openstack
/
tooz
Code Issues Proposed changes

Try to use PSETEX when possible 

In order to provide more accurate heartbeating expiry we should
try to use the PSETEX command when we can (which supports millisecond
resolution expiry instead of using the SETEX which only supports
second level expiry).

Change-Id: I4f6e6b20ec26d9da03caf508c8e6b4c54c156f93
This commit is contained in:
Joshua Harlow 2014-10-29 18:12:15 -07:00
parent d995cade75
commit c22f2076a0
1 changed files with 15 additions and 4 deletions
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19
tooz/drivers/redis.py
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@ -197,7 +197,7 @@ class RedisDriver(coordination.CoordinationDriver):
self._encoding = encoding[-1]
timeout = options.get('timeout', [self._CLIENT_DEFAULT_SOCKET_TO])
self.timeout = int(timeout[-1])
self.membership_timeout = int(options.get(
self.membership_timeout = float(options.get(
'membership_timeout', timeout)[-1])
lock_timeout = options.get('lock_timeout', [self.timeout])
self.lock_timeout = int(lock_timeout[-1])
@ -341,9 +341,20 @@ class RedisDriver(coordination.CoordinationDriver):
def heartbeat(self):
with _translate_failures():
self._client.setex(self._encode_beat_id(self._member_id),
time=self.membership_timeout,
value=b"Not dead!")
beat_id = self._encode_beat_id(self._member_id)
# Use milliseconds if we can (which are more accurate than
# just seconds); but this PSETEX support was added in 2.6.0 or
# newer so we can only use it then...
supports_psetex, _version = self._check_fetch_redis_version(
'2.6.0', not_existent=False)
if not supports_psetex:
expiry_secs = max(0, int(self.membership_timeout))
self._client.setex(beat_id, time=expiry_secs,
value=b"Not dead!")
else:
expiry_ms = max(0, int(self.membership_timeout * 1000.0))
self._client.psetex(beat_id, time_ms=expiry_ms,
value=b"Not dead!")
for lock in self._acquired_locks:
try:
lock.heartbeat()