openstack/swift
Code Issues Proposed changes

New log_max_line_length option.

Browse Source 
Log lines can get quite large, as we previously noticed with rsync error
log lines. We added a setting to cap those, but it really looks like we
should have just done this overall limit. We noticed the issue when we
switched to UDP syslogging and it would occasionally blow past the 16436
lo MTU! This causes Python's logging code to get an error and hilarity
ensues.

Change-Id: I44bdbe68babd58da58c14360379e8fef8a6b75f7
This commit is contained in:
gholt 2014-05-22 19:37:53 +00:00
parent 553007865f
commit 2d00f7b7ba
10 changed files with 114 additions and 3 deletions
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13
doc/source/deployment_guide.rst
View File

@ -367,6 +367,9 @@ max_clients 1024 Maximum number of clients one worker can
concurrently.
disable_fallocate false Disable "fast fail" fallocate checks if the
underlying filesystem does not support it.
log_max_line_length 0 Caps the length of log lines to the
value given; no limit if set to 0, the
default.
log_custom_handlers None Comma-separated list of functions to call
to setup custom log handlers.
eventlet_debug false If true, turn on debug logging for eventlet
@ -566,6 +569,9 @@ max_clients 1024 Maximum number of clients one worker can
user swift User to run as
disable_fallocate false Disable "fast fail" fallocate checks if the
underlying filesystem does not support it.
log_max_line_length 0 Caps the length of log lines to the
value given; no limit if set to 0, the
default.
log_custom_handlers None Comma-separated list of functions to call
to setup custom log handlers.
eventlet_debug false If true, turn on debug logging for eventlet
@ -695,6 +701,9 @@ db_preallocation off If you don't mind the extra disk space usage in
fragmentation.
disable_fallocate false Disable "fast fail" fallocate checks if the
underlying filesystem does not support it.
log_max_line_length 0 Caps the length of log lines to the
value given; no limit if set to 0, the
default.
log_custom_handlers None Comma-separated list of functions to call
to setup custom log handlers.
eventlet_debug false If true, turn on debug logging for eventlet
@ -825,6 +834,10 @@ cors_allow_origin This is a list of hosts that
Access-Control-Allow-Origin
header in addition to what
the container has set.
log_max_line_length 0 Caps the length of log
lines to the value given;
no limit if set to 0, the
default.
log_custom_handlers None Comma separated list of functions
to call to setup custom log
handlers.

12
doc/source/logs.rst
View File

@ -8,6 +8,18 @@ overview, Swift's logs are sent to syslog and organized by log level and
syslog facility. All log lines related to the same request have the same
transaction id. This page documents the log formats used in the system.
.. note::
By default, Swift will log full log lines. However, with the
``log_max_line_length`` setting and depending on your logging server
software, lines may be truncated or shortened. With ``log_max_line_length <
7``, the log line will be truncated. With ``log_max_line_length >= 7``, the
log line will be "shortened": about half the max length followed by " ... "
followed by the other half the max length. Unless you use exceptionally
short values, you are unlikely to run across this with the following
documented log lines, but you may see it with debugging and error log
lines.
----------
Proxy Logs
----------

3
etc/account-server.conf-sample
View File

@ -21,6 +21,9 @@
# log_facility = LOG_LOCAL0
# log_level = INFO
# log_address = /dev/log
# The following caps the length of log lines to the value given; no limit if
# set to 0, the default.
# log_max_line_length = 0
#
# comma separated list of functions to call to setup custom log handlers.
# functions get passed: conf, name, log_to_console, log_route, fmt, logger,

3
etc/container-server.conf-sample
View File

@ -27,6 +27,9 @@
# log_facility = LOG_LOCAL0
# log_level = INFO
# log_address = /dev/log
# The following caps the length of log lines to the value given; no limit if
# set to 0, the default.
# log_max_line_length = 0
#
# comma separated list of functions to call to setup custom log handlers.
# functions get passed: conf, name, log_to_console, log_route, fmt, logger,

3
etc/drive-audit.conf-sample
View File

@ -3,6 +3,9 @@
# log_facility = LOG_LOCAL0
# log_level = INFO
# log_address = /dev/log
# The following caps the length of log lines to the value given; no limit if
# set to 0, the default.
# log_max_line_length = 0
# minutes = 60
# error_limit = 1
#

3
etc/object-expirer.conf-sample
View File

@ -6,6 +6,9 @@
# log_facility = LOG_LOCAL0
# log_level = INFO
# log_address = /dev/log
# The following caps the length of log lines to the value given; no limit if
# set to 0, the default.
# log_max_line_length = 0
#
# comma separated list of functions to call to setup custom log handlers.
# functions get passed: conf, name, log_to_console, log_route, fmt, logger,

3
etc/object-server.conf-sample
View File

@ -23,6 +23,9 @@
# log_facility = LOG_LOCAL0
# log_level = INFO
# log_address = /dev/log
# The following caps the length of log lines to the value given; no limit if
# set to 0, the default.
# log_max_line_length = 0
#
# comma separated list of functions to call to setup custom log handlers.
# functions get passed: conf, name, log_to_console, log_route, fmt, logger,

3
etc/proxy-server.conf-sample
View File

@ -41,6 +41,9 @@
# log_level = INFO
# log_headers = false
# log_address = /dev/log
# The following caps the length of log lines to the value given; no limit if
# set to 0, the default.
# log_max_line_length = 0
#
# This optional suffix (default is empty) that would be appended to the swift transaction
# id allows one to easily figure out from which cluster that X-Trans-Id belongs to.

19
swift/common/utils.py
View File

@ -1023,10 +1023,15 @@ class LogAdapter(logging.LoggerAdapter, object):
class SwiftLogFormatter(logging.Formatter):
"""
Custom logging.Formatter will append txn_id to a log message if the record
has one and the message does not.
Custom logging.Formatter will append txn_id to a log message if the
record has one and the message does not. Optionally it can shorten
overly long log lines.
"""
def __init__(self, fmt=None, datefmt=None, max_line_length=0):
logging.Formatter.__init__(self, fmt=fmt, datefmt=datefmt)
self.max_line_length = max_line_length
def format(self, record):
if not hasattr(record, 'server'):
# Catch log messages that were not initiated by swift
@ -1058,6 +1063,12 @@ class SwiftLogFormatter(logging.Formatter):
record.levelno != logging.INFO and
record.client_ip not in msg):
msg = "%s (client_ip: %s)" % (msg, record.client_ip)
if self.max_line_length > 0 and len(msg) > self.max_line_length:
if self.max_line_length < 7:
msg = msg[:self.max_line_length]
else:
approxhalf = (self.max_line_length - 5) / 2
msg = msg[:approxhalf] + " ... " + msg[-approxhalf:]
return msg
@ -1071,6 +1082,7 @@ def get_logger(conf, name=None, log_to_console=False, log_route=None,
log_facility = LOG_LOCAL0
log_level = INFO
log_name = swift
log_max_line_length = 0
log_udp_host = (disabled)
log_udp_port = logging.handlers.SYSLOG_UDP_PORT
log_address = /dev/log
@ -1096,7 +1108,8 @@ def get_logger(conf, name=None, log_to_console=False, log_route=None,
logger = logging.getLogger(log_route)
logger.propagate = False
# all new handlers will get the same formatter
formatter = SwiftLogFormatter(fmt)
formatter = SwiftLogFormatter(
fmt=fmt, max_line_length=int(conf.get('log_max_line_length', 0)))
# get_logger will only ever add one SysLog Handler to a logger
if not hasattr(get_logger, 'handler4logger'):

55
test/unit/common/test_utils.py
View File

@ -702,6 +702,61 @@ class TestUtils(unittest.TestCase):
logger.logger.removeHandler(handler)
reset_loggers()
def test_swift_log_formatter_max_line_length(self):
# setup stream logging
sio = StringIO()
logger = utils.get_logger(None)
handler = logging.StreamHandler(sio)
formatter = utils.SwiftLogFormatter(max_line_length=10)
handler.setFormatter(formatter)
logger.logger.addHandler(handler)
def strip_value(sio):
v = sio.getvalue()
sio.truncate(0)
return v
try:
logger.info('12345')
self.assertEqual(strip_value(sio), '12345\n')
logger.info('1234567890')
self.assertEqual(strip_value(sio), '1234567890\n')
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '12 ... de\n')
formatter.max_line_length = 11
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '123 ... cde\n')
formatter.max_line_length = 0
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '1234567890abcde\n')
formatter.max_line_length = 1
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '1\n')
formatter.max_line_length = 2
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '12\n')
formatter.max_line_length = 3
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '123\n')
formatter.max_line_length = 4
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '1234\n')
formatter.max_line_length = 5
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '12345\n')
formatter.max_line_length = 6
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '123456\n')
formatter.max_line_length = 7
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '1 ... e\n')
formatter.max_line_length = -10
logger.info('1234567890abcde')
self.assertEqual(strip_value(sio), '1234567890abcde\n')
finally:
logger.logger.removeHandler(handler)
reset_loggers()
def test_swift_log_formatter(self):
# setup stream logging
sio = StringIO()