1814dae6b7
SELECT FOR UPDATE expression, which is triggered with the use of the
SQLAlchemy Query object's with_lockmode('update') method, is
detrimental to performance and scalability of the database
performance code in Neutron due to the lock contention it produces.
SELECT FOR UPDATE can be entirely avoided in release_segment methods
with the use of single-shot UPDATE and DELETE expressions, and this
patch clears a number of uses of SELECT FOR UPDATE by consolidating
multiple SQL expressions into one.
Partial-Bug: #1330562
Change-Id: I29ffcafc8d4d73ac1cb50c94df5da85514d47a3f
# -- Welcome!
You have come across a cloud computing network fabric controller. It has identified itself as "Neutron." It aims to tame your (cloud) networking!
# -- External Resources:
The homepage for Neutron is: http://launchpad.net/neutron . Use this site for asking for help, and filing bugs. Code is available on github at <http://github.com/openstack/neutron>.
The latest and most in-depth documentation on how to use Neutron is available at: <http://docs.openstack.org>. This includes:
Neutron Administrator Guide http://docs.openstack.org/trunk/openstack-network/admin/content/
Neutron API Reference: http://docs.openstack.org/api/openstack-network/2.0/content/
The start of some developer documentation is available at: http://wiki.openstack.org/NeutronDevelopment
For help using or hacking on Neutron, you can send mail to <mailto:openstack-dev@lists.openstack.org>.