Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * walreceiver.h
4 : : * Exports from replication/walreceiverfuncs.c.
5 : : *
6 : : * Portions Copyright (c) 2010-2024, PostgreSQL Global Development Group
7 : : *
8 : : * src/include/replication/walreceiver.h
9 : : *
10 : : *-------------------------------------------------------------------------
11 : : */
12 : : #ifndef _WALRECEIVER_H
13 : : #define _WALRECEIVER_H
14 : :
15 : : #include <netdb.h>
16 : :
17 : : #include "access/xlog.h"
18 : : #include "access/xlogdefs.h"
19 : : #include "pgtime.h"
20 : : #include "port/atomics.h"
21 : : #include "replication/logicalproto.h"
22 : : #include "replication/walsender.h"
23 : : #include "storage/condition_variable.h"
24 : : #include "storage/latch.h"
25 : : #include "storage/spin.h"
26 : : #include "utils/tuplestore.h"
27 : :
28 : : /* user-settable parameters */
29 : : extern PGDLLIMPORT int wal_receiver_status_interval;
30 : : extern PGDLLIMPORT int wal_receiver_timeout;
31 : : extern PGDLLIMPORT bool hot_standby_feedback;
32 : :
33 : : /*
34 : : * MAXCONNINFO: maximum size of a connection string.
35 : : *
36 : : * XXX: Should this move to pg_config_manual.h?
37 : : */
38 : : #define MAXCONNINFO 1024
39 : :
40 : : /* Can we allow the standby to accept replication connection from another standby? */
41 : : #define AllowCascadeReplication() (EnableHotStandby && max_wal_senders > 0)
42 : :
43 : : /*
44 : : * Values for WalRcv->walRcvState.
45 : : */
46 : : typedef enum
47 : : {
48 : : WALRCV_STOPPED, /* stopped and mustn't start up again */
49 : : WALRCV_STARTING, /* launched, but the process hasn't
50 : : * initialized yet */
51 : : WALRCV_STREAMING, /* walreceiver is streaming */
52 : : WALRCV_WAITING, /* stopped streaming, waiting for orders */
53 : : WALRCV_RESTARTING, /* asked to restart streaming */
54 : : WALRCV_STOPPING, /* requested to stop, but still running */
55 : : } WalRcvState;
56 : :
57 : : /* Shared memory area for management of walreceiver process */
58 : : typedef struct
59 : : {
60 : : /*
61 : : * PID of currently active walreceiver process, its current state and
62 : : * start time (actually, the time at which it was requested to be
63 : : * started).
64 : : */
65 : : pid_t pid;
66 : : WalRcvState walRcvState;
67 : : ConditionVariable walRcvStoppedCV;
68 : : pg_time_t startTime;
69 : :
70 : : /*
71 : : * receiveStart and receiveStartTLI indicate the first byte position and
72 : : * timeline that will be received. When startup process starts the
73 : : * walreceiver, it sets these to the point where it wants the streaming to
74 : : * begin.
75 : : */
76 : : XLogRecPtr receiveStart;
77 : : TimeLineID receiveStartTLI;
78 : :
79 : : /*
80 : : * flushedUpto-1 is the last byte position that has already been received,
81 : : * and receivedTLI is the timeline it came from. At the first startup of
82 : : * walreceiver, these are set to receiveStart and receiveStartTLI. After
83 : : * that, walreceiver updates these whenever it flushes the received WAL to
84 : : * disk.
85 : : */
86 : : XLogRecPtr flushedUpto;
87 : : TimeLineID receivedTLI;
88 : :
89 : : /*
90 : : * latestChunkStart is the starting byte position of the current "batch"
91 : : * of received WAL. It's actually the same as the previous value of
92 : : * flushedUpto before the last flush to disk. Startup process can use
93 : : * this to detect whether it's keeping up or not.
94 : : */
95 : : XLogRecPtr latestChunkStart;
96 : :
97 : : /*
98 : : * Time of send and receive of any message received.
99 : : */
100 : : TimestampTz lastMsgSendTime;
101 : : TimestampTz lastMsgReceiptTime;
102 : :
103 : : /*
104 : : * Latest reported end of WAL on the sender
105 : : */
106 : : XLogRecPtr latestWalEnd;
107 : : TimestampTz latestWalEndTime;
108 : :
109 : : /*
110 : : * connection string; initially set to connect to the primary, and later
111 : : * clobbered to hide security-sensitive fields.
112 : : */
113 : : char conninfo[MAXCONNINFO];
114 : :
115 : : /*
116 : : * Host name (this can be a host name, an IP address, or a directory path)
117 : : * and port number of the active replication connection.
118 : : */
119 : : char sender_host[NI_MAXHOST];
120 : : int sender_port;
121 : :
122 : : /*
123 : : * replication slot name; is also used for walreceiver to connect with the
124 : : * primary
125 : : */
126 : : char slotname[NAMEDATALEN];
127 : :
128 : : /*
129 : : * If it's a temporary replication slot, it needs to be recreated when
130 : : * connecting.
131 : : */
132 : : bool is_temp_slot;
133 : :
134 : : /* set true once conninfo is ready to display (obfuscated pwds etc) */
135 : : bool ready_to_display;
136 : :
137 : : /*
138 : : * Latch used by startup process to wake up walreceiver after telling it
139 : : * where to start streaming (after setting receiveStart and
140 : : * receiveStartTLI), and also to tell it to send apply feedback to the
141 : : * primary whenever specially marked commit records are applied. This is
142 : : * normally mapped to procLatch when walreceiver is running.
143 : : */
144 : : Latch *latch;
145 : :
146 : : slock_t mutex; /* locks shared variables shown above */
147 : :
148 : : /*
149 : : * Like flushedUpto, but advanced after writing and before flushing,
150 : : * without the need to acquire the spin lock. Data can be read by another
151 : : * process up to this point, but shouldn't be used for data integrity
152 : : * purposes.
153 : : */
154 : : pg_atomic_uint64 writtenUpto;
155 : :
156 : : /*
157 : : * force walreceiver reply? This doesn't need to be locked; memory
158 : : * barriers for ordering are sufficient. But we do need atomic fetch and
159 : : * store semantics, so use sig_atomic_t.
160 : : */
161 : : sig_atomic_t force_reply; /* used as a bool */
162 : : } WalRcvData;
163 : :
164 : : extern PGDLLIMPORT WalRcvData *WalRcv;
165 : :
166 : : typedef struct
167 : : {
168 : : bool logical; /* True if this is logical replication stream,
169 : : * false if physical stream. */
170 : : char *slotname; /* Name of the replication slot or NULL. */
171 : : XLogRecPtr startpoint; /* LSN of starting point. */
172 : :
173 : : union
174 : : {
175 : : struct
176 : : {
177 : : TimeLineID startpointTLI; /* Starting timeline */
178 : : } physical;
179 : : struct
180 : : {
181 : : uint32 proto_version; /* Logical protocol version */
182 : : List *publication_names; /* String list of publications */
183 : : bool binary; /* Ask publisher to use binary */
184 : : char *streaming_str; /* Streaming of large transactions */
185 : : bool twophase; /* Streaming of two-phase transactions at
186 : : * prepare time */
187 : : char *origin; /* Only publish data originating from the
188 : : * specified origin */
189 : : } logical;
190 : : } proto;
191 : : } WalRcvStreamOptions;
192 : :
193 : : struct WalReceiverConn;
194 : : typedef struct WalReceiverConn WalReceiverConn;
195 : :
196 : : /*
197 : : * Status of walreceiver query execution.
198 : : *
199 : : * We only define statuses that are currently used.
200 : : */
201 : : typedef enum
202 : : {
203 : : WALRCV_ERROR, /* There was error when executing the query. */
204 : : WALRCV_OK_COMMAND, /* Query executed utility or replication
205 : : * command. */
206 : : WALRCV_OK_TUPLES, /* Query returned tuples. */
207 : : WALRCV_OK_COPY_IN, /* Query started COPY FROM. */
208 : : WALRCV_OK_COPY_OUT, /* Query started COPY TO. */
209 : : WALRCV_OK_COPY_BOTH, /* Query started COPY BOTH replication
210 : : * protocol. */
211 : : } WalRcvExecStatus;
212 : :
213 : : /*
214 : : * Return value for walrcv_exec, returns the status of the execution and
215 : : * tuples if any.
216 : : */
217 : : typedef struct WalRcvExecResult
218 : : {
219 : : WalRcvExecStatus status;
220 : : int sqlstate;
221 : : char *err;
222 : : Tuplestorestate *tuplestore;
223 : : TupleDesc tupledesc;
224 : : } WalRcvExecResult;
225 : :
226 : : /* WAL receiver - libpqwalreceiver hooks */
227 : :
228 : : /*
229 : : * walrcv_connect_fn
230 : : *
231 : : * Establish connection to a cluster. 'replication' is true if the
232 : : * connection is a replication connection, and false if it is a
233 : : * regular connection. If it is a replication connection, it could
234 : : * be either logical or physical based on input argument 'logical'.
235 : : * 'appname' is a name associated to the connection, to use for example
236 : : * with fallback_application_name or application_name. Returns the
237 : : * details about the connection established, as defined by
238 : : * WalReceiverConn for each WAL receiver module. On error, NULL is
239 : : * returned with 'err' including the error generated.
240 : : */
241 : : typedef WalReceiverConn *(*walrcv_connect_fn) (const char *conninfo,
242 : : bool replication,
243 : : bool logical,
244 : : bool must_use_password,
245 : : const char *appname,
246 : : char **err);
247 : :
248 : : /*
249 : : * walrcv_check_conninfo_fn
250 : : *
251 : : * Parse and validate the connection string given as of 'conninfo'.
252 : : */
253 : : typedef void (*walrcv_check_conninfo_fn) (const char *conninfo,
254 : : bool must_use_password);
255 : :
256 : : /*
257 : : * walrcv_get_conninfo_fn
258 : : *
259 : : * Returns a user-displayable conninfo string. Note that any
260 : : * security-sensitive fields should be obfuscated.
261 : : */
262 : : typedef char *(*walrcv_get_conninfo_fn) (WalReceiverConn *conn);
263 : :
264 : : /*
265 : : * walrcv_get_senderinfo_fn
266 : : *
267 : : * Provide information of the WAL sender this WAL receiver is connected
268 : : * to, as of 'sender_host' for the host of the sender and 'sender_port'
269 : : * for its port.
270 : : */
271 : : typedef void (*walrcv_get_senderinfo_fn) (WalReceiverConn *conn,
272 : : char **sender_host,
273 : : int *sender_port);
274 : :
275 : : /*
276 : : * walrcv_identify_system_fn
277 : : *
278 : : * Run IDENTIFY_SYSTEM on the cluster connected to and validate the
279 : : * identity of the cluster. Returns the system ID of the cluster
280 : : * connected to. 'primary_tli' is the timeline ID of the sender.
281 : : */
282 : : typedef char *(*walrcv_identify_system_fn) (WalReceiverConn *conn,
283 : : TimeLineID *primary_tli);
284 : :
285 : : /*
286 : : * walrcv_get_dbname_from_conninfo_fn
287 : : *
288 : : * Returns the database name from the primary_conninfo
289 : : */
290 : : typedef char *(*walrcv_get_dbname_from_conninfo_fn) (const char *conninfo);
291 : :
292 : : /*
293 : : * walrcv_server_version_fn
294 : : *
295 : : * Returns the version number of the cluster connected to.
296 : : */
297 : : typedef int (*walrcv_server_version_fn) (WalReceiverConn *conn);
298 : :
299 : : /*
300 : : * walrcv_readtimelinehistoryfile_fn
301 : : *
302 : : * Fetch from cluster the timeline history file for timeline 'tli'.
303 : : * Returns the name of the timeline history file as of 'filename', its
304 : : * contents as of 'content' and its 'size'.
305 : : */
306 : : typedef void (*walrcv_readtimelinehistoryfile_fn) (WalReceiverConn *conn,
307 : : TimeLineID tli,
308 : : char **filename,
309 : : char **content,
310 : : int *size);
311 : :
312 : : /*
313 : : * walrcv_startstreaming_fn
314 : : *
315 : : * Start streaming WAL data from given streaming options. Returns true
316 : : * if the connection has switched successfully to copy-both mode and false
317 : : * if the server received the command and executed it successfully, but
318 : : * didn't switch to copy-mode.
319 : : */
320 : : typedef bool (*walrcv_startstreaming_fn) (WalReceiverConn *conn,
321 : : const WalRcvStreamOptions *options);
322 : :
323 : : /*
324 : : * walrcv_endstreaming_fn
325 : : *
326 : : * Stop streaming of WAL data. Returns the next timeline ID of the cluster
327 : : * connected to in 'next_tli', or 0 if there was no report.
328 : : */
329 : : typedef void (*walrcv_endstreaming_fn) (WalReceiverConn *conn,
330 : : TimeLineID *next_tli);
331 : :
332 : : /*
333 : : * walrcv_receive_fn
334 : : *
335 : : * Receive a message available from the WAL stream. 'buffer' is a pointer
336 : : * to a buffer holding the message received. Returns the length of the data,
337 : : * 0 if no data is available yet ('wait_fd' is a socket descriptor which can
338 : : * be waited on before a retry), and -1 if the cluster ended the COPY.
339 : : */
340 : : typedef int (*walrcv_receive_fn) (WalReceiverConn *conn,
341 : : char **buffer,
342 : : pgsocket *wait_fd);
343 : :
344 : : /*
345 : : * walrcv_send_fn
346 : : *
347 : : * Send a message of size 'nbytes' to the WAL stream with 'buffer' as
348 : : * contents.
349 : : */
350 : : typedef void (*walrcv_send_fn) (WalReceiverConn *conn,
351 : : const char *buffer,
352 : : int nbytes);
353 : :
354 : : /*
355 : : * walrcv_create_slot_fn
356 : : *
357 : : * Create a new replication slot named 'slotname'. 'temporary' defines
358 : : * if the slot is temporary. 'snapshot_action' defines the behavior wanted
359 : : * for an exported snapshot (see replication protocol for more details).
360 : : * 'lsn' includes the LSN position at which the created slot became
361 : : * consistent. Returns the name of the exported snapshot for a logical
362 : : * slot, or NULL for a physical slot.
363 : : */
364 : : typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
365 : : const char *slotname,
366 : : bool temporary,
367 : : bool two_phase,
368 : : bool failover,
369 : : CRSSnapshotAction snapshot_action,
370 : : XLogRecPtr *lsn);
371 : :
372 : : /*
373 : : * walrcv_alter_slot_fn
374 : : *
375 : : * Change the definition of a replication slot. Currently, it only supports
376 : : * changing the failover property of the slot.
377 : : */
378 : : typedef void (*walrcv_alter_slot_fn) (WalReceiverConn *conn,
379 : : const char *slotname,
380 : : bool failover);
381 : :
382 : : /*
383 : : * walrcv_get_backend_pid_fn
384 : : *
385 : : * Returns the PID of the remote backend process.
386 : : */
387 : : typedef pid_t (*walrcv_get_backend_pid_fn) (WalReceiverConn *conn);
388 : :
389 : : /*
390 : : * walrcv_exec_fn
391 : : *
392 : : * Send generic queries (and commands) to the remote cluster. 'nRetTypes'
393 : : * is the expected number of returned attributes, and 'retTypes' an array
394 : : * including their type OIDs. Returns the status of the execution and
395 : : * tuples if any.
396 : : */
397 : : typedef WalRcvExecResult *(*walrcv_exec_fn) (WalReceiverConn *conn,
398 : : const char *query,
399 : : const int nRetTypes,
400 : : const Oid *retTypes);
401 : :
402 : : /*
403 : : * walrcv_disconnect_fn
404 : : *
405 : : * Disconnect with the cluster.
406 : : */
407 : : typedef void (*walrcv_disconnect_fn) (WalReceiverConn *conn);
408 : :
409 : : typedef struct WalReceiverFunctionsType
410 : : {
411 : : walrcv_connect_fn walrcv_connect;
412 : : walrcv_check_conninfo_fn walrcv_check_conninfo;
413 : : walrcv_get_conninfo_fn walrcv_get_conninfo;
414 : : walrcv_get_senderinfo_fn walrcv_get_senderinfo;
415 : : walrcv_identify_system_fn walrcv_identify_system;
416 : : walrcv_get_dbname_from_conninfo_fn walrcv_get_dbname_from_conninfo;
417 : : walrcv_server_version_fn walrcv_server_version;
418 : : walrcv_readtimelinehistoryfile_fn walrcv_readtimelinehistoryfile;
419 : : walrcv_startstreaming_fn walrcv_startstreaming;
420 : : walrcv_endstreaming_fn walrcv_endstreaming;
421 : : walrcv_receive_fn walrcv_receive;
422 : : walrcv_send_fn walrcv_send;
423 : : walrcv_create_slot_fn walrcv_create_slot;
424 : : walrcv_alter_slot_fn walrcv_alter_slot;
425 : : walrcv_get_backend_pid_fn walrcv_get_backend_pid;
426 : : walrcv_exec_fn walrcv_exec;
427 : : walrcv_disconnect_fn walrcv_disconnect;
428 : : } WalReceiverFunctionsType;
429 : :
430 : : extern PGDLLIMPORT WalReceiverFunctionsType *WalReceiverFunctions;
431 : :
432 : : #define walrcv_connect(conninfo, replication, logical, must_use_password, appname, err) \
433 : : WalReceiverFunctions->walrcv_connect(conninfo, replication, logical, must_use_password, appname, err)
434 : : #define walrcv_check_conninfo(conninfo, must_use_password) \
435 : : WalReceiverFunctions->walrcv_check_conninfo(conninfo, must_use_password)
436 : : #define walrcv_get_conninfo(conn) \
437 : : WalReceiverFunctions->walrcv_get_conninfo(conn)
438 : : #define walrcv_get_senderinfo(conn, sender_host, sender_port) \
439 : : WalReceiverFunctions->walrcv_get_senderinfo(conn, sender_host, sender_port)
440 : : #define walrcv_identify_system(conn, primary_tli) \
441 : : WalReceiverFunctions->walrcv_identify_system(conn, primary_tli)
442 : : #define walrcv_get_dbname_from_conninfo(conninfo) \
443 : : WalReceiverFunctions->walrcv_get_dbname_from_conninfo(conninfo)
444 : : #define walrcv_server_version(conn) \
445 : : WalReceiverFunctions->walrcv_server_version(conn)
446 : : #define walrcv_readtimelinehistoryfile(conn, tli, filename, content, size) \
447 : : WalReceiverFunctions->walrcv_readtimelinehistoryfile(conn, tli, filename, content, size)
448 : : #define walrcv_startstreaming(conn, options) \
449 : : WalReceiverFunctions->walrcv_startstreaming(conn, options)
450 : : #define walrcv_endstreaming(conn, next_tli) \
451 : : WalReceiverFunctions->walrcv_endstreaming(conn, next_tli)
452 : : #define walrcv_receive(conn, buffer, wait_fd) \
453 : : WalReceiverFunctions->walrcv_receive(conn, buffer, wait_fd)
454 : : #define walrcv_send(conn, buffer, nbytes) \
455 : : WalReceiverFunctions->walrcv_send(conn, buffer, nbytes)
456 : : #define walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn) \
457 : : WalReceiverFunctions->walrcv_create_slot(conn, slotname, temporary, two_phase, failover, snapshot_action, lsn)
458 : : #define walrcv_alter_slot(conn, slotname, failover) \
459 : : WalReceiverFunctions->walrcv_alter_slot(conn, slotname, failover)
460 : : #define walrcv_get_backend_pid(conn) \
461 : : WalReceiverFunctions->walrcv_get_backend_pid(conn)
462 : : #define walrcv_exec(conn, exec, nRetTypes, retTypes) \
463 : : WalReceiverFunctions->walrcv_exec(conn, exec, nRetTypes, retTypes)
464 : : #define walrcv_disconnect(conn) \
465 : : WalReceiverFunctions->walrcv_disconnect(conn)
466 : :
467 : : static inline void
2579 peter_e@gmx.net 468 :CBC 1656 : walrcv_clear_result(WalRcvExecResult *walres)
469 : : {
470 [ - + ]: 1656 : if (!walres)
2579 peter_e@gmx.net 471 :UBC 0 : return;
472 : :
2579 peter_e@gmx.net 473 [ - + ]:CBC 1656 : if (walres->err)
2579 peter_e@gmx.net 474 :UBC 0 : pfree(walres->err);
475 : :
2579 peter_e@gmx.net 476 [ + + ]:CBC 1656 : if (walres->tuplestore)
477 : 939 : tuplestore_end(walres->tuplestore);
478 : :
479 [ + + ]: 1656 : if (walres->tupledesc)
480 : 939 : FreeTupleDesc(walres->tupledesc);
481 : :
482 : 1656 : pfree(walres);
483 : : }
484 : :
485 : : /* prototypes for functions in walreceiver.c */
486 : : extern void WalReceiverMain(char *startup_data, size_t startup_data_len) pg_attribute_noreturn();
487 : : extern void ProcessWalRcvInterrupts(void);
488 : : extern void WalRcvForceReply(void);
489 : :
490 : : /* prototypes for functions in walreceiverfuncs.c */
491 : : extern Size WalRcvShmemSize(void);
492 : : extern void WalRcvShmemInit(void);
493 : : extern void ShutdownWalRcv(void);
494 : : extern bool WalRcvStreaming(void);
495 : : extern bool WalRcvRunning(void);
496 : : extern void RequestXLogStreaming(TimeLineID tli, XLogRecPtr recptr,
497 : : const char *conninfo, const char *slotname,
498 : : bool create_temp_slot);
499 : : extern XLogRecPtr GetWalRcvFlushRecPtr(XLogRecPtr *latestChunkStart, TimeLineID *receiveTLI);
500 : : extern XLogRecPtr GetWalRcvWriteRecPtr(void);
501 : : extern int GetReplicationApplyDelay(void);
502 : : extern int GetReplicationTransferLatency(void);
503 : :
504 : : #endif /* _WALRECEIVER_H */
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