PostgreSQL Source Code: src/bin/pg_archivecleanup/pg_archivecleanup.c Source File

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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 "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 */
57static void
58 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 if (stat(archiveLocation, &stat_buf) != 0 ||
67 !S_ISDIR(stat_buf.st_mode))
68 {
69 pg_log_error("archive location \"%s\" does not exist",
70 archiveLocation);
71 exit(2);
72 }
73}
74
75static void
76 TrimExtension(char *filename, char *extension)
77{
78 int flen;
79 int elen;
80
81 if (extension == NULL)
82 return;
83
84 elen = strlen(extension);
85 flen = strlen(filename);
86
87 if (flen > elen && strcmp(filename + flen - elen, extension) == 0)
88 filename[flen - elen] = '0円';
89}
90
91static void
92 CleanupPriorWALFiles(void)
93{
94 int rc;
95 DIR *xldir;
96 struct dirent *xlde;
97 char walfile[MAXPGPATH];
98
99 xldir = opendir(archiveLocation);
100 if (xldir == NULL)
101 pg_fatal("could not open archive location \"%s\": %m",
102 archiveLocation);
103
104 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 strlcpy(walfile, xlde->d_name, MAXPGPATH);
116 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 if (!IsXLogFileName(walfile) && !IsPartialXLogFileName(walfile) &&
123 !(cleanBackupHistory && IsBackupHistoryFileName(walfile)))
124 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 if (strcmp(walfile + 8, exclusiveCleanupFileName + 8) >= 0)
140 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 snprintf(WALFilePath, sizeof(WALFilePath), "%s/%s",
147 archiveLocation, xlde->d_name);
148
149 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 printf("%s\n", WALFilePath);
157 pg_log_debug("file \"%s\" would be removed", WALFilePath);
158 continue;
159 }
160
161 pg_log_debug("removing file \"%s\"", WALFilePath);
162
163 rc = unlink(WALFilePath);
164 if (rc != 0)
165 pg_fatal("could not remove file \"%s\": %m",
166 WALFilePath);
167 }
168
169 if (errno)
170 pg_fatal("could not read archive location \"%s\": %m",
171 archiveLocation);
172 if (closedir(xldir))
173 pg_fatal("could not close archive location \"%s\": %m",
174 archiveLocation);
175}
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 */
183static void
184 SetWALFileNameForCleanup(void)
185{
186 bool fnameOK = false;
187
188 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 if (IsXLogFileName(restartWALFileName))
199 {
200 strcpy(exclusiveCleanupFileName, restartWALFileName);
201 fnameOK = true;
202 }
203 else if (IsPartialXLogFileName(restartWALFileName))
204 {
205 int args;
206 uint32 tli = 1,
207 log = 0,
208 seg = 0;
209
210 args = sscanf(restartWALFileName, "%08X%08X%08X.partial",
211 &tli, &log, &seg);
212 if (args == 3)
213 {
214 fnameOK = true;
215
216 /*
217 * Use just the prefix of the filename, ignore everything after
218 * first period
219 */
220 XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
221 }
222 }
223 else if (IsBackupHistoryFileName(restartWALFileName))
224 {
225 int args;
226 uint32 tli = 1,
227 log = 0,
228 seg = 0,
229 offset = 0;
230
231 args = sscanf(restartWALFileName, "%08X%08X%08X.%08X.backup", &tli, &log, &seg, &offset);
232 if (args == 4)
233 {
234 fnameOK = true;
235
236 /*
237 * Use just the prefix of the filename, ignore everything after
238 * first period
239 */
240 XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
241 }
242 }
243
244 if (!fnameOK)
245 {
246 pg_log_error("invalid file name argument");
247 pg_log_error_hint("Try \"%s --help\" for more information.", progname);
248 exit(2);
249 }
250}
251
252/* =====================================================================
253 * End of Customizable section
254 * =====================================================================
255 */
256
257static void
258 usage(void)
259{
260 printf(_("%s removes older WAL files from PostgreSQL archives.\n\n"), progname);
261 printf(_("Usage:\n"));
262 printf(_(" %s [OPTION]... ARCHIVELOCATION OLDESTKEPTWALFILE\n"), progname);
263 printf(_("\nOptions:\n"));
264 printf(_(" -b, --clean-backup-history clean up files including backup history files\n"));
265 printf(_(" -d, --debug generate debug output (verbose mode)\n"));
266 printf(_(" -n, --dry-run dry run, show the names of the files that would be\n"
267 " removed\n"));
268 printf(_(" -V, --version output version information, then exit\n"));
269 printf(_(" -x, --strip-extension=EXT strip this extension before identifying files for\n"
270 " clean up\n"));
271 printf(_(" -?, --help show this help, then exit\n"));
272 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 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 printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
282 printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
283}
284
285/*------------ MAIN ----------------------------------------*/
286int
287 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 pg_logging_init(argv[0]);
299 set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_archivecleanup"));
300 progname = get_progname(argv[0]);
301
302 if (argc > 1)
303 {
304 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
305 {
306 usage();
307 exit(0);
308 }
309 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
310 {
311 puts("pg_archivecleanup (PostgreSQL) " PG_VERSION);
312 exit(0);
313 }
314 }
315
316 while ((c = getopt_long(argc, argv, "bdnx:", long_options, NULL)) != -1)
317 {
318 switch (c)
319 {
320 case 'b': /* Remove backup history files as well */
321 cleanBackupHistory = true;
322 break;
323 case 'd': /* Debug mode */
324 pg_logging_increase_verbosity();
325 break;
326 case 'n': /* Dry-Run mode */
327 dryrun = true;
328 break;
329 case 'x':
330 additional_ext = pg_strdup(optarg); /* Extension to remove
331 * from xlogfile names */
332 break;
333 default:
334 /* getopt already emitted a complaint */
335 pg_log_error_hint("Try \"%s --help\" for more information.", progname);
336 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 if (optind < argc)
348 {
349 archiveLocation = argv[optind];
350 optind++;
351 }
352 else
353 {
354 pg_log_error("must specify archive location");
355 pg_log_error_hint("Try \"%s --help\" for more information.", progname);
356 exit(2);
357 }
358
359 if (optind < argc)
360 {
361 restartWALFileName = argv[optind];
362 optind++;
363 }
364 else
365 {
366 pg_log_error("must specify oldest kept WAL file");
367 pg_log_error_hint("Try \"%s --help\" for more information.", progname);
368 exit(2);
369 }
370
371 if (optind < argc)
372 {
373 pg_log_error("too many command-line arguments");
374 pg_log_error_hint("Try \"%s --help\" for more information.", progname);
375 exit(2);
376 }
377
378 /*
379 * Check archive exists and other initialization if required.
380 */
381 Initialize();
382
383 /*
384 * Check filename is a valid name, then process to find cut-off
385 */
386 SetWALFileNameForCleanup();
387
388 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 CleanupPriorWALFiles();
395
396 exit(0);
397}
#define PG_TEXTDOMAIN(domain)
Definition: c.h:1213
uint32_t uint32
Definition: c.h:538
void set_pglocale_pgservice(const char *argv0, const char *app)
Definition: exec.c:430
int closedir(DIR *)
Definition: dirent.c:127
struct dirent * readdir(DIR *)
Definition: dirent.c:78
DIR * opendir(const char *)
Definition: dirent.c:33
_
#define _(x)
Definition: elog.c:91
char * pg_strdup(const char *in)
Definition: fe_memutils.c:85
int getopt_long(int argc, char *const argv[], const char *optstring, const struct option *longopts, int *longindex)
Definition: getopt_long.c:60
#define no_argument
Definition: getopt_long.h:25
#define required_argument
Definition: getopt_long.h:26
void pg_logging_increase_verbosity(void)
Definition: logging.c:185
void pg_logging_init(const char *argv0)
Definition: logging.c:83
#define pg_log_error(...)
Definition: logging.h:106
#define pg_log_error_hint(...)
Definition: logging.h:112
#define pg_log_debug(...)
Definition: logging.h:133
args
static char * restartWALFileName
int main(int argc, char **argv)
static char * archiveLocation
static char * additional_ext
static bool cleanBackupHistory
static char exclusiveCleanupFileName[MAXFNAMELEN]
static void SetWALFileNameForCleanup(void)
static void CleanupPriorWALFiles(void)
static void Initialize(void)
static const char * progname
static void usage(void)
static void TrimExtension(char *filename, char *extension)
static bool dryrun
#define pg_fatal(...)
#define MAXPGPATH
static char * filename
Definition: pg_dumpall.c:120
PGDLLIMPORT int optind
Definition: getopt.c:51
PGDLLIMPORT char * optarg
Definition: getopt.c:53
#define snprintf
Definition: port.h:239
const char * get_progname(const char *argv0)
Definition: path.c:652
#define printf(...)
Definition: port.h:245
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
c
char * c
Definition: preproc-cursor.c:31
static Walfile * walfile
Definition: receivelog.c:29
Definition: dirent.c:26
Definition: dirent.h:10
char d_name[MAX_PATH]
Definition: dirent.h:15
Definition: win32_port.h:255
unsigned short st_mode
Definition: win32_port.h:258
#define stat
Definition: win32_port.h:274
#define S_ISDIR(m)
Definition: win32_port.h:315
static bool IsXLogFileName(const char *fname)
Definition: xlog_internal.h:180
#define MAXFNAMELEN
Definition: xlog_internal.h:156
static bool IsBackupHistoryFileName(const char *fname)
Definition: xlog_internal.h:253
static void XLogFileNameById(char *fname, TimeLineID tli, uint32 log, uint32 seg)
Definition: xlog_internal.h:174
static bool IsPartialXLogFileName(const char *fname)
Definition: xlog_internal.h:192

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