Autoscaling with Xen or XenServer

Question

I need to learn how to implement autoscaling with a Xen platform or Citrix XenServer, just like it works on AWS. I made a search on Google, but I could not find something about that.

If my question is too broad and there's no a simple answer like "Enable feature X", I will appreciate your advice about what I should research to do it.

Answer 1

No with only XenServer, you can enable WLB but it's only to distribute your host resource better between your VM.

CloudPlatform is the product Citrix sell for that. (autoscale with your host)

Check step 3. You see that it manage your host.

When the CloudPlatform user submits the AutoScale configuration, the following events occur:

1. CloudPlatform uses the NetScaler NITRO API to push the AutoScale configuration to the NetScaler appliance, creating AutoScale-related entities on the appliance. The entities include a load balancing virtual server, a service group, and monitors.
2. The AutoScale engine on the NetScaler appliance sends API requests to CloudPlatform to initially deploy the minimum number of virtual machines required.
3. CloudPlatform provisions the minimum number of instances (VMs) on the hypervisors (virtualization hosts) that it manages.
4. The NetScaler appliance discovers the IP addresses assigned by CloudPlatform to the newly created VMs and binds them, as services, to the service group representing them. The NetScaler appliance can then load balance traffic to the VMs.
5. NetScaler monitors bound to the service group start monitoring the load by collecting SNMP metrics from the instances.
6. The AutoScale engine on the NetScaler appliance monitors the metrics collected from the VMs and triggers scale-up and scale-down events whenever the metrics breach the configured threshold for the specified period. As part of the scale-up trigger, the NetScaler AutoScale engine sends an API request to CloudPlatform to deploy a new VM. After the virtual machine is deployed, the AutoScale engine binds the service representing the VM (IP address and port) to the service group and, after the configured quiet time, starts forwarding load balanced traffic to the new virtual machine. Likewise, as part of the scale-down trigger, the NetScaler AutoScale engine selects a VM, stops forwarding new requests to that instance, and waits for the configured quiet time (to allow for the processing of current requests to complete) before it sends an API request to CloudPlatform to destroy the chosen instance.

In this way, the NetScaler appliance monitors the application and triggers scale-up and scale-down events on the basis of application load and/or performance.