Determining the need for high availability cluster

If you have critical applications then you most likely require a high availability cluster. This is because if you do not have the cluster then you won’t be able to ensure that the applications remain available even when there is a crash. In other words, if the server that you are using to run the applications crashes then consequently you will have to deal with unavailability of the applications. Of course, if you try to fix the server then it will take some time. In the meanwhile, if your applications continue to remain unavailable then you will have to incur losses as far as your business is concerned.

Interestingly, if you have the high availability cluster with you then you won’t have to worry about the aforesaid situations. Just to let you know, the cluster won’t be able to prevent your server from crashing. However, if it is reliable then it will certainly succeed in detecting some of the relevant faults related to hardware as well as software. Of course, timely detection will give you some time to prepare for situations where applications may be unavailable. Nevertheless, the cluster won’t only detect faults but is also likely to restart the applications. Surprisingly, the applications can be easily restarted without any administrative intervention. 

Furthermore, if the cluster is good enough then it can easily take full advantage of another system for restarting the applications. Interestingly, for ensuring that your applications continue to remain available, the cluster may have to configure some things. For example, it might happen that the applications that have stopped running because of the crashed server will only run if some supporting applications continue to run as they were running before the crash. In such a situation, the cluster should do everything that is required for keeping the applications up and running. The bottom line is that without the cluster, your critical applications are unlikely to help you with your business. 

Anyways, if you want that the applications should be continuously available then you’d also have to give some thought to replication. For this, you may start looking for a solution that is not only efficient as far as replication is concerned buy also ensures that your TCO gets reduced. Perhaps if you look for a solution that has the capability of replicating such data and applications that are considered to be a part of shared storage cluster then you’d be able to achieve what is desired or expected.

Making application high availability the least of your worries

Ensuring application high availability (HA) is in your best interest, but only if you have the right solution to do the needful. Otherwise, HA can pose a serious problem, increasing your chances of lagging behind, and providing competitors with an opportunity to do better. However, it is possible to avoid any situation, if you are careful when making the choice and avoid finalizing the first solution, at least not before you have ascertained its viability. Anyways, firstly you must ensure that the solution is fit for the environment you work in; therefore, differentiating between Linux and Windows environments is more or less inevitable.

As soon as you are sure of the environment for which you actually require the solution, you can try and ask for evaluation software, if at all it is available. For this, you may have to be specific and convey that it is application high availability that is on your mind, in order to ensure that only the relevant solution is given to you. Of course, in addition to requesting the evaluation software, you must also ensure that the solution has all or most of the desired characteristics and can come in handy when you are having trouble with HA.

For example, no matter how good the solution is, if it requires you to invest in expensive hardware, you may not want to opt for it especially if with your budgetary constraints, it is not possible for you extend HA to applications in an uneconomical manner. Likewise, you may or may not have experts working for you and can therefore face difficulty in making the most of any solution, especially a complex one. Therefore, looking for a solution that brings in easiness is your only option unless you are sure that complexity will not make the matters worse for you.

Meanwhile, all efforts made to ensure HA, scouring a feasible solution being one of them, can go in vain if you are yet to think about disaster recovery. Therefore, as soon as availability is dealt with, you should start looking for disaster recovery software or may be something that combines the two. Though you can always find out what’s best for your business, wizard-based software is likely to the serve the purpose most of the times. At the same time, if the software not only supports recovery at the basic level, i.e. within LAN's, but also extends its scope to virtualized environments, you are making the right decision.