Bug: omeroweb takes out exclusive lock on config.xml

[jamoore]

See: ​https://chat.glencoesoftware.com/chatlogs/devteam/2013-05-15.html#11:40:51.566169

On launching bin/omero admin diagnostics from two terminals, it's possible to get the error:

portalocker.LockException: (1, 'Resource temporarily unavailable')

At least one occurrence of this was caused by omeroweb/settings.py taking an exclusive lock on config.xml. By passing exclusive=False to the omero.config.Config constructor, this won't happen.

Note: there may be other code paths that are doing the same thing.

[wmoore]

I noticed a similar issue when doing:

$ bin/omero admin restart

in one terminal window while simultaneously starting web manually in another:

/OmeroWeb/omeroweb $ python manage.py runserver
$ python manage.py runserver
Traceback (most recent call last):
  File "manage.py", line 34, in <module>
    import settings # Assumed to be in the same directory.
  File "/Users/will/Desktop/OMERO/components/tools/OmeroWeb/omeroweb/settings.py", line 146, in <module>
    raise exctype, value
portalocker.LockException: (1, 'Resource temporarily unavailable')

After making the suggested edit, ​https://github.com/will-moore/openmicroscopy/tree/settings.py_locks_config.xml_10905

I no-longer get an error running web server, BUT I do get a new error in OMERO restart terminal

$ bin/omero admin restart                                    # THEN do $ python manage.py runserver in another terminal...
Waiting on shutdown. Use CTRL-C to exit
.No descriptor given. Using etc/grid/default.xml
Waiting on startup. Use CTRL-C to exit
ERROR:ConfigXml:Failed to removed lock file, ignoring
Traceback (most recent call last):
  File "/Users/will/Desktop/OMERO/dist/lib/python/omero/config.py", line 154, in _close_lock
    os.remove("%s.lock" % self.filename)
OSError: [Errno 2] No such file or directory: '/Users/will/Desktop/OMERO/dist/etc/grid/config.xml.lock'

[jamoore]

After attempts by Will, pushing and lowering priority.

[jamoore]

This should now be handled (minimally for web's usage):

• ​https://github.com/openmicroscopy/openmicroscopy/pull/2273
• ​http://trac.openmicroscopy.org.uk/ome/ticket/12002#comment:5