *message, int sharded); unsigned int keyHashSlot(char *key, int keylen); void slotToKeyAddEntry(dictEntry *entry, redisDb *db); void slotToKeyDelEntry(dictEntry *entry, redisDb *db); void slotToKeyReplaceEntry(dictEntry *entry, redisDb *db); void slotToKeyInit(redisDb *db); void slotToKeyFlush(redisDb *db); void slotToKeyDestroy(redisDb *db); void clusterUpdateMyselfFlags(void); void clusterUpdateMyselfIp(void); void slotToChannelAdd(sds channel); void slotToChannelDel(sds channel); void clusterUpdateMyselfHostname(void); void clusterUpdateMyselfAnnouncedPorts(void); void freeClusterLink(clusterLink *link); #endif /* __CLUSTER_H */