Difference between revisions of "Neutron/LBaaS/HowToRun"
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replacing <servername> with "server1" and "server2" as appropriate. Once the server is started, you'll see incoming HTTP GET requests.. that's the load balancer health check in action! | replacing <servername> with "server1" and "server2" as appropriate. Once the server is started, you'll see incoming HTTP GET requests.. that's the load balancer health check in action! | ||
− | If you have python installed, you can also create an index.html with the text "server1" or "server2" then in the same directory run | + | If you have python installed, you can also create an index.html with the text "server1" or "server2" then in the same directory run |
+ | |||
+ | <pre>sudo python -m SimpleHTTPServer 80</pre> | ||
Finally, to test real load balancing, from your client, use wget to make sure your requests are load-balanced across server1 and server2 as expected. | Finally, to test real load balancing, from your client, use wget to make sure your requests are load-balanced across server1 and server2 as expected. |
Revision as of 15:04, 16 December 2013
Contents
Getting the Code
LBaaS introduces changes in the following modules: (currently all changes are in master branch)
- quantum
- python-quantumclient
- horizon
- devstack
Devstack Setup
Add the following lines to your localrc:
enable_service q-lbaas
Then run stack.sh
After stack.sh completes you'll be able to manage your Load Balancer via the CLI tools and within Horizon
Ubuntu Packages Setup
Install the quantum-lbaas-agent and haproxy:
sudo apt-get install quantum-lbaas-agent haproxy
Once packages are installed make the directory for the LBaaS service and copy the configuration into place:
sudo mkdir -p /etc/quantum/plugins/services/agent_loadbalancer/ sudo cp /etc/quantum/lbaas_agent.ini /etc/quantum/plugins/services/agent_loadbalancer/lbaas_agent.ini
And edit the service_plugins in [DEFAULT] section in quantum.conf to enable the service:
sudo sed -i.bak "s/\#\ service_plugins\ \=/service_plugins = quantum.plugins.services.agent_loadbalancer.plugin.LoadBalancerPlugin/g" /etc/quantum/quantum.confFinally enable the Load Balancer section in Horizon by editing
/etc/openstack-dashboard/local_settings.pyand changing:
OPENSTACK_QUANTUM_NETWORK = { 'enable_lb': False }
to
OPENSTACK_QUANTUM_NETWORK = { 'enable_lb': True }
Once done restart your Quantum services and Apache to start using.
Topology Setup
Spin up three VMs, two to be servers, and one to be a client.
nova boot --image <image-uuid> --flavor 1 server1 nova boot --image <image-uuid> --flavor 1 server2 nova boot --image <image-uuid> --flavor 1 client
Get the UUID of the private subnet.
neutron subnet-list
Create a Pool:
neutron lb-pool-create --lb-method ROUND_ROBIN --name mypool --protocol HTTP --subnet-id <subnet-id>
Create Members (using the IPs of server1 and server2):
nova list neutron lb-member-create --address <server1-ip> --protocol-port 80 mypool neutron lb-member-create --address <server2-ip> --protocol-port 80 mypool
Create a Healthmonitor and associated it with the pool:
neutron lb-healthmonitor-create --delay 3 --type HTTP --max-retries 3 --timeout 3 neutron lb-healthmonitor-associate <healthmonitor-uuid> mypool
Create a VIP
neutron lb-vip-create --name myvip --protocol-port 80 --protocol HTTP --subnet-id <subnet-id> mypool
note the address for use below.
Validation
We now have two hosts with a load balancer pointed at them, but those hosts are serving up any HTTP content.
A simple trick is to use netcat on the hosts to implement a simple webserver. For example, run:
while true; do echo -e 'HTTP/1.0 200 OK\r\n\r\n<servername>' | sudo nc -l -p 80 ; done
replacing <servername> with "server1" and "server2" as appropriate. Once the server is started, you'll see incoming HTTP GET requests.. that's the load balancer health check in action!
If you have python installed, you can also create an index.html with the text "server1" or "server2" then in the same directory run
sudo python -m SimpleHTTPServer 80
Finally, to test real load balancing, from your client, use wget to make sure your requests are load-balanced across server1 and server2 as expected.
wget -O - http://<server1-ip> wget -O - http://<server2-ip>
Then use wget to hit the VIP IP several times in succession. You should bounce between seeing server1 and server2.
wget -O - http://<vip-ip> wget -O - http://<vip-ip> wget -O - http://<vip-ip> wget -O - http://<vip-ip>
Full list of LBaaS CLI commands is available at Quantum/LBaaS/CLI
Troubleshooting
LBaas is implemented similar to L3 + DHCP using namespaces. You can use "ip netns list" to find the namespace named qlbaas-<pool_id>, and then test connectivity from that namespace.
Use "screen -x stack" to view the q-svc and q-lbaas tabs for errors.
Grep syslog for "haproxy" to see messages from Haproxy (though they are quite cryptic!)