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pg_archivecleanup.c
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1 /*
2  * src/bin/pg_archivecleanup/pg_archivecleanup.c
3  *
4  * pg_archivecleanup.c
5  *
6  * Production-ready example of an archive_cleanup_command
7  * used to clean an archive when using standby_mode = on in 9.0
8  * or for standalone use for any version of PostgreSQL 8.0+.
9  *
10  * Original author: Simon Riggs simon@2ndquadrant.com
11  * Current maintainer: Simon Riggs
12  */
13 #include "postgres_fe.h"
14 
15 #include <ctype.h>
16 #include <dirent.h>
17 #include <sys/stat.h>
18 #include <fcntl.h>
19 #include <signal.h>
20 #include <sys/time.h>
21 
22 #include "pg_getopt.h"
23 
24 #include "access/xlog_internal.h"
25 
26 const char *progname;
27 
28 /* Options and defaults */
29 bool debug = false; /* are we debugging? */
30 bool dryrun = false; /* are we performing a dry-run operation? */
31 char *additional_ext = NULL; /* Extension to remove from filenames */
32 
33 char *archiveLocation; /* where to find the archive? */
34 char *restartWALFileName; /* the file from which we can restart restore */
35 char WALFilePath[MAXPGPATH * 2]; /* the file path including archive */
36 char exclusiveCleanupFileName[MAXFNAMELEN]; /* the oldest file we want
37  * to remain in archive */
38 
39 
40 /* =====================================================================
41  *
42  * Customizable section
43  *
44  * =====================================================================
45  *
46  * Currently, this section assumes that the Archive is a locally
47  * accessible directory. If you want to make other assumptions,
48  * such as using a vendor-specific archive and access API, these
49  * routines are the ones you'll need to change. You're
50  * encouraged to submit any changes to pgsql-hackers@postgresql.org
51  * or personally to the current maintainer. Those changes may be
52  * folded in to later versions of this program.
53  */
54 
55 /*
56  * Initialize allows customized commands into the archive cleanup program.
57  *
58  * You may wish to add code to check for tape libraries, etc..
59  */
60 static void
62 {
63  /*
64  * This code assumes that archiveLocation is a directory, so we use stat
65  * to test if it's accessible.
66  */
67  struct stat stat_buf;
68 
69  if (stat(archiveLocation, &stat_buf) != 0 ||
70  !S_ISDIR(stat_buf.st_mode))
71  {
72  fprintf(stderr, _("%s: archive location \"%s\" does not exist\n"),
74  exit(2);
75  }
76 }
77 
78 static void
79 TrimExtension(char *filename, char *extension)
80 {
81  int flen;
82  int elen;
83 
84  if (extension == NULL)
85  return;
86 
87  elen = strlen(extension);
88  flen = strlen(filename);
89 
90  if (flen > elen && strcmp(filename + flen - elen, extension) == 0)
91  filename[flen - elen] = '\0';
92 }
93 
94 static void
96 {
97  int rc;
98  DIR *xldir;
99  struct dirent *xlde;
100  char walfile[MAXPGPATH];
101 
102  if ((xldir = opendir(archiveLocation)) != NULL)
103  {
104  while (errno = 0, (xlde = readdir(xldir)) != NULL)
105  {
106  /*
107  * Truncation is essentially harmless, because we skip names of
108  * length other than XLOG_FNAME_LEN. (In principle, one could use
109  * a 1000-character additional_ext and get trouble.)
110  */
111  strlcpy(walfile, xlde->d_name, MAXPGPATH);
112  TrimExtension(walfile, additional_ext);
113 
114  /*
115  * We ignore the timeline part of the XLOG segment identifiers in
116  * deciding whether a segment is still needed. This ensures that
117  * we won't prematurely remove a segment from a parent timeline.
118  * We could probably be a little more proactive about removing
119  * segments of non-parent timelines, but that would be a whole lot
120  * more complicated.
121  *
122  * We use the alphanumeric sorting property of the filenames to
123  * decide which ones are earlier than the exclusiveCleanupFileName
124  * file. Note that this means files are not removed in the order
125  * they were originally written, in case this worries you.
126  */
127  if ((IsXLogFileName(walfile) || IsPartialXLogFileName(walfile)) &&
128  strcmp(walfile + 8, exclusiveCleanupFileName + 8) < 0)
129  {
130  /*
131  * Use the original file name again now, including any
132  * extension that might have been chopped off before testing
133  * the sequence.
134  */
135  snprintf(WALFilePath, sizeof(WALFilePath), "%s/%s",
136  archiveLocation, xlde->d_name);
137 
138  if (dryrun)
139  {
140  /*
141  * Prints the name of the file to be removed and skips the
142  * actual removal. The regular printout is so that the
143  * user can pipe the output into some other program.
144  */
145  printf("%s\n", WALFilePath);
146  if (debug)
147  fprintf(stderr,
148  _("%s: file \"%s\" would be removed\n"),
150  continue;
151  }
152 
153  if (debug)
154  fprintf(stderr, _("%s: removing file \"%s\"\n"),
156 
157  rc = unlink(WALFilePath);
158  if (rc != 0)
159  {
160  fprintf(stderr, _("%s: ERROR: could not remove file \"%s\": %s\n"),
161  progname, WALFilePath, strerror(errno));
162  break;
163  }
164  }
165  }
166 
167  if (errno)
168  fprintf(stderr, _("%s: could not read archive location \"%s\": %s\n"),
170  if (closedir(xldir))
171  fprintf(stderr, _("%s: could not close archive location \"%s\": %s\n"),
173  }
174  else
175  fprintf(stderr, _("%s: could not open archive location \"%s\": %s\n"),
177 }
178 
179 /*
180  * SetWALFileNameForCleanup()
181  *
182  * Set the earliest WAL filename that we want to keep on the archive
183  * and decide whether we need cleanup
184  */
185 static void
187 {
188  bool fnameOK = false;
189 
191 
192  /*
193  * If restartWALFileName is a WAL file name then just use it directly. If
194  * restartWALFileName is a .partial or .backup filename, make sure we use
195  * the prefix of the filename, otherwise we will remove wrong files since
196  * 000000010000000000000010.partial and
197  * 000000010000000000000010.00000020.backup are after
198  * 000000010000000000000010.
199  */
201  {
203  fnameOK = true;
204  }
206  {
207  int args;
208  uint32 tli = 1,
209  log = 0,
210  seg = 0;
211 
212  args = sscanf(restartWALFileName, "%08X%08X%08X.partial",
213  &tli, &log, &seg);
214  if (args == 3)
215  {
216  fnameOK = true;
217 
218  /*
219  * Use just the prefix of the filename, ignore everything after
220  * first period
221  */
223  }
224  }
226  {
227  int args;
228  uint32 tli = 1,
229  log = 0,
230  seg = 0,
231  offset = 0;
232 
233  args = sscanf(restartWALFileName, "%08X%08X%08X.%08X.backup", &tli, &log, &seg, &offset);
234  if (args == 4)
235  {
236  fnameOK = true;
237 
238  /*
239  * Use just the prefix of the filename, ignore everything after
240  * first period
241  */
243  }
244  }
245 
246  if (!fnameOK)
247  {
248  fprintf(stderr, _("%s: invalid filename input\n"), progname);
249  fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
250  exit(2);
251  }
252 }
253 
254 /* =====================================================================
255  * End of Customizable section
256  * =====================================================================
257  */
258 
259 static void
260 usage(void)
261 {
262  printf(_("%s removes older WAL files from PostgreSQL archives.\n\n"), progname);
263  printf(_("Usage:\n"));
264  printf(_(" %s [OPTION]... ARCHIVELOCATION OLDESTKEPTWALFILE\n"), progname);
265  printf(_("\nOptions:\n"));
266  printf(_(" -d generate debug output (verbose mode)\n"));
267  printf(_(" -n dry run, show the names of the files that would be removed\n"));
268  printf(_(" -V, --version output version information, then exit\n"));
269  printf(_(" -x EXT clean up files if they have this extension\n"));
270  printf(_(" -?, --help show this help, then exit\n"));
271  printf(_("\n"
272  "For use as archive_cleanup_command in recovery.conf when standby_mode = on:\n"
273  " archive_cleanup_command = 'pg_archivecleanup [OPTION]... ARCHIVELOCATION %%r'\n"
274  "e.g.\n"
275  " archive_cleanup_command = 'pg_archivecleanup /mnt/server/archiverdir %%r'\n"));
276  printf(_("\n"
277  "Or for use as a standalone archive cleaner:\n"
278  "e.g.\n"
279  " pg_archivecleanup /mnt/server/archiverdir 000000010000000000000010.00000020.backup\n"));
280  printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
281 }
282 
283 /*------------ MAIN ----------------------------------------*/
284 int
285 main(int argc, char **argv)
286 {
287  int c;
288 
289  set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_archivecleanup"));
290  progname = get_progname(argv[0]);
291 
292  if (argc > 1)
293  {
294  if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
295  {
296  usage();
297  exit(0);
298  }
299  if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
300  {
301  puts("pg_archivecleanup (PostgreSQL) " PG_VERSION);
302  exit(0);
303  }
304  }
305 
306  while ((c = getopt(argc, argv, "x:dn")) != -1)
307  {
308  switch (c)
309  {
310  case 'd': /* Debug mode */
311  debug = true;
312  break;
313  case 'n': /* Dry-Run mode */
314  dryrun = true;
315  break;
316  case 'x':
317  additional_ext = pg_strdup(optarg); /* Extension to remove
318  * from xlogfile names */
319  break;
320  default:
321  fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
322  exit(2);
323  break;
324  }
325  }
326 
327  /*
328  * We will go to the archiveLocation to check restartWALFileName.
329  * restartWALFileName may not exist anymore, which would not be an error,
330  * so we separate the archiveLocation and restartWALFileName so we can
331  * check separately whether archiveLocation exists, if not that is an
332  * error
333  */
334  if (optind < argc)
335  {
336  archiveLocation = argv[optind];
337  optind++;
338  }
339  else
340  {
341  fprintf(stderr, _("%s: must specify archive location\n"), progname);
342  fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
343  exit(2);
344  }
345 
346  if (optind < argc)
347  {
348  restartWALFileName = argv[optind];
349  optind++;
350  }
351  else
352  {
353  fprintf(stderr, _("%s: must specify restartfilename\n"), progname);
354  fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
355  exit(2);
356  }
357 
358  if (optind < argc)
359  {
360  fprintf(stderr, _("%s: too many parameters\n"), progname);
361  fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
362  exit(2);
363  }
364 
365  /*
366  * Check archive exists and other initialization if required.
367  */
368  Initialize();
369 
370  /*
371  * Check filename is a valid name, then process to find cut-off
372  */
374 
375  if (debug)
376  {
377  snprintf(WALFilePath, MAXPGPATH, "%s/%s",
379  fprintf(stderr, _("%s: keep WAL file \"%s\" and later\n"),
381  }
382 
383  /*
384  * Remove WAL files older than cut-off
385  */
387 
388  exit(0);
389 }
static void CleanupPriorWALFiles(void)
static void SetWALFileNameForCleanup(void)
const char * get_progname(const char *argv0)
Definition: path.c:453
int closedir(DIR *)
Definition: dirent.c:111
#define XLogFileNameById(fname, tli, log, seg)
int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3
char * archiveLocation
Definition: dirent.h:9
int getopt(int nargc, char *const *nargv, const char *ostr)
Definition: getopt.c:72
static void usage(void)
bool debug
static void TrimExtension(char *filename, char *extension)
char WALFilePath[MAXPGPATH *2]
int optind
Definition: getopt.c:51
Definition: dirent.c:25
#define IsXLogFileName(fname)
#define MAXPGPATH
static Walfile * walfile
Definition: receivelog.c:33
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:268
int unlink(const char *filename)
#define IsBackupHistoryFileName(fname)
const char * progname
#define MAXFNAMELEN
bool dryrun
#define PG_TEXTDOMAIN(domain)
Definition: c.h:1012
char exclusiveCleanupFileName[MAXFNAMELEN]
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
#define NULL
Definition: c.h:229
struct dirent * readdir(DIR *)
Definition: dirent.c:77
int main(int argc, char **argv)
static char * filename
Definition: pg_dumpall.c:89
#define IsPartialXLogFileName(fname)
void set_pglocale_pgservice(const char *argv0, const char *app)
Definition: exec.c:550
char * optarg
Definition: getopt.c:53
const char * strerror(int errnum)
Definition: strerror.c:19
static void Initialize(void)
char d_name[MAX_PATH]
Definition: dirent.h:14
#define _(x)
Definition: elog.c:84
char * additional_ext