[ZODB-Dev] persistent client caches okay to use again in ZODB 3.9.6?
Chris Withers
chris at simplistix.co.uk
Wed Oct 13 20:28:26 EDT 2010
On 12/10/2010 17:56, Jim Fulton wrote:
> Currently the only configuration "docs" are in the .xml Alan provided a link to.
>
> The best size will depend on the app.
Is there a downside to "too big", provided there's plenty of disk space
free on the app servers?
> There are some docs in
> http://svn.zope.org/ZODB/trunk/doc/, although I don't know if they're accurate.
...yeah, those look a lot like the original docs that Guido(?) wrote.
> In ZODB 3.10, the cache tracing analysis tools actually work and produce
> meaningful numbers if you start tracing with an empty cache.
Okay, does that mean the stuff that's documented should be ignored for
ZODB 3.9?
I went for the following in the end:
...
cache-size 200Mb
client app
wait on
</zeoclient>
mount-point /
cache-size 50000
cache-size-bytes 500Mb
Any obvious issues with that?
One problem I did hit, though, was if I restarted an app server, I got:
File
"/var/buildout-eggs/ZODB3-3.9.6-py2.6-linux-i686.egg/ZODB/config.py",
line 210, in open
**options)
File
"/var/buildout-eggs/ZODB3-3.9.6-py2.6-linux-i686.egg/ZEO/ClientStorage.py",
line 395, in __init__
self._cache = self.ClientCacheClass(cache_path, size=cache_size)
File
"/var/buildout-eggs/ZODB3-3.9.6-py2.6-linux-i686.egg/ZEO/cache.py", line
194, in __init__
self._lock_file = zc.lockfile.LockFile(path + '.lock')
File
"/var/buildout-eggs/zc.lockfile-1.0.0-py2.6.egg/zc/lockfile/__init__.py", line
76, in __init__
_lock_file(fp)
File
"/var/buildout-eggs/zc.lockfile-1.0.0-py2.6.egg/zc/lockfile/__init__.py", line
59, in _lock_file
raise LockError("Couldn't lock %r" % file.name)
LockError: Couldn't lock '....zec.lock'
...and yet the app server came up fine. What does this error message imply?
The above did not, however, occur if I stopped and then started the app
server...
Race condition?
Chris
--
Simplistix - Content Management, Batch Processing & Python Consulting
- http://www.simplistix.co.uk
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