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pg_rewind.c File Reference
#include "postgres_fe.h"
#include <sys/stat.h>
#include <fcntl.h>
#include <time.h>
#include <unistd.h>
#include "access/timeline.h"
#include "access/xlog_internal.h"
#include "catalog/catversion.h"
#include "catalog/pg_control.h"
#include "common/controldata_utils.h"
#include "common/file_perm.h"
#include "common/restricted_token.h"
#include "common/string.h"
#include "fe_utils/option_utils.h"
#include "fe_utils/recovery_gen.h"
#include "fe_utils/string_utils.h"
#include "file_ops.h"
#include "filemap.h"
#include "getopt_long.h"
#include "pg_rewind.h"
#include "rewind_source.h"
#include "storage/bufpage.h"
Include dependency graph for pg_rewind.c:

Go to the source code of this file.

Functions

static void usage (const char *progname)
 
static void perform_rewind (filemap_t *filemap, rewind_source *source, XLogRecPtr chkptrec, TimeLineID chkpttli, XLogRecPtr chkptredo)
 
static void createBackupLabel (XLogRecPtr startpoint, TimeLineID starttli, XLogRecPtr checkpointloc)
 
static void digestControlFile (ControlFileData *ControlFile, const char *content, size_t size)
 
static void getRestoreCommand (const char *argv0)
 
static void sanityChecks (void)
 
static TimeLineHistoryEntrygetTimelineHistory (TimeLineID tli, bool is_source, int *nentries)
 
static void findCommonAncestorTimeline (TimeLineHistoryEntry *a_history, int a_nentries, TimeLineHistoryEntry *b_history, int b_nentries, XLogRecPtr *recptr, int *tliIndex)
 
static void ensureCleanShutdown (const char *argv0)
 
static void disconnect_atexit (void)
 
int main (int argc, char **argv)
 
void progress_report (bool finished)
 
static XLogRecPtr MinXLogRecPtr (XLogRecPtr a, XLogRecPtr b)
 
static void checkControlFile (ControlFileData *ControlFile)
 

Variables

static ControlFileData ControlFile_target
 
static ControlFileData ControlFile_source
 
static ControlFileData ControlFile_source_after
 
static const char * progname
 
int WalSegSz
 
char * datadir_target = NULL
 
static char * datadir_source = NULL
 
static char * connstr_source = NULL
 
static char * restore_command = NULL
 
static char * config_file = NULL
 
static bool debug = false
 
bool showprogress = false
 
bool dry_run = false
 
bool do_sync = true
 
static bool restore_wal = false
 
DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC
 
TimeLineHistoryEntrytargetHistory
 
int targetNentries
 
uint64 fetch_size
 
uint64 fetch_done
 
static PGconnconn
 
static rewind_sourcesource
 

Function Documentation

◆ checkControlFile()

static void checkControlFile ( ControlFileData ControlFile)
static

Definition at line 1004 of file pg_rewind.c.

1005 {
1006  pg_crc32c crc;
1007 
1008  /* Calculate CRC */
1009  INIT_CRC32C(crc);
1010  COMP_CRC32C(crc, (char *) ControlFile, offsetof(ControlFileData, crc));
1011  FIN_CRC32C(crc);
1012 
1013  /* And simply compare it */
1014  if (!EQ_CRC32C(crc, ControlFile->crc))
1015  pg_fatal("unexpected control file CRC");
1016 }
#define pg_fatal(...)
uint32 pg_crc32c
Definition: pg_crc32c.h:38
#define COMP_CRC32C(crc, data, len)
Definition: pg_crc32c.h:98
#define EQ_CRC32C(c1, c2)
Definition: pg_crc32c.h:42
#define INIT_CRC32C(crc)
Definition: pg_crc32c.h:41
#define FIN_CRC32C(crc)
Definition: pg_crc32c.h:103
return crc
pg_crc32c crc
Definition: pg_control.h:232
static ControlFileData * ControlFile
Definition: xlog.c:574

References COMP_CRC32C, ControlFile, ControlFileData::crc, crc, EQ_CRC32C, FIN_CRC32C, INIT_CRC32C, and pg_fatal.

Referenced by digestControlFile().

◆ createBackupLabel()

static void createBackupLabel ( XLogRecPtr  startpoint,
TimeLineID  starttli,
XLogRecPtr  checkpointloc 
)
static

Definition at line 961 of file pg_rewind.c.

962 {
963  XLogSegNo startsegno;
964  time_t stamp_time;
965  char strfbuf[128];
966  char xlogfilename[MAXFNAMELEN];
967  struct tm *tmp;
968  char buf[1000];
969  int len;
970 
971  XLByteToSeg(startpoint, startsegno, WalSegSz);
972  XLogFileName(xlogfilename, starttli, startsegno, WalSegSz);
973 
974  /*
975  * Construct backup label file
976  */
977  stamp_time = time(NULL);
978  tmp = localtime(&stamp_time);
979  strftime(strfbuf, sizeof(strfbuf), "%Y-%m-%d %H:%M:%S %Z", tmp);
980 
981  len = snprintf(buf, sizeof(buf),
982  "START WAL LOCATION: %X/%X (file %s)\n"
983  "CHECKPOINT LOCATION: %X/%X\n"
984  "BACKUP METHOD: pg_rewind\n"
985  "BACKUP FROM: standby\n"
986  "START TIME: %s\n",
987  /* omit LABEL: line */
988  LSN_FORMAT_ARGS(startpoint), xlogfilename,
989  LSN_FORMAT_ARGS(checkpointloc),
990  strfbuf);
991  if (len >= sizeof(buf))
992  pg_fatal("backup label buffer too small"); /* shouldn't happen */
993 
994  /* TODO: move old file out of the way, if any. */
995  open_target_file("backup_label", true); /* BACKUP_LABEL_FILE */
998 }
void close_target_file(void)
Definition: file_ops.c:75
void open_target_file(const char *path, bool trunc)
Definition: file_ops.c:47
void write_target_range(char *buf, off_t begin, size_t size)
Definition: file_ops.c:88
static struct pg_tm tm
Definition: localtime.c:104
const void size_t len
int WalSegSz
Definition: pg_rewind.c:64
static char * buf
Definition: pg_test_fsync.c:72
#define snprintf
Definition: port.h:238
#define MAXFNAMELEN
#define XLByteToSeg(xlrp, logSegNo, wal_segsz_bytes)
static void XLogFileName(char *fname, TimeLineID tli, XLogSegNo logSegNo, int wal_segsz_bytes)
#define LSN_FORMAT_ARGS(lsn)
Definition: xlogdefs.h:43
uint64 XLogSegNo
Definition: xlogdefs.h:48

References buf, close_target_file(), len, LSN_FORMAT_ARGS, MAXFNAMELEN, open_target_file(), pg_fatal, snprintf, tm, WalSegSz, write_target_range(), XLByteToSeg, and XLogFileName().

Referenced by perform_rewind().

◆ digestControlFile()

static void digestControlFile ( ControlFileData ControlFile,
const char *  content,
size_t  size 
)
static

Definition at line 1023 of file pg_rewind.c.

1025 {
1026  if (size != PG_CONTROL_FILE_SIZE)
1027  pg_fatal("unexpected control file size %d, expected %d",
1028  (int) size, PG_CONTROL_FILE_SIZE);
1029 
1030  memcpy(ControlFile, content, sizeof(ControlFileData));
1031 
1032  /* set and validate WalSegSz */
1034 
1036  {
1037  pg_log_error(ngettext("invalid WAL segment size in control file (%d byte)",
1038  "invalid WAL segment size in control file (%d bytes)",
1039  WalSegSz),
1040  WalSegSz);
1041  pg_log_error_detail("The WAL segment size must be a power of two between 1 MB and 1 GB.");
1042  exit(1);
1043  }
1044 
1045  /* Additional checks on control file */
1047 }
#define ngettext(s, p, n)
Definition: c.h:1184
exit(1)
#define pg_log_error(...)
Definition: logging.h:106
#define pg_log_error_detail(...)
Definition: logging.h:109
#define PG_CONTROL_FILE_SIZE
Definition: pg_control.h:250
static void checkControlFile(ControlFileData *ControlFile)
Definition: pg_rewind.c:1004
static pg_noinline void Size size
Definition: slab.c:607
uint32 xlog_seg_size
Definition: pg_control.h:211
#define IsValidWalSegSize(size)
Definition: xlog_internal.h:96

References checkControlFile(), ControlFile, exit(), IsValidWalSegSize, ngettext, PG_CONTROL_FILE_SIZE, pg_fatal, pg_log_error, pg_log_error_detail, size, WalSegSz, and ControlFileData::xlog_seg_size.

Referenced by main(), and perform_rewind().

◆ disconnect_atexit()

static void disconnect_atexit ( void  )
static

Definition at line 1200 of file pg_rewind.c.

1201 {
1202  if (conn != NULL)
1203  PQfinish(conn);
1204 }
void PQfinish(PGconn *conn)
Definition: fe-connect.c:4879
static PGconn * conn
Definition: pg_rewind.c:88

References conn, and PQfinish().

Referenced by main().

◆ ensureCleanShutdown()

static void ensureCleanShutdown ( const char *  argv0)
static

Definition at line 1129 of file pg_rewind.c.

1130 {
1131  int ret;
1132  char exec_path[MAXPGPATH];
1133  PQExpBuffer postgres_cmd;
1134 
1135  /* locate postgres binary */
1136  if ((ret = find_other_exec(argv0, "postgres",
1138  exec_path)) < 0)
1139  {
1140  char full_path[MAXPGPATH];
1141 
1142  if (find_my_exec(argv0, full_path) < 0)
1143  strlcpy(full_path, progname, sizeof(full_path));
1144 
1145  if (ret == -1)
1146  pg_fatal("program \"%s\" is needed by %s but was not found in the same directory as \"%s\"",
1147  "postgres", progname, full_path);
1148  else
1149  pg_fatal("program \"%s\" was found by \"%s\" but was not the same version as %s",
1150  "postgres", full_path, progname);
1151  }
1152 
1153  pg_log_info("executing \"%s\" for target server to complete crash recovery",
1154  exec_path);
1155 
1156  /*
1157  * Skip processing if requested, but only after ensuring presence of
1158  * postgres.
1159  */
1160  if (dry_run)
1161  return;
1162 
1163  /*
1164  * Finally run postgres in single-user mode. There is no need to use
1165  * fsync here. This makes the recovery faster, and the target data folder
1166  * is synced at the end anyway.
1167  */
1168  postgres_cmd = createPQExpBuffer();
1169 
1170  /* path to postgres, properly quoted */
1171  appendShellString(postgres_cmd, exec_path);
1172 
1173  /* add set of options with properly quoted data directory */
1174  appendPQExpBufferStr(postgres_cmd, " --single -F -D ");
1175  appendShellString(postgres_cmd, datadir_target);
1176 
1177  /* add custom configuration file only if requested */
1178  if (config_file != NULL)
1179  {
1180  appendPQExpBufferStr(postgres_cmd, " -c config_file=");
1181  appendShellString(postgres_cmd, config_file);
1182  }
1183 
1184  /* finish with the database name, and a properly quoted redirection */
1185  appendPQExpBufferStr(postgres_cmd, " template1 < ");
1186  appendShellString(postgres_cmd, DEVNULL);
1187 
1188  fflush(NULL);
1189  if (system(postgres_cmd->data) != 0)
1190  {
1191  pg_log_error("postgres single-user mode in target cluster failed");
1192  pg_log_error_detail("Command was: %s", postgres_cmd->data);
1193  exit(1);
1194  }
1195 
1196  destroyPQExpBuffer(postgres_cmd);
1197 }
int find_my_exec(const char *argv0, char *retpath)
Definition: exec.c:160
int find_other_exec(const char *argv0, const char *target, const char *versionstr, char *retpath)
Definition: exec.c:310
static void const char fflush(stdout)
#define pg_log_info(...)
Definition: logging.h:124
#define MAXPGPATH
static char * argv0
Definition: pg_ctl.c:93
static char * exec_path
Definition: pg_ctl.c:88
char * datadir_target
Definition: pg_rewind.c:67
static char * config_file
Definition: pg_rewind.c:71
bool dry_run
Definition: pg_rewind.c:75
static const char * progname
Definition: pg_rewind.c:63
#define DEVNULL
Definition: port.h:160
#define PG_BACKEND_VERSIONSTR
Definition: port.h:143
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
PQExpBuffer createPQExpBuffer(void)
Definition: pqexpbuffer.c:72
void destroyPQExpBuffer(PQExpBuffer str)
Definition: pqexpbuffer.c:114
void appendPQExpBufferStr(PQExpBuffer str, const char *data)
Definition: pqexpbuffer.c:367
void appendShellString(PQExpBuffer buf, const char *str)
Definition: string_utils.c:429

References appendPQExpBufferStr(), appendShellString(), argv0, config_file, createPQExpBuffer(), PQExpBufferData::data, datadir_target, destroyPQExpBuffer(), DEVNULL, dry_run, exec_path, exit(), fflush(), find_my_exec(), find_other_exec(), MAXPGPATH, PG_BACKEND_VERSIONSTR, pg_fatal, pg_log_error, pg_log_error_detail, pg_log_info, progname, and strlcpy().

Referenced by main().

◆ findCommonAncestorTimeline()

static void findCommonAncestorTimeline ( TimeLineHistoryEntry a_history,
int  a_nentries,
TimeLineHistoryEntry b_history,
int  b_nentries,
XLogRecPtr recptr,
int *  tliIndex 
)
static

Definition at line 919 of file pg_rewind.c.

922 {
923  int i,
924  n;
925 
926  /*
927  * Trace the history forward, until we hit the timeline diverge. It may
928  * still be possible that the source and target nodes used the same
929  * timeline number in their history but with different start position
930  * depending on the history files that each node has fetched in previous
931  * recovery processes. Hence check the start position of the new timeline
932  * as well and move down by one extra timeline entry if they do not match.
933  */
934  n = Min(a_nentries, b_nentries);
935  for (i = 0; i < n; i++)
936  {
937  if (a_history[i].tli != b_history[i].tli ||
938  a_history[i].begin != b_history[i].begin)
939  break;
940  }
941 
942  if (i > 0)
943  {
944  i--;
945  *recptr = MinXLogRecPtr(a_history[i].end, b_history[i].end);
946  *tliIndex = i;
947  return;
948  }
949  else
950  {
951  pg_fatal("could not find common ancestor of the source and target cluster's timelines");
952  }
953 }
#define Min(x, y)
Definition: c.h:1007
int i
Definition: isn.c:72
static XLogRecPtr MinXLogRecPtr(XLogRecPtr a, XLogRecPtr b)
Definition: pg_rewind.c:842

References i, Min, MinXLogRecPtr(), and pg_fatal.

Referenced by main().

◆ getRestoreCommand()

static void getRestoreCommand ( const char *  argv0)
static

Definition at line 1056 of file pg_rewind.c.

1057 {
1058  int rc;
1059  char postgres_exec_path[MAXPGPATH];
1060  PQExpBuffer postgres_cmd;
1061 
1062  if (!restore_wal)
1063  return;
1064 
1065  /* find postgres executable */
1066  rc = find_other_exec(argv0, "postgres",
1068  postgres_exec_path);
1069 
1070  if (rc < 0)
1071  {
1072  char full_path[MAXPGPATH];
1073 
1074  if (find_my_exec(argv0, full_path) < 0)
1075  strlcpy(full_path, progname, sizeof(full_path));
1076 
1077  if (rc == -1)
1078  pg_fatal("program \"%s\" is needed by %s but was not found in the same directory as \"%s\"",
1079  "postgres", progname, full_path);
1080  else
1081  pg_fatal("program \"%s\" was found by \"%s\" but was not the same version as %s",
1082  "postgres", full_path, progname);
1083  }
1084 
1085  /*
1086  * Build a command able to retrieve the value of GUC parameter
1087  * restore_command, if set.
1088  */
1089  postgres_cmd = createPQExpBuffer();
1090 
1091  /* path to postgres, properly quoted */
1092  appendShellString(postgres_cmd, postgres_exec_path);
1093 
1094  /* add -D switch, with properly quoted data directory */
1095  appendPQExpBufferStr(postgres_cmd, " -D ");
1096  appendShellString(postgres_cmd, datadir_target);
1097 
1098  /* add custom configuration file only if requested */
1099  if (config_file != NULL)
1100  {
1101  appendPQExpBufferStr(postgres_cmd, " -c config_file=");
1102  appendShellString(postgres_cmd, config_file);
1103  }
1104 
1105  /* add -C switch, for restore_command */
1106  appendPQExpBufferStr(postgres_cmd, " -C restore_command");
1107 
1108  restore_command = pipe_read_line(postgres_cmd->data);
1109  if (restore_command == NULL)
1110  pg_fatal("could not read \"restore_command\" from target cluster");
1111 
1113 
1114  if (strcmp(restore_command, "") == 0)
1115  pg_fatal("\"restore_command\" is not set in the target cluster");
1116 
1117  pg_log_debug("using for rewind \"restore_command = \'%s\'\"",
1118  restore_command);
1119 
1120  destroyPQExpBuffer(postgres_cmd);
1121 }
char * pipe_read_line(char *cmd)
Definition: exec.c:352
#define pg_log_debug(...)
Definition: logging.h:133
static char * restore_command
Definition: pg_rewind.c:70
static bool restore_wal
Definition: pg_rewind.c:77
int pg_strip_crlf(char *str)
Definition: string.c:154

References appendPQExpBufferStr(), appendShellString(), argv0, config_file, createPQExpBuffer(), PQExpBufferData::data, datadir_target, destroyPQExpBuffer(), find_my_exec(), find_other_exec(), MAXPGPATH, PG_BACKEND_VERSIONSTR, pg_fatal, pg_log_debug, pg_strip_crlf(), pipe_read_line(), progname, restore_command, restore_wal, and strlcpy().

Referenced by main().

◆ getTimelineHistory()

static TimeLineHistoryEntry * getTimelineHistory ( TimeLineID  tli,
bool  is_source,
int *  nentries 
)
static

Definition at line 856 of file pg_rewind.c.

857 {
858  TimeLineHistoryEntry *history;
859 
860  /*
861  * Timeline 1 does not have a history file, so there is no need to check
862  * and fake an entry with infinite start and end positions.
863  */
864  if (tli == 1)
865  {
866  history = (TimeLineHistoryEntry *) pg_malloc(sizeof(TimeLineHistoryEntry));
867  history->tli = tli;
868  history->begin = history->end = InvalidXLogRecPtr;
869  *nentries = 1;
870  }
871  else
872  {
873  char path[MAXPGPATH];
874  char *histfile;
875 
876  TLHistoryFilePath(path, tli);
877 
878  /* Get history file from appropriate source */
879  if (is_source)
880  histfile = source->fetch_file(source, path, NULL);
881  else
882  histfile = slurpFile(datadir_target, path, NULL);
883 
884  history = rewind_parseTimeLineHistory(histfile, tli, nentries);
885  pg_free(histfile);
886  }
887 
888  /* In debugging mode, print what we read */
889  if (debug)
890  {
891  int i;
892 
893  if (is_source)
894  pg_log_debug("Source timeline history:");
895  else
896  pg_log_debug("Target timeline history:");
897 
898  for (i = 0; i < *nentries; i++)
899  {
900  TimeLineHistoryEntry *entry;
901 
902  entry = &history[i];
903  pg_log_debug("%u: %X/%X - %X/%X", entry->tli,
904  LSN_FORMAT_ARGS(entry->begin),
905  LSN_FORMAT_ARGS(entry->end));
906  }
907  }
908 
909  return history;
910 }
void pg_free(void *ptr)
Definition: fe_memutils.c:105
void * pg_malloc(size_t size)
Definition: fe_memutils.c:47
char * slurpFile(const char *datadir, const char *path, size_t *filesize)
Definition: file_ops.c:314
static bool debug
Definition: pg_rewind.c:73
static rewind_source * source
Definition: pg_rewind.c:89
TimeLineHistoryEntry * rewind_parseTimeLineHistory(char *buffer, TimeLineID targetTLI, int *nentries)
Definition: timeline.c:28
XLogRecPtr begin
Definition: timeline.h:28
TimeLineID tli
Definition: timeline.h:27
XLogRecPtr end
Definition: timeline.h:29
char *(* fetch_file)(struct rewind_source *, const char *path, size_t *filesize)
Definition: rewind_source.h:37
static void TLHistoryFilePath(char *path, TimeLineID tli)
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28

References TimeLineHistoryEntry::begin, datadir_target, debug, TimeLineHistoryEntry::end, rewind_source::fetch_file, i, InvalidXLogRecPtr, LSN_FORMAT_ARGS, MAXPGPATH, pg_free(), pg_log_debug, pg_malloc(), rewind_parseTimeLineHistory(), slurpFile(), source, TLHistoryFilePath(), and TimeLineHistoryEntry::tli.

Referenced by main().

◆ main()

int main ( int  argc,
char **  argv 
)

Definition at line 121 of file pg_rewind.c.

122 {
123  static struct option long_options[] = {
124  {"help", no_argument, NULL, '?'},
125  {"target-pgdata", required_argument, NULL, 'D'},
126  {"write-recovery-conf", no_argument, NULL, 'R'},
127  {"source-pgdata", required_argument, NULL, 1},
128  {"source-server", required_argument, NULL, 2},
129  {"no-ensure-shutdown", no_argument, NULL, 4},
130  {"config-file", required_argument, NULL, 5},
131  {"version", no_argument, NULL, 'V'},
132  {"restore-target-wal", no_argument, NULL, 'c'},
133  {"dry-run", no_argument, NULL, 'n'},
134  {"no-sync", no_argument, NULL, 'N'},
135  {"progress", no_argument, NULL, 'P'},
136  {"debug", no_argument, NULL, 3},
137  {"sync-method", required_argument, NULL, 6},
138  {NULL, 0, NULL, 0}
139  };
140  int option_index;
141  int c;
142  XLogRecPtr divergerec;
143  int lastcommontliIndex;
144  XLogRecPtr chkptrec;
145  TimeLineID chkpttli;
146  XLogRecPtr chkptredo;
147  TimeLineID source_tli;
148  TimeLineID target_tli;
149  XLogRecPtr target_wal_endrec;
150  size_t size;
151  char *buffer;
152  bool no_ensure_shutdown = false;
153  bool rewind_needed;
154  bool writerecoveryconf = false;
155  filemap_t *filemap;
156 
157  pg_logging_init(argv[0]);
158  set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_rewind"));
159  progname = get_progname(argv[0]);
160 
161  /* Process command-line arguments */
162  if (argc > 1)
163  {
164  if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
165  {
166  usage(progname);
167  exit(0);
168  }
169  if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
170  {
171  puts("pg_rewind (PostgreSQL) " PG_VERSION);
172  exit(0);
173  }
174  }
175 
176  while ((c = getopt_long(argc, argv, "cD:nNPR", long_options, &option_index)) != -1)
177  {
178  switch (c)
179  {
180  case 'c':
181  restore_wal = true;
182  break;
183 
184  case 'P':
185  showprogress = true;
186  break;
187 
188  case 'n':
189  dry_run = true;
190  break;
191 
192  case 'N':
193  do_sync = false;
194  break;
195 
196  case 'R':
197  writerecoveryconf = true;
198  break;
199 
200  case 3:
201  debug = true;
203  break;
204 
205  case 'D': /* -D or --target-pgdata */
207  break;
208 
209  case 1: /* --source-pgdata */
211  break;
212 
213  case 2: /* --source-server */
215  break;
216 
217  case 4:
218  no_ensure_shutdown = true;
219  break;
220 
221  case 5:
223  break;
224 
225  case 6:
227  exit(1);
228  break;
229 
230  default:
231  /* getopt_long already emitted a complaint */
232  pg_log_error_hint("Try \"%s --help\" for more information.", progname);
233  exit(1);
234  }
235  }
236 
237  if (datadir_source == NULL && connstr_source == NULL)
238  {
239  pg_log_error("no source specified (--source-pgdata or --source-server)");
240  pg_log_error_hint("Try \"%s --help\" for more information.", progname);
241  exit(1);
242  }
243 
244  if (datadir_source != NULL && connstr_source != NULL)
245  {
246  pg_log_error("only one of --source-pgdata or --source-server can be specified");
247  pg_log_error_hint("Try \"%s --help\" for more information.", progname);
248  exit(1);
249  }
250 
251  if (datadir_target == NULL)
252  {
253  pg_log_error("no target data directory specified (--target-pgdata)");
254  pg_log_error_hint("Try \"%s --help\" for more information.", progname);
255  exit(1);
256  }
257 
258  if (writerecoveryconf && connstr_source == NULL)
259  {
260  pg_log_error("no source server information (--source-server) specified for --write-recovery-conf");
261  pg_log_error_hint("Try \"%s --help\" for more information.", progname);
262  exit(1);
263  }
264 
265  if (optind < argc)
266  {
267  pg_log_error("too many command-line arguments (first is \"%s\")",
268  argv[optind]);
269  pg_log_error_hint("Try \"%s --help\" for more information.", progname);
270  exit(1);
271  }
272 
273  /*
274  * Don't allow pg_rewind to be run as root, to avoid overwriting the
275  * ownership of files in the data directory. We need only check for root
276  * -- any other user won't have sufficient permissions to modify files in
277  * the data directory.
278  */
279 #ifndef WIN32
280  if (geteuid() == 0)
281  {
282  pg_log_error("cannot be executed by \"root\"");
283  pg_log_error_hint("You must run %s as the PostgreSQL superuser.",
284  progname);
285  exit(1);
286  }
287 #endif
288 
290 
291  /* Set mask based on PGDATA permissions */
293  pg_fatal("could not read permissions of directory \"%s\": %m",
295 
296  umask(pg_mode_mask);
297 
298  getRestoreCommand(argv[0]);
299 
300  atexit(disconnect_atexit);
301 
302  /*
303  * Ok, we have all the options and we're ready to start. First, connect to
304  * remote server.
305  */
306  if (connstr_source)
307  {
309 
310  if (PQstatus(conn) == CONNECTION_BAD)
311  pg_fatal("%s", PQerrorMessage(conn));
312 
313  if (showprogress)
314  pg_log_info("connected to server");
315 
317  }
318  else
320 
321  /*
322  * Check the status of the target instance.
323  *
324  * If the target instance was not cleanly shut down, start and stop the
325  * target cluster once in single-user mode to enforce recovery to finish,
326  * ensuring that the cluster can be used by pg_rewind. Note that if
327  * no_ensure_shutdown is specified, pg_rewind ignores this step, and users
328  * need to make sure by themselves that the target cluster is in a clean
329  * state.
330  */
331  buffer = slurpFile(datadir_target, "global/pg_control", &size);
333  pg_free(buffer);
334 
335  if (!no_ensure_shutdown &&
338  {
339  ensureCleanShutdown(argv[0]);
340 
341  buffer = slurpFile(datadir_target, "global/pg_control", &size);
343  pg_free(buffer);
344  }
345 
346  buffer = source->fetch_file(source, "global/pg_control", &size);
348  pg_free(buffer);
349 
350  sanityChecks();
351 
352  /*
353  * Usually, the TLI can be found in the latest checkpoint record. But if
354  * the source server is just being promoted (or it's a standby that's
355  * following a primary that's just being promoted), and the checkpoint
356  * requested by the promotion hasn't completed yet, the latest timeline is
357  * in minRecoveryPoint. So we check which is later, the TLI of the
358  * minRecoveryPoint or the latest checkpoint.
359  */
362 
363  /* Similarly for the target. */
366 
367  /*
368  * Find the common ancestor timeline between the clusters.
369  *
370  * If both clusters are already on the same timeline, there's nothing to
371  * do.
372  */
373  if (target_tli == source_tli)
374  {
375  pg_log_info("source and target cluster are on the same timeline");
376  rewind_needed = false;
377  target_wal_endrec = 0;
378  }
379  else
380  {
381  XLogRecPtr chkptendrec;
382  TimeLineHistoryEntry *sourceHistory;
383  int sourceNentries;
384 
385  /*
386  * Retrieve timelines for both source and target, and find the point
387  * where they diverged.
388  */
389  sourceHistory = getTimelineHistory(source_tli, true, &sourceNentries);
390  targetHistory = getTimelineHistory(target_tli, false, &targetNentries);
391 
392  findCommonAncestorTimeline(sourceHistory, sourceNentries,
394  &divergerec, &lastcommontliIndex);
395 
396  pg_log_info("servers diverged at WAL location %X/%X on timeline %u",
397  LSN_FORMAT_ARGS(divergerec),
398  targetHistory[lastcommontliIndex].tli);
399 
400  /*
401  * Don't need the source history anymore. The target history is still
402  * needed by the routines in parsexlog.c, when we read the target WAL.
403  */
404  pfree(sourceHistory);
405 
406 
407  /*
408  * Determine the end-of-WAL on the target.
409  *
410  * The WAL ends at the last shutdown checkpoint, or at
411  * minRecoveryPoint if it was a standby. (If we supported rewinding a
412  * server that was not shut down cleanly, we would need to replay
413  * until we reach the first invalid record, like crash recovery does.)
414  */
415 
416  /* read the checkpoint record on the target to see where it ends. */
417  chkptendrec = readOneRecord(datadir_target,
419  targetNentries - 1,
421 
422  if (ControlFile_target.minRecoveryPoint > chkptendrec)
423  {
424  target_wal_endrec = ControlFile_target.minRecoveryPoint;
425  }
426  else
427  {
428  target_wal_endrec = chkptendrec;
429  }
430 
431  /*
432  * Check for the possibility that the target is in fact a direct
433  * ancestor of the source. In that case, there is no divergent history
434  * in the target that needs rewinding.
435  */
436  if (target_wal_endrec > divergerec)
437  {
438  rewind_needed = true;
439  }
440  else
441  {
442  /* the last common checkpoint record must be part of target WAL */
443  Assert(target_wal_endrec == divergerec);
444 
445  rewind_needed = false;
446  }
447  }
448 
449  if (!rewind_needed)
450  {
451  pg_log_info("no rewind required");
452  if (writerecoveryconf && !dry_run)
454  GenerateRecoveryConfig(conn, NULL, NULL));
455  exit(0);
456  }
457 
458  /* Initialize hashtable that tracks WAL files protected from removal */
459  keepwal_init();
460 
461  findLastCheckpoint(datadir_target, divergerec, lastcommontliIndex,
462  &chkptrec, &chkpttli, &chkptredo, restore_command);
463  pg_log_info("rewinding from last common checkpoint at %X/%X on timeline %u",
464  LSN_FORMAT_ARGS(chkptrec), chkpttli);
465 
466  /* Initialize the hash table to track the status of each file */
467  filehash_init();
468 
469  /*
470  * Collect information about all files in the both data directories.
471  */
472  if (showprogress)
473  pg_log_info("reading source file list");
475 
476  if (showprogress)
477  pg_log_info("reading target file list");
479 
480  /*
481  * Read the target WAL from last checkpoint before the point of fork, to
482  * extract all the pages that were modified on the target cluster after
483  * the fork.
484  */
485  if (showprogress)
486  pg_log_info("reading WAL in target");
487  extractPageMap(datadir_target, chkptrec, lastcommontliIndex,
488  target_wal_endrec, restore_command);
489 
490  /*
491  * We have collected all information we need from both systems. Decide
492  * what to do with each file.
493  */
494  filemap = decide_file_actions();
495  if (showprogress)
496  calculate_totals(filemap);
497 
498  /* this is too verbose even for verbose mode */
499  if (debug)
500  print_filemap(filemap);
501 
502  /*
503  * Ok, we're ready to start copying things over.
504  */
505  if (showprogress)
506  {
507  pg_log_info("need to copy %lu MB (total source directory size is %lu MB)",
508  (unsigned long) (filemap->fetch_size / (1024 * 1024)),
509  (unsigned long) (filemap->total_size / (1024 * 1024)));
510 
511  fetch_size = filemap->fetch_size;
512  fetch_done = 0;
513  }
514 
515  /*
516  * We have now collected all the information we need from both systems,
517  * and we are ready to start modifying the target directory.
518  *
519  * This is the point of no return. Once we start copying things, there is
520  * no turning back!
521  */
522  perform_rewind(filemap, source, chkptrec, chkpttli, chkptredo);
523 
524  if (showprogress)
525  pg_log_info("syncing target data directory");
526  sync_target_dir();
527 
528  /* Also update the standby configuration, if requested. */
529  if (writerecoveryconf && !dry_run)
531  GenerateRecoveryConfig(conn, NULL, NULL));
532 
533  /* don't need the source connection anymore */
535  if (conn)
536  {
537  PQfinish(conn);
538  conn = NULL;
539  }
540 
541  pg_log_info("Done!");
542 
543  return 0;
544 }
#define Max(x, y)
Definition: c.h:1001
#define Assert(condition)
Definition: c.h:861
#define PG_TEXTDOMAIN(domain)
Definition: c.h:1217
void set_pglocale_pgservice(const char *argv0, const char *app)
Definition: exec.c:429
char * PQerrorMessage(const PGconn *conn)
Definition: fe-connect.c:7200
ConnStatusType PQstatus(const PGconn *conn)
Definition: fe-connect.c:7137
PGconn * PQconnectdb(const char *conninfo)
Definition: fe-connect.c:745
char * pg_strdup(const char *in)
Definition: fe_memutils.c:85
void traverse_datadir(const char *datadir, process_file_callback_t callback)
Definition: file_ops.c:362
void sync_target_dir(void)
Definition: file_ops.c:294
int pg_mode_mask
Definition: file_perm.c:25
bool GetDataDirectoryCreatePerm(const char *dataDir)
void filehash_init(void)
Definition: filemap.c:196
void process_source_file(const char *path, file_type_t type, size_t size, const char *link_target)
Definition: filemap.c:279
void print_filemap(filemap_t *filemap)
Definition: filemap.c:540
void keepwal_init(void)
Definition: filemap.c:242
void process_target_file(const char *path, file_type_t type, size_t size, const char *link_target)
Definition: filemap.c:315
filemap_t * decide_file_actions(void)
Definition: filemap.c:861
void calculate_totals(filemap_t *filemap)
Definition: filemap.c:499
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:24
#define required_argument
Definition: getopt_long.h:25
@ CONNECTION_BAD
Definition: libpq-fe.h:82
rewind_source * init_libpq_source(PGconn *conn)
Definition: libpq_source.c:81
rewind_source * init_local_source(const char *datadir)
Definition: local_source.c:38
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_hint(...)
Definition: logging.h:112
void pfree(void *pointer)
Definition: mcxt.c:1521
bool parse_sync_method(const char *optarg, DataDirSyncMethod *sync_method)
Definition: option_utils.c:90
void extractPageMap(const char *datadir, XLogRecPtr startpoint, int tliIndex, XLogRecPtr endpoint, const char *restoreCommand)
Definition: parsexlog.c:66
void findLastCheckpoint(const char *datadir, XLogRecPtr forkptr, int tliIndex, XLogRecPtr *lastchkptrec, TimeLineID *lastchkpttli, XLogRecPtr *lastchkptredo, const char *restoreCommand)
Definition: parsexlog.c:168
XLogRecPtr readOneRecord(const char *datadir, XLogRecPtr ptr, int tliIndex, const char *restoreCommand)
Definition: parsexlog.c:124
static bool writerecoveryconf
@ DB_SHUTDOWNED_IN_RECOVERY
Definition: pg_control.h:93
@ DB_SHUTDOWNED
Definition: pg_control.h:92
PGDLLIMPORT int optind
Definition: getopt.c:51
PGDLLIMPORT char * optarg
Definition: getopt.c:53
static ControlFileData ControlFile_source
Definition: pg_rewind.c:60
static void usage(const char *progname)
Definition: pg_rewind.c:92
static void sanityChecks(void)
Definition: pg_rewind.c:733
static char * datadir_source
Definition: pg_rewind.c:68
static void findCommonAncestorTimeline(TimeLineHistoryEntry *a_history, int a_nentries, TimeLineHistoryEntry *b_history, int b_nentries, XLogRecPtr *recptr, int *tliIndex)
Definition: pg_rewind.c:919
static void ensureCleanShutdown(const char *argv0)
Definition: pg_rewind.c:1129
TimeLineHistoryEntry * targetHistory
Definition: pg_rewind.c:81
static ControlFileData ControlFile_target
Definition: pg_rewind.c:59
static TimeLineHistoryEntry * getTimelineHistory(TimeLineID tli, bool is_source, int *nentries)
Definition: pg_rewind.c:856
static void digestControlFile(ControlFileData *ControlFile, const char *content, size_t size)
Definition: pg_rewind.c:1023
static char * connstr_source
Definition: pg_rewind.c:69
static void getRestoreCommand(const char *argv0)
Definition: pg_rewind.c:1056
bool do_sync
Definition: pg_rewind.c:76
uint64 fetch_done
Definition: pg_rewind.c:86
int targetNentries
Definition: pg_rewind.c:82
uint64 fetch_size
Definition: pg_rewind.c:85
DataDirSyncMethod sync_method
Definition: pg_rewind.c:78
bool showprogress
Definition: pg_rewind.c:74
static void perform_rewind(filemap_t *filemap, rewind_source *source, XLogRecPtr chkptrec, TimeLineID chkpttli, XLogRecPtr chkptredo)
Definition: pg_rewind.c:553
static void disconnect_atexit(void)
Definition: pg_rewind.c:1200
const char * get_progname(const char *argv0)
Definition: path.c:575
char * c
void WriteRecoveryConfig(PGconn *pgconn, const char *target_dir, PQExpBuffer contents)
Definition: recovery_gen.c:124
PQExpBuffer GenerateRecoveryConfig(PGconn *pgconn, const char *replication_slot, char *dbname)
Definition: recovery_gen.c:27
void get_restricted_token(void)
TimeLineID ThisTimeLineID
Definition: pg_control.h:39
CheckPoint checkPointCopy
Definition: pg_control.h:135
XLogRecPtr minRecoveryPoint
Definition: pg_control.h:168
XLogRecPtr checkPoint
Definition: pg_control.h:133
TimeLineID minRecoveryPointTLI
Definition: pg_control.h:169
uint64 total_size
Definition: filemap.h:92
uint64 fetch_size
Definition: filemap.h:93
void(* traverse_files)(struct rewind_source *, process_file_callback_t callback)
Definition: rewind_source.h:29
void(* destroy)(struct rewind_source *)
Definition: rewind_source.h:76
uint64 XLogRecPtr
Definition: xlogdefs.h:21
uint32 TimeLineID
Definition: xlogdefs.h:59

References Assert, calculate_totals(), ControlFileData::checkPoint, ControlFileData::checkPointCopy, config_file, conn, CONNECTION_BAD, connstr_source, ControlFile_source, ControlFile_target, datadir_source, datadir_target, DB_SHUTDOWNED, DB_SHUTDOWNED_IN_RECOVERY, debug, decide_file_actions(), rewind_source::destroy, digestControlFile(), disconnect_atexit(), do_sync, dry_run, ensureCleanShutdown(), exit(), extractPageMap(), fetch_done, rewind_source::fetch_file, filemap_t::fetch_size, fetch_size, filehash_init(), findCommonAncestorTimeline(), findLastCheckpoint(), GenerateRecoveryConfig(), get_progname(), get_restricted_token(), GetDataDirectoryCreatePerm(), getopt_long(), getRestoreCommand(), getTimelineHistory(), init_libpq_source(), init_local_source(), keepwal_init(), LSN_FORMAT_ARGS, Max, ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, no_argument, optarg, optind, parse_sync_method(), perform_rewind(), pfree(), pg_fatal, pg_free(), pg_log_error, pg_log_error_hint, pg_log_info, pg_logging_increase_verbosity(), pg_logging_init(), pg_mode_mask, pg_strdup(), PG_TEXTDOMAIN, PQconnectdb(), PQerrorMessage(), PQfinish(), PQstatus(), print_filemap(), process_source_file(), process_target_file(), progname, readOneRecord(), required_argument, restore_command, restore_wal, sanityChecks(), set_pglocale_pgservice(), showprogress, size, slurpFile(), source, ControlFileData::state, sync_method, sync_target_dir(), targetHistory, targetNentries, CheckPoint::ThisTimeLineID, filemap_t::total_size, traverse_datadir(), rewind_source::traverse_files, usage(), writerecoveryconf, and WriteRecoveryConfig().

◆ MinXLogRecPtr()

static XLogRecPtr MinXLogRecPtr ( XLogRecPtr  a,
XLogRecPtr  b 
)
static

Definition at line 842 of file pg_rewind.c.

843 {
844  if (XLogRecPtrIsInvalid(a))
845  return b;
846  else if (XLogRecPtrIsInvalid(b))
847  return a;
848  else
849  return Min(a, b);
850 }
int b
Definition: isn.c:69
int a
Definition: isn.c:68
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29

References a, b, Min, and XLogRecPtrIsInvalid.

Referenced by findCommonAncestorTimeline().

◆ perform_rewind()

static void perform_rewind ( filemap_t filemap,
rewind_source source,
XLogRecPtr  chkptrec,
TimeLineID  chkpttli,
XLogRecPtr  chkptredo 
)
static

Definition at line 553 of file pg_rewind.c.

557 {
558  XLogRecPtr endrec;
559  TimeLineID endtli;
560  ControlFileData ControlFile_new;
561  size_t size;
562  char *buffer;
563 
564  /*
565  * Execute the actions in the file map, fetching data from the source
566  * system as needed.
567  */
568  for (int i = 0; i < filemap->nentries; i++)
569  {
570  file_entry_t *entry = filemap->entries[i];
571 
572  /*
573  * If this is a relation file, copy the modified blocks.
574  *
575  * This is in addition to any other changes.
576  */
577  if (entry->target_pages_to_overwrite.bitmapsize > 0)
578  {
580  BlockNumber blkno;
581  off_t offset;
582 
584  while (datapagemap_next(iter, &blkno))
585  {
586  offset = blkno * BLCKSZ;
587  source->queue_fetch_range(source, entry->path, offset, BLCKSZ);
588  }
589  pg_free(iter);
590  }
591 
592  switch (entry->action)
593  {
594  case FILE_ACTION_NONE:
595  /* nothing else to do */
596  break;
597 
598  case FILE_ACTION_COPY:
599  source->queue_fetch_file(source, entry->path, entry->source_size);
600  break;
601 
603  truncate_target_file(entry->path, entry->source_size);
604  break;
605 
608  entry->target_size,
609  entry->source_size - entry->target_size);
610  break;
611 
612  case FILE_ACTION_REMOVE:
613  remove_target(entry);
614  break;
615 
616  case FILE_ACTION_CREATE:
617  create_target(entry);
618  break;
619 
621  pg_fatal("no action decided for file \"%s\"", entry->path);
622  break;
623  }
624  }
625 
626  /* Complete any remaining range-fetches that we queued up above. */
628 
630 
631  progress_report(true);
632 
633  /*
634  * Fetch the control file from the source last. This ensures that the
635  * minRecoveryPoint is up-to-date.
636  */
637  buffer = source->fetch_file(source, "global/pg_control", &size);
639  pg_free(buffer);
640 
641  /*
642  * Sanity check: If the source is a local system, the control file should
643  * not have changed since we started.
644  *
645  * XXX: We assume it hasn't been modified, but actually, what could go
646  * wrong? The logic handles a libpq source that's modified concurrently,
647  * why not a local datadir?
648  */
649  if (datadir_source &&
651  sizeof(ControlFileData)) != 0)
652  {
653  pg_fatal("source system was modified while pg_rewind was running");
654  }
655 
656  if (showprogress)
657  pg_log_info("creating backup label and updating control file");
658 
659  /*
660  * Create a backup label file, to tell the target where to begin the WAL
661  * replay. Normally, from the last common checkpoint between the source
662  * and the target. But if the source is a standby server, it's possible
663  * that the last common checkpoint is *after* the standby's restartpoint.
664  * That implies that the source server has applied the checkpoint record,
665  * but hasn't performed a corresponding restartpoint yet. Make sure we
666  * start at the restartpoint's redo point in that case.
667  *
668  * Use the old version of the source's control file for this. The server
669  * might have finished the restartpoint after we started copying files,
670  * but we must begin from the redo point at the time that started copying.
671  */
672  if (ControlFile_source.checkPointCopy.redo < chkptredo)
673  {
676  chkptrec = ControlFile_source.checkPoint;
677  }
678  createBackupLabel(chkptredo, chkpttli, chkptrec);
679 
680  /*
681  * Update control file of target, to tell the target how far it must
682  * replay the WAL (minRecoveryPoint).
683  */
684  if (connstr_source)
685  {
686  /*
687  * The source is a live server. Like in an online backup, it's
688  * important that we recover all the WAL that was generated while we
689  * were copying files.
690  */
692  {
693  /*
694  * Source is a standby server. We must replay to its
695  * minRecoveryPoint.
696  */
699  }
700  else
701  {
702  /*
703  * Source is a production, non-standby, server. We must replay to
704  * the last WAL insert location.
705  */
707  pg_fatal("source system was in unexpected state at end of rewind");
708 
712  }
713  }
714  else
715  {
716  /*
717  * Source is a local data directory. It should've shut down cleanly,
718  * and we must replay to the latest shutdown checkpoint.
719  */
722  }
723 
724  memcpy(&ControlFile_new, &ControlFile_source_after, sizeof(ControlFileData));
725  ControlFile_new.minRecoveryPoint = endrec;
726  ControlFile_new.minRecoveryPointTLI = endtli;
727  ControlFile_new.state = DB_IN_ARCHIVE_RECOVERY;
728  if (!dry_run)
729  update_controlfile(datadir_target, &ControlFile_new, do_sync);
730 }
uint32 BlockNumber
Definition: block.h:31
void update_controlfile(const char *DataDir, ControlFileData *ControlFile, bool do_sync)
bool datapagemap_next(datapagemap_iterator_t *iter, BlockNumber *blkno)
Definition: datapagemap.c:87
datapagemap_iterator_t * datapagemap_iterate(datapagemap_t *map)
Definition: datapagemap.c:75
void truncate_target_file(const char *path, off_t newsize)
Definition: file_ops.c:206
void remove_target(file_entry_t *entry)
Definition: file_ops.c:130
void create_target(file_entry_t *entry)
Definition: file_ops.c:156
@ FILE_ACTION_REMOVE
Definition: filemap.h:27
@ FILE_ACTION_COPY
Definition: filemap.h:21
@ FILE_ACTION_NONE
Definition: filemap.h:24
@ FILE_ACTION_COPY_TAIL
Definition: filemap.h:22
@ FILE_ACTION_UNDECIDED
Definition: filemap.h:18
@ FILE_ACTION_TRUNCATE
Definition: filemap.h:26
@ FILE_ACTION_CREATE
Definition: filemap.h:20
@ DB_IN_PRODUCTION
Definition: pg_control.h:97
@ DB_IN_ARCHIVE_RECOVERY
Definition: pg_control.h:96
static void createBackupLabel(XLogRecPtr startpoint, TimeLineID starttli, XLogRecPtr checkpointloc)
Definition: pg_rewind.c:961
static ControlFileData ControlFile_source_after
Definition: pg_rewind.c:61
void progress_report(bool finished)
Definition: pg_rewind.c:791
XLogRecPtr redo
Definition: pg_control.h:37
int bitmapsize
Definition: datapagemap.h:17
Definition: filemap.h:50
datapagemap_t target_pages_to_overwrite
Definition: filemap.h:68
const char * path
Definition: filemap.h:53
size_t source_size
Definition: filemap.h:75
size_t target_size
Definition: filemap.h:61
file_action_t action
Definition: filemap.h:81
file_entry_t * entries[FLEXIBLE_ARRAY_MEMBER]
Definition: filemap.h:96
int nentries
Definition: filemap.h:95
void(* queue_fetch_file)(struct rewind_source *, const char *path, size_t len)
Definition: rewind_source.h:60
void(* finish_fetch)(struct rewind_source *)
Definition: rewind_source.h:66
XLogRecPtr(* get_current_wal_insert_lsn)(struct rewind_source *)
Definition: rewind_source.h:71
void(* queue_fetch_range)(struct rewind_source *, const char *path, off_t offset, size_t len)
Definition: rewind_source.h:47

References file_entry_t::action, datapagemap::bitmapsize, ControlFileData::checkPoint, ControlFileData::checkPointCopy, close_target_file(), connstr_source, ControlFile_source, ControlFile_source_after, create_target(), createBackupLabel(), datadir_source, datadir_target, datapagemap_iterate(), datapagemap_next(), DB_IN_ARCHIVE_RECOVERY, DB_IN_PRODUCTION, digestControlFile(), do_sync, dry_run, filemap_t::entries, rewind_source::fetch_file, FILE_ACTION_COPY, FILE_ACTION_COPY_TAIL, FILE_ACTION_CREATE, FILE_ACTION_NONE, FILE_ACTION_REMOVE, FILE_ACTION_TRUNCATE, FILE_ACTION_UNDECIDED, rewind_source::finish_fetch, rewind_source::get_current_wal_insert_lsn, i, Max, ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, filemap_t::nentries, file_entry_t::path, pg_fatal, pg_free(), pg_log_info, progress_report(), rewind_source::queue_fetch_file, rewind_source::queue_fetch_range, CheckPoint::redo, remove_target(), showprogress, size, source, file_entry_t::source_size, ControlFileData::state, file_entry_t::target_pages_to_overwrite, file_entry_t::target_size, CheckPoint::ThisTimeLineID, truncate_target_file(), and update_controlfile().

Referenced by main().

◆ progress_report()

static void progress_report ( bool  finished)

Definition at line 791 of file pg_rewind.c.

792 {
793  static pg_time_t last_progress_report = 0;
794  int percent;
795  char fetch_done_str[32];
796  char fetch_size_str[32];
797  pg_time_t now;
798 
799  if (!showprogress)
800  return;
801 
802  now = time(NULL);
803  if (now == last_progress_report && !finished)
804  return; /* Max once per second */
805 
807  percent = fetch_size ? (int) ((fetch_done) * 100 / fetch_size) : 0;
808 
809  /*
810  * Avoid overflowing past 100% or the full size. This may make the total
811  * size number change as we approach the end of the backup (the estimate
812  * will always be wrong if WAL is included), but that's better than having
813  * the done column be bigger than the total.
814  */
815  if (percent > 100)
816  percent = 100;
817  if (fetch_done > fetch_size)
819 
820  snprintf(fetch_done_str, sizeof(fetch_done_str), UINT64_FORMAT,
821  fetch_done / 1024);
822  snprintf(fetch_size_str, sizeof(fetch_size_str), UINT64_FORMAT,
823  fetch_size / 1024);
824 
825  fprintf(stderr, _("%*s/%s kB (%d%%) copied"),
826  (int) strlen(fetch_size_str), fetch_done_str, fetch_size_str,
827  percent);
828 
829  /*
830  * Stay on the same line if reporting to a terminal and we're not done
831  * yet.
832  */
833  fputc((!finished && isatty(fileno(stderr))) ? '\r' : '\n', stderr);
834 }
Datum now(PG_FUNCTION_ARGS)
Definition: timestamp.c:1608
#define UINT64_FORMAT
Definition: c.h:552
#define _(x)
Definition: elog.c:90
static pg_time_t last_progress_report
Definition: pg_amcheck.c:146
int64 pg_time_t
Definition: pgtime.h:23
#define fprintf
Definition: port.h:242

References _, fetch_done, fetch_size, fprintf, last_progress_report, now(), showprogress, snprintf, and UINT64_FORMAT.

Referenced by perform_rewind().

◆ sanityChecks()

static void sanityChecks ( void  )
static

Definition at line 733 of file pg_rewind.c.

734 {
735  /* TODO Check that there's no backup_label in either cluster */
736 
737  /* Check system_identifier match */
739  pg_fatal("source and target clusters are from different systems");
740 
741  /* check version */
746  {
747  pg_fatal("clusters are not compatible with this version of pg_rewind");
748  }
749 
750  /*
751  * Target cluster need to use checksums or hint bit wal-logging, this to
752  * prevent from data corruption that could occur because of hint bits.
753  */
756  {
757  pg_fatal("target server needs to use either data checksums or \"wal_log_hints = on\"");
758  }
759 
760  /*
761  * Target cluster better not be running. This doesn't guard against
762  * someone starting the cluster concurrently. Also, this is probably more
763  * strict than necessary; it's OK if the target node was not shut down
764  * cleanly, as long as it isn't running at the moment.
765  */
768  pg_fatal("target server must be shut down cleanly");
769 
770  /*
771  * When the source is a data directory, also require that the source
772  * server is shut down. There isn't any very strong reason for this
773  * limitation, but better safe than sorry.
774  */
775  if (datadir_source &&
778  pg_fatal("source data directory must be shut down cleanly");
779 }
#define PG_DATA_CHECKSUM_VERSION
Definition: bufpage.h:206
#define CATALOG_VERSION_NO
Definition: catversion.h:60
#define PG_CONTROL_VERSION
Definition: pg_control.h:25
uint32 pg_control_version
Definition: pg_control.h:125
uint32 data_checksum_version
Definition: pg_control.h:222
uint64 system_identifier
Definition: pg_control.h:110
uint32 catalog_version_no
Definition: pg_control.h:126

References CATALOG_VERSION_NO, ControlFileData::catalog_version_no, ControlFile_source, ControlFile_target, ControlFileData::data_checksum_version, datadir_source, DB_SHUTDOWNED, DB_SHUTDOWNED_IN_RECOVERY, PG_CONTROL_VERSION, ControlFileData::pg_control_version, PG_DATA_CHECKSUM_VERSION, pg_fatal, ControlFileData::state, ControlFileData::system_identifier, and ControlFileData::wal_log_hints.

Referenced by main().

◆ usage()

static void usage ( const char *  progname)
static

Definition at line 92 of file pg_rewind.c.

93 {
94  printf(_("%s resynchronizes a PostgreSQL cluster with another copy of the cluster.\n\n"), progname);
95  printf(_("Usage:\n %s [OPTION]...\n\n"), progname);
96  printf(_("Options:\n"));
97  printf(_(" -c, --restore-target-wal use \"restore_command\" in target configuration to\n"
98  " retrieve WAL files from archives\n"));
99  printf(_(" -D, --target-pgdata=DIRECTORY existing data directory to modify\n"));
100  printf(_(" --source-pgdata=DIRECTORY source data directory to synchronize with\n"));
101  printf(_(" --source-server=CONNSTR source server to synchronize with\n"));
102  printf(_(" -n, --dry-run stop before modifying anything\n"));
103  printf(_(" -N, --no-sync do not wait for changes to be written\n"
104  " safely to disk\n"));
105  printf(_(" -P, --progress write progress messages\n"));
106  printf(_(" -R, --write-recovery-conf write configuration for replication\n"
107  " (requires --source-server)\n"));
108  printf(_(" --config-file=FILENAME use specified main server configuration\n"
109  " file when running target cluster\n"));
110  printf(_(" --debug write a lot of debug messages\n"));
111  printf(_(" --no-ensure-shutdown do not automatically fix unclean shutdown\n"));
112  printf(_(" --sync-method=METHOD set method for syncing files to disk\n"));
113  printf(_(" -V, --version output version information, then exit\n"));
114  printf(_(" -?, --help show this help, then exit\n"));
115  printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
116  printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
117 }
#define printf(...)
Definition: port.h:244

References _, printf, and progname.

Referenced by main().

Variable Documentation

◆ config_file

char* config_file = NULL
static

Definition at line 71 of file pg_rewind.c.

Referenced by ensureCleanShutdown(), getRestoreCommand(), and main().

◆ conn

PGconn* conn
static

Definition at line 88 of file pg_rewind.c.

Referenced by disconnect_atexit(), and main().

◆ connstr_source

char* connstr_source = NULL
static

Definition at line 69 of file pg_rewind.c.

Referenced by main(), and perform_rewind().

◆ ControlFile_source

ControlFileData ControlFile_source
static

Definition at line 60 of file pg_rewind.c.

Referenced by main(), perform_rewind(), and sanityChecks().

◆ ControlFile_source_after

ControlFileData ControlFile_source_after
static

Definition at line 61 of file pg_rewind.c.

Referenced by perform_rewind().

◆ ControlFile_target

ControlFileData ControlFile_target
static

Definition at line 59 of file pg_rewind.c.

Referenced by main(), and sanityChecks().

◆ datadir_source

char* datadir_source = NULL
static

Definition at line 68 of file pg_rewind.c.

Referenced by main(), perform_rewind(), and sanityChecks().

◆ datadir_target

◆ debug

bool debug = false
static

Definition at line 73 of file pg_rewind.c.

Referenced by getTimelineHistory(), and main().

◆ do_sync

bool do_sync = true

Definition at line 76 of file pg_rewind.c.

Referenced by main(), and perform_rewind().

◆ dry_run

bool dry_run = false

Definition at line 75 of file pg_rewind.c.

Referenced by ensureCleanShutdown(), main(), and perform_rewind().

◆ fetch_done

uint64 fetch_done

Definition at line 86 of file pg_rewind.c.

Referenced by main(), progress_report(), and write_target_range().

◆ fetch_size

uint64 fetch_size

Definition at line 85 of file pg_rewind.c.

Referenced by main(), postgresAcquireSampleRowsFunc(), and progress_report().

◆ progname

const char* progname
static

Definition at line 63 of file pg_rewind.c.

Referenced by ensureCleanShutdown(), getRestoreCommand(), main(), and usage().

◆ restore_command

char* restore_command = NULL
static

Definition at line 70 of file pg_rewind.c.

Referenced by getRestoreCommand(), and main().

◆ restore_wal

bool restore_wal = false
static

Definition at line 77 of file pg_rewind.c.

Referenced by getRestoreCommand(), and main().

◆ showprogress

bool showprogress = false

Definition at line 74 of file pg_rewind.c.

Referenced by main(), perform_rewind(), and progress_report().

◆ source

rewind_source* source
static

Definition at line 89 of file pg_rewind.c.

Referenced by append_pathkeys(), appendByteaLiteral(), appendStringLiteral(), ApplySetting(), bpchar(), BufFileAppend(), call_bool_check_hook(), call_enum_check_hook(), call_int_check_hook(), call_real_check_hook(), call_string_check_hook(), check_datestyle(), check_default_table_access_method(), check_default_tablespace(), check_default_text_search_config(), check_locale_messages(), check_random_seed(), check_role(), check_session_authorization(), check_temp_buffers(), check_temp_tablespaces(), check_timezone_abbreviations(), compute_remaining_iovec(), CopyIndexTuple(), exprLocation(), fmgr_security_definer(), gets_fromFile(), getTimelineHistory(), index_truncate_tuple(), initClosestMatch(), InitializeGUCOptionsFromEnvironment(), interval_support(), libpq_destroy(), libpq_fetch_file(), libpq_finish_fetch(), libpq_get_current_wal_insert_lsn(), libpq_queue_fetch_file(), libpq_queue_fetch_range(), libpq_traverse_files(), local_destroy(), local_fetch_file(), local_queue_fetch_file(), local_queue_fetch_range(), local_traverse_files(), main(), MainLoop(), numeric_support(), packGraph(), parse_and_validate_value(), perform_rewind(), pg_utf8_islegal(), pg_utf8_string_len(), pglz_compress(), pglz_decompress(), plsample_func_handler(), plsample_trigger_handler(), PQescapeStringInternal(), process_backslash_command(), ProcessGUCArray(), quote_if_needed(), raw_expression_tree_walker_impl(), reconstruct_from_incremental_file(), selectColorTrigrams(), set_config_option(), set_config_option_ext(), set_config_with_handle(), set_debug_options(), set_plan_disabling_options(), SetConfigOption(), string_to_uuid(), strip_quotes(), syntax_error(), TemporalSimplify(), transform_MERGE_to_join(), translate(), varbit_support(), varchar(), varchar_support(), varstr_levenshtein(), XLogCompressBackupBlock(), XLogFileRead(), and XLogFileReadAnyTLI().

◆ sync_method

Definition at line 78 of file pg_rewind.c.

Referenced by main().

◆ targetHistory

TimeLineHistoryEntry* targetHistory

Definition at line 81 of file pg_rewind.c.

Referenced by main(), and SimpleXLogPageRead().

◆ targetNentries

int targetNentries

Definition at line 82 of file pg_rewind.c.

Referenced by main(), and SimpleXLogPageRead().

◆ WalSegSz

int WalSegSz

Definition at line 64 of file pg_rewind.c.

Referenced by createBackupLabel(), and digestControlFile().