Line data Source code
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 "getopt_long.h"
21 :
22 : static const char *progname;
23 :
24 : /* Options and defaults */
25 : static bool dryrun = false; /* are we performing a dry-run operation? */
26 : static bool cleanBackupHistory = false; /* remove files including backup
27 : * history files */
28 : static char *additional_ext = NULL; /* Extension to remove from filenames */
29 :
30 : static char *archiveLocation; /* where to find the archive? */
31 : static char *restartWALFileName; /* the file from which we can restart
32 : * restore */
33 : static char exclusiveCleanupFileName[MAXFNAMELEN]; /* the oldest file we want
34 : * to remain in archive */
35 :
36 :
37 : /* =====================================================================
38 : *
39 : * Customizable section
40 : *
41 : * =====================================================================
42 : *
43 : * Currently, this section assumes that the Archive is a locally
44 : * accessible directory. If you want to make other assumptions,
45 : * such as using a vendor-specific archive and access API, these
46 : * routines are the ones you'll need to change. You're
47 : * encouraged to submit any changes to pgsql-hackers@lists.postgresql.org
48 : * or personally to the current maintainer. Those changes may be
49 : * folded in to later versions of this program.
50 : */
51 :
52 : /*
53 : * Initialize allows customized commands into the archive cleanup program.
54 : *
55 : * You may wish to add code to check for tape libraries, etc..
56 : */
57 : static void
58 14 : Initialize(void)
59 : {
60 : /*
61 : * This code assumes that archiveLocation is a directory, so we use stat
62 : * to test if it's accessible.
63 : */
64 : struct stat stat_buf;
65 :
66 14 : if (stat(archiveLocation, &stat_buf) != 0 ||
67 12 : !S_ISDIR(stat_buf.st_mode))
68 : {
69 2 : pg_log_error("archive location \"%s\" does not exist",
70 : archiveLocation);
71 2 : exit(2);
72 : }
73 12 : }
74 :
75 : static void
76 82 : TrimExtension(char *filename, char *extension)
77 : {
78 : int flen;
79 : int elen;
80 :
81 82 : if (extension == NULL)
82 28 : return;
83 :
84 54 : elen = strlen(extension);
85 54 : flen = strlen(filename);
86 :
87 54 : if (flen > elen && strcmp(filename + flen - elen, extension) == 0)
88 6 : filename[flen - elen] = '\0';
89 : }
90 :
91 : static void
92 10 : CleanupPriorWALFiles(void)
93 : {
94 : int rc;
95 : DIR *xldir;
96 : struct dirent *xlde;
97 : char walfile[MAXPGPATH];
98 :
99 10 : xldir = opendir(archiveLocation);
100 10 : if (xldir == NULL)
101 0 : pg_fatal("could not open archive location \"%s\": %m",
102 : archiveLocation);
103 :
104 80 : while (errno = 0, (xlde = readdir(xldir)) != NULL)
105 : {
106 : char WALFilePath[MAXPGPATH * 2]; /* the file path including
107 : * archive */
108 :
109 : /*
110 : * Truncation is essentially harmless, because we skip files whose
111 : * format is different from WAL files and backup history files. (In
112 : * principle, one could use a 1000-character additional_ext and get
113 : * trouble.)
114 : */
115 70 : strlcpy(walfile, xlde->d_name, MAXPGPATH);
116 70 : TrimExtension(walfile, additional_ext);
117 :
118 : /*
119 : * Ignore anything does that not look like a WAL segment, a .partial
120 : * WAL segment or a backup history file (if requested).
121 : */
122 70 : if (!IsXLogFileName(walfile) && !IsPartialXLogFileName(walfile) &&
123 36 : !(cleanBackupHistory && IsBackupHistoryFileName(walfile)))
124 54 : continue;
125 :
126 : /*
127 : * We ignore the timeline part of the XLOG segment identifiers in
128 : * deciding whether a segment is still needed. This ensures that we
129 : * won't prematurely remove a segment from a parent timeline. We could
130 : * probably be a little more proactive about removing segments of
131 : * non-parent timelines, but that would be a whole lot more
132 : * complicated.
133 : *
134 : * We use the alphanumeric sorting property of the filenames to decide
135 : * which ones are earlier than the exclusiveCleanupFileName file. Note
136 : * that this means files are not removed in the order they were
137 : * originally written, in case this worries you.
138 : */
139 36 : if (strcmp(walfile + 8, exclusiveCleanupFileName + 8) >= 0)
140 18 : continue;
141 :
142 : /*
143 : * Use the original file name again now, including any extension that
144 : * might have been chopped off before testing the sequence.
145 : */
146 18 : snprintf(WALFilePath, sizeof(WALFilePath), "%s/%s",
147 18 : archiveLocation, xlde->d_name);
148 :
149 18 : if (dryrun)
150 : {
151 : /*
152 : * Prints the name of the file to be removed and skips the actual
153 : * removal. The regular printout is so that the user can pipe the
154 : * output into some other program.
155 : */
156 2 : printf("%s\n", WALFilePath);
157 2 : pg_log_debug("file \"%s\" would be removed", WALFilePath);
158 2 : continue;
159 : }
160 :
161 16 : pg_log_debug("removing file \"%s\"", WALFilePath);
162 :
163 16 : rc = unlink(WALFilePath);
164 16 : if (rc != 0)
165 0 : pg_fatal("could not remove file \"%s\": %m",
166 : WALFilePath);
167 : }
168 :
169 10 : if (errno)
170 0 : pg_fatal("could not read archive location \"%s\": %m",
171 : archiveLocation);
172 10 : if (closedir(xldir))
173 0 : pg_fatal("could not close archive location \"%s\": %m",
174 : archiveLocation);
175 10 : }
176 :
177 : /*
178 : * SetWALFileNameForCleanup()
179 : *
180 : * Set the earliest WAL filename that we want to keep on the archive
181 : * and decide whether we need cleanup
182 : */
183 : static void
184 12 : SetWALFileNameForCleanup(void)
185 : {
186 12 : bool fnameOK = false;
187 :
188 12 : TrimExtension(restartWALFileName, additional_ext);
189 :
190 : /*
191 : * If restartWALFileName is a WAL file name then just use it directly. If
192 : * restartWALFileName is a .partial or .backup filename, make sure we use
193 : * the prefix of the filename, otherwise we will remove wrong files since
194 : * 000000010000000000000010.partial and
195 : * 000000010000000000000010.00000020.backup are after
196 : * 000000010000000000000010.
197 : */
198 12 : if (IsXLogFileName(restartWALFileName))
199 : {
200 6 : strcpy(exclusiveCleanupFileName, restartWALFileName);
201 6 : fnameOK = true;
202 : }
203 6 : else if (IsPartialXLogFileName(restartWALFileName))
204 : {
205 : int args;
206 2 : uint32 tli = 1,
207 2 : log = 0,
208 2 : seg = 0;
209 :
210 2 : args = sscanf(restartWALFileName, "%08X%08X%08X.partial",
211 : &tli, &log, &seg);
212 2 : if (args == 3)
213 : {
214 2 : fnameOK = true;
215 :
216 : /*
217 : * Use just the prefix of the filename, ignore everything after
218 : * first period
219 : */
220 2 : XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
221 : }
222 : }
223 4 : else if (IsBackupHistoryFileName(restartWALFileName))
224 : {
225 : int args;
226 2 : uint32 tli = 1,
227 2 : log = 0,
228 2 : seg = 0,
229 2 : offset = 0;
230 :
231 2 : args = sscanf(restartWALFileName, "%08X%08X%08X.%08X.backup", &tli, &log, &seg, &offset);
232 2 : if (args == 4)
233 : {
234 2 : fnameOK = true;
235 :
236 : /*
237 : * Use just the prefix of the filename, ignore everything after
238 : * first period
239 : */
240 2 : XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
241 : }
242 : }
243 :
244 12 : if (!fnameOK)
245 : {
246 2 : pg_log_error("invalid file name argument");
247 2 : pg_log_error_hint("Try \"%s --help\" for more information.", progname);
248 2 : exit(2);
249 : }
250 10 : }
251 :
252 : /* =====================================================================
253 : * End of Customizable section
254 : * =====================================================================
255 : */
256 :
257 : static void
258 2 : usage(void)
259 : {
260 2 : printf(_("%s removes older WAL files from PostgreSQL archives.\n\n"), progname);
261 2 : printf(_("Usage:\n"));
262 2 : printf(_(" %s [OPTION]... ARCHIVELOCATION OLDESTKEPTWALFILE\n"), progname);
263 2 : printf(_("\nOptions:\n"));
264 2 : printf(_(" -b, --clean-backup-history clean up files including backup history files\n"));
265 2 : printf(_(" -d, --debug generate debug output (verbose mode)\n"));
266 2 : printf(_(" -n, --dry-run dry run, show the names of the files that would be\n"
267 : " removed\n"));
268 2 : printf(_(" -V, --version output version information, then exit\n"));
269 2 : printf(_(" -x, --strip-extension=EXT strip this extension before identifying files for\n"
270 : " clean up\n"));
271 2 : printf(_(" -?, --help show this help, then exit\n"));
272 2 : printf(_("\n"
273 : "For use as archive_cleanup_command in postgresql.conf:\n"
274 : " archive_cleanup_command = 'pg_archivecleanup [OPTION]... ARCHIVELOCATION %%r'\n"
275 : "e.g.\n"
276 : " archive_cleanup_command = 'pg_archivecleanup /mnt/server/archiverdir %%r'\n"));
277 2 : printf(_("\n"
278 : "Or for use as a standalone archive cleaner:\n"
279 : "e.g.\n"
280 : " pg_archivecleanup /mnt/server/archiverdir 000000010000000000000010.00000020.backup\n"));
281 2 : printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
282 2 : printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
283 2 : }
284 :
285 : /*------------ MAIN ----------------------------------------*/
286 : int
287 26 : main(int argc, char **argv)
288 : {
289 : static struct option long_options[] = {
290 : {"clean-backup-history", no_argument, NULL, 'b'},
291 : {"debug", no_argument, NULL, 'd'},
292 : {"dry-run", no_argument, NULL, 'n'},
293 : {"strip-extension", required_argument, NULL, 'x'},
294 : {NULL, 0, NULL, 0}
295 : };
296 : int c;
297 :
298 26 : pg_logging_init(argv[0]);
299 26 : set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_archivecleanup"));
300 26 : progname = get_progname(argv[0]);
301 :
302 26 : if (argc > 1)
303 : {
304 24 : if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
305 : {
306 2 : usage();
307 2 : exit(0);
308 : }
309 22 : if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
310 : {
311 2 : puts("pg_archivecleanup (PostgreSQL) " PG_VERSION);
312 2 : exit(0);
313 : }
314 : }
315 :
316 34 : while ((c = getopt_long(argc, argv, "bdnx:", long_options, NULL)) != -1)
317 : {
318 14 : switch (c)
319 : {
320 2 : case 'b': /* Remove backup history files as well */
321 2 : cleanBackupHistory = true;
322 2 : break;
323 2 : case 'd': /* Debug mode */
324 2 : pg_logging_increase_verbosity();
325 2 : break;
326 2 : case 'n': /* Dry-Run mode */
327 2 : dryrun = true;
328 2 : break;
329 6 : case 'x':
330 6 : additional_ext = pg_strdup(optarg); /* Extension to remove
331 : * from xlogfile names */
332 6 : break;
333 2 : default:
334 : /* getopt already emitted a complaint */
335 2 : pg_log_error_hint("Try \"%s --help\" for more information.", progname);
336 2 : exit(2);
337 : }
338 : }
339 :
340 : /*
341 : * We will go to the archiveLocation to check restartWALFileName.
342 : * restartWALFileName may not exist anymore, which would not be an error,
343 : * so we separate the archiveLocation and restartWALFileName so we can
344 : * check separately whether archiveLocation exists, if not that is an
345 : * error
346 : */
347 20 : if (optind < argc)
348 : {
349 18 : archiveLocation = argv[optind];
350 18 : optind++;
351 : }
352 : else
353 : {
354 2 : pg_log_error("must specify archive location");
355 2 : pg_log_error_hint("Try \"%s --help\" for more information.", progname);
356 2 : exit(2);
357 : }
358 :
359 18 : if (optind < argc)
360 : {
361 16 : restartWALFileName = argv[optind];
362 16 : optind++;
363 : }
364 : else
365 : {
366 2 : pg_log_error("must specify oldest kept WAL file");
367 2 : pg_log_error_hint("Try \"%s --help\" for more information.", progname);
368 2 : exit(2);
369 : }
370 :
371 16 : if (optind < argc)
372 : {
373 2 : pg_log_error("too many command-line arguments");
374 2 : pg_log_error_hint("Try \"%s --help\" for more information.", progname);
375 2 : exit(2);
376 : }
377 :
378 : /*
379 : * Check archive exists and other initialization if required.
380 : */
381 14 : Initialize();
382 :
383 : /*
384 : * Check filename is a valid name, then process to find cut-off
385 : */
386 12 : SetWALFileNameForCleanup();
387 :
388 10 : pg_log_debug("keeping WAL file \"%s/%s\" and later",
389 : archiveLocation, exclusiveCleanupFileName);
390 :
391 : /*
392 : * Remove WAL files older than cut-off
393 : */
394 10 : CleanupPriorWALFiles();
395 :
396 10 : exit(0);
397 : }
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