/* ------------------------------------------------------------------------- * * walprotocol.h * Definitions relevant to the streaming WAL transmission protocol. * * Portions Copyright (c) 2010-2012, PostgreSQL Global Development Group * * src/include/replication/walprotocol.h * * We tried to expand the traditional WAL protocol to transfer the separated replication data with * the specified #ref_xlog which could benefit from both the xlog synchronization and the I/O reducing. * ------------------------------------------------------------------------- */ #ifndef _WALPROTOCOL_H #define _WALPROTOCOL_H #include "access/xlogdefs.h" #include "datatype/timestamp.h" #include "replication/replicainternal.h" #include "pgxc/barrier.h" #define XLOG_NAME_LENGTH 24 /* * All messages from WalSender must contain these fields to allow us to * correctly calculate the replication delay. */ typedef struct ConfigModifyTimeMessage { time_t config_modify_time; } ConfigModifyTimeMessage; /* * All messages from WalSender must contain these fields to allow us to * correctly calculate the replication delay. */ typedef struct { /* Current end of WAL on the sender */ XLogRecPtr walEnd; ServerMode peer_role; DbState peer_state; /* Sender's system clock at the time of transmission */ TimestampTz sendTime; /* * If replyRequested is set, the client should reply immediately to this * message, to avoid a timeout disconnect. */ bool replyRequested; bool catchup; bool uwal_catchup; bool fullSync = false; } WalSndrMessage; /* * Refence :PrimaryKeepaliveMessage * All messages from WalSender must contain these fields to allow us to * correctly calculate the replication delay. */ typedef struct RmXLogMessage { /* Current end of WAL on the sender */ ServerMode peer_role; DbState peer_state; /* Sender's system clock at the time of transmission */ TimestampTz sendTime; /* * If replyRequested is set, the client should reply immediately to this * message, to avoid a timeout disconnect. */ bool replyRequested; } RmXLogMessage; /* * Refence :PrimaryKeepaliveMessage */ typedef struct EndXLogMessage { /* Current end of WAL on the sender */ ServerMode peer_role; DbState peer_state; /* Sender's system clock at the time of transmission */ TimestampTz sendTime; int percent; } EndXLogMessage; /* * Header for a WAL data message (message type 'w'). This is wrapped within * a CopyData message at the FE/BE protocol level. * * The header is followed by actual WAL data. Note that the data length is * not specified in the header --- it's just whatever remains in the message. * * walEnd and sendTime are not essential data, but are provided in case * the receiver wants to adjust its behavior depending on how far behind * it is. */ typedef struct { /* WAL start location of the data included in this message */ XLogRecPtr dataStart; /* Current end of WAL on the sender */ XLogRecPtr walEnd; /* Sender's system clock at the time of transmission */ TimestampTz sendTime; XLogRecPtr sender_sent_location; XLogRecPtr sender_write_location; XLogRecPtr sender_flush_location; XLogRecPtr sender_replay_location; bool catchup; } WalDataMessageHeader; /* * Header for a data replication message (message type 'd'). This is wrapped within * a CopyData message at the FE/BE protocol level. * * The header is followed by actual data page. Note that the data length is * not specified in the header --- it's just whatever remains in the message. * * walEnd and sendTime are not essential data, but are provided in case * the receiver wants to adjust its behavior depending on how far behind * it is. */ typedef struct { /* the corresponding data_start_ptr and data_end_ptr */ XLogRecPtr start_ptr; XLogRecPtr end_ptr; /* Sender's system clock at the time of transmission */ TimestampTz sendTime; } WalDataPageMessageHeader; /* * Refence :ArchiveXlogMessage */ typedef struct ArchiveXlogMessage { XLogRecPtr targetLsn; uint term; int sub_term; uint slice; uint32 tli; char slot_name[NAMEDATALEN]; } ArchiveXlogMessage; /* * Refence :ArchiveXlogResponseMessage */ typedef struct ArchiveXlogResponseMessage { bool pitr_result; XLogRecPtr targetLsn; char slot_name[NAMEDATALEN]; } ArchiveXlogResponseMessage; /* * Keepalive message from primary (message type 'k'). (lowercase k) * This is wrapped within a CopyData message at the FE/BE protocol level. * * Note that the data length is not specified here. */ typedef WalSndrMessage PrimaryKeepaliveMessage; /* * switchover response */ typedef enum { SWITCHOVER_NONE = 0, SWITCHOVER_PROMOTE_REQUEST, SWITCHOVER_DEMOTE_FAILED, SWITCHOVER_DEMOTE_CATCHUP_EXIST } SwitchResponseCode; typedef enum { PITR_TASK_NONE = 0, PITR_TASK_GET, PITR_TASK_DONE } PITR_TASK_STATUS; /* * switchover response message from primary (message type 'p'). This is wrapped within * a CopyData message at the FE/BE protocol level. * * Note that the data length is not specified here. */ typedef struct { int switchResponse; /* Current end of WAL on the sender */ XLogRecPtr walEnd; /* Sender's system clock at the time of transmission */ TimestampTz sendTime; } PrimarySwitchResponseMessage; /* * Reply message from standby (message type 'r'). This is wrapped within * a CopyData message at the FE/BE protocol level. * * Note that the data length is not specified here. */ typedef struct StandbyReplyMessage { /* * The xlog locations that have been received, written, flushed, and applied by * standby-side. These may be invalid if the standby-side is unable to or * chooses not to report these. */ XLogRecPtr receive; XLogRecPtr write; XLogRecPtr flush; XLogRecPtr apply; XLogRecPtr applyRead; /* local role on walreceiver, they will be sent to walsender */ ServerMode peer_role; DbState peer_state; /* Sender's system clock at the time of transmission */ TimestampTz sendTime; /* * If replyRequested is set, the server should reply immediately to this * message, to avoid a timeout disconnect. */ bool replyRequested; /* flag array * 0x00000001 flag IS_PAUSE_BY_TARGET_BARRIER * * 0x00000010 flag IS_CANCEL_LOG_CTRL * If this flag is true, the walsend will set */ uint32 replyFlags; } StandbyReplyMessage; typedef struct UwalCatchEndMessage { /* Sender's system clock at the time of transmission */ TimestampTz sendTime; bool replyRequested; } UwalCatchEndMessage; /* * Hot Standby feedback from standby (message type 'h'). This is wrapped within * a CopyData message at the FE/BE protocol level. * * Note that the data length is not specified here. */ typedef struct StandbyHSFeedbackMessage { /* * The current xmin and epoch from the standby, for Hot Standby feedback. * This may be invalid if the standby-side does not support feedback, or * Hot Standby is not yet available. */ TransactionId xmin; /* Sender's system clock at the time of transmission */ TimestampTz sendTime; } StandbyHSFeedbackMessage; /* * @@GaussDB@@ * switchover request message from standby (message type 's'). This is wrapped within * a CopyData message at the FE/BE protocol level. * * Note that the data length is not specified here. */ typedef struct StandbySwitchRequestMessage { /* primary demote mode */ int demoteMode; /* receiver's system clock at the time of transmission */ TimestampTz sendTime; } StandbySwitchRequestMessage; /* * @@GaussDB@@ * switchover request message from standby (message type 'C'). This is wrapped within * a CopyData message at the FE/BE protocol level. * * Note that the data length is not specified here. */ typedef struct { /* instance name of slot to be cleaned */ NameData slotName; /* receiver's system clock at the time of transmission */ TimestampTz sendTime; } CleanSlotRequestMessage; /* * @@GaussDB@@ * switchover request message from standby (message type 'S'). This is wrapped within * a CopyData message at the FE/BE protocol level. * * Note that the data length is not specified here. */ typedef struct { /* cleaned slot name */ NameData slotName; /* receiver's system clock at the time of transmission */ TimestampTz sendTime; } CompleteCleanSlotRequestMessage; /* * switchover request message in the streaming dr (message type ''). This is wrapped within * a CopyData message at the FE/BE protocol level. * * */ typedef struct { /* The barrier LSN used by the streaming dr switchover this time */ XLogRecPtr switchoverBarrierLsn; bool isMasterInstanceReady; } HadrSwitchoverMessage; /* * Reply message from hadr standby (message type 'R'). * * Note that the data length is not specified here. */ typedef struct HadrReplyMessage { /* The target barrier Id in standby cluster */ char targetBarrierId[MAX_BARRIER_ID_LENGTH]; /* receiver's system clock at the time of transmission */ TimestampTz sendTime; /* The target barrier LSN used by the streaming dr */ XLogRecPtr targetBarrierLsn; /* reserved fields */ uint32 pad1; uint32 pad2; uint64 pad3; uint64 pad4; } HadrReplyMessage; /* * Maximum data payload in a WAL data message. Must be >= XLOG_BLCKSZ. * * We don't have a good idea of what a good value would be; there's some * overhead per message in both walsender and walreceiver, but on the other * hand sending large batches makes walsender less responsive to signals * because signals are checked only between messages. 128kB (with * default 8k blocks) seems like a reasonable guess for now. */ #define MAX_SEND_SIZE (XLOG_BLCKSZ * 16) #endif /* _WALPROTOCOL_H */