openstack/cinder
Code Issues Proposed changes

Merge "Ceph: Add option to keep only last n snapshots per backup"

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This commit is contained in:
Zuul
2024-09-27 11:55:28 +00:00
committed by Gerrit Code Review
parent e57c350d0b 03cbcd3cd0
commit b07e4147f9
5 changed files with 181 additions and 10 deletions
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125
cinder/backup/drivers/ceph.py
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@@ -48,6 +48,7 @@ import os
import re
import subprocess
import tempfile
import textwrap
import time
from typing import Dict, List, Optional, Tuple
@@ -62,6 +63,8 @@ from cinder.backup import driver
from cinder import exception
from cinder.i18n import _
from cinder import interface
from cinder.message import api as message_api
from cinder.message import message_field
from cinder import objects
from cinder import utils
import cinder.volume.drivers.rbd as rbd_driver
@@ -95,6 +98,19 @@ service_opts = [
cfg.BoolOpt('backup_ceph_image_journals', default=False,
help='If True, apply JOURNALING and EXCLUSIVE_LOCK feature '
'bits to the backup RBD objects to allow mirroring'),
cfg.IntOpt('backup_ceph_max_snapshots', default=0,
help=textwrap.dedent("""\
Number of the most recent snapshots to keep.
0 indicates to keep an unlimited number of snapshots.
Configuring this option can save disk space by only keeping
a limited number of snapshots on the source volume storage.
However, if a user deletes all incremental backups which
still have snapshots on the source storage, the next
incremental backup will automatically become a full backup
as no common snapshot exists anymore.
""")),
cfg.BoolOpt('restore_discard_excess_bytes', default=True,
help='If True, always discard excess bytes when restoring '
'volumes i.e. pad with zeroes.')
@@ -200,6 +216,8 @@ class CephBackupDriver(driver.BackupDriver):
self._ceph_backup_pool = CONF.backup_ceph_pool
self._ceph_backup_conf = CONF.backup_ceph_conf
self.message_api = message_api.API()
@staticmethod
def get_driver_options() -> list:
return service_opts
@@ -808,24 +826,62 @@ class CephBackupDriver(driver.BackupDriver):
rbd_conf = volume_file.rbd_conf
source_rbd_image = eventlet.tpool.Proxy(volume_file.rbd_image)
volume_id = backup.volume_id
base_name = None
base_name = self._get_backup_base_name(volume_id, backup=backup)
snaps_to_keep = CONF.backup_ceph_max_snapshots
# If backup.parent_id is None performs full RBD backup
if backup.parent_id is None:
base_name = self._get_backup_base_name(volume_id, backup=backup)
from_snap, image_created = self._full_rbd_backup(backup.container,
base_name,
length)
# Otherwise performs incremental rbd backup
else:
# Find the base name from the parent backup's service_metadata
base_name = self._get_backup_base_name(volume_id, backup=backup)
rbd_img = source_rbd_image
from_snap, image_created = self._incremental_rbd_backup(backup,
base_name,
length,
rbd_img,
volume_id)
# Check if there is at least one snapshot to base an incremental
# backup on. If not, we cannot perform an incremental backup and
# fall back to full backup.
no_source_snaps = snaps_to_keep > 0 and \
self._get_backup_snap_name(
source_rbd_image,
base_name,
backup.parent_id) is None
# If true, force full backup
if no_source_snaps:
# Unset parent so we get a new backup base name
backup.parent = None
# The backup will be a full one, so it has no parent ID.
# This will mark the backup as a full backup in the database.
backup.parent_id = None
backup.save()
base_name = self.\
_get_backup_base_name(volume_id, backup=backup)
LOG.info("Incremental backup was requested, but there are no "
"snapshots present to use as base, "
"forcing full backup.")
self.message_api.create(
context=self.context,
action=message_field.Action.BACKUP_CREATE,
resource_uuid=volume_id,
detail=message_field.Detail.
INCREMENTAL_BACKUP_FORCES_FULL_BACKUP,
level="WARNING"
)
from_snap, image_created = self._full_rbd_backup(
backup.container,
base_name,
length)
else:
# Incremental backup
rbd_img = source_rbd_image
from_snap, image_created = \
self._incremental_rbd_backup(backup,
base_name,
length,
rbd_img,
volume_id)
LOG.debug("Using --from-snap '%(snap)s' for incremental backup of "
"volume %(volume)s.",
@@ -856,6 +912,13 @@ class CephBackupDriver(driver.BackupDriver):
LOG.debug("Differential backup transfer completed in %.4fs",
(time.time() - before))
# only keep last n snapshots and delete older ones
if snaps_to_keep > 0:
self._remove_last_snapshots(source_rbd_image, snaps_to_keep)
else:
LOG.debug("Not deleting any snapshots because "
"all should be kept")
except exception.BackupRBDOperationFailed:
with excutils.save_and_reraise_exception():
LOG.debug("Differential backup transfer failed")
@@ -872,6 +935,48 @@ class CephBackupDriver(driver.BackupDriver):
return {'service_metadata': '{"base": "%s"}' % base_name}
def _remove_last_snapshots(self, source_rbd_image, snaps_to_keep: int):
# only keep last n snapshots and delete older ones for the source
# image provided
snap_list = []
try:
snap_list = self.get_backup_snaps(source_rbd_image)
except Exception as e:
LOG.debug(
"Failed to get snapshot list for %s: %s", source_rbd_image, e
)
remaining_snaps = len(snap_list)
LOG.debug("Snapshot list: %s", snap_list)
if remaining_snaps > snaps_to_keep:
snaps_to_delete = remaining_snaps - snaps_to_keep
LOG.debug(
"There are %s snapshots and %s should be kept, "
"deleting the oldest %s snapshots",
remaining_snaps,
snaps_to_keep,
snaps_to_delete,
)
for i in range(snaps_to_delete):
LOG.debug("Deleting snapshot %s", snap_list[i])
try:
source_rbd_image.remove_snap(snap_list[i]["name"])
except Exception as e:
LOG.debug(
"Failed to delete snapshot %s: %s", snap_list[i], e
)
else:
LOG.debug(
"There are %s snapshots and %s should be kept, "
"not deleting any snapshots",
remaining_snaps,
snaps_to_keep,
)
@staticmethod
def _file_is_rbd(volume_file: linuxrbd.RBDVolumeIOWrapper) -> bool:
"""Returns True if the volume_file is actually an RBD image."""