In my earlier post about concurrency control I mentioned that due to the exponential characteristic of response time with increasing concurrency it is better to potentially reject the extra requests than letting them negatively affect your system. While rejecting these requests is an option it is not the most desirable option. Request Queuing offers a [...]
Filed under: High Availability, operations, Software As A Service | Tagged: concurrency control, ha, request queue | 7 Comments »
One important high availability principle is concurrency control. The idea is to allow only that much traffic through to your system which your system can handle successfully. For example: if your system is certified to handle a concurrency of 100 then the 101st request should either timeout, be asked to try later or wait until [...]
Filed under: High Availability, operations, Software As A Service | Tagged: ha, operations, saas | 3 Comments »
In many instances I have heard people discussing and then trying to measure the mean time between failures -(MTBF) of components in their architectures. While this may be an interesting exercise it is typically misguided. The focus needs to be toward measuring the mean time to recovery (MTTR) after failure. Assume the failure. Going through [...]
Filed under: High Availability, Software As A Service | Tagged: ha, operations, saas | 5 Comments »
I contend that Software As a Service offerings are not less reliable than on premise solutions as measured by uptime. As an example lets compare the following scenarios Scenario 1 : SaaS Lets assume that a SaaS provider has 1,000 customers. Lets assume that this provider has a track record of 1 severe outage every [...]
Filed under: Software As A Service | Tagged: ha, operations, saas | 4 Comments »
