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walreceiver.h
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1 /*-------------------------------------------------------------------------
2  *
3  * walreceiver.h
4  * Exports from replication/walreceiverfuncs.c.
5  *
6  * Portions Copyright (c) 2010-2019, 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 "access/xlog.h"
16 #include "access/xlogdefs.h"
17 #include "getaddrinfo.h" /* for NI_MAXHOST */
19 #include "replication/walsender.h"
20 #include "storage/latch.h"
21 #include "storage/spin.h"
22 #include "pgtime.h"
23 #include "utils/tuplestore.h"
24 
25 /* user-settable parameters */
27 extern int wal_receiver_timeout;
28 extern bool hot_standby_feedback;
29 
30 /*
31  * MAXCONNINFO: maximum size of a connection string.
32  *
33  * XXX: Should this move to pg_config_manual.h?
34  */
35 #define MAXCONNINFO 1024
36 
37 /* Can we allow the standby to accept replication connection from another standby? */
38 #define AllowCascadeReplication() (EnableHotStandby && max_wal_senders > 0)
39 
40 /*
41  * Values for WalRcv->walRcvState.
42  */
43 typedef enum
44 {
45  WALRCV_STOPPED, /* stopped and mustn't start up again */
46  WALRCV_STARTING, /* launched, but the process hasn't
47  * initialized yet */
48  WALRCV_STREAMING, /* walreceiver is streaming */
49  WALRCV_WAITING, /* stopped streaming, waiting for orders */
50  WALRCV_RESTARTING, /* asked to restart streaming */
51  WALRCV_STOPPING /* requested to stop, but still running */
52 } WalRcvState;
53 
54 /* Shared memory area for management of walreceiver process */
55 typedef struct
56 {
57  /*
58  * PID of currently active walreceiver process, its current state and
59  * start time (actually, the time at which it was requested to be
60  * started).
61  */
62  pid_t pid;
65 
66  /*
67  * receiveStart and receiveStartTLI indicate the first byte position and
68  * timeline that will be received. When startup process starts the
69  * walreceiver, it sets these to the point where it wants the streaming to
70  * begin.
71  */
74 
75  /*
76  * receivedUpto-1 is the last byte position that has already been
77  * received, and receivedTLI is the timeline it came from. At the first
78  * startup of walreceiver, these are set to receiveStart and
79  * receiveStartTLI. After that, walreceiver updates these whenever it
80  * flushes the received WAL to disk.
81  */
84 
85  /*
86  * latestChunkStart is the starting byte position of the current "batch"
87  * of received WAL. It's actually the same as the previous value of
88  * receivedUpto before the last flush to disk. Startup process can use
89  * this to detect whether it's keeping up or not.
90  */
92 
93  /*
94  * Time of send and receive of any message received.
95  */
98 
99  /*
100  * Latest reported end of WAL on the sender
101  */
104 
105  /*
106  * connection string; initially set to connect to the primary, and later
107  * clobbered to hide security-sensitive fields.
108  */
109  char conninfo[MAXCONNINFO];
110 
111  /*
112  * Host name (this can be a host name, an IP address, or a directory path)
113  * and port number of the active replication connection.
114  */
115  char sender_host[NI_MAXHOST];
117 
118  /*
119  * replication slot name; is also used for walreceiver to connect with the
120  * primary
121  */
122  char slotname[NAMEDATALEN];
123 
124  /* set true once conninfo is ready to display (obfuscated pwds etc) */
126 
127  /*
128  * Latch used by startup process to wake up walreceiver after telling it
129  * where to start streaming (after setting receiveStart and
130  * receiveStartTLI), and also to tell it to send apply feedback to the
131  * primary whenever specially marked commit records are applied. This is
132  * normally mapped to procLatch when walreceiver is running.
133  */
135 
136  slock_t mutex; /* locks shared variables shown above */
137 
138  /*
139  * force walreceiver reply? This doesn't need to be locked; memory
140  * barriers for ordering are sufficient. But we do need atomic fetch and
141  * store semantics, so use sig_atomic_t.
142  */
143  sig_atomic_t force_reply; /* used as a bool */
144 } WalRcvData;
145 
146 extern WalRcvData *WalRcv;
147 
148 typedef struct
149 {
150  bool logical; /* True if this is logical replication stream,
151  * false if physical stream. */
152  char *slotname; /* Name of the replication slot or NULL. */
153  XLogRecPtr startpoint; /* LSN of starting point. */
154 
155  union
156  {
157  struct
158  {
159  TimeLineID startpointTLI; /* Starting timeline */
160  } physical;
161  struct
162  {
163  uint32 proto_version; /* Logical protocol version */
164  List *publication_names; /* String list of publications */
165  } logical;
166  } proto;
168 
169 struct WalReceiverConn;
171 
172 /*
173  * Status of walreceiver query execution.
174  *
175  * We only define statuses that are currently used.
176  */
177 typedef enum
178 {
179  WALRCV_ERROR, /* There was error when executing the query. */
180  WALRCV_OK_COMMAND, /* Query executed utility or replication
181  * command. */
182  WALRCV_OK_TUPLES, /* Query returned tuples. */
183  WALRCV_OK_COPY_IN, /* Query started COPY FROM. */
184  WALRCV_OK_COPY_OUT, /* Query started COPY TO. */
185  WALRCV_OK_COPY_BOTH /* Query started COPY BOTH replication
186  * protocol. */
188 
189 /*
190  * Return value for walrcv_exec, returns the status of the execution and
191  * tuples if any.
192  */
193 typedef struct WalRcvExecResult
194 {
196  char *err;
200 
201 /* libpqwalreceiver hooks */
202 typedef WalReceiverConn *(*walrcv_connect_fn) (const char *conninfo, bool logical,
203  const char *appname,
204  char **err);
205 typedef void (*walrcv_check_conninfo_fn) (const char *conninfo);
206 typedef char *(*walrcv_get_conninfo_fn) (WalReceiverConn *conn);
208  char **sender_host,
209  int *sender_port);
210 typedef char *(*walrcv_identify_system_fn) (WalReceiverConn *conn,
211  TimeLineID *primary_tli);
214  TimeLineID tli,
215  char **filename,
216  char **content, int *size);
220  TimeLineID *next_tli);
221 typedef int (*walrcv_receive_fn) (WalReceiverConn *conn, char **buffer,
222  pgsocket *wait_fd);
223 typedef void (*walrcv_send_fn) (WalReceiverConn *conn, const char *buffer,
224  int nbytes);
225 typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn,
226  const char *slotname, bool temporary,
227  CRSSnapshotAction snapshot_action,
228  XLogRecPtr *lsn);
229 typedef WalRcvExecResult *(*walrcv_exec_fn) (WalReceiverConn *conn,
230  const char *query,
231  const int nRetTypes,
232  const Oid *retTypes);
234 
236 {
252 
254 
255 #define walrcv_connect(conninfo, logical, appname, err) \
256  WalReceiverFunctions->walrcv_connect(conninfo, logical, appname, err)
257 #define walrcv_check_conninfo(conninfo) \
258  WalReceiverFunctions->walrcv_check_conninfo(conninfo)
259 #define walrcv_get_conninfo(conn) \
260  WalReceiverFunctions->walrcv_get_conninfo(conn)
261 #define walrcv_get_senderinfo(conn, sender_host, sender_port) \
262  WalReceiverFunctions->walrcv_get_senderinfo(conn, sender_host, sender_port)
263 #define walrcv_identify_system(conn, primary_tli) \
264  WalReceiverFunctions->walrcv_identify_system(conn, primary_tli)
265 #define walrcv_server_version(conn) \
266  WalReceiverFunctions->walrcv_server_version(conn)
267 #define walrcv_readtimelinehistoryfile(conn, tli, filename, content, size) \
268  WalReceiverFunctions->walrcv_readtimelinehistoryfile(conn, tli, filename, content, size)
269 #define walrcv_startstreaming(conn, options) \
270  WalReceiverFunctions->walrcv_startstreaming(conn, options)
271 #define walrcv_endstreaming(conn, next_tli) \
272  WalReceiverFunctions->walrcv_endstreaming(conn, next_tli)
273 #define walrcv_receive(conn, buffer, wait_fd) \
274  WalReceiverFunctions->walrcv_receive(conn, buffer, wait_fd)
275 #define walrcv_send(conn, buffer, nbytes) \
276  WalReceiverFunctions->walrcv_send(conn, buffer, nbytes)
277 #define walrcv_create_slot(conn, slotname, temporary, snapshot_action, lsn) \
278  WalReceiverFunctions->walrcv_create_slot(conn, slotname, temporary, snapshot_action, lsn)
279 #define walrcv_exec(conn, exec, nRetTypes, retTypes) \
280  WalReceiverFunctions->walrcv_exec(conn, exec, nRetTypes, retTypes)
281 #define walrcv_disconnect(conn) \
282  WalReceiverFunctions->walrcv_disconnect(conn)
283 
284 static inline void
286 {
287  if (!walres)
288  return;
289 
290  if (walres->err)
291  pfree(walres->err);
292 
293  if (walres->tuplestore)
294  tuplestore_end(walres->tuplestore);
295 
296  if (walres->tupledesc)
297  FreeTupleDesc(walres->tupledesc);
298 
299  pfree(walres);
300 }
301 
302 /* prototypes for functions in walreceiver.c */
303 extern void WalReceiverMain(void) pg_attribute_noreturn();
304 extern void ProcessWalRcvInterrupts(void);
305 
306 /* prototypes for functions in walreceiverfuncs.c */
307 extern Size WalRcvShmemSize(void);
308 extern void WalRcvShmemInit(void);
309 extern void ShutdownWalRcv(void);
310 extern bool WalRcvStreaming(void);
311 extern bool WalRcvRunning(void);
312 extern void RequestXLogStreaming(TimeLineID tli, XLogRecPtr recptr,
313  const char *conninfo, const char *slotname);
315 extern int GetReplicationApplyDelay(void);
316 extern int GetReplicationTransferLatency(void);
317 extern void WalRcvForceReply(void);
318 
319 #endif /* _WALRECEIVER_H */
walrcv_identify_system_fn walrcv_identify_system
Definition: walreceiver.h:241
int sender_port
Definition: walreceiver.h:116
int slock_t
Definition: s_lock.h:934
XLogRecPtr GetWalRcvWriteRecPtr(XLogRecPtr *latestChunkStart, TimeLineID *receiveTLI)
bool hot_standby_feedback
Definition: walreceiver.c:77
bool WalRcvStreaming(void)
walrcv_server_version_fn walrcv_server_version
Definition: walreceiver.h:242
uint32 TimeLineID
Definition: xlogdefs.h:52
int64 pg_time_t
Definition: pgtime.h:23
void ShutdownWalRcv(void)
slock_t mutex
Definition: walreceiver.h:136
walrcv_startstreaming_fn walrcv_startstreaming
Definition: walreceiver.h:244
PGDLLIMPORT WalReceiverFunctionsType * WalReceiverFunctions
Definition: walreceiver.c:81
int64 TimestampTz
Definition: timestamp.h:39
sig_atomic_t force_reply
Definition: walreceiver.h:143
WalRcvState walRcvState
Definition: walreceiver.h:63
WalReceiverConn *(* walrcv_connect_fn)(const char *conninfo, bool logical, const char *appname, char **err)
Definition: walreceiver.h:202
void(* walrcv_disconnect_fn)(WalReceiverConn *conn)
Definition: walreceiver.h:233
WalRcvExecStatus
Definition: walreceiver.h:177
TimeLineID receivedTLI
Definition: walreceiver.h:83
void ProcessWalRcvInterrupts(void)
Definition: walreceiver.c:147
unsigned int Oid
Definition: postgres_ext.h:31
TimestampTz lastMsgReceiptTime
Definition: walreceiver.h:97
TimestampTz lastMsgSendTime
Definition: walreceiver.h:96
pg_time_t startTime
Definition: walreceiver.h:64
int GetReplicationApplyDelay(void)
#define PGDLLIMPORT
Definition: c.h:1243
void WalRcvShmemInit(void)
WalRcvState
Definition: walreceiver.h:43
walrcv_receive_fn walrcv_receive
Definition: walreceiver.h:246
#define NAMEDATALEN
WalRcvData * WalRcv
static void walrcv_clear_result(WalRcvExecResult *walres)
Definition: walreceiver.h:285
void pfree(void *pointer)
Definition: mcxt.c:1056
#define NI_MAXHOST
Definition: getaddrinfo.h:88
struct WalRcvExecResult WalRcvExecResult
TupleDesc tupledesc
Definition: walreceiver.h:198
void WalRcvForceReply(void)
Definition: walreceiver.c:1297
PGconn * conn
Definition: streamutil.c:56
pid_t pid
Definition: walreceiver.h:62
#define MAXCONNINFO
Definition: walreceiver.h:35
XLogRecPtr latestChunkStart
Definition: walreceiver.h:91
int wal_receiver_timeout
Definition: walreceiver.c:76
int GetReplicationTransferLatency(void)
Definition: latch.h:110
void(* walrcv_send_fn)(WalReceiverConn *conn, const char *buffer, int nbytes)
Definition: walreceiver.h:223
walrcv_send_fn walrcv_send
Definition: walreceiver.h:247
char *(* walrcv_create_slot_fn)(WalReceiverConn *conn, const char *slotname, bool temporary, CRSSnapshotAction snapshot_action, XLogRecPtr *lsn)
Definition: walreceiver.h:225
XLogRecPtr startpoint
Definition: walreceiver.h:153
unsigned int uint32
Definition: c.h:358
int pgsocket
Definition: port.h:31
XLogRecPtr receivedUpto
Definition: walreceiver.h:82
TimeLineID receiveStartTLI
Definition: walreceiver.h:73
void(* walrcv_get_senderinfo_fn)(WalReceiverConn *conn, char **sender_host, int *sender_port)
Definition: walreceiver.h:207
Latch * latch
Definition: walreceiver.h:134
static char ** options
WalRcvExecResult *(* walrcv_exec_fn)(WalReceiverConn *conn, const char *query, const int nRetTypes, const Oid *retTypes)
Definition: walreceiver.h:229
void(* walrcv_check_conninfo_fn)(const char *conninfo)
Definition: walreceiver.h:205
static TimeLineID receiveTLI
Definition: xlog.c:209
void(* walrcv_readtimelinehistoryfile_fn)(WalReceiverConn *conn, TimeLineID tli, char **filename, char **content, int *size)
Definition: walreceiver.h:213
int(* walrcv_receive_fn)(WalReceiverConn *conn, char **buffer, pgsocket *wait_fd)
Definition: walreceiver.h:221
bool ready_to_display
Definition: walreceiver.h:125
bool(* walrcv_startstreaming_fn)(WalReceiverConn *conn, const WalRcvStreamOptions *options)
Definition: walreceiver.h:217
walrcv_get_conninfo_fn walrcv_get_conninfo
Definition: walreceiver.h:239
walrcv_disconnect_fn walrcv_disconnect
Definition: walreceiver.h:250
TimestampTz latestWalEndTime
Definition: walreceiver.h:103
walrcv_endstreaming_fn walrcv_endstreaming
Definition: walreceiver.h:245
int wal_receiver_status_interval
Definition: walreceiver.c:75
XLogRecPtr latestWalEnd
Definition: walreceiver.h:102
void RequestXLogStreaming(TimeLineID tli, XLogRecPtr recptr, const char *conninfo, const char *slotname)
Tuplestorestate * tuplestore
Definition: walreceiver.h:197
walrcv_readtimelinehistoryfile_fn walrcv_readtimelinehistoryfile
Definition: walreceiver.h:243
uint64 XLogRecPtr
Definition: xlogdefs.h:21
WalRcvExecStatus status
Definition: walreceiver.h:195
walrcv_get_senderinfo_fn walrcv_get_senderinfo
Definition: walreceiver.h:240
void WalReceiverMain(void) pg_attribute_noreturn()
Definition: walreceiver.c:167
void(* walrcv_endstreaming_fn)(WalReceiverConn *conn, TimeLineID *next_tli)
Definition: walreceiver.h:219
size_t Size
Definition: c.h:466
Size WalRcvShmemSize(void)
void tuplestore_end(Tuplestorestate *state)
Definition: tuplestore.c:453
walrcv_exec_fn walrcv_exec
Definition: walreceiver.h:249
struct WalReceiverFunctionsType WalReceiverFunctionsType
void FreeTupleDesc(TupleDesc tupdesc)
Definition: tupdesc.c:313
#define pg_attribute_noreturn()
Definition: c.h:147
static char * filename
Definition: pg_dumpall.c:91
walrcv_create_slot_fn walrcv_create_slot
Definition: walreceiver.h:248
bool WalRcvRunning(void)
CRSSnapshotAction
Definition: walsender.h:20
TimeLineID startpointTLI
Definition: walreceiver.h:159
walrcv_check_conninfo_fn walrcv_check_conninfo
Definition: walreceiver.h:238
XLogRecPtr receiveStart
Definition: walreceiver.h:72
char *(* walrcv_get_conninfo_fn)(WalReceiverConn *conn)
Definition: walreceiver.h:206
int(* walrcv_server_version_fn)(WalReceiverConn *conn)
Definition: walreceiver.h:212
walrcv_connect_fn walrcv_connect
Definition: walreceiver.h:237
Definition: pg_list.h:50
unsigned char bool
Definition: c.h:308
char *(* walrcv_identify_system_fn)(WalReceiverConn *conn, TimeLineID *primary_tli)
Definition: walreceiver.h:210