Rackspace Cloud Load balancer with Active/Active and Active/Standby ScaleArc
|Release||Document Status||DB Platform||Categories|
|3.8 or higher||INFO||All||Cluster Settings|
How does ScaleArc work with Rackspace Cloud Load Balancer?
In configuring Active/Active or Active/Passive ScaleArc on Rackspace public cloud, it requires a Rackspace cloud load balancer to be configured to load balance the traffic between the two ScaleArc systems.
To configure the Rackspace cloud load balancer:
1. Create the Rackspace Load Balancer - Networking > Load Balancers > Create Load Balancer
2. Name the load balancer, choose the Region where the ScaleArc systems exist, choose the vip to be placed in the public or private Virtual IP, select the port to be load balanced (TCP:3306, or TCP:1433), Round Robin. Add the ScaleArc cloud server nodes to be load balanced.
3. Configure the health check. This health check is executed on the instance that are being load balanced. It will check the protocol and port is open and available to determine what the status of the instance is. Be careful, you can only have 1 health check per Cloud Load balancer. If you have multiple ScaleArc clusters, all services will be unavailable if the 1 health check is failing.
4. When HA is triggered in ScaleArc, the switchover to the standby is less than a second, however, when using the cloud load balancer, the health check of the load balancer takes some time to complete its check and mark the standby online. We normally recommend 5 second intervals, 5 second timeout with 2 attempts. With these health check settings, we've observed that it could take the load balancer 15-30 seconds to mark the secondary online. The health check is also captured as a connection in ScaleArc analytics and adds some noise to the clinet/server connections graph.
5. Keep in mind, when HA switch occurs, client connections are severed from the active scalearc and will error, then retry on the passive scalearc (once promoted to active). ScaleArc connections to the database servers are transparent.
Configuring ScaleArc Active/Passive HA:
1. SSH to each of the ScaleArc nodes. Change /system/iscloud.txt to value 2:
echo 2 > /system/iscloud.txt
2. Setup HA from the ScaleArc UI: https://support.scalearc.com/kb/articles/2176
If you are experiencing issues with ScaleArc or with any of it's features, please contact ScaleArc Support. We are available 24x7 by phone at 855 800 7225 or +1 408 412 7315. For general support inquiries, you can also e-mail us at email@example.com.
2901 Tasman Drive Santa Clara, CA 95054 | Email: firstname.lastname@example.org