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
Initialize(void)61 Initialize(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"),
73 progname, archiveLocation);
74 exit(2);
75 }
76 }
77
78 static void
TrimExtension(char * filename,char * extension)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
CleanupPriorWALFiles(void)95 CleanupPriorWALFiles(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"),
149 progname, WALFilePath);
150 continue;
151 }
152
153 if (debug)
154 fprintf(stderr, _("%s: removing file \"%s\"\n"),
155 progname, WALFilePath);
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"),
169 progname, archiveLocation, strerror(errno));
170 if (closedir(xldir))
171 fprintf(stderr, _("%s: could not close archive location \"%s\": %s\n"),
172 progname, archiveLocation, strerror(errno));
173 }
174 else
175 fprintf(stderr, _("%s: could not open archive location \"%s\": %s\n"),
176 progname, archiveLocation, strerror(errno));
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
SetWALFileNameForCleanup(void)186 SetWALFileNameForCleanup(void)
187 {
188 bool fnameOK = false;
189
190 TrimExtension(restartWALFileName, additional_ext);
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 */
200 if (IsXLogFileName(restartWALFileName))
201 {
202 strcpy(exclusiveCleanupFileName, restartWALFileName);
203 fnameOK = true;
204 }
205 else if (IsPartialXLogFileName(restartWALFileName))
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 */
222 XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
223 }
224 }
225 else if (IsBackupHistoryFileName(restartWALFileName))
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 */
242 XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
243 }
244 }
245
246 if (!fnameOK)
247 {
248 fprintf(stderr, _("%s: invalid file name argument\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
usage(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
main(int argc,char ** argv)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 oldest kept WAL file\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 command-line arguments\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 */
373 SetWALFileNameForCleanup();
374
375 if (debug)
376 {
377 snprintf(WALFilePath, MAXPGPATH, "%s/%s",
378 archiveLocation, exclusiveCleanupFileName);
379 fprintf(stderr, _("%s: keeping WAL file \"%s\" and later\n"),
380 progname, WALFilePath);
381 }
382
383 /*
384 * Remove WAL files older than cut-off
385 */
386 CleanupPriorWALFiles();
387
388 exit(0);
389 }
390