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Diffstat (limited to 'src/cluster.h')
| -rw-r--r-- | src/cluster.h | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/src/cluster.h b/src/cluster.h new file mode 100644 index 0000000..6dd69a0 --- /dev/null +++ b/src/cluster.h @@ -0,0 +1,263 @@ +#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_DEFAULT_NODE_TIMEOUT 15000 +#define CLUSTER_DEFAULT_SLAVE_VALIDITY 10 /* Slave max data age factor. */ +#define CLUSTER_DEFAULT_REQUIRE_FULL_COVERAGE 1 +#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_FAIL_UNDO_TIME_ADD 10 /* Some additional time. */ +#define CLUSTER_FAILOVER_DELAY 5 /* Seconds */ +#define CLUSTER_DEFAULT_MIGRATION_BARRIER 1 +#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. */ + +struct clusterNode; + +/* clusterLink encapsulates everything needed to talk with a remote node. */ +typedef struct clusterLink { + mstime_t ctime; /* Link creation time */ + int fd; /* TCP socket file descriptor */ + sds sndbuf; /* Packet send buffer */ + sds rcvbuf; /* Packet reception buffer */ + struct clusterNode *node; /* Node related to this link if any, or NULL */ +} 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 elegible for replica migration. */ +#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) + +/* 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. */ + +/* 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 */ + 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. */ + mstime_t ping_sent; /* Unix time we sent latest ping */ + mstime_t pong_received; /* Unix time we received the pong */ + 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 */ + int port; /* Latest known clients port of this node */ + int cport; /* Latest known cluster port of this node. */ + clusterLink *link; /* TCP/IP link with this node */ + list *fail_reports; /* List of nodes signaling this as failing */ +} clusterNode; + +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]; + zskiplist *slots_to_keys; + /* 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 zero if stil not received. */ + int mf_can_start; /* If non-zero signal that the manual failover + can start requesting masters vote. */ + /* The followign 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(). */ + long long stats_bus_messages_sent; /* Num of msg sent via cluster bus. */ + long long stats_bus_messages_received; /* Num of msg rcvd via cluster bus.*/ +} clusterState; + +/* 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) + +/* Redis cluster messages header */ + +/* 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 */ + +/* 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 */ + uint32_t notused1; +} clusterMsgDataGossip; + +typedef struct { + char nodename[CLUSTER_NAMELEN]; +} clusterMsgDataFail; + +typedef struct { + uint32_t channel_len; + uint32_t message_len; + /* We can't reclare bulk_data as bulk_data[] since this structure is + * nested. The 8 bytes are removed from the count during the message + * length computation. */ + unsigned char bulk_data[8]; +} 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; + +union clusterMsgData { + /* PING, MEET and PONG */ + struct { + /* Array of N clusterMsgDataGossip structures */ + clusterMsgDataGossip gossip[1]; + } ping; + + /* FAIL */ + struct { + clusterMsgDataFail about; + } fail; + + /* PUBLISH */ + struct { + clusterMsgDataPublish msg; + } publish; + + /* UPDATE */ + struct { + clusterMsgDataUpdate nodecfg; + } update; +}; + +#define CLUSTER_PROTO_VER 1 /* Cluster bus protocol version. */ + +typedef struct { + char sig[4]; /* Siganture "RCmb" (Redis Cluster message bus). */ + uint32_t totlen; /* Total length of this message */ + uint16_t ver; /* Protocol version, currently set to 0. */ + 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. */ + char notused1[34]; /* 34 bytes reserved for future usage. */ + 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; + +#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. */ + +/* ---------------------- API exported outside cluster.c -------------------- */ +clusterNode *getNodeByQuery(client *c, struct redisCommand *cmd, robj **argv, int argc, int *hashslot, int *ask); +int clusterRedirectBlockedClientIfNeeded(client *c); +void clusterRedirectClient(client *c, clusterNode *n, int hashslot, int error_code); + +#endif /* __CLUSTER_H */ |