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<p>Hi list,</p>
<p> </p>
<p>I've got a bit of a bizarre issue with MapServer holding locks on MapProxy tiles.</p>
<p> </p>
<p>Our setup is: 4 x Windows Server 2008 running MapProxy 1.5.0 via WSGI in Apache, 1 x Windows Server 2008 running mapproxy-seed.exe in scheduled tasks, 1 x Windows Server 2008 storing the .yaml config files.</p>
<p> </p>
<p>Our four MapProxy instances are using sources of the WMS type that point back to the MapServer .exe locally i.e.
<a href="http://localhost/cgi-bin/mapserv.exe?map=something.map">http://localhost/cgi-bin/mapserv.exe?map=something.map</a></p>
<p> </p>
<p>In our log files from MapProxy and from mapproxy-seed we're periodically getting errors from lock.py line 124, e.g.</p>
<p> </p>
<p>[12:17:04] 7 75.00% 13775786.98567, -5465442.18332, 15654303.39280, -5009377.0<br>
8570 (477 tiles) ETA: 2013-01-07-12:17:25<br>
Exception in thread Thread-2:<br>
Traceback (most recent call last):<br>
File "C:\Python27\Lib\threading.py", line 554, in __bootstrap_inner<br>
self.run()<br>
File "c:\pythonenv\mapproxy-srss\lib\site-packages\mapproxy-1.5.0a_20130107-py<br>
2.7.egg\mapproxy\seed\seeder.py", line 92, in run<br>
self.work_loop()<br>
File "c:\pythonenv\mapproxy-srss\lib\site-packages\mapproxy-1.5.0a_20130107-py<br>
2.7.egg\mapproxy\seed\seeder.py", line 104, in work_loop<br>
exceptions=(SourceError, IOError), ignore_exceptions=(LockTimeout, ))<br>
File "c:\pythonenv\mapproxy-srss\lib\site-packages\mapproxy-1.5.0a_20130107-py<br>
2.7.egg\mapproxy\seed\util.py", line 222, in exp_backoff<br>
result = func(*args, **kw)<br>
File "c:\pythonenv\mapproxy-srss\lib\site-packages\mapproxy-1.5.0a_20130107-py<br>
2.7.egg\mapproxy\cache\tile.py", line 126, in load_tile_coords<br>
created_tiles = creator.create_tiles(uncached_tiles)<br>
File "c:\pythonenv\mapproxy-srss\lib\site-packages\mapproxy-1.5.0a_20130107-py<br>
2.7.egg\mapproxy\cache\tile.py", line 227, in create_tiles<br>
created_tiles = self._create_meta_tiles(meta_tiles)<br>
File "c:\pythonenv\mapproxy-srss\lib\site-packages\mapproxy-1.5.0a_20130107-py<br>
2.7.egg\mapproxy\cache\tile.py", line 300, in _create_meta_tiles<br>
created_tiles.extend(self._create_meta_tile(meta_tile))<br>
File "c:\pythonenv\mapproxy-srss\lib\site-packages\mapproxy-1.5.0a_20130107-py<br>
2.7.egg\mapproxy\cache\tile.py", line 307, in _create_meta_tile<br>
with self.tile_mgr.lock(main_tile):<br>
File "c:\pythonenv\mapproxy-srss\lib\site-packages\mapproxy-1.5.0a_20130107-py<br>
2.7.egg\mapproxy\cache\tile.py", line 143, in lock<br>
return self.cache.lock(tile)<br>
File "c:\pythonenv\mapproxy-srss\lib\site-packages\mapproxy-1.5.0a_20130107-py<br>
2.7.egg\mapproxy\cache\base.py", line 115, in lock<br>
cleanup_lockdir(self.lock_dir, force=False)<br>
File "c:\pythonenv\mapproxy-srss\lib\site-packages\mapproxy-1.5.0a_20130107-py<br>
2.7.egg\mapproxy\platform\cpython\lock.py", line 124, in cleanup_lockdir<br>
raise e<br>
WindowsError: [Error 32] The process cannot access the file because it is being<br>
used by another process: '\\\\10.0.0.70\\c_drive\\mapproxy\\cache\\layer7_fhs_la<br>
st_0_72.shp_EPSG900913\\tile_locks\\1d5b8827382a79fba940cc62e989aead-14883-6072-<br>
14.lck'</p>
<p> </p>
<p>Using Process Explorer I've managed to track the file locks down to the mapserv.exe process. In a typical case mapserv.exe will have locks on a PNG and a few of the .lck files. My understanding was that there's no link between the sources and the PNG tiles
that MapProxy creates, so I'm at somewhat of a loss as to how mapserv.exe can come to have any knowledge of these PNG and .lck files.</p>
<p> </p>
<p>One pretty out-there thought we've had was that perhaps it's something to do with mapproxy-seed, Apache, and MapProxy all using the same user account and somehow because of that there's some shared file handle issue.</p>
<p> </p>
<p>Am I missing something obvious here? :)</p>
<p> </p>
<p>Cheers,</p>
<p> </p>
<p>Keith</p>
<p> </p>
<div style="FONT-FAMILY: Tahoma; FONT-SIZE: 13px">__________________________________
<br>
Keith Moss<br>
Satellite Remote Sensing Services<br>
Operations<br>
Landgate<br>
65 Brockway Road, FLOREAT WA 6014<br>
PO Box 741 Wembley WA 6913<br>
Ph. (08) 9387 0332 | Fx. (08) 9383 7142<br>
<a tabindex="0" href="mailto:keith.moss@landgate.wa.gov.au" target="">keith.moss@landgate.wa.gov.au</a><br>
<a tabindex="0" href="http://www.landgate.wa.gov.au/" target="">http://www.landgate.wa.gov.au/</a></div>
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