Choosing High Availability Hosting
A VPS or virtualized private server is a system in which you operate your website on a virtual system that works like a private server. What works like your own server may actually be located on several individual machines. If you are paying for 8 GBs of storage, you may be getting four two byte parcels. Usually, VPS servers are fairly low demand systems. Most of the time, you can only access the amount of storage and processing you paid for. However, in emergencies, the VPS system can steal resources temporarily from other VPS systems, leading to some of the same reliability problems as conventional shared servers. In theory, if you are paying for eight GB of RAM, you may sometimes find yourself getting only six GB. The VPS system is less expensive than the dedicated server, however if you expect to grow your site significantly, you may find that the partitioning off of a physical server really limits your upgrade options.
For higher levels of use, to avoid some bottlenecks, a dedicated server may be an alternative. These solutions are considerably more expensive than a shared server system, but make a reasonable expectation of reliability and efficiency possible. The dedicated server means that your website will have its own server system and that resources are no longer shared. Dedicated servers will allow considerably more traffic and use at higher speeds than a shared server, without variation due to traffic overload.
Dedicated servers do have limited scalability. The limitations of the server are the limitations of your growth potential. Dedicated servers can never guarantee continuous availability. Any malfunction of the server will mean that your site becomes unavailable at least temporarily. Those with active commercial sites that require close to 100% availability may find the reliability of dedicated servers inadequate.
High availability (HA) hosting is a promise offered by server hosts. The promise, offered in the sales agreement, is that your website or hosted content will never be inaccessible, always online. Keeping this promise requires
- a special connection via a router,
- power,
- cooling
- and other special hardware.
It requires high redundancy using additional equipment to cover against possible failure or malfunction, with the software that instantaneously switches to backup. The promise requires that expensive equipment be installed, equipment that will not be used most of the time, or maybe never.
Thus, dedicated servers offering high availability guarantees are usually very expensive.
Cloud hosting simplifies the problem of high availability because redundancy is part of the architecture of the cloud. In the cloud, your entire web hosting account is stored in a virtualized container that could span many pieces of real hardware. High quality cloud providers make use of VMware for virtualization. Cloud hosting is always fully redundant within a network. In the event of an individual hardware failure your data is instantaneously moved to backup servers.
High availability server users can expect better than 99% reliability. For most, 99% reliability, which means the site could be down nearly 2 hours a week, is not adequate. The standard promise of high reliability servers is reliability of 99.99% or better which means a chance of 10 minutes of disruption a week.
Applied Innovations have been cloud hosting experts since 2008. Please contact us to see how we can help you.
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