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Chapter 15. Configure Load Balancing-as-a-Service with the Networking LBaaSv2 API

15.1. Overview of LBaaS

Load Balancing-as-a-Service (LBaaS) enables OpenStack Networking to distribute incoming requests evenly between designated instances. Complete the steps in this section to configure OpenStack Networking to use LBaaS with the Open vSwitch (OVS) plug-in.

Load Balancing-as-a-Service (LBaaS) enables OpenStack Networking to distribute incoming requests evenly between designated instances. This ensures the workload is shared predictably among instances, and allows more effective use of system resources. Incoming requests are distributed using one of the following load balancing methods:

  • Round robin - Rotates requests evenly between multiple instances.
  • Source IP - Requests from a unique source IP address are consistently directed to the same instance.
  • Least connections - Allocates requests to the instance with the least number of active connections.

Table 15.1. LBaaS features

FeatureDescription

Monitors

LBaaS provides availability monitoring with the PING, TCP, HTTP and HTTPS GET methods. Monitors determine whether pool members are available to handle requests.

Management

LBaaS is managed using a variety of tool sets. The REST API is available for programmatic administration and scripting. Users perform administrative management of load balancers through either the CLI (neutron) or the OpenStack dashboard.

Connection limits

Ingress traffic can be shaped with connection limits. This feature allows workload control and can also assist with mitigating DoS (Denial of Service) attacks.

Session persistence

LBaaS supports session persistence by ensuring incoming requests are routed to the same instance within a pool of multiple instances. LBaaS supports routing decisions based on cookies and source IP address.

Note

LBaaS is currently supported only with IPv4 addressing.

15.2. OpenStack Networking and LBaaS Topology

OpenStack Networking (neutron) services can be broadly classified into two categories.

Neutron API server - This service runs the OpenStack Networking API server, which has the main responsibility of providing an API for end users and services to interact with OpenStack Networking. This server also has the responsibility of interacting with the underlying database to store and retrieve tenant network, router, and loadbalancer details, among others.

Neutron Agents - These are the services that deliver various network functionality for OpenStack Networking.

  • neutron-dhcp-agent - manages DHCP IP addressing for tenant private networks.
  • neutron-l3-agent - facilitates layer 3 routing between tenant private networks, the external network, and other networks.
Note

The neutron-lbaasv2-agent (with HAProxy) is deprecated. For the preferred load-balancing reference implementation with octavia, see the Using Octavia for Load Balancing-as-a-Service guide.

The following diagram shows the flow of HTTPS traffic through to a pool member:

lbaas

15.2.1. Support Status of LBaaS

  • LBaaS v1 API was removed in version 10.
  • LBaaS v2 API is deprecated and removed after Red Hat OpenStack Platform 13. (Octavia is the replacement.)
  • LBaaS deployment is not currently supported in Red Hat OpenStack Platform director.
Note

The neutron-lbaasv2-agent (with HAProxy) is deprecated. For the preferred load-balancing reference implementation with Octavia, see the Using Octavia for Load Balancing-as-a-Service guide. The neutron-lbaas RPMs are still available to support the API for third-party plugin support.

15.3. Configuring LBaaS

This procedure configures OpenStack Networking (neutron) to use LBaaS with the Open vSwitch (OVS) plugin.

Note

Perform these steps on nodes running the neutron-server service:

Procedure

On the Controller node (API Server):

  1. Enable LBaaS: 

    # yum install openstack-neutron-lbaas -y

  2. Add the LBaaS tables to the neutron database: 

    $ neutron-db-manage --subproject neutron-lbaas --config-file /var/lib/config-data/neutron/etc/neutron/neutron.conf --config-file /var/lib/config-data/neutron/etc/neutron/plugins/ml2/ml2_conf.ini upgrade head

  3. Change the service provider in /var/lib/config-data/neutron/etc/neutron/neutron_lbaas.conf. In the [service providers] section, comment out (#) all entries except for this entry: 

    service_provider=LOADBALANCERV2:Haproxy:neutron_lbaas.drivers.haproxy.plugin_driver.HaproxyOnHostPluginDriver:default

  4. In /var/lib/config-data/neutron/etc/neutron/neutron.conf, confirm that you have the LBaaS v2 plugin configured in service_plugins: 

    service_plugins=neutron_lbaas.services.loadbalancer.plugin.LoadBalancerPluginv2

    You can also expect to see any other plugins you have previously added.

    Note

    If you have lbaasv1 configured, replace it with the above setting for lbaasv2.

  5. In /var/lib/config-data/neutron/etc/neutron/lbaas_agent.ini, add the following to the [DEFAULT] section: 

    ovs_use_veth = False
interface_driver =neutron.agent.linux.interface.OVSInterfaceDriver

  6. In /var/lib/config-data/neutron/etc/neutron/services_lbaas.conf, add the following to the [haproxy] section: 

    user_group = haproxy

    1. Comment out any other device driver entries.

      Note

      If the l3-agent is in a failed mode, see the l3_agent log files. You may need to edit /var/lib/config-data/neutron/etc/neutron/neutron.conf and comment out certain values in [DEFAULT], and uncomment the corresponding values in oslo_messaging_rabbit, as described in the log file.

  7. Configure the LbaaS services, and review their status:

    1. Stop the lbaasv1 services and start lbaasv2: 

      # systemctl disable neutron-lbaas-agent.service
# systemctl stop neutron-lbaas-agent.service
# systemctl mask neutron-lbaas-agent.service
# systemctl enable neutron-lbaasv2-agent.service
# systemctl start neutron-lbaasv2-agent.service

    2. Review the status of lbaasv2: 

      # systemctl status neutron-lbaasv2-agent.service

    3. Restart neutron-server and check the status: 

      # systemctl restart neutron-server.service
# systemctl status neutron-server.service

    4. Check the Loadbalancerv2 agent: 

      $ openstack network agent list