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 "pg_getopt.h"
19
20 #include "common/logging.h"
21
22 #include "access/xlog_internal.h"
23
24 const char *progname;
25
26 /* Options and defaults */
27 bool dryrun = false; /* are we performing a dry-run operation? */
28 char *additional_ext = NULL; /* Extension to remove from filenames */
29
30 char *archiveLocation; /* where to find the archive? */
31 char *restartWALFileName; /* the file from which we can restart restore */
32 char exclusiveCleanupFileName[MAXFNAMELEN]; /* the oldest file we want
33 * to remain in archive */
34
35
36 /* =====================================================================
37 *
38 * Customizable section
39 *
40 * =====================================================================
41 *
42 * Currently, this section assumes that the Archive is a locally
43 * accessible directory. If you want to make other assumptions,
44 * such as using a vendor-specific archive and access API, these
45 * routines are the ones you'll need to change. You're
46 * encouraged to submit any changes to pgsql-hackers@lists.postgresql.org
47 * or personally to the current maintainer. Those changes may be
48 * folded in to later versions of this program.
49 */
50
51 /*
52 * Initialize allows customized commands into the archive cleanup program.
53 *
54 * You may wish to add code to check for tape libraries, etc..
55 */
56 static void
Initialize(void)57 Initialize(void)
58 {
59 /*
60 * This code assumes that archiveLocation is a directory, so we use stat
61 * to test if it's accessible.
62 */
63 struct stat stat_buf;
64
65 if (stat(archiveLocation, &stat_buf) != 0 ||
66 !S_ISDIR(stat_buf.st_mode))
67 {
68 pg_log_error("archive location \"%s\" does not exist",
69 archiveLocation);
70 exit(2);
71 }
72 }
73
74 static void
TrimExtension(char * filename,char * extension)75 TrimExtension(char *filename, char *extension)
76 {
77 int flen;
78 int elen;
79
80 if (extension == NULL)
81 return;
82
83 elen = strlen(extension);
84 flen = strlen(filename);
85
86 if (flen > elen && strcmp(filename + flen - elen, extension) == 0)
87 filename[flen - elen] = '\0';
88 }
89
90 static void
CleanupPriorWALFiles(void)91 CleanupPriorWALFiles(void)
92 {
93 int rc;
94 DIR *xldir;
95 struct dirent *xlde;
96 char walfile[MAXPGPATH];
97
98 if ((xldir = opendir(archiveLocation)) != NULL)
99 {
100 while (errno = 0, (xlde = readdir(xldir)) != NULL)
101 {
102 /*
103 * Truncation is essentially harmless, because we skip names of
104 * length other than XLOG_FNAME_LEN. (In principle, one could use
105 * a 1000-character additional_ext and get trouble.)
106 */
107 strlcpy(walfile, xlde->d_name, MAXPGPATH);
108 TrimExtension(walfile, additional_ext);
109
110 /*
111 * We ignore the timeline part of the XLOG segment identifiers in
112 * deciding whether a segment is still needed. This ensures that
113 * we won't prematurely remove a segment from a parent timeline.
114 * We could probably be a little more proactive about removing
115 * segments of non-parent timelines, but that would be a whole lot
116 * more complicated.
117 *
118 * We use the alphanumeric sorting property of the filenames to
119 * decide which ones are earlier than the exclusiveCleanupFileName
120 * file. Note that this means files are not removed in the order
121 * they were originally written, in case this worries you.
122 */
123 if ((IsXLogFileName(walfile) || IsPartialXLogFileName(walfile)) &&
124 strcmp(walfile + 8, exclusiveCleanupFileName + 8) < 0)
125 {
126 char WALFilePath[MAXPGPATH * 2]; /* the file path
127 * including archive */
128
129 /*
130 * Use the original file name again now, including any
131 * extension that might have been chopped off before testing
132 * the sequence.
133 */
134 snprintf(WALFilePath, sizeof(WALFilePath), "%s/%s",
135 archiveLocation, xlde->d_name);
136
137 if (dryrun)
138 {
139 /*
140 * Prints the name of the file to be removed and skips the
141 * actual removal. The regular printout is so that the
142 * user can pipe the output into some other program.
143 */
144 printf("%s\n", WALFilePath);
145 pg_log_debug("file \"%s\" would be removed", WALFilePath);
146 continue;
147 }
148
149 pg_log_debug("removing file \"%s\"", WALFilePath);
150
151 rc = unlink(WALFilePath);
152 if (rc != 0)
153 {
154 pg_log_error("could not remove file \"%s\": %m",
155 WALFilePath);
156 break;
157 }
158 }
159 }
160
161 if (errno)
162 pg_log_error("could not read archive location \"%s\": %m",
163 archiveLocation);
164 if (closedir(xldir))
165 pg_log_error("could not close archive location \"%s\": %m",
166 archiveLocation);
167 }
168 else
169 pg_log_error("could not open archive location \"%s\": %m",
170 archiveLocation);
171 }
172
173 /*
174 * SetWALFileNameForCleanup()
175 *
176 * Set the earliest WAL filename that we want to keep on the archive
177 * and decide whether we need cleanup
178 */
179 static void
SetWALFileNameForCleanup(void)180 SetWALFileNameForCleanup(void)
181 {
182 bool fnameOK = false;
183
184 TrimExtension(restartWALFileName, additional_ext);
185
186 /*
187 * If restartWALFileName is a WAL file name then just use it directly. If
188 * restartWALFileName is a .partial or .backup filename, make sure we use
189 * the prefix of the filename, otherwise we will remove wrong files since
190 * 000000010000000000000010.partial and
191 * 000000010000000000000010.00000020.backup are after
192 * 000000010000000000000010.
193 */
194 if (IsXLogFileName(restartWALFileName))
195 {
196 strcpy(exclusiveCleanupFileName, restartWALFileName);
197 fnameOK = true;
198 }
199 else if (IsPartialXLogFileName(restartWALFileName))
200 {
201 int args;
202 uint32 tli = 1,
203 log = 0,
204 seg = 0;
205
206 args = sscanf(restartWALFileName, "%08X%08X%08X.partial",
207 &tli, &log, &seg);
208 if (args == 3)
209 {
210 fnameOK = true;
211
212 /*
213 * Use just the prefix of the filename, ignore everything after
214 * first period
215 */
216 XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
217 }
218 }
219 else if (IsBackupHistoryFileName(restartWALFileName))
220 {
221 int args;
222 uint32 tli = 1,
223 log = 0,
224 seg = 0,
225 offset = 0;
226
227 args = sscanf(restartWALFileName, "%08X%08X%08X.%08X.backup", &tli, &log, &seg, &offset);
228 if (args == 4)
229 {
230 fnameOK = true;
231
232 /*
233 * Use just the prefix of the filename, ignore everything after
234 * first period
235 */
236 XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
237 }
238 }
239
240 if (!fnameOK)
241 {
242 pg_log_error("invalid file name argument");
243 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
244 exit(2);
245 }
246 }
247
248 /* =====================================================================
249 * End of Customizable section
250 * =====================================================================
251 */
252
253 static void
usage(void)254 usage(void)
255 {
256 printf(_("%s removes older WAL files from PostgreSQL archives.\n\n"), progname);
257 printf(_("Usage:\n"));
258 printf(_(" %s [OPTION]... ARCHIVELOCATION OLDESTKEPTWALFILE\n"), progname);
259 printf(_("\nOptions:\n"));
260 printf(_(" -d generate debug output (verbose mode)\n"));
261 printf(_(" -n dry run, show the names of the files that would be removed\n"));
262 printf(_(" -V, --version output version information, then exit\n"));
263 printf(_(" -x EXT clean up files if they have this extension\n"));
264 printf(_(" -?, --help show this help, then exit\n"));
265 printf(_("\n"
266 "For use as archive_cleanup_command in postgresql.conf:\n"
267 " archive_cleanup_command = 'pg_archivecleanup [OPTION]... ARCHIVELOCATION %%r'\n"
268 "e.g.\n"
269 " archive_cleanup_command = 'pg_archivecleanup /mnt/server/archiverdir %%r'\n"));
270 printf(_("\n"
271 "Or for use as a standalone archive cleaner:\n"
272 "e.g.\n"
273 " pg_archivecleanup /mnt/server/archiverdir 000000010000000000000010.00000020.backup\n"));
274 printf(_("\nReport bugs to <pgsql-bugs@lists.postgresql.org>.\n"));
275 }
276
277 /*------------ MAIN ----------------------------------------*/
278 int
main(int argc,char ** argv)279 main(int argc, char **argv)
280 {
281 int c;
282
283 pg_logging_init(argv[0]);
284 set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_archivecleanup"));
285 progname = get_progname(argv[0]);
286
287 if (argc > 1)
288 {
289 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
290 {
291 usage();
292 exit(0);
293 }
294 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
295 {
296 puts("pg_archivecleanup (PostgreSQL) " PG_VERSION);
297 exit(0);
298 }
299 }
300
301 while ((c = getopt(argc, argv, "x:dn")) != -1)
302 {
303 switch (c)
304 {
305 case 'd': /* Debug mode */
306 pg_logging_set_level(PG_LOG_DEBUG);
307 break;
308 case 'n': /* Dry-Run mode */
309 dryrun = true;
310 break;
311 case 'x':
312 additional_ext = pg_strdup(optarg); /* Extension to remove
313 * from xlogfile names */
314 break;
315 default:
316 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
317 exit(2);
318 break;
319 }
320 }
321
322 /*
323 * We will go to the archiveLocation to check restartWALFileName.
324 * restartWALFileName may not exist anymore, which would not be an error,
325 * so we separate the archiveLocation and restartWALFileName so we can
326 * check separately whether archiveLocation exists, if not that is an
327 * error
328 */
329 if (optind < argc)
330 {
331 archiveLocation = argv[optind];
332 optind++;
333 }
334 else
335 {
336 pg_log_error("must specify archive location");
337 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
338 exit(2);
339 }
340
341 if (optind < argc)
342 {
343 restartWALFileName = argv[optind];
344 optind++;
345 }
346 else
347 {
348 pg_log_error("must specify oldest kept WAL file");
349 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
350 exit(2);
351 }
352
353 if (optind < argc)
354 {
355 pg_log_error("too many command-line arguments");
356 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
357 exit(2);
358 }
359
360 /*
361 * Check archive exists and other initialization if required.
362 */
363 Initialize();
364
365 /*
366 * Check filename is a valid name, then process to find cut-off
367 */
368 SetWALFileNameForCleanup();
369
370 pg_log_debug("keeping WAL file \"%s/%s\" and later",
371 archiveLocation, exclusiveCleanupFileName);
372
373 /*
374 * Remove WAL files older than cut-off
375 */
376 CleanupPriorWALFiles();
377
378 exit(0);
379 }
380