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shell_archive.c
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1 /*-------------------------------------------------------------------------
2  *
3  * shell_archive.c
4  *
5  * This archiving function uses a user-specified shell command (the
6  * archive_command GUC) to copy write-ahead log files. It is used as the
7  * default, but other modules may define their own custom archiving logic.
8  *
9  * Copyright (c) 2022-2024, PostgreSQL Global Development Group
10  *
11  * IDENTIFICATION
12  * src/backend/archive/shell_archive.c
13  *
14  *-------------------------------------------------------------------------
15  */
16 #include "postgres.h"
17 
18 #include <sys/wait.h>
19 
20 #include "access/xlog.h"
21 #include "archive/archive_module.h"
22 #include "archive/shell_archive.h"
23 #include "common/percentrepl.h"
24 #include "pgstat.h"
25 
28  const char *file,
29  const char *path);
31 
33  .startup_cb = NULL,
34  .check_configured_cb = shell_archive_configured,
35  .archive_file_cb = shell_archive_file,
36  .shutdown_cb = shell_archive_shutdown
37 };
38 
41 {
43 }
44 
45 static bool
47 {
48  if (XLogArchiveCommand[0] != '\0')
49  return true;
50 
51  arch_module_check_errdetail("%s is not set.",
52  "archive_command");
53  return false;
54 }
55 
56 static bool
58  const char *path)
59 {
60  char *xlogarchcmd;
61  char *nativePath = NULL;
62  int rc;
63 
64  if (path)
65  {
66  nativePath = pstrdup(path);
67  make_native_path(nativePath);
68  }
69 
71  "archive_command", "fp",
72  file, nativePath);
73 
75  (errmsg_internal("executing archive command \"%s\"",
76  xlogarchcmd)));
77 
78  fflush(NULL);
79  pgstat_report_wait_start(WAIT_EVENT_ARCHIVE_COMMAND);
80  rc = system(xlogarchcmd);
82 
83  if (rc != 0)
84  {
85  /*
86  * If either the shell itself, or a called command, died on a signal,
87  * abort the archiver. We do this because system() ignores SIGINT and
88  * SIGQUIT while waiting; so a signal is very likely something that
89  * should have interrupted us too. Also die if the shell got a hard
90  * "command not found" type of error. If we overreact it's no big
91  * deal, the postmaster will just start the archiver again.
92  */
93  int lev = wait_result_is_any_signal(rc, true) ? FATAL : LOG;
94 
95  if (WIFEXITED(rc))
96  {
97  ereport(lev,
98  (errmsg("archive command failed with exit code %d",
99  WEXITSTATUS(rc)),
100  errdetail("The failed archive command was: %s",
101  xlogarchcmd)));
102  }
103  else if (WIFSIGNALED(rc))
104  {
105 #if defined(WIN32)
106  ereport(lev,
107  (errmsg("archive command was terminated by exception 0x%X",
108  WTERMSIG(rc)),
109  errhint("See C include file \"ntstatus.h\" for a description of the hexadecimal value."),
110  errdetail("The failed archive command was: %s",
111  xlogarchcmd)));
112 #else
113  ereport(lev,
114  (errmsg("archive command was terminated by signal %d: %s",
115  WTERMSIG(rc), pg_strsignal(WTERMSIG(rc))),
116  errdetail("The failed archive command was: %s",
117  xlogarchcmd)));
118 #endif
119  }
120  else
121  {
122  ereport(lev,
123  (errmsg("archive command exited with unrecognized status %d",
124  rc),
125  errdetail("The failed archive command was: %s",
126  xlogarchcmd)));
127  }
128  pfree(xlogarchcmd);
129 
130  return false;
131  }
132  pfree(xlogarchcmd);
133 
134  elog(DEBUG1, "archived write-ahead log file \"%s\"", file);
135  return true;
136 }
137 
138 static void
140 {
141  elog(DEBUG1, "archiver process shutting down");
142 }
#define arch_module_check_errdetail
int errmsg_internal(const char *fmt,...)
Definition: elog.c:1157
int errdetail(const char *fmt,...)
Definition: elog.c:1203
int errhint(const char *fmt,...)
Definition: elog.c:1317
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define LOG
Definition: elog.h:31
#define DEBUG3
Definition: elog.h:28
#define FATAL
Definition: elog.h:41
#define DEBUG1
Definition: elog.h:30
#define elog(elevel,...)
Definition: elog.h:224
#define ereport(elevel,...)
Definition: elog.h:149
static void const char fflush(stdout)
char * pstrdup(const char *in)
Definition: mcxt.c:1695
void pfree(void *pointer)
Definition: mcxt.c:1520
char * replace_percent_placeholders(const char *instr, const char *param_name, const char *letters,...)
Definition: percentrepl.c:59
const char * pg_strsignal(int signum)
Definition: pgstrsignal.c:39
void make_native_path(char *filename)
Definition: path.c:167
static void shell_archive_shutdown(ArchiveModuleState *state)
static const ArchiveModuleCallbacks shell_archive_callbacks
Definition: shell_archive.c:32
const ArchiveModuleCallbacks * shell_archive_init(void)
Definition: shell_archive.c:40
static bool shell_archive_configured(ArchiveModuleState *state)
Definition: shell_archive.c:46
static bool shell_archive_file(ArchiveModuleState *state, const char *file, const char *path)
Definition: shell_archive.c:57
ArchiveStartupCB startup_cb
Definition: regguts.h:323
bool wait_result_is_any_signal(int exit_status, bool include_command_not_found)
Definition: wait_error.c:121
static void pgstat_report_wait_start(uint32 wait_event_info)
Definition: wait_event.h:82
static void pgstat_report_wait_end(void)
Definition: wait_event.h:98
#define WIFEXITED(w)
Definition: win32_port.h:152
#define WIFSIGNALED(w)
Definition: win32_port.h:153
#define WTERMSIG(w)
Definition: win32_port.h:155
#define WEXITSTATUS(w)
Definition: win32_port.h:154
char * XLogArchiveCommand
Definition: xlog.c:120