Clustered Computing

Clustered Computing encompasses two primary concepts:

  • High-Performance: the ability of a service to aptly respond to rapidly increasing loads.
  • High-Availability: the ability of a service to be consistently and predictably available.

High Availability: Failover VPS

The failover assigns your VPS to a cluster of high-availability VPS nodes. This ensures that a failure of your primary host node would result in your entire VPS environment being automatically launched on a secondary/backup node, within an average of 1-2 minutes.

We use DRBD to ensure disk storage data consistency between nodes, and to facilitate whole-VPS failover functions.

Is failover for you?

If you are looking to minimize the duration of an outage caused by unexpected total hardware failures, then use of a failover VPS is recommended.

What is DRBD?

The Distributed Replicated Block Device (DRBD) is a Linux Kernel module that constitutes a distributed storage system. You can use DRBD to share block devices between Linux servers and, in turn, share file systems and data.

DRBD implements a block device which can be used for storage and which is replicated from a primary server to one or more secondary servers. The distributed block device is handled by the DRBD service. Writes to the DRBD block device are distributed among the servers. Each DRBD service writes the information from the DRBD block device to a local physical block device (hard disk).

On the primary data writes are written both to the underlying physical block device and distributed to the secondary DRBD services. On the secondary, the writes received through DRBD and written to the local physical block device. On both the primary and the secondary, reads from the DRBD block device are handled by the underlying physical block device. The information is shared between the primary DRBD server and the secondary DRBD server synchronously and at a block level, and this means that DRBD can be used in high-availability solutions where you need failover support.

High Performance: Load Balancing

We utilize various tools to measure utilization, and to automatically move virtual machines among physical servers; ensuring that you will receive the highest possible performance at all times. In the event your VPS is not performing as expected, a Virtual Dedicated Server or Virtual Physical Server may be more appropriate for your needs. Resource allocations are discussed on our support site.