def __init__(self, srequest, storlet_pipe_path, storlet_logger_path,
timeout, logger, extra_sources=None):
self.srequest = srequest
self.storlet_pipe_path = storlet_pipe_path
self.storlet_logger_path = storlet_logger_path
self.storlet_logger = StorletLogger(self.storlet_logger_path,
'storlet_invoke')
self.logger = logger
self.timeout = timeout
# local side file descriptors
self.data_read_fd = None
self.data_write_fd = None
self.metadata_read_fd = None
self.metadata_write_fd = None
self.execution_str_read_fd = None
self.execution_str_write_fd = None
self.task_id = None
self._input_data_read_fd = None
self._input_data_write_fd = None
self.extra_data_sources = []
extra_sources = extra_sources or []
for source in extra_sources:
if source.has_fd:
# TODO(kota_): it may be data_fd in the future.
raise Exception(
'extra_source no requires data_fd just data_iter')
self.extra_data_sources.append(
{'read_fd': None, 'write_fd': None,
'user_metadata': source.user_metadata,
'data_iter': source.data_iter})
if not os.path.exists(storlet_logger_path):
os.makedirs(storlet_logger_path)
def __init__(self, srequest, storlet_pipe_path, storlet_logger_path,
timeout, logger, extra_sources=None):
self.srequest = srequest
self.storlet_pipe_path = storlet_pipe_path
self.storlet_logger_path = storlet_logger_path
self.storlet_logger = StorletLogger(self.storlet_logger_path,
'storlet_invoke')
self.logger = logger
self.timeout = timeout
# local side file descriptors
self.data_read_fd = None
self.data_write_fd = None
self.metadata_read_fd = None
self.metadata_write_fd = None
self.execution_str_read_fd = None
self.execution_str_write_fd = None
self.task_id = None
self._input_data_read_fd = None
self._input_data_write_fd = None
self.extra_data_sources = []
extra_sources = extra_sources or []
for source in extra_sources:
if source.has_fd:
# TODO(kota_): it may be data_fd in the future.
raise Exception(
'extra_source no requires data_fd just data_iter')
self.extra_data_sources.append(
{'read_fd': None, 'write_fd': None,
'user_metadata': source.user_metadata,
'data_iter': source.data_iter})
if not os.path.exists(storlet_logger_path):
os.makedirs(storlet_logger_path)
class StorletInvocationProtocol(object):
"""
StorletInvocationProtocol class
This class serves communictaion with a Docker container to run an
application
:param srequest: StorletRequest instance
:param storlet_pipe_path: path string to pipe
:param storlet_logger_path: path string to log file
:param timeout: integer of timeout for waiting the resp from container
:param logger: logger instance
:param extra_sources (WIP): a list of StorletRequest instances
which keep data_iter for adding extra source
as data stream
"""
def __init__(self, srequest, storlet_pipe_path, storlet_logger_path,
timeout, logger, extra_sources=None):
self.srequest = srequest
self.storlet_pipe_path = storlet_pipe_path
self.storlet_logger_path = storlet_logger_path
self.storlet_logger = StorletLogger(self.storlet_logger_path,
'storlet_invoke')
self.logger = logger
self.timeout = timeout
# local side file descriptors
self.data_read_fd = None
self.data_write_fd = None
self.metadata_read_fd = None
self.metadata_write_fd = None
self.execution_str_read_fd = None
self.execution_str_write_fd = None
self.task_id = None
self._input_data_read_fd = None
self._input_data_write_fd = None
self.extra_data_sources = []
extra_sources = extra_sources or []
for source in extra_sources:
if source.has_fd:
# TODO(kota_): it may be data_fd in the future.
raise Exception(
'extra_source no requires data_fd just data_iter')
self.extra_data_sources.append(
{'read_fd': None, 'write_fd': None,
'user_metadata': source.user_metadata,
'data_iter': source.data_iter})
if not os.path.exists(storlet_logger_path):
os.makedirs(storlet_logger_path)
@property
def input_data_read_fd(self):
"""
File descriptor to read the input body content
"""
if self.srequest.has_fd:
return self.srequest.data_fd
else:
return self._input_data_read_fd
@property
def remote_fds(self):
"""
File descriptors to be passed to container side
"""
remote_fds = [self.input_data_read_fd,
self.execution_str_write_fd,
self.data_write_fd,
self.metadata_write_fd,
self.storlet_logger.getfd()]
for source in self.extra_data_sources:
remote_fds.append(source['read_fd'])
return remote_fds
@property
def remote_fds_metadata(self):
"""
Metadata about file descriptors to be passed to container side
"""
input_fd_metadata = FDMetadata(
sbus_fd.SBUS_FD_INPUT_OBJECT,
storage_metadata=self.srequest.user_metadata)
if self.srequest.user_metadata:
input_fd_metadata.storage_metadata.update(
self.srequest.user_metadata)
if self.srequest.has_range:
input_fd_metadata.storlets_metadata['start'] = \
str(self.srequest.start)
input_fd_metadata.storlets_metadata['end'] = \
str(self.srequest.end)
fds_metadata = [
input_fd_metadata.to_dict(),
FDMetadata(sbus_fd.SBUS_FD_OUTPUT_TASK_ID).to_dict(),
FDMetadata(sbus_fd.SBUS_FD_OUTPUT_OBJECT).to_dict(),
FDMetadata(sbus_fd.SBUS_FD_OUTPUT_OBJECT_METADATA).to_dict(),
FDMetadata(sbus_fd.SBUS_FD_LOGGER).to_dict()]
for source in self.extra_data_sources:
fdmd = FDMetadata(
sbus_fd.SBUS_FD_INPUT_OBJECT,
storage_metadata=source['user_metadata'])
fds_metadata.append(fdmd.to_dict())
return fds_metadata
@contextmanager
def _activate_invocation_descriptors(self):
"""
Contextmanager about file descriptors used in storlet invocation
NOTE: This context manager now only closes remote side fds,
so you should close local side fds
"""
self._prepare_invocation_descriptors()
try:
yield
finally:
self._close_remote_side_descriptors()
def _prepare_invocation_descriptors(self):
"""
Create all pipse used for Storlet execution
"""
if not self.srequest.has_fd:
self._input_data_read_fd, self._input_data_write_fd = os.pipe()
self.data_read_fd, self.data_write_fd = os.pipe()
self.execution_str_read_fd, self.execution_str_write_fd = os.pipe()
self.metadata_read_fd, self.metadata_write_fd = os.pipe()
for source in self.extra_data_sources:
source['read_fd'], source['write_fd'] = os.pipe()
def _safe_close(self, fds):
"""
Make sure that all of the file descriptors get closed
:param fds: a list of file descriptors
"""
for fd in fds:
try:
os.close(fd)
except OSError as err:
if err.errno != errno.EBADF:
raise
# TODO(kota_): fd might be closed already, so if already
# closed, OSError will be raised. we need more refactor to
# keep clean the file discriptors.
pass
def _close_remote_side_descriptors(self):
"""
Close all of the container side descriptors
"""
fds = [self.data_write_fd, self.metadata_write_fd,
self.execution_str_write_fd]
if not self.srequest.has_fd:
fds.append(self.input_data_read_fd)
fds.extend([source['read_fd'] for source in self.extra_data_sources])
for fd in fds:
os.close(fd)
def _close_local_side_descriptors(self):
"""
Close all of the host side descriptors
"""
fds = [self.data_read_fd, self.metadata_read_fd,
self.execution_str_read_fd]
fds.extend([source['write_fd'] for source in self.extra_data_sources])
self._safe_close(fds)
def _cancel(self):
"""
Cancel on-going storlet execution
"""
with _open_pipe() as (read_fd, write_fd):
dtg = SBusServiceDatagram(
sbus_cmd.SBUS_CMD_CANCEL,
[write_fd],
[FDMetadata(sbus_fd.SBUS_FD_SERVICE_OUT).to_dict()],
None,
self.task_id)
rc = SBus.send(self.storlet_pipe_path, dtg)
if (rc < 0):
raise StorletRuntimeException('Failed to cancel task')
# TODO(takashi): Check the response here
os.read(read_fd, 10)
def _invoke(self):
"""
Send an execution command to the remote daemon factory
"""
with self.storlet_logger.activate(),\
self._activate_invocation_descriptors():
self._send_execute_command()
self._wait_for_read_with_timeout(self.execution_str_read_fd)
# TODO(kota_): need an assertion for task_id format
self.task_id = os.read(self.execution_str_read_fd, 10)
os.close(self.execution_str_read_fd)
def _send_execute_command(self):
"""
Send execute command to the remote daemon factory to invoke storlet
execution
"""
dtg = SBusExecuteDatagram(
sbus_cmd.SBUS_CMD_EXECUTE,
self.remote_fds,
self.remote_fds_metadata,
self.srequest.params)
rc = SBus.send(self.storlet_pipe_path, dtg)
if (rc < 0):
raise StorletRuntimeException("Failed to send execute command")
def _wait_for_read_with_timeout(self, fd):
"""
Wait while the read file descriptor gets ready
:param fd: File descriptor to read
:raises StorletTimeout: Exception raised when it times out to cancel
the existing task
:raises StorletRuntimeException: Exception raised when it fails to
cancel the existing task
"""
try:
with StorletTimeout(self.timeout):
r, w, e = select.select([fd], [], [])
except StorletTimeout:
exc_type, exc_value, exc_traceback = sys.exc_info()
# When there is a task already running, we should cancel it.
if self.task_id:
try:
self._cancel()
except StorletRuntimeException:
self.logger.warning(
'Task %s timed out, but failed to get canceled'
% self.task_id)
pass
six.reraise(exc_type, exc_value, exc_traceback)
if fd not in r:
raise StorletRuntimeException('Read fd is not ready')
def _read_metadata(self):
"""
Read metadata in the storlet execution result from fd
:returns: a dict of metadata
"""
self._wait_for_read_with_timeout(self.metadata_read_fd)
flat_json = os.read(self.metadata_read_fd, MAX_METADATA_SIZE)
os.close(self.metadata_read_fd)
try:
return json.loads(flat_json)
except ValueError:
self.logger.exception('Failed to load metadata from json')
raise StorletRuntimeException('Got invalid format about metadata')
def _wait_for_write_with_timeout(self, fd):
"""
Wait while the write file descriptor gets ready
:param fd: File descriptor to write
:raises StorletTimeout: Exception raised when it times out to cancel
the existing task
:raises StorletRuntimeException: Exception raised when it fails to
cancel the existing task
"""
with StorletTimeout(self.timeout):
r, w, e = select.select([], [fd], [])
if fd not in w:
raise StorletRuntimeException('Write fd is not ready')
def _close_input_data_descriptors(self):
fds = [self._input_data_read_fd, self._input_data_write_fd]
self._safe_close(fds)
def communicate(self):
try:
self._invoke()
if not self.srequest.has_fd:
self._wait_for_write_with_timeout(self._input_data_write_fd)
# We do the writing in a different thread.
# Otherwise, we can run into the following deadlock
# 1. middleware writes to Storlet
# 2. Storlet reads and starts to write metadata and then data
# 3. middleware continues writing
# 4. Storlet continues writing and gets stuck as middleware
# is busy writing, but still not consuming the reader end
# of the Storlet writer.
eventlet.spawn_n(self._write_input_data,
self._input_data_write_fd,
self.srequest.data_iter)
for source in self.extra_data_sources:
# NOTE(kota_): not sure right now if using eventlet.spawn_n is
# right way. GreenPool is better? I don't get
# whole for the dead lock described in above.
self._wait_for_write_with_timeout(source['write_fd'])
eventlet.spawn_n(self._write_input_data,
source['write_fd'],
source['data_iter'])
out_md = self._read_metadata()
self._wait_for_read_with_timeout(self.data_read_fd)
return StorletResponse(out_md, data_fd=self.data_read_fd,
cancel=self._cancel)
except Exception:
self._close_local_side_descriptors()
if not self.srequest.has_fd:
self._close_input_data_descriptors()
raise
@contextmanager
def _open_writer(self, fd):
with os.fdopen(fd, 'w') as writer:
yield writer
def _write_input_data(self, fd, data_iter):
try:
# double try/except block saving from unexpected errors
try:
with self._open_writer(fd) as writer:
for chunk in data_iter:
with StorletTimeout(self.timeout):
writer.write(chunk)
except (OSError, TypeError, ValueError):
self.logger.exception('fdopen failed')
except IOError:
# this will happen at sort of broken pipe while writer.write
self.logger.exception('IOError with writing fd %s' % fd)
except StorletTimeout:
self.logger.exception(
'Timeout (%s)s with writing fd %s' % (self.timeout, fd))
except Exception:
# _write_input_data is designed to run eventlet thread
# so that we should catch and suppress it here
self.logger.exception('Unexpected error at writing input data')
class StorletInvocationProtocol(object):
"""
StorletInvocationProtocol class
This class serves communictaion with a Docker container to run an
application
:param srequest: StorletRequest instance
:param storlet_pipe_path: path string to pipe
:param storlet_logger_path: path string to log file
:param timeout: integer of timeout for waiting the resp from container
:param logger: logger instance
:param extra_sources (WIP): a list of StorletRequest instances
which keep data_iter for adding extra source
as data stream
"""
def __init__(self, srequest, storlet_pipe_path, storlet_logger_path,
timeout, logger, extra_sources=None):
self.srequest = srequest
self.storlet_pipe_path = storlet_pipe_path
self.storlet_logger_path = storlet_logger_path
self.storlet_logger = StorletLogger(self.storlet_logger_path,
'storlet_invoke')
self.logger = logger
self.timeout = timeout
# local side file descriptors
self.data_read_fd = None
self.data_write_fd = None
self.metadata_read_fd = None
self.metadata_write_fd = None
self.execution_str_read_fd = None
self.execution_str_write_fd = None
self.task_id = None
self._input_data_read_fd = None
self._input_data_write_fd = None
self.extra_data_sources = []
extra_sources = extra_sources or []
for source in extra_sources:
if source.has_fd:
# TODO(kota_): it may be data_fd in the future.
raise Exception(
'extra_source no requires data_fd just data_iter')
self.extra_data_sources.append(
{'read_fd': None, 'write_fd': None,
'user_metadata': source.user_metadata,
'data_iter': source.data_iter})
if not os.path.exists(storlet_logger_path):
os.makedirs(storlet_logger_path)
@property
def input_data_read_fd(self):
"""
File descriptor to read the input body content
"""
if self.srequest.has_fd:
return self.srequest.data_fd
else:
return self._input_data_read_fd
@property
def remote_fds(self):
"""
File descriptors to be passed to container side
"""
remote_fds = [self.input_data_read_fd,
self.execution_str_write_fd,
self.data_write_fd,
self.metadata_write_fd,
self.storlet_logger.getfd()]
for source in self.extra_data_sources:
remote_fds.append(source['read_fd'])
return remote_fds
@property
def remote_fds_metadata(self):
"""
Metadata about file descriptors to be passed to container side
"""
input_fd_metadata = FDMetadata(
sbus_fd.SBUS_FD_INPUT_OBJECT,
storage_metadata=self.srequest.user_metadata)
if self.srequest.user_metadata:
input_fd_metadata.storage_metadata.update(
self.srequest.user_metadata)
if self.srequest.has_range:
input_fd_metadata.storlets_metadata['start'] = \
str(self.srequest.start)
input_fd_metadata.storlets_metadata['end'] = \
str(self.srequest.end)
fds_metadata = [
input_fd_metadata.to_dict(),
FDMetadata(sbus_fd.SBUS_FD_OUTPUT_TASK_ID).to_dict(),
FDMetadata(sbus_fd.SBUS_FD_OUTPUT_OBJECT).to_dict(),
FDMetadata(sbus_fd.SBUS_FD_OUTPUT_OBJECT_METADATA).to_dict(),
FDMetadata(sbus_fd.SBUS_FD_LOGGER).to_dict()]
for source in self.extra_data_sources:
fdmd = FDMetadata(
sbus_fd.SBUS_FD_INPUT_OBJECT,
storage_metadata=source['user_metadata'])
fds_metadata.append(fdmd.to_dict())
return fds_metadata
@contextmanager
def _activate_invocation_descriptors(self):
"""
Contextmanager about file descriptors used in storlet invocation
NOTE: This context manager now only closes remote side fds,
so you should close local side fds
"""
self._prepare_invocation_descriptors()
try:
yield
finally:
self._close_remote_side_descriptors()
def _prepare_invocation_descriptors(self):
"""
Create all pipse used for Storlet execution
"""
if not self.srequest.has_fd:
self._input_data_read_fd, self._input_data_write_fd = os.pipe()
self.data_read_fd, self.data_write_fd = os.pipe()
self.execution_str_read_fd, self.execution_str_write_fd = os.pipe()
self.metadata_read_fd, self.metadata_write_fd = os.pipe()
for source in self.extra_data_sources:
source['read_fd'], source['write_fd'] = os.pipe()
def _safe_close(self, fds):
"""
Make sure that all of the file descriptors get closed
:param fds: a list of file descriptors
"""
for fd in fds:
try:
os.close(fd)
except OSError as err:
if err.errno != errno.EBADF:
raise
# TODO(kota_): fd might be closed already, so if already
# closed, OSError will be raised. we need more refactor to
# keep clean the file discriptors.
pass
def _close_remote_side_descriptors(self):
"""
Close all of the container side descriptors
"""
fds = [self.data_write_fd, self.metadata_write_fd,
self.execution_str_write_fd]
if not self.srequest.has_fd:
fds.append(self.input_data_read_fd)
fds.extend([source['read_fd'] for source in self.extra_data_sources])
for fd in fds:
os.close(fd)
def _close_local_side_descriptors(self):
"""
Close all of the host side descriptors
"""
fds = [self.data_read_fd, self.metadata_read_fd,
self.execution_str_read_fd]
fds.extend([source['write_fd'] for source in self.extra_data_sources])
self._safe_close(fds)
def _cancel(self):
"""
Cancel on-going storlet execution
"""
with _open_pipe() as (read_fd, write_fd):
dtg = SBusDatagram.create_service_datagram(
sbus_cmd.SBUS_CMD_CANCEL,
write_fd,
None,
self.task_id)
rc = SBus.send(self.storlet_pipe_path, dtg)
if (rc < 0):
raise StorletRuntimeException('Failed to cancel task')
# TODO(takashi): Check the reponse here
os.read(read_fd, 10)
def _invoke(self):
"""
Send an execution command to the remote daemon factory
"""
with self.storlet_logger.activate(),\
self._activate_invocation_descriptors():
self._send_execute_command()
self._wait_for_read_with_timeout(self.execution_str_read_fd)
# TODO(kota_): need an assertion for task_id format
self.task_id = os.read(self.execution_str_read_fd, 10)
os.close(self.execution_str_read_fd)
def _send_execute_command(self):
"""
Send execute command to the remote daemon factory to invoke storlet
execution
"""
dtg = SBusDatagram(
sbus_cmd.SBUS_CMD_EXECUTE,
self.remote_fds,
self.remote_fds_metadata,
self.srequest.params)
rc = SBus.send(self.storlet_pipe_path, dtg)
if (rc < 0):
raise StorletRuntimeException("Failed to send execute command")
def _wait_for_read_with_timeout(self, fd):
"""
Wait while the read file descriptor gets ready
:param fd: File descriptor to read
:raises StorletTimeout: Exception raised when it times out to cancel
the existing task
:raises StorletRuntimeException: Exception raised when it fails to
cancel the existing task
"""
try:
with StorletTimeout(self.timeout):
r, w, e = select.select([fd], [], [])
except StorletTimeout:
exc_type, exc_value, exc_traceback = sys.exc_info()
# When there is a task already running, we should cancel it.
if self.task_id:
try:
self._cancel()
except StorletRuntimeException:
self.logger.warning(
'Task %s timed out, but failed to get canceled'
% self.task_id)
pass
six.reraise(exc_type, exc_value, exc_traceback)
if fd not in r:
raise StorletRuntimeException('Read fd is not ready')
def _read_metadata(self):
"""
Read metadata in the storlet execution result from fd
:returns: a dict of metadata
"""
self._wait_for_read_with_timeout(self.metadata_read_fd)
flat_json = os.read(self.metadata_read_fd, MAX_METADATA_SIZE)
os.close(self.metadata_read_fd)
try:
return json.loads(flat_json)
except ValueError:
self.logger.exception('Failed to load metadata from json')
raise StorletRuntimeException('Got invalid format about metadata')
def _wait_for_write_with_timeout(self, fd):
"""
Wait while the write file descriptor gets ready
:param fd: File descriptor to write
:raises StorletTimeout: Exception raised when it times out to cancel
the existing task
:raises StorletRuntimeException: Exception raised when it fails to
cancel the existing task
"""
with StorletTimeout(self.timeout):
r, w, e = select.select([], [fd], [])
if fd not in w:
raise StorletRuntimeException('Write fd is not ready')
def _close_input_data_descriptors(self):
fds = [self._input_data_read_fd, self._input_data_write_fd]
self._safe_close(fds)
def communicate(self):
try:
self._invoke()
if not self.srequest.has_fd:
self._wait_for_write_with_timeout(self._input_data_write_fd)
# We do the writing in a different thread.
# Otherwise, we can run into the following deadlock
# 1. middleware writes to Storlet
# 2. Storlet reads and starts to write metadata and then data
# 3. middleware continues writing
# 4. Storlet continues writing and gets stuck as middleware
# is busy writing, but still not consuming the reader end
# of the Storlet writer.
eventlet.spawn_n(self._write_input_data,
self._input_data_write_fd,
self.srequest.data_iter)
for source in self.extra_data_sources:
# NOTE(kota_): not sure right now if using eventlet.spawn_n is
# right way. GreenPool is better? I don't get
# whole for the dead lock described in above.
self._wait_for_write_with_timeout(source['write_fd'])
eventlet.spawn_n(self._write_input_data,
source['write_fd'],
source['data_iter'])
out_md = self._read_metadata()
self._wait_for_read_with_timeout(self.data_read_fd)
return StorletResponse(out_md, data_fd=self.data_read_fd,
cancel=self._cancel)
except Exception:
self._close_local_side_descriptors()
if not self.srequest.has_fd:
self._close_input_data_descriptors()
raise
@contextmanager
def _open_writer(self, fd):
try:
writer = os.fdopen(fd, 'w')
except (OSError, TypeError, ValueError):
exc_type, exc_value, exc_traceback = sys.exc_info()
try:
os.close(fd)
except Exception:
# any error is ok to close this operation because even if it
# happens, we cannot do anything.
pass
six.reraise(exc_type, exc_value, exc_traceback)
try:
yield writer
finally:
writer.close()
# NOTE(takashi): writer.close() also closes fd, so we don't have to
# close fd again.
def _write_input_data(self, fd, data_iter):
try:
# double try/except block saving from unexpected errors
try:
with self._open_writer(fd) as writer:
for chunk in data_iter:
with StorletTimeout(self.timeout):
writer.write(chunk)
except (OSError, TypeError, ValueError):
self.logger.exception('fdopen failed')
except IOError:
# this will happen at sort of broken pipe while writer.write
self.logger.exception('IOError with writing fd %s' % fd)
except StorletTimeout:
self.logger.exception(
'Timeout (%s)s with writing fd %s' % (self.timeout, fd))
except Exception:
# _write_input_data is designed to run eventlet thread
# so that we should catch and suppress it here
self.logger.exception('Unexpected error at writing input data')
def setUp(self):
self.log_dir = tempfile.mkdtemp()
self.log_path = tempfile.mktemp(dir=self.log_dir)
self.logger = StorletLogger(self.log_path)
class TestStorletLogger(unittest.TestCase):
def setUp(self):
self.log_dir = tempfile.mkdtemp()
self.log_path = tempfile.mktemp(dir=self.log_dir)
self.logger = StorletLogger(self.log_path)
def tearDown(self):
if os.path.isdir(self.log_dir):
shutil.rmtree(self.log_dir)
def test_open_close(self):
self.assertIsNone(self.logger._file)
self.logger.open()
self.assertIsNotNone(self.logger._file)
self.assertTrue(os.path.isfile(self.log_path))
self.logger.close()
self.assertIsNone(self.logger._file)
# Make sure that log_dir is deleted
shutil.rmtree(self.log_dir)
# As log_dir does not exists, open should create it
self.logger.open()
self.assertIsNotNone(self.logger._file)
self.assertTrue(os.path.isdir(self.log_dir))
self.assertTrue(os.path.isfile(self.log_path))
self.logger.close()
self.assertIsNone(self.logger._file)
# opened twice
self.logger.open()
with self.assertRaises(StorletLoggerError):
self.logger.open()
self.logger.close()
# closed twice
self.logger.open()
self.logger.close()
with self.assertRaises(StorletLoggerError):
self.logger.close()
def test_getfd(self):
self.assertIsNone(self.logger.getfd())
self.logger.open()
self.assertIsNotNone(self.logger.getfd())
self.logger.close()
def test_getsize(self):
self.logger.open()
self.logger._file.write('a' * 1024)
self.logger.close()
self.assertEqual(1024, self.logger.getsize())
