midokura / neutron

Quantum is a virtual network service for Openstack, and a part of Netstack.
http://openstack.org
Apache License 2.0
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Protect contentious transactions with a semaphore #49

Closed davecahill closed 10 years ago

davecahill commented 10 years ago

The create_port and delete_port request generates highly contentious transactions to (de)allocate an unique IP addresses updating a single table. Exclusive Locks work better than transactions to handle concurrency here.

rossella commented 10 years ago

Hey @davecahill just curious....why did you change this code? some problem triggered it?

davecahill commented 10 years ago

Full details at https://midobugs.atlassian.net/browse/MN-908 - short version is that PoC customer had issues launching multiple VMs simultaneously, and this is the fix @takayukiu created for Folsom, works also for Grizzly.