Source code for osprofiler.sqlalchemy

# Copyright 2014 Mirantis Inc.
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

import contextlib
import logging as log

from oslo_utils import reflection

from osprofiler import profiler

LOG = log.getLogger(__name__)

_DISABLED = False


[docs]def disable(): """Disable tracing of all DB queries. Reduce a lot size of profiles.""" global _DISABLED _DISABLED = True
[docs]def enable(): """add_tracing adds event listeners for sqlalchemy.""" global _DISABLED _DISABLED = False
[docs]def add_tracing(sqlalchemy, engine, name, hide_result=True): """Add tracing to all sqlalchemy calls.""" if not _DISABLED: sqlalchemy.event.listen(engine, "before_cursor_execute", _before_cursor_execute(name)) sqlalchemy.event.listen( engine, "after_cursor_execute", _after_cursor_execute(hide_result=hide_result) ) sqlalchemy.event.listen(engine, "handle_error", handle_error)
[docs]@contextlib.contextmanager def wrap_session(sqlalchemy, sess): with sess as s: if not getattr(s.bind, "traced", False): add_tracing(sqlalchemy, s.bind, "db") s.bind.traced = True yield s
def _before_cursor_execute(name): """Add listener that will send trace info before query is executed.""" def handler(conn, cursor, statement, params, context, executemany): info = {"db": { "statement": statement, "params": params} } profiler.start(name, info=info) return handler def _after_cursor_execute(hide_result=True): """Add listener that will send trace info after query is executed. :param hide_result: Boolean value to hide or show SQL result in trace. True - hide SQL result (default). False - show SQL result in trace. """ def handler(conn, cursor, statement, params, context, executemany): if not hide_result: # Add SQL result to trace info in *-stop phase info = { "db": { "result": str(cursor._rows) } } profiler.stop(info=info) else: profiler.stop() return handler
[docs]def handle_error(exception_context): """Handle SQLAlchemy errors""" exception_class_name = reflection.get_class_name( exception_context.original_exception) original_exception = str(exception_context.original_exception) chained_exception = str(exception_context.chained_exception) info = { "etype": exception_class_name, "message": original_exception, "db": { "original_exception": original_exception, "chained_exception": chained_exception } } profiler.stop(info=info) LOG.debug("OSProfiler has handled SQLAlchemy error: %s", original_exception)