PostgreSQL Source Code  git master
pg_archivecleanup.c
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1 /*
2  * pg_archivecleanup.c
3  *
4  * To be used as archive_cleanup_command to clean an archive when using
5  * standby mode.
6  *
7  * src/bin/pg_archivecleanup/pg_archivecleanup.c
8  */
9 #include "postgres_fe.h"
10 
11 #include <ctype.h>
12 #include <dirent.h>
13 #include <sys/stat.h>
14 #include <fcntl.h>
15 #include <signal.h>
16 #include <sys/time.h>
17 
18 #include "access/xlog_internal.h"
19 #include "common/logging.h"
20 #include "pg_getopt.h"
21 
22 const char *progname;
23 
24 /* Options and defaults */
25 bool dryrun = false; /* are we performing a dry-run operation? */
26 char *additional_ext = NULL; /* Extension to remove from filenames */
27 
28 char *archiveLocation; /* where to find the archive? */
29 char *restartWALFileName; /* the file from which we can restart restore */
30 char exclusiveCleanupFileName[MAXFNAMELEN]; /* the oldest file we want
31  * to remain in archive */
32 
33 
34 /* =====================================================================
35  *
36  * Customizable section
37  *
38  * =====================================================================
39  *
40  * Currently, this section assumes that the Archive is a locally
41  * accessible directory. If you want to make other assumptions,
42  * such as using a vendor-specific archive and access API, these
43  * routines are the ones you'll need to change. You're
44  * encouraged to submit any changes to pgsql-hackers@lists.postgresql.org
45  * or personally to the current maintainer. Those changes may be
46  * folded in to later versions of this program.
47  */
48 
49 /*
50  * Initialize allows customized commands into the archive cleanup program.
51  *
52  * You may wish to add code to check for tape libraries, etc..
53  */
54 static void
56 {
57  /*
58  * This code assumes that archiveLocation is a directory, so we use stat
59  * to test if it's accessible.
60  */
61  struct stat stat_buf;
62 
63  if (stat(archiveLocation, &stat_buf) != 0 ||
64  !S_ISDIR(stat_buf.st_mode))
65  {
66  pg_log_error("archive location \"%s\" does not exist",
68  exit(2);
69  }
70 }
71 
72 static void
73 TrimExtension(char *filename, char *extension)
74 {
75  int flen;
76  int elen;
77 
78  if (extension == NULL)
79  return;
80 
81  elen = strlen(extension);
82  flen = strlen(filename);
83 
84  if (flen > elen && strcmp(filename + flen - elen, extension) == 0)
85  filename[flen - elen] = '\0';
86 }
87 
88 static void
90 {
91  int rc;
92  DIR *xldir;
93  struct dirent *xlde;
94  char walfile[MAXPGPATH];
95 
96  if ((xldir = opendir(archiveLocation)) != NULL)
97  {
98  while (errno = 0, (xlde = readdir(xldir)) != NULL)
99  {
100  /*
101  * Truncation is essentially harmless, because we skip names of
102  * length other than XLOG_FNAME_LEN. (In principle, one could use
103  * a 1000-character additional_ext and get trouble.)
104  */
105  strlcpy(walfile, xlde->d_name, MAXPGPATH);
106  TrimExtension(walfile, additional_ext);
107 
108  /*
109  * We ignore the timeline part of the XLOG segment identifiers in
110  * deciding whether a segment is still needed. This ensures that
111  * we won't prematurely remove a segment from a parent timeline.
112  * We could probably be a little more proactive about removing
113  * segments of non-parent timelines, but that would be a whole lot
114  * more complicated.
115  *
116  * We use the alphanumeric sorting property of the filenames to
117  * decide which ones are earlier than the exclusiveCleanupFileName
118  * file. Note that this means files are not removed in the order
119  * they were originally written, in case this worries you.
120  */
121  if ((IsXLogFileName(walfile) || IsPartialXLogFileName(walfile)) &&
122  strcmp(walfile + 8, exclusiveCleanupFileName + 8) < 0)
123  {
124  char WALFilePath[MAXPGPATH * 2]; /* the file path
125  * including archive */
126 
127  /*
128  * Use the original file name again now, including any
129  * extension that might have been chopped off before testing
130  * the sequence.
131  */
132  snprintf(WALFilePath, sizeof(WALFilePath), "%s/%s",
133  archiveLocation, xlde->d_name);
134 
135  if (dryrun)
136  {
137  /*
138  * Prints the name of the file to be removed and skips the
139  * actual removal. The regular printout is so that the
140  * user can pipe the output into some other program.
141  */
142  printf("%s\n", WALFilePath);
143  pg_log_debug("file \"%s\" would be removed", WALFilePath);
144  continue;
145  }
146 
147  pg_log_debug("removing file \"%s\"", WALFilePath);
148 
149  rc = unlink(WALFilePath);
150  if (rc != 0)
151  {
152  pg_log_error("could not remove file \"%s\": %m",
153  WALFilePath);
154  break;
155  }
156  }
157  }
158 
159  if (errno)
160  pg_log_error("could not read archive location \"%s\": %m",
162  if (closedir(xldir))
163  pg_log_error("could not close archive location \"%s\": %m",
165  }
166  else
167  pg_log_error("could not open archive location \"%s\": %m",
169 }
170 
171 /*
172  * SetWALFileNameForCleanup()
173  *
174  * Set the earliest WAL filename that we want to keep on the archive
175  * and decide whether we need cleanup
176  */
177 static void
179 {
180  bool fnameOK = false;
181 
183 
184  /*
185  * If restartWALFileName is a WAL file name then just use it directly. If
186  * restartWALFileName is a .partial or .backup filename, make sure we use
187  * the prefix of the filename, otherwise we will remove wrong files since
188  * 000000010000000000000010.partial and
189  * 000000010000000000000010.00000020.backup are after
190  * 000000010000000000000010.
191  */
193  {
195  fnameOK = true;
196  }
198  {
199  int args;
200  uint32 tli = 1,
201  log = 0,
202  seg = 0;
203 
204  args = sscanf(restartWALFileName, "%08X%08X%08X.partial",
205  &tli, &log, &seg);
206  if (args == 3)
207  {
208  fnameOK = true;
209 
210  /*
211  * Use just the prefix of the filename, ignore everything after
212  * first period
213  */
215  }
216  }
218  {
219  int args;
220  uint32 tli = 1,
221  log = 0,
222  seg = 0,
223  offset = 0;
224 
225  args = sscanf(restartWALFileName, "%08X%08X%08X.%08X.backup", &tli, &log, &seg, &offset);
226  if (args == 4)
227  {
228  fnameOK = true;
229 
230  /*
231  * Use just the prefix of the filename, ignore everything after
232  * first period
233  */
235  }
236  }
237 
238  if (!fnameOK)
239  {
240  pg_log_error("invalid file name argument");
241  fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
242  exit(2);
243  }
244 }
245 
246 /* =====================================================================
247  * End of Customizable section
248  * =====================================================================
249  */
250 
251 static void
252 usage(void)
253 {
254  printf(_("%s removes older WAL files from PostgreSQL archives.\n\n"), progname);
255  printf(_("Usage:\n"));
256  printf(_(" %s [OPTION]... ARCHIVELOCATION OLDESTKEPTWALFILE\n"), progname);
257  printf(_("\nOptions:\n"));
258  printf(_(" -d generate debug output (verbose mode)\n"));
259  printf(_(" -n dry run, show the names of the files that would be removed\n"));
260  printf(_(" -V, --version output version information, then exit\n"));
261  printf(_(" -x EXT clean up files if they have this extension\n"));
262  printf(_(" -?, --help show this help, then exit\n"));
263  printf(_("\n"
264  "For use as archive_cleanup_command in postgresql.conf:\n"
265  " archive_cleanup_command = 'pg_archivecleanup [OPTION]... ARCHIVELOCATION %%r'\n"
266  "e.g.\n"
267  " archive_cleanup_command = 'pg_archivecleanup /mnt/server/archiverdir %%r'\n"));
268  printf(_("\n"
269  "Or for use as a standalone archive cleaner:\n"
270  "e.g.\n"
271  " pg_archivecleanup /mnt/server/archiverdir 000000010000000000000010.00000020.backup\n"));
272  printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
273  printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
274 }
275 
276 /*------------ MAIN ----------------------------------------*/
277 int
278 main(int argc, char **argv)
279 {
280  int c;
281 
282  pg_logging_init(argv[0]);
283  set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_archivecleanup"));
284  progname = get_progname(argv[0]);
285 
286  if (argc > 1)
287  {
288  if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
289  {
290  usage();
291  exit(0);
292  }
293  if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
294  {
295  puts("pg_archivecleanup (PostgreSQL) " PG_VERSION);
296  exit(0);
297  }
298  }
299 
300  while ((c = getopt(argc, argv, "x:dn")) != -1)
301  {
302  switch (c)
303  {
304  case 'd': /* Debug mode */
306  break;
307  case 'n': /* Dry-Run mode */
308  dryrun = true;
309  break;
310  case 'x':
311  additional_ext = pg_strdup(optarg); /* Extension to remove
312  * from xlogfile names */
313  break;
314  default:
315  fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
316  exit(2);
317  break;
318  }
319  }
320 
321  /*
322  * We will go to the archiveLocation to check restartWALFileName.
323  * restartWALFileName may not exist anymore, which would not be an error,
324  * so we separate the archiveLocation and restartWALFileName so we can
325  * check separately whether archiveLocation exists, if not that is an
326  * error
327  */
328  if (optind < argc)
329  {
330  archiveLocation = argv[optind];
331  optind++;
332  }
333  else
334  {
335  pg_log_error("must specify archive location");
336  fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
337  exit(2);
338  }
339 
340  if (optind < argc)
341  {
342  restartWALFileName = argv[optind];
343  optind++;
344  }
345  else
346  {
347  pg_log_error("must specify oldest kept WAL file");
348  fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
349  exit(2);
350  }
351 
352  if (optind < argc)
353  {
354  pg_log_error("too many command-line arguments");
355  fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
356  exit(2);
357  }
358 
359  /*
360  * Check archive exists and other initialization if required.
361  */
362  Initialize();
363 
364  /*
365  * Check filename is a valid name, then process to find cut-off
366  */
368 
369  pg_log_debug("keeping WAL file \"%s/%s\" and later",
371 
372  /*
373  * Remove WAL files older than cut-off
374  */
376 
377  exit(0);
378 }
static void CleanupPriorWALFiles(void)
static void SetWALFileNameForCleanup(void)
const char * get_progname(const char *argv0)
Definition: path.c:453
#define pg_log_error(...)
Definition: logging.h:79
void pg_logging_init(const char *argv0)
Definition: logging.c:81
int closedir(DIR *)
Definition: dirent.c:113
#define XLogFileNameById(fname, tli, log, seg)
#define printf(...)
Definition: port.h:199
char * archiveLocation
#define fprintf
Definition: port.h:197
Definition: dirent.h:9
int getopt(int nargc, char *const *nargv, const char *ostr)
Definition: getopt.c:71
static void usage(void)
static void TrimExtension(char *filename, char *extension)
int optind
Definition: getopt.c:50
Definition: dirent.c:25
#define IsXLogFileName(fname)
#define pg_log_debug(...)
Definition: logging.h:91
#define MAXPGPATH
static Walfile * walfile
Definition: receivelog.c:31
DIR * opendir(const char *)
Definition: dirent.c:33
char * restartWALFileName
char * c
char * pg_strdup(const char *in)
Definition: fe_memutils.c:85
unsigned int uint32
Definition: c.h:367
#define IsBackupHistoryFileName(fname)
const char * progname
#define stat(a, b)
Definition: win32_port.h:255
#define MAXFNAMELEN
bool dryrun
#define PG_TEXTDOMAIN(domain)
Definition: c.h:1177
char exclusiveCleanupFileName[MAXFNAMELEN]
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
char WALFilePath[MAXPGPATH *2]
Definition: pg_standby.c:60
struct dirent * readdir(DIR *)
Definition: dirent.c:77
int main(int argc, char **argv)
#define S_ISDIR(m)
Definition: win32_port.h:296
static char * filename
Definition: pg_dumpall.c:90
#define IsPartialXLogFileName(fname)
void set_pglocale_pgservice(const char *argv0, const char *app)
Definition: exec.c:434
char * optarg
Definition: getopt.c:52
void pg_logging_set_level(enum pg_log_level new_level)
Definition: logging.c:161
static void Initialize(void)
char d_name[MAX_PATH]
Definition: dirent.h:14
#define snprintf
Definition: port.h:193
#define _(x)
Definition: elog.c:88
char * additional_ext