PostgreSQL Source Code  git master
startup.c
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1 /*-------------------------------------------------------------------------
2  *
3  * startup.c
4  *
5  * The Startup process initialises the server and performs any recovery
6  * actions that have been specified. Notice that there is no "main loop"
7  * since the Startup process ends as soon as initialisation is complete.
8  * (in standby mode, one can think of the replay loop as a main loop,
9  * though.)
10  *
11  *
12  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
13  *
14  *
15  * IDENTIFICATION
16  * src/backend/postmaster/startup.c
17  *
18  *-------------------------------------------------------------------------
19  */
20 #include "postgres.h"
21 
22 #include "access/xlog.h"
23 #include "access/xlogrecovery.h"
24 #include "access/xlogutils.h"
25 #include "libpq/pqsignal.h"
26 #include "miscadmin.h"
27 #include "postmaster/auxprocess.h"
28 #include "postmaster/startup.h"
29 #include "storage/ipc.h"
30 #include "storage/pmsignal.h"
31 #include "storage/procsignal.h"
32 #include "storage/standby.h"
33 #include "utils/guc.h"
34 #include "utils/memutils.h"
35 #include "utils/timeout.h"
36 
37 
38 #ifndef USE_POSTMASTER_DEATH_SIGNAL
39 /*
40  * On systems that need to make a system call to find out if the postmaster has
41  * gone away, we'll do so only every Nth call to HandleStartupProcInterrupts().
42  * This only affects how long it takes us to detect the condition while we're
43  * busy replaying WAL. Latch waits and similar which should react immediately
44  * through the usual techniques.
45  */
46 #define POSTMASTER_POLL_RATE_LIMIT 1024
47 #endif
48 
49 /*
50  * Flags set by interrupt handlers for later service in the redo loop.
51  */
52 static volatile sig_atomic_t got_SIGHUP = false;
53 static volatile sig_atomic_t shutdown_requested = false;
54 static volatile sig_atomic_t promote_signaled = false;
55 
56 /*
57  * Flag set when executing a restore command, to tell SIGTERM signal handler
58  * that it's safe to just proc_exit.
59  */
60 static volatile sig_atomic_t in_restore_command = false;
61 
62 /*
63  * Time at which the most recent startup operation started.
64  */
66 
67 /*
68  * Indicates whether the startup progress interval mentioned by the user is
69  * elapsed or not. TRUE if timeout occurred, FALSE otherwise.
70  */
71 static volatile sig_atomic_t startup_progress_timer_expired = false;
72 
73 /*
74  * Time between progress updates for long-running startup operations.
75  */
76 int log_startup_progress_interval = 10000; /* 10 sec */
77 
78 /* Signal handlers */
81 
82 /* Callbacks */
83 static void StartupProcExit(int code, Datum arg);
84 
85 
86 /* --------------------------------
87  * signal handler routines
88  * --------------------------------
89  */
90 
91 /* SIGUSR2: set flag to finish recovery */
92 static void
94 {
95  promote_signaled = true;
97 }
98 
99 /* SIGHUP: set flag to re-read config file at next convenient time */
100 static void
102 {
103  got_SIGHUP = true;
104  WakeupRecovery();
105 }
106 
107 /* SIGTERM: set flag to abort redo and exit */
108 static void
110 {
111  if (in_restore_command)
112  proc_exit(1);
113  else
114  shutdown_requested = true;
115  WakeupRecovery();
116 }
117 
118 /*
119  * Re-read the config file.
120  *
121  * If one of the critical walreceiver options has changed, flag xlog.c
122  * to restart it.
123  */
124 static void
126 {
127  char *conninfo = pstrdup(PrimaryConnInfo);
128  char *slotname = pstrdup(PrimarySlotName);
129  bool tempSlot = wal_receiver_create_temp_slot;
130  bool conninfoChanged;
131  bool slotnameChanged;
132  bool tempSlotChanged = false;
133 
135 
136  conninfoChanged = strcmp(conninfo, PrimaryConnInfo) != 0;
137  slotnameChanged = strcmp(slotname, PrimarySlotName) != 0;
138 
139  /*
140  * wal_receiver_create_temp_slot is used only when we have no slot
141  * configured. We do not need to track this change if it has no effect.
142  */
143  if (!slotnameChanged && strcmp(PrimarySlotName, "") == 0)
144  tempSlotChanged = tempSlot != wal_receiver_create_temp_slot;
145  pfree(conninfo);
146  pfree(slotname);
147 
148  if (conninfoChanged || slotnameChanged || tempSlotChanged)
150 }
151 
152 /* Handle various signals that might be sent to the startup process */
153 void
155 {
156 #ifdef POSTMASTER_POLL_RATE_LIMIT
157  static uint32 postmaster_poll_count = 0;
158 #endif
159 
160  /*
161  * Process any requests or signals received recently.
162  */
163  if (got_SIGHUP)
164  {
165  got_SIGHUP = false;
167  }
168 
169  /*
170  * Check if we were requested to exit without finishing recovery.
171  */
172  if (shutdown_requested)
173  proc_exit(1);
174 
175  /*
176  * Emergency bailout if postmaster has died. This is to avoid the
177  * necessity for manual cleanup of all postmaster children. Do this less
178  * frequently on systems for which we don't have signals to make that
179  * cheap.
180  */
181  if (IsUnderPostmaster &&
183  postmaster_poll_count++ % POSTMASTER_POLL_RATE_LIMIT == 0 &&
184 #endif
186  exit(1);
187 
188  /* Process barrier events */
191 
192  /* Perform logging of memory contexts of this process */
195 }
196 
197 
198 /* --------------------------------
199  * signal handler routines
200  * --------------------------------
201  */
202 static void
204 {
205  /* Shutdown the recovery environment */
208 }
209 
210 
211 /* ----------------------------------
212  * Startup Process main entry point
213  * ----------------------------------
214  */
215 void
216 StartupProcessMain(char *startup_data, size_t startup_data_len)
217 {
218  Assert(startup_data_len == 0);
219 
222 
223  /* Arrange to clean up at startup process exit */
225 
226  /*
227  * Properly accept or ignore signals the postmaster might send us.
228  */
229  pqsignal(SIGHUP, StartupProcSigHupHandler); /* reload config file */
230  pqsignal(SIGINT, SIG_IGN); /* ignore query cancel */
231  pqsignal(SIGTERM, StartupProcShutdownHandler); /* request shutdown */
232  /* SIGQUIT handler was already set up by InitPostmasterChild */
233  InitializeTimeouts(); /* establishes SIGALRM handler */
237 
238  /*
239  * Reset some signals that are accepted by postmaster but not here
240  */
242 
243  /*
244  * Register timeouts needed for standby mode
245  */
249 
250  /*
251  * Unblock signals (they were blocked when the postmaster forked us)
252  */
253  sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
254 
255  /*
256  * Do what we came for.
257  */
258  StartupXLOG();
259 
260  /*
261  * Exit normally. Exit code 0 tells postmaster that we completed recovery
262  * successfully.
263  */
264  proc_exit(0);
265 }
266 
267 void
269 {
270  /*
271  * Set in_restore_command to tell the signal handler that we should exit
272  * right away on SIGTERM. We know that we're at a safe point to do that.
273  * Check if we had already received the signal, so that we don't miss a
274  * shutdown request received just before this.
275  */
276  in_restore_command = true;
277  if (shutdown_requested)
278  proc_exit(1);
279 }
280 
281 void
283 {
284  in_restore_command = false;
285 }
286 
287 bool
289 {
290  return promote_signaled;
291 }
292 
293 void
295 {
296  promote_signaled = false;
297 }
298 
299 /*
300  * Set a flag indicating that it's time to log a progress report.
301  */
302 void
304 {
306 }
307 
308 void
310 {
311  /* Feature is disabled. */
313  return;
314 
317 }
318 
319 /*
320  * Set the start timestamp of the current operation and enable the timeout.
321  */
322 void
324 {
325  TimestampTz fin_time;
326 
327  /* Feature is disabled. */
329  return;
330 
336 }
337 
338 /*
339  * A thin wrapper to first disable and then enable the startup progress
340  * timeout.
341  */
342 void
344 {
345  /* Feature is disabled. */
347  return;
348 
351 }
352 
353 /*
354  * Report whether startup progress timeout has occurred. Reset the timer flag
355  * if it did, set the elapsed time to the out parameters and return true,
356  * otherwise return false.
357  */
358 bool
360 {
361  long seconds;
362  int useconds;
364 
365  /* No timeout has occurred. */
367  return false;
368 
369  /* Calculate the elapsed time. */
372 
373  *secs = seconds;
374  *usecs = useconds;
376 
377  return true;
378 }
void AuxiliaryProcessMainCommon(void)
Definition: auxprocess.c:44
sigset_t UnBlockSig
Definition: pqsignal.c:22
void HandleStartupProcInterrupts(void)
Definition: startup.c:154
void disable_startup_progress_timeout(void)
Definition: startup.c:309
#define POSTMASTER_POLL_RATE_LIMIT
Definition: startup.c:46
static volatile sig_atomic_t startup_progress_timer_expired
Definition: startup.c:71
static volatile sig_atomic_t in_restore_command
Definition: startup.c:60
static void StartupProcExit(int code, Datum arg)
Definition: startup.c:203
bool IsPromoteSignaled(void)
Definition: startup.c:288
void PreRestoreCommand(void)
Definition: startup.c:268
void startup_progress_timeout_handler(void)
Definition: startup.c:303
static volatile sig_atomic_t shutdown_requested
Definition: startup.c:53
static void StartupProcShutdownHandler(SIGNAL_ARGS)
Definition: startup.c:109
void begin_startup_progress_phase(void)
Definition: startup.c:343
void ResetPromoteSignaled(void)
Definition: startup.c:294
static void StartupProcSigHupHandler(SIGNAL_ARGS)
Definition: startup.c:101
static volatile sig_atomic_t got_SIGHUP
Definition: startup.c:52
void StartupProcessMain(char *startup_data, size_t startup_data_len)
Definition: startup.c:216
static TimestampTz startup_progress_phase_start_time
Definition: startup.c:65
static volatile sig_atomic_t promote_signaled
Definition: startup.c:54
void PostRestoreCommand(void)
Definition: startup.c:282
static void StartupProcTriggerHandler(SIGNAL_ARGS)
Definition: startup.c:93
int log_startup_progress_interval
Definition: startup.c:76
void enable_startup_progress_timeout(void)
Definition: startup.c:323
bool has_startup_progress_timeout_expired(long *secs, int *usecs)
Definition: startup.c:359
static void StartupRereadConfig(void)
Definition: startup.c:125
void TimestampDifference(TimestampTz start_time, TimestampTz stop_time, long *secs, int *microsecs)
Definition: timestamp.c:1730
TimestampTz GetCurrentTimestamp(void)
Definition: timestamp.c:1654
Datum now(PG_FUNCTION_ARGS)
Definition: timestamp.c:1618
unsigned int uint32
Definition: c.h:493
#define SIGNAL_ARGS
Definition: c.h:1332
int64 TimestampTz
Definition: timestamp.h:39
volatile sig_atomic_t LogMemoryContextPending
Definition: globals.c:39
volatile sig_atomic_t ProcSignalBarrierPending
Definition: globals.c:38
bool IsUnderPostmaster
Definition: globals.c:117
@ PGC_SIGHUP
Definition: guc.h:71
void ProcessConfigFile(GucContext context)
void on_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:365
void proc_exit(int code)
Definition: ipc.c:104
Assert(fmt[strlen(fmt) - 1] !='\n')
exit(1)
char * pstrdup(const char *in)
Definition: mcxt.c:1683
void pfree(void *pointer)
Definition: mcxt.c:1508
void ProcessLogMemoryContextInterrupt(void)
Definition: mcxt.c:1276
@ B_STARTUP
Definition: miscadmin.h:355
BackendType MyBackendType
Definition: miscinit.c:63
void * arg
#define PostmasterIsAlive()
Definition: pmsignal.h:102
pqsigfunc pqsignal(int signo, pqsigfunc func)
uintptr_t Datum
Definition: postgres.h:64
void ProcessProcSignalBarrier(void)
Definition: procsignal.c:464
void procsignal_sigusr1_handler(SIGNAL_ARGS)
Definition: procsignal.c:635
void StandbyTimeoutHandler(void)
Definition: standby.c:944
void StandbyLockTimeoutHandler(void)
Definition: standby.c:953
void StandbyDeadLockHandler(void)
Definition: standby.c:935
void ShutdownRecoveryTransactionEnvironment(void)
Definition: standby.c:160
void InitializeTimeouts(void)
Definition: timeout.c:470
void enable_timeout_every(TimeoutId id, TimestampTz fin_time, int delay_ms)
Definition: timeout.c:584
void disable_timeout(TimeoutId id, bool keep_indicator)
Definition: timeout.c:685
TimeoutId RegisterTimeout(TimeoutId id, timeout_handler_proc handler)
Definition: timeout.c:505
@ STARTUP_PROGRESS_TIMEOUT
Definition: timeout.h:38
@ STANDBY_LOCK_TIMEOUT
Definition: timeout.h:32
@ STANDBY_DEADLOCK_TIMEOUT
Definition: timeout.h:30
@ STANDBY_TIMEOUT
Definition: timeout.h:31
#define TimestampTzPlusMilliseconds(tz, ms)
Definition: timestamp.h:85
#define SIGCHLD
Definition: win32_port.h:178
#define SIGHUP
Definition: win32_port.h:168
#define SIG_DFL
Definition: win32_port.h:163
#define SIGPIPE
Definition: win32_port.h:173
#define SIGUSR1
Definition: win32_port.h:180
#define SIGUSR2
Definition: win32_port.h:181
#define SIG_IGN
Definition: win32_port.h:165
void StartupXLOG(void)
Definition: xlog.c:5307
void StartupRequestWalReceiverRestart(void)
char * PrimarySlotName
Definition: xlogrecovery.c:97
void WakeupRecovery(void)
bool wal_receiver_create_temp_slot
Definition: xlogrecovery.c:98
char * PrimaryConnInfo
Definition: xlogrecovery.c:96
HotStandbyState standbyState
Definition: xlogutils.c:53
@ STANDBY_DISABLED
Definition: xlogutils.h:49