diff options
| -rw-r--r-- | doc/src/sgml/ref/pg_rewind.sgml | 14 | ||||
| -rw-r--r-- | src/backend/replication/basebackup.c | 3 | ||||
| -rw-r--r-- | src/bin/pg_rewind/filemap.c | 144 |
3 files changed, 148 insertions, 13 deletions
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml index 8e492498268..520d843f0ec 100644 --- a/doc/src/sgml/ref/pg_rewind.sgml +++ b/doc/src/sgml/ref/pg_rewind.sgml @@ -231,7 +231,19 @@ PostgreSQL documentation <para> Copy all other files such as <filename>pg_xact</filename> and configuration files from the source cluster to the target cluster - (everything except the relation files). + (everything except the relation files). Similarly to base backups, + the contents of the directories <filename>pg_dynshmem/</filename>, + <filename>pg_notify/</filename>, <filename>pg_replslot/</filename>, + <filename>pg_serial/</filename>, <filename>pg_snapshots/</filename>, + <filename>pg_stat_tmp/</filename>, and + <filename>pg_subtrans/</filename> are omitted from the data copied + from the source cluster. Any file or directory beginning with + <filename>pgsql_tmp</filename> is omitted, as well as are + <filename>backup_label</filename>, + <filename>tablespace_map</filename>, + <filename>pg_internal.init</filename>, + <filename>postmaster.opts</filename> and + <filename>postmaster.pid</filename>. </para> </step> <step> diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c index 654d0832da2..516eea57f8d 100644 --- a/src/backend/replication/basebackup.c +++ b/src/backend/replication/basebackup.c @@ -103,6 +103,9 @@ static TimestampTz throttled_last; * The contents of these directories are removed or recreated during server * start so they are not included in backups. The directories themselves are * kept and included as empty to preserve access permissions. + * + * Note: this list should be kept in sync with the filter lists in pg_rewind's + * filemap.c. */ static const char *excludeDirContents[] = { diff --git a/src/bin/pg_rewind/filemap.c b/src/bin/pg_rewind/filemap.c index 6122f177fe0..876a62ad589 100644 --- a/src/bin/pg_rewind/filemap.c +++ b/src/bin/pg_rewind/filemap.c @@ -31,6 +31,83 @@ static char *datasegpath(RelFileNode rnode, ForkNumber forknum, static int path_cmp(const void *a, const void *b); static int final_filemap_cmp(const void *a, const void *b); static void filemap_list_to_array(filemap_t *map); +static bool check_file_excluded(const char *path, const char *type); + +/* + * The contents of these directories are removed or recreated during server + * start so they are not included in data processed by pg_rewind. + * + * Note: those lists should be kept in sync with what basebackup.c provides. + * Some of the values, contrary to what basebackup.c uses, are hardcoded as + * they are defined in backend-only headers. So this list is maintained + * with a best effort in mind. + */ +static const char *excludeDirContents[] = +{ + /* + * Skip temporary statistics files. PG_STAT_TMP_DIR must be skipped even + * when stats_temp_directory is set because PGSS_TEXT_FILE is always + * created there. + */ + "pg_stat_tmp", /* defined as PG_STAT_TMP_DIR */ + + /* + * It is generally not useful to backup the contents of this directory + * even if the intention is to restore to another master. See backup.sgml + * for a more detailed description. + */ + "pg_replslot", + + /* Contents removed on startup, see dsm_cleanup_for_mmap(). */ + "pg_dynshmem", /* defined as PG_DYNSHMEM_DIR */ + + /* Contents removed on startup, see AsyncShmemInit(). */ + "pg_notify", + + /* + * Old contents are loaded for possible debugging but are not required for + * normal operation, see OldSerXidInit(). + */ + "pg_serial", + + /* Contents removed on startup, see DeleteAllExportedSnapshotFiles(). */ + "pg_snapshots", + + /* Contents zeroed on startup, see StartupSUBTRANS(). */ + "pg_subtrans", + + /* end of list */ + NULL +}; + +/* + * List of files excluded from filemap processing. + */ +static const char *excludeFiles[] = +{ + /* Skip auto conf temporary file. */ + "postgresql.auto.conf.tmp", /* defined as PG_AUTOCONF_FILENAME */ + + /* Skip current log file temporary file */ + "current_logfiles.tmp", /* defined as LOG_METAINFO_DATAFILE_TMP */ + + /* Skip relation cache because it is rebuilt on startup */ + "pg_internal.init", /* defined as RELCACHE_INIT_FILENAME */ + + /* + * If there's a backup_label or tablespace_map file, it belongs to a + * backup started by the user with pg_start_backup(). It is *not* correct + * for this backup. Our backup_label is written later on separately. + */ + "backup_label", /* defined as BACKUP_LABEL_FILE */ + "tablespace_map", /* defined as TABLESPACE_MAP */ + + "postmaster.pid", + "postmaster.opts", + + /* end of list */ + NULL +}; /* * Create a new file map (stored in the global pointer "filemap"). @@ -71,11 +148,8 @@ process_source_file(const char *path, file_type_t type, size_t newsize, Assert(map->array == NULL); - /* - * Completely ignore some special files in source and destination. - */ - if (strcmp(path, "postmaster.pid") == 0 || - strcmp(path, "postmaster.opts") == 0) + /* ignore any path matching the exclusion filters */ + if (check_file_excluded(path, "source")) return; /* @@ -260,6 +334,14 @@ process_target_file(const char *path, file_type_t type, size_t oldsize, filemap_t *map = filemap; file_entry_t *entry; + /* + * Ignore any path matching the exclusion filters. This is not actually + * mandatory for target files, but this does not hurt and let's be + * consistent with the source processing. + */ + if (check_file_excluded(path, "target")) + return; + snprintf(localpath, sizeof(localpath), "%s/%s", datadir_target, path); if (lstat(localpath, &statbuf) < 0) { @@ -287,13 +369,6 @@ process_target_file(const char *path, file_type_t type, size_t oldsize, } /* - * Completely ignore some special files - */ - if (strcmp(path, "postmaster.pid") == 0 || - strcmp(path, "postmaster.opts") == 0) - return; - - /* * Like in process_source_file, pretend that xlog is always a directory. */ if (strcmp(path, "pg_wal") == 0 && type == FILE_TYPE_SYMLINK) @@ -413,6 +488,51 @@ process_block_change(ForkNumber forknum, RelFileNode rnode, BlockNumber blkno) } /* + * Is this the path of file that pg_rewind can skip copying? + */ +static bool +check_file_excluded(const char *path, const char *type) +{ + char localpath[MAXPGPATH]; + int excludeIdx; + const char *filename; + + /* check individual files... */ + for (excludeIdx = 0; excludeFiles[excludeIdx] != NULL; excludeIdx++) + { + filename = last_dir_separator(path); + if (filename == NULL) + filename = path; + else + filename++; + if (strcmp(filename, excludeFiles[excludeIdx]) == 0) + { + pg_log(PG_DEBUG, "entry \"%s\" excluded from %s file list\n", + path, type); + return true; + } + } + + /* + * ... And check some directories. Note that this includes any contents + * within the directories themselves. + */ + for (excludeIdx = 0; excludeDirContents[excludeIdx] != NULL; excludeIdx++) + { + snprintf(localpath, sizeof(localpath), "%s/", + excludeDirContents[excludeIdx]); + if (strstr(path, localpath) == path) + { + pg_log(PG_DEBUG, "entry \"%s\" excluded from %s file list\n", + path, type); + return true; + } + } + + return false; +} + +/* * Convert the linked list of entries in map->first/last to the array, * map->array. */ |