iSCSI multipath: improve logging on connect

The new iSCSI multipath code uses multithreading to do the connections,
but since the context is a thread local variable it will not be present
in those threads so we will not see the request id or other information
from the context in those thread's log entries.

This is a small inconvenience when looking at the logs if we try to
filter by the request id,.

To resolve this we introduce a new Thread class that inherits the
context from the calling thread, this way any log entries will have the
right context and present expected information.

Change-Id: I27624a59738809d30531c0c4f37308f897dd9654
This commit is contained in:
Gorka Eguileor 2017-06-22 14:13:20 +02:00
parent 31bec05d72
commit 32ab0d1670
3 changed files with 100 additions and 4 deletions

View File

@ -18,7 +18,10 @@
and root_helper settings, so this provides that hook.
"""
import threading
from oslo_concurrency import processutils as putils
from oslo_context import context as context_utils
from oslo_utils import encodeutils
from os_brick.privileged import rootwrap as priv_rootwrap
@ -60,3 +63,22 @@ class Executor(object):
def set_root_helper(self, helper):
self._root_helper = helper
class Thread(threading.Thread):
"""Thread class that inherits the parent's context.
This is useful when you are spawning a thread and want LOG entries to
display the right context information, such as the request.
"""
def __init__(self, *args, **kwargs):
# Store the caller's context as a private variable shared among threads
self.__context__ = context_utils.get_current()
super(Thread, self).__init__(*args, **kwargs)
def run(self):
# Store the context in the current thread's request store
if self.__context__:
self.__context__.update_store()
super(Thread, self).run()

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@ -17,7 +17,6 @@ import collections
import glob
import os
import re
import threading
import time
from oslo_concurrency import lockutils
@ -27,6 +26,7 @@ from oslo_utils import excutils
from oslo_utils import strutils
from os_brick import exception
from os_brick import executor
from os_brick.i18n import _
from os_brick import initiator
from os_brick.initiator.connectors import base
@ -642,7 +642,7 @@ class ISCSIConnector(base.BaseLinuxConnector, base_iscsi.BaseISCSIConnector):
for ip, iqn, lun in ips_iqns_luns:
props = connection_properties.copy()
props.update(target_portal=ip, target_iqn=iqn, target_lun=lun)
threads.append(threading.Thread(target=self._connect_vol,
threads.append(executor.Thread(target=self._connect_vol,
args=(retries, props, data)))
for thread in threads:
thread.start()

View File

@ -13,10 +13,11 @@
# License for the specific language governing permissions and limitations
# under the License.
# import time
import threading
import mock
from oslo_concurrency import processutils as putils
from oslo_context import context as context_utils
import six
import testtools
@ -87,3 +88,76 @@ class TestExecutor(base.TestCase):
stdout, stderr = executor._execute()
self.assertEqual(u'Espa\xf1a', stdout)
self.assertEqual(u'Z\xfcrich', stderr)
class TestThread(base.TestCase):
def _store_context(self, result):
"""Stores current thread's context in result list."""
result.append(context_utils.get_current())
def _run_threads(self, threads):
for thread in threads:
thread.start()
for thread in threads:
thread.join()
def _do_test(self, thread_class, expected, result=None):
if result is None:
result = []
threads = [thread_class(target=self._store_context, args=[result])
for i in range(3)]
self._run_threads(threads)
self.assertEqual([expected] * len(threads), result)
def test_normal_thread(self):
"""Test normal threads don't inherit parent's context."""
context = context_utils.RequestContext()
context.update_store()
self._do_test(threading.Thread, None)
def test_no_context(self, result=None):
"""Test when parent has no context."""
context_utils._request_store.context = None
self._do_test(brick_executor.Thread, None, result)
def test_with_context(self, result=None):
"""Test that our class actually inherits the context."""
context = context_utils.RequestContext()
context.update_store()
self._do_test(brick_executor.Thread, context, result)
def _run_test(self, test_method, test_args, result):
"""Run one of the normal tests and store the result.
Meant to be run in a different thread, thus the need to store the
result, because by the time the join call completes the test's stack
is no longer available and the exception will have been lost.
"""
try:
test_method(test_args)
result.append(True)
except Exception:
result.append(False)
raise
def test_no_cross_mix(self):
"""Test there's no shared global context between threads."""
result = []
contexts = [[], [], []]
threads = [threading.Thread(target=self._run_test,
args=[self.test_with_context,
contexts[0],
result]),
threading.Thread(target=self._run_test,
args=[self.test_no_context,
contexts[1],
result]),
threading.Thread(target=self._run_test,
args=[self.test_with_context,
contexts[2],
result])]
self._run_threads(threads)
# Check that all tests run without raising an exception
self.assertEqual([True, True, True], result)
# Check that the context were not shared
self.assertNotEqual(contexts[0], contexts[2])