patroni.postgresql.rewind module
- class patroni.postgresql.rewind.REWIND_STATUS(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)View on GitHub
Bases:
IntEnum
- CHECK = 2
- CHECKPOINT = 1
- FAILED = 6
- INITIAL = 0
- NEED = 3
- NOT_NEED = 4
- SUCCESS = 5
- class patroni.postgresql.rewind.Rewind(postgresql: Postgresql)View on GitHub
Bases:
object
- __checkpoint(task: CriticalTask, wakeup: Callable[[...], Any]) None
- __init__(postgresql: Postgresql) None View on GitHub
- _archive_ready_wals() None View on GitHub
Try to archive WALs that have .ready files just in case archive_mode was not set to ‘always’ before promote, while after it the WALs were recycled on the promoted replica. With this we prevent the entire loss of such WALs and the consequent old leader’s start failure.
- _buid_archiver_command(command: str, wal_filename: str) str View on GitHub
Replace placeholders in the given archiver command’s template. Applicable for archive_command and restore_command. Can also be used for archive_cleanup_command and recovery_end_command, however %r value is always set to 000000010000000000000001.
- _check_timeline_and_lsn(leader: Leader | RemoteMember) None View on GitHub
- _conn_kwargs(member: Leader | RemoteMember, auth: Dict[str, Any]) Dict[str, Any] View on GitHub
- _fetch_missing_wal(restore_command: str, wal_filename: str) bool View on GitHub
- _find_missing_wal(data: bytes) str | None View on GitHub
- _get_checkpoint_end(timeline: int, lsn: int) int View on GitHub
Get the end of checkpoint record from WAL.
Note
The checkpoint record size in WAL depends on postgres major version and platform (memory alignment). Hence, the only reliable way to figure out where it ends, is to read the record from file with the help of
pg_waldump
and parse the output.We are trying to read two records, and expect that it will fail to read the second record with message:
fatal: error in WAL record at 0/182E220: invalid record length at 0/182E298: wanted 24, got 0; or
fatal: error in WAL record at 0/182E220: invalid record length at 0/182E298: expected at least 24, got 0
The error message contains information about LSN of the next record, which is exactly where checkpoint ends.
- _get_local_timeline_lsn_from_controldata() Tuple[bool | None, int | None, int | None] View on GitHub
- _maybe_clean_pg_replslot() None View on GitHub
Clean pg_replslot directory if pg version is less then 11 (pg_rewind deletes $PGDATA/pg_replslot content only since pg11).
- property can_rewind: bool
check if pg_rewind executable is there and that pg_controldata indicates we have either wal_log_hints or checksums turned on
- checkpoint_after_promote() bool View on GitHub
- cleanup_archive_status() None View on GitHub
- ensure_checkpoint_after_promote(wakeup: Callable[[...], Any]) None View on GitHub
After promote issue a CHECKPOINT from a new thread and asynchronously check the result. In case if CHECKPOINT failed, just check that timeline in pg_control was updated.
- ensure_clean_shutdown() bool | None View on GitHub
- execute(leader: Leader | RemoteMember) bool | None View on GitHub
- read_postmaster_opts() Dict[str, str] View on GitHub
returns the list of option names/values from postgres.opts, Empty dict if read failed or no file
- reset_state() None View on GitHub
- rewind_or_reinitialize_needed_and_possible(leader: Leader | RemoteMember | None) bool View on GitHub
- single_user_mode(communicate: Dict[str, Any] | None = None, options: Dict[str, str] | None = None) int | None View on GitHub
run a given command in a single-user mode. If the command is empty - then just start and stop
- trigger_check_diverged_lsn() None View on GitHub