OpenStack OVS/OVN QoS

Neutron ML2/OVN and Placement API (minimum bandwidth scheduling)

Do you know how Nova knows where to spawn a virtual machine? With the Nova scheduler service. This service allows to define a set of filters that should match with the host resources in order to define and spawn the virtual machines. Since Newton (a log time ago…) a new resource tracker was introduced: the […]

OpenStack OVS/OVN

ML2/OVN mechanism driver and the “secret agents”

Today’s topic is related to the OVN backend driver in OpenStack Neutron. This is the last in-tree ML2 driver added, initially deployed as an external plugin. From the website, “OVN (Open Virtual Network) is a series of daemons for the Open vSwitch that translate virtual network configurations into OpenFlow”. OVN is based on Open […]

L3/routing OpenStack

Routing two external networks

Welcome back! Unlike other posts in this blog, used to advertise my own achievements in OpenStack (really?, how you dare), this post will help you to understand how can you connect one virtual machine to two external networks. Of course, avoiding the direct approach of directly creating two ports on each network. No, let’s do […]

High availability (HA) OpenStack OVS/OVN

High availability router gateway ports in OVN

Today’s post is… a bit dense, I will admit. And to make things a bit more complex, I’m going to talk about the external ports too but for a reason. Actually this post comes from a bug (no way!) that claims that the external ports are usually bound to chassis different to the router gateway […]

DHCP OpenStack

Reduce the Neutron DHCP agent redundancy

How long have you been waiting when the DHCP agent service was restarted? If you raised your hand and shouted “too long!”, this is your post. OpenStack Neutron DHCP agent. From the Red Hat OSP16 documentation, “the OpenStack Networking DHCP agent manages the network namespaces that are spawned for each project network to act as […]

Database OpenStack

Neutron’s quota driver

Some months ago I implemented a new Neutron’s quota driver. The aim of this new driver, as described in the Launchpad bug 1926787 and Bugzilla bug 1955661, was to avoid the permanent database lock contention status generated when using the Neutron’s quota engine. Why that was happening? Follow me… What do we need to count? […]

OpenStack RabbitMQ

Debugging RabbitMQ issues in OpenStack

Let’s start this new post entry in “professor” mode, doing a statement: “AMQP is the messaging technology chosen by the OpenStack cloud“. This link refers to Nova but is valid for any other OpenStack project. AMQP is used to facilitate the inter process communication. For example, if the Neutron DHCP agent needs to retrieve some […]

OpenStack Tech

Testing Keepalived

Welcome back! I just finished my lethargic aestival period, emerging from the swimming pool like a manatee. Back to the (awaited) office routine, I had a clash with Keepalived; actually with around four hundred instances. Yes, 400 instances spawned to control the same number of high availability routers in OpenStack. The OpenStack L3 agent is […]


ovsdbapp, your library for Open vSwitch and OVN

The first thing you will notice reviewing the code of this library is a common pattern: Terry Wilson, one of the fathers of the creature. It has many other contributors, but he is the main maintainer. Thanks! This library provides a Python native implementation to access to the Open vSwitch database, using the OVSDB management […]

OpenStack Tech

Network namespaces and containers

Openstack can be deployed in several ways. For example, for testing and development, devstack is used. For production environments, Kolla-Ansible provides a set of tools to define, create and deploy a set of containers running the needed services. TripleO is another deployment tool that can be configured to run the services on containers. Neutron, the […]