mongo/buildscripts/resmokelib/testing/hooks/periodic_kill_secondaries.py

359 lines
17 KiB
Python

"""
Testing hook for verifying correctness of a secondary's behavior during
an unclean shutdown.
"""
from __future__ import absolute_import
import time
import bson
import pymongo
import pymongo.errors
from . import dbhash
from . import interface
from . import validate
from ..fixtures import interface as fixture
from ..fixtures import replicaset
from ... import errors
class PeriodicKillSecondaries(interface.Hook):
"""
Periodically kills the secondaries in a replica set and verifies
that they can reach the SECONDARY state without having connectivity
to the primary after an unclean shutdown.
"""
DEFAULT_PERIOD_SECS = 30
def __init__(self, hook_logger, rs_fixture, period_secs=DEFAULT_PERIOD_SECS):
if not isinstance(rs_fixture, replicaset.ReplicaSetFixture):
raise TypeError("{} either does not support replication or does not support writing to"
" its oplog early".format(rs_fixture.__class__.__name__))
if rs_fixture.num_nodes <= 1:
raise ValueError("PeriodicKillSecondaries requires the replica set to contain at least"
" one secondary")
description = ("PeriodicKillSecondaries (kills the secondary after running tests for a"
" configurable period of time)")
interface.Hook.__init__(self, hook_logger, rs_fixture, description)
self._period_secs = period_secs
self._start_time = None
self._last_test = None
def after_suite(self, test_report):
if self._start_time is not None:
# Ensure that we test killing the secondary and having it reach state SECONDARY after
# being restarted at least once when running the suite.
# The if condition ensures we haven't already run after the last test, making this
# equivalent to an 'after_test' call for the last test.
self._run(test_report)
def before_test(self, test, test_report):
if self._start_time is not None:
# The "rsSyncApplyStop" failpoint is already enabled.
return
for secondary in self.fixture.get_secondaries():
# Enable the "rsSyncApplyStop" failpoint on the secondary to prevent them from
# applying any oplog entries while the test is running.
self._enable_rssyncapplystop(secondary)
self._start_time = time.time()
def after_test(self, test, test_report):
self._last_test = test
# Kill the secondaries and verify that they can reach the SECONDARY state if the specified
# period has elapsed.
should_check_secondaries = time.time() - self._start_time >= self._period_secs
if not should_check_secondaries:
return
self._run(test_report)
def _run(self, test_report):
hook_test_case = PeriodicKillSecondariesTestCase.create_after_test(
self.logger.test_case_logger, self._last_test, self, test_report)
hook_test_case.configure(self.fixture)
hook_test_case.run_dynamic_test(test_report)
# Set the hook back into a state where it will disable oplog application at the start
# of the next test that runs.
self._start_time = None
def _enable_rssyncapplystop(self, secondary):
# Enable the "rsSyncApplyStop" failpoint on the secondary to prevent them from
# applying any oplog entries while the test is running.
client = secondary.mongo_client()
try:
client.admin.command(
bson.SON([("configureFailPoint", "rsSyncApplyStop"), ("mode", "alwaysOn")]))
except pymongo.errors.OperationFailure as err:
self.logger.exception("Unable to disable oplog application on the mongod on port %d",
secondary.port)
raise errors.ServerFailure(
"Unable to disable oplog application on the mongod on port {}: {}".format(
secondary.port, err.args[0]))
def _disable_rssyncapplystop(self, secondary):
# Disable the "rsSyncApplyStop" failpoint on the secondary to have it resume applying
# oplog entries.
client = secondary.mongo_client()
try:
client.admin.command(
bson.SON([("configureFailPoint", "rsSyncApplyStop"), ("mode", "off")]))
except pymongo.errors.OperationFailure as err:
self.logger.exception("Unable to re-enable oplog application on the mongod on port %d",
secondary.port)
raise errors.ServerFailure(
"Unable to re-enable oplog application on the mongod on port {}: {}".format(
secondary.port, err.args[0]))
class PeriodicKillSecondariesTestCase(interface.DynamicTestCase):
def __init__(self, logger, test_name, description, base_test_name, hook, test_report):
interface.DynamicTestCase.__init__(self, logger, test_name, description, base_test_name,
hook)
self._test_report = test_report
def run_test(self):
self._kill_secondaries()
self._check_secondaries_and_restart_fixture()
# The CheckReplDBHash hook waits until all operations have replicated to and have been
# applied on the secondaries, so we run the ValidateCollections hook after it to ensure
# we're validating the entire contents of the collection.
#
# Verify that the dbhashes match across all nodes after having the secondaries reconcile
# the end of their oplogs.
self._check_repl_dbhash(self._test_report)
# Validate all collections on all nodes after having the secondaries reconcile the end
# of their oplogs.
self._validate_collections(self._test_report)
self._restart_and_clear_fixture()
def _kill_secondaries(self):
for secondary in self.fixture.get_secondaries():
# Disable the "rsSyncApplyStop" failpoint on the secondary to have it resume applying
# oplog entries.
self._hook._disable_rssyncapplystop(secondary)
# Wait a little bit for the secondary to start apply oplog entries so that we are more
# likely to kill the mongod process while it is partway into applying a batch.
time.sleep(0.1)
# Check that the secondary is still running before forcibly terminating it. This ensures
# we still detect some cases in which the secondary has already crashed.
if not secondary.is_running():
raise errors.ServerFailure(
"mongod on port {} was expected to be running in"
" PeriodicKillSecondaries.after_test(), but wasn't.".format(secondary.port))
self.logger.info("Killing the secondary on port %d...", secondary.port)
secondary.mongod.stop(kill=True)
try:
self.fixture.teardown()
except errors.ServerFailure:
# Teardown may or may not be considered a success as a result of killing a secondary,
# so we ignore ServerFailure raised during teardown.
pass
def _check_secondaries_and_restart_fixture(self):
preserve_dbpaths = []
for node in self.fixture.nodes:
preserve_dbpaths.append(node.preserve_dbpath)
node.preserve_dbpath = True
for secondary in self.fixture.get_secondaries():
self._check_invariants_as_standalone(secondary)
# Start the 'secondary' mongod back up as part of the replica set and wait for it to
# reach state SECONDARY.
secondary.setup()
secondary.await_ready()
self._await_secondary_state(secondary)
try:
secondary.teardown()
except errors.ServerFailure:
raise errors.ServerFailure(
"{} did not exit cleanly after reconciling the end of its oplog".format(
secondary))
self.logger.info("Starting the fixture back up again with its data files intact...")
try:
self.fixture.setup()
self.fixture.await_ready()
finally:
for (i, node) in enumerate(self.fixture.nodes):
node.preserve_dbpath = preserve_dbpaths[i]
def _validate_collections(self, test_report):
validate_test_case = validate.ValidateCollections(self._hook.logger, self.fixture)
validate_test_case.before_suite(test_report)
validate_test_case.before_test(self, test_report)
validate_test_case.after_test(self, test_report)
validate_test_case.after_suite(test_report)
def _check_repl_dbhash(self, test_report):
dbhash_test_case = dbhash.CheckReplDBHash(self._hook.logger, self.fixture)
dbhash_test_case.before_suite(test_report)
dbhash_test_case.before_test(self, test_report)
dbhash_test_case.after_test(self, test_report)
dbhash_test_case.after_suite(test_report)
def _restart_and_clear_fixture(self):
# We restart the fixture after setting 'preserve_dbpath' back to its original value in order
# to clear the contents of the data directory if desired. The CleanEveryN hook cannot be
# used in combination with the PeriodicKillSecondaries hook because we may attempt to call
# Fixture.teardown() while the "rsSyncApplyStop" failpoint is still enabled on the
# secondaries, causing them to exit with a non-zero return code.
self.logger.info("Finished verifying data consistency, stopping the fixture...")
try:
self.fixture.teardown()
except errors.ServerFailure:
raise errors.ServerFailure(
"{} did not exit cleanly after verifying data consistency".format(self.fixture))
self.logger.info("Starting the fixture back up again...")
self.fixture.setup()
self.fixture.await_ready()
def _check_invariants_as_standalone(self, secondary):
# We remove the --replSet option in order to start the node as a standalone.
replset_name = secondary.mongod_options.pop("replSet")
try:
secondary.setup()
secondary.await_ready()
client = secondary.mongo_client()
minvalid_doc = client.local["replset.minvalid"].find_one()
oplog_truncate_after_doc = client.local["replset.oplogTruncateAfterPoint"].find_one()
self.logger.info("minValid: {}, oTAP: {}".format(minvalid_doc,
oplog_truncate_after_doc))
latest_oplog_doc = client.local["oplog.rs"].find_one(sort=[("$natural",
pymongo.DESCENDING)])
null_ts = bson.Timestamp(0, 0)
# The oplog could be empty during initial sync. If so, we default it to null.
latest_oplog_entry_ts = null_ts
if latest_oplog_doc is not None:
latest_oplog_entry_ts = latest_oplog_doc.get("ts")
if latest_oplog_entry_ts is None:
raise errors.ServerFailure(
"Latest oplog entry had no 'ts' field: {}".format(latest_oplog_doc))
# The "oplogTruncateAfterPoint" document may not exist at startup. If so, we default
# it to null.
oplog_truncate_after_ts = null_ts
if oplog_truncate_after_doc is not None:
oplog_truncate_after_ts = oplog_truncate_after_doc.get(
"oplogTruncateAfterPoint", null_ts)
if minvalid_doc is not None:
applied_through_ts = minvalid_doc.get("begin", {}).get("ts", null_ts)
minvalid_ts = minvalid_doc.get("ts", null_ts)
if minvalid_ts == null_ts:
# The server treats the "ts" field in the minValid document as missing when its
# value is the null timestamp.
minvalid_ts = applied_through_ts
if latest_oplog_entry_ts == null_ts:
# If the oplog is empty, we treat the "minValid" as the latest oplog entry.
latest_oplog_entry_ts = minvalid_ts
if oplog_truncate_after_ts == null_ts:
# The server treats the "oplogTruncateAfterPoint" field as missing when its
# value is the null timestamp. When it is null, the oplog is complete and
# should not be truncated, so it is effectively the top of the oplog.
oplog_truncate_after_ts = latest_oplog_entry_ts
# Check the ordering invariants before the secondary has reconciled the end of
# its oplog.
# The "oplogTruncateAfterPoint" is set to the first timestamp of each batch of
# oplog entries before they are written to the oplog. Thus, it can be ahead
# of the top of the oplog before any oplog entries are written, and behind it
# after some are written. Thus, we cannot compare it to the top of the oplog.
# appliedThrough <= minValid
# appliedThrough represents the end of the previous batch, so it is always the
# earliest.
if not applied_through_ts <= minvalid_ts:
raise errors.ServerFailure(
"The condition appliedThrough <= minValid ({} <= {}) doesn't hold: minValid"
" document={}, latest oplog entry={}".format(
applied_through_ts, minvalid_ts, minvalid_doc, latest_oplog_doc))
# minValid <= oplogTruncateAfterPoint
# This is true because this hook is never run after a rollback. Thus, we only
# move "minValid" to the end of each batch after the batch is written to the oplog.
# We reset the "oplogTruncateAfterPoint" to null before we move "minValid" from
# the end of the previous batch to the end of the current batch. Thus "minValid"
# must be less than or equal to the "oplogTruncateAfterPoint".
if not minvalid_ts <= oplog_truncate_after_ts:
raise errors.ServerFailure(
"The condition minValid <= oplogTruncateAfterPoint ({} <= {}) doesn't"
" hold: minValid document={}, oplogTruncateAfterPoint document={},"
" latest oplog entry={}".format(minvalid_ts, oplog_truncate_after_ts,
minvalid_doc, oplog_truncate_after_doc,
latest_oplog_doc))
# minvalid <= latest oplog entry
# "minValid" is set to the end of a batch after the batch is written to the oplog.
# Thus it is always less than or equal to the top of the oplog.
if not minvalid_ts <= latest_oplog_entry_ts:
raise errors.ServerFailure(
"The condition minValid <= top of oplog ({} <= {}) doesn't"
" hold: minValid document={}, latest oplog entry={}".format(
minvalid_ts, latest_oplog_entry_ts, minvalid_doc, latest_oplog_doc))
try:
secondary.teardown()
except errors.ServerFailure:
raise errors.ServerFailure(
"{} did not exit cleanly after being started up as a standalone".format(
secondary))
except pymongo.errors.OperationFailure as err:
self.logger.exception(
"Failed to read the minValid document, the oplogTruncateAfterPoint document,"
" the checkpointTimestamp document, or the latest oplog entry from the mongod on"
" port %d", secondary.port)
raise errors.ServerFailure(
"Failed to read the minValid document, the oplogTruncateAfterPoint document,"
" the checkpointTimestamp document, or the latest oplog entry from the mongod on"
" port {}: {}".format(secondary.port, err.args[0]))
finally:
# Set the secondary's options back to their original values.
secondary.mongod_options["replSet"] = replset_name
def _await_secondary_state(self, secondary):
client = secondary.mongo_client()
try:
client.admin.command(
bson.SON([
("replSetTest", 1),
("waitForMemberState", 2), # 2 = SECONDARY
("timeoutMillis", fixture.ReplFixture.AWAIT_REPL_TIMEOUT_MINS * 60 * 1000)
]))
except pymongo.errors.OperationFailure as err:
self.logger.exception(
"mongod on port %d failed to reach state SECONDARY after %d seconds",
secondary.port, fixture.ReplFixture.AWAIT_REPL_TIMEOUT_MINS * 60)
raise errors.ServerFailure(
"mongod on port {} failed to reach state SECONDARY after {} seconds: {}".format(
secondary.port, fixture.ReplFixture.AWAIT_REPL_TIMEOUT_MINS * 60, err.args[0]))