Ensure Sufficient Capacity

Ensure Sufficient Capacity

Successful deployment of any system includes making sure that the server capacity and network capacity is sufficient to support the application.

60East recommends using the capacity planning metrics in the latest version of the AMPS User Guide to ensure sufficient memory, disk, and network capacity.

Notice that the advice in the AMPS User Guide also recommends allowing extra capacity to ensure that the system has "headroom" in the case of unexpected increases in traffic.

Capacity Testing

60East recommends testing capacity estimates by running the system in a test environment with hardware and networking as similar to the production environment as possible. In these tests, it is important to simulate peak production load (often 150-200% or more of the historical peak of the system) to ensure that the system can handle load with the expected SLA.

Work with the consumers of the application to ensure that the application is not doing unnecessary work (for example, publishing messages that no subscriber is expected to consume, or publishing fields that are not used by subscribers).

Capacity for Virtual Machines

There is no difference in the capacity planning guidance for AMPS instances hosted on a virtual machine as compared with AMPS instances hosted on physical hardware.

When the AMPS instance will be deployed on a virtual machine (VM), consider both the capacity needs of the host system as well as the capacity needs of all of the virtual machines hosted on the system. In particular, 60East recommends that the total maximum capacity of all virtual machines hosted on the system, including "headroom" is less than the total capacity available on the host.

In cases where the physical hardware is overprovisioned for the demands of the virtual machines that are hosted on that hardware, performance can suffer. In an overprovisioning situation, AMPS and other applications often see performance degradation due to the physical hardware being unable to meet the demands of the VMs that the hardware hosts.

60East does not recommend overprovisioning systems when using virtual machines. Failing to provide enough capacity for all of the VMs on the physical host operating at peak capacity can lead to inconsistent or degraded performance.