desktopcouch can start multiple times leading to several running couchdbs

[Roman Yepishev]

ubuntuone-preferences and ubuntuone-login both wait for CredentialsFound signal (in Lucid).
Both processes will interact with couchdb upon receiving of the signal, the first one will read replication exclusion, the latter will put a pairing record to the db.

It turns out that they are running so head-to-head that they initialize 2 desktopcouches. Desktopcouch checks the pid and if it is not there it will start the couchdb, however, since there are 2 simultaneous calls both processes start their own couchdb. Eventually only one pid will be written to the file, and only one couchdb will be contacted (because of dbus response being returned only by one desktopcouch instance)

This bug prevents CouchDB pairing with Ubuntu One from working consistently, which prevents users from syncing contacts and bookmarks in Lucid with CouchDB from backports installed.

TEST CASE:
1. Ensure that no couchdb and desktopcouch-service processes are running:
1.1 /usr/lib/desktopcouch/desktopcouch-stop
1.2 killall desktopcouch-service
1.3 killall beam
1.4 killall beam.smp
2. Ensure that ubuntuone-syncdaemon is running (we need ubuntuone-login to be running to test for double start)
3. Open ubuntuone-preferences from terminal
4. Run sudo netstat -lntp | grep beam, there should be only one process with beam / beam.smp
5. Verify that there is only one "Apache CouchDB has started on http://127.0.0.1:$port" line in ~/.cache/desktop-couch/desktop-couchdb.log.1

[Clint Byrum (clint-fewbar)]

APPROVED: the package uploaded to lucid-proposed should be accepted.

[Martin Pitt (pitti)]

Accepted desktopcouch into lucid-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

[Pedro Villavicencio (pedro)]

I've verified the desktopcouch proposed package, with the new version of proposed you indeed see just one beam process, same goes for the "Apache couchdb *" line on the logs, marking this as verification-done; thanks a lot for the fix.

[Launchpad Janitor (janitor)]

This bug was fixed in the package desktopcouch - 0.6.4-0ubuntu3.2

---------------
desktopcouch (0.6.4-0ubuntu3.2) lucid-proposed; urgency=low

  * Add debian/patches/lp_726597.patch
    - Avoid race for startup of couchdb (LP: #726597)
 -- Chad MILLER <email address hidden> Thu, 03 Mar 2011 11:06:01 -0500