import 15.2.5

[ceph.git] / ceph / qa / tasks / cephfs / test_recovery_pool.py

"""
Test our tools for recovering metadata from the data pool into an alternate pool
"""

import logging
import traceback
from collections import namedtuple

from teuthology.orchestra.run import CommandFailedError
from tasks.cephfs.cephfs_test_case import CephFSTestCase

log = logging.getLogger(__name__)


ValidationError = namedtuple("ValidationError", ["exception", "backtrace"])


class OverlayWorkload(object):
    def __init__(self, orig_fs, recovery_fs, orig_mount, recovery_mount):
        self._orig_fs = orig_fs
        self._recovery_fs = recovery_fs
        self._orig_mount = orig_mount
        self._recovery_mount = recovery_mount
        self._initial_state = None

        # Accumulate backtraces for every failed validation, and return them.  Backtraces
        # are rather verbose, but we only see them when something breaks, and they
        # let us see which check failed without having to decorate each check with
        # a string
        self._errors = []

    def assert_equal(self, a, b):
        try:
            if a != b:
                raise AssertionError("{0} != {1}".format(a, b))
        except AssertionError as e:
            self._errors.append(
                ValidationError(e, traceback.format_exc(3))
            )

    def write(self):
        """
        Write the workload files to the mount
        """
        raise NotImplementedError()

    def validate(self):
        """
        Read from the mount and validate that the workload files are present (i.e. have
        survived or been reconstructed from the test scenario)
        """
        raise NotImplementedError()

    def damage(self):
        """
        Damage the filesystem pools in ways that will be interesting to recover from.  By
        default just wipe everything in the metadata pool
        """
        # Delete every object in the metadata pool
        objects = self._orig_fs.rados(["ls"]).split("\n")
        for o in objects:
            self._orig_fs.rados(["rm", o])

    def flush(self):
        """
        Called after client unmount, after write: flush whatever you want
        """
        self._orig_fs.mds_asok(["flush", "journal"])
        self._recovery_fs.mds_asok(["flush", "journal"])


class SimpleOverlayWorkload(OverlayWorkload):
    """
    Single file, single directory, check that it gets recovered and so does its size
    """
    def write(self):
        self._orig_mount.run_shell(["mkdir", "subdir"])
        self._orig_mount.write_n_mb("subdir/sixmegs", 6)
        self._initial_state = self._orig_mount.stat("subdir/sixmegs")

    def validate(self):
        self._recovery_mount.run_shell(["ls", "subdir"])
        st = self._recovery_mount.stat("subdir/sixmegs")
        self.assert_equal(st['st_size'], self._initial_state['st_size'])
        return self._errors

class TestRecoveryPool(CephFSTestCase):
    MDSS_REQUIRED = 2
    CLIENTS_REQUIRED = 2
    REQUIRE_RECOVERY_FILESYSTEM = True

    def is_marked_damaged(self, rank):
        mds_map = self.fs.get_mds_map()
        return rank in mds_map['damaged']

    def _rebuild_metadata(self, workload, other_pool=None, workers=1):
        """
        That when all objects in metadata pool are removed, we can rebuild a metadata pool
        based on the contents of a data pool, and a client can see and read our files.
        """

        # First, inject some files

        workload.write()

        # Unmount the client and flush the journal: the tool should also cope with
        # situations where there is dirty metadata, but we'll test that separately
        self.mount_a.umount_wait()
        self.mount_b.umount_wait()
        workload.flush()

        # Create the alternate pool if requested
        recovery_fs = self.recovery_fs.name
        recovery_pool = self.recovery_fs.get_metadata_pool_name()
        self.recovery_fs.data_scan(['init', '--force-init',
                                    '--filesystem', recovery_fs,
                                    '--alternate-pool', recovery_pool])
        self.recovery_fs.mon_manager.raw_cluster_cmd('-s')
        self.recovery_fs.table_tool([recovery_fs + ":0", "reset", "session"])
        self.recovery_fs.table_tool([recovery_fs + ":0", "reset", "snap"])
        self.recovery_fs.table_tool([recovery_fs + ":0", "reset", "inode"])

        # Stop the MDS
        self.fs.mds_stop()
        self.fs.mds_fail()

        # After recovery, we need the MDS to not be strict about stats (in production these options
        # are off by default, but in QA we need to explicitly disable them)
        self.fs.set_ceph_conf('mds', 'mds verify scatter', False)
        self.fs.set_ceph_conf('mds', 'mds debug scatterstat', False)

        # Apply any data damage the workload wants
        workload.damage()

        # Reset the MDS map in case multiple ranks were in play: recovery procedure
        # only understands how to rebuild metadata under rank 0
        self.fs.mon_manager.raw_cluster_cmd('fs', 'reset', self.fs.name,
                '--yes-i-really-mean-it')

        self.fs.table_tool([self.fs.name + ":0", "reset", "session"])
        self.fs.table_tool([self.fs.name + ":0", "reset", "snap"])
        self.fs.table_tool([self.fs.name + ":0", "reset", "inode"])

        # Run the recovery procedure
        if False:
            with self.assertRaises(CommandFailedError):
                # Normal reset should fail when no objects are present, we'll use --force instead
                self.fs.journal_tool(["journal", "reset"], 0)

        self.fs.mds_stop()
        self.fs.data_scan(['scan_extents', '--alternate-pool',
                           recovery_pool, '--filesystem', self.fs.name,
                           self.fs.get_data_pool_name()])
        self.fs.data_scan(['scan_inodes', '--alternate-pool',
                           recovery_pool, '--filesystem', self.fs.name,
                           '--force-corrupt', '--force-init',
                           self.fs.get_data_pool_name()])
        self.fs.journal_tool(['event', 'recover_dentries', 'list',
                              '--alternate-pool', recovery_pool], 0)

        self.fs.data_scan(['init', '--force-init', '--filesystem',
                           self.fs.name])
        self.fs.data_scan(['scan_inodes', '--filesystem', self.fs.name,
                           '--force-corrupt', '--force-init',
                           self.fs.get_data_pool_name()])
        self.fs.journal_tool(['event', 'recover_dentries', 'list'], 0)

        self.recovery_fs.journal_tool(['journal', 'reset', '--force'], 0)
        self.fs.journal_tool(['journal', 'reset', '--force'], 0)
        self.fs.mon_manager.raw_cluster_cmd('mds', 'repaired',
                                            recovery_fs + ":0")

        # Mark the MDS repaired
        self.fs.mon_manager.raw_cluster_cmd('mds', 'repaired', '0')

        # Start the MDS
        self.fs.mds_restart()
        self.recovery_fs.mds_restart()
        self.fs.wait_for_daemons()
        self.recovery_fs.wait_for_daemons()
        status = self.recovery_fs.status()
        for rank in self.recovery_fs.get_ranks(status=status):
            self.fs.mon_manager.raw_cluster_cmd('tell', "mds." + rank['name'],
                                                'injectargs', '--debug-mds=20')
            self.fs.rank_tell(['scrub', 'start', '/', 'recursive', 'repair'], rank=rank['rank'], status=status)
        log.info(str(self.mds_cluster.status()))

        # Mount a client
        self.mount_a.mount_wait()
        self.mount_b.mount_wait(mount_fs_name=recovery_fs)

        # See that the files are present and correct
        errors = workload.validate()
        if errors:
            log.error("Validation errors found: {0}".format(len(errors)))
            for e in errors:
                log.error(e.exception)
                log.error(e.backtrace)
            raise AssertionError("Validation failed, first error: {0}\n{1}".format(
                errors[0].exception, errors[0].backtrace
            ))

    def test_rebuild_simple(self):
        self._rebuild_metadata(SimpleOverlayWorkload(self.fs, self.recovery_fs,
                                                     self.mount_a, self.mount_b))