How Fast Are Your Web Services?

By Author: Joseph Mathew
Total Articles: 11
Comment this article

Every day we rely on services provided by other people. Making a phone call, getting a car fixed, and ordering a pizza are all dependent on services. The more dependent we are on these services, the more we are waiting on other organizations and other people, and the more our productivity and happiness rely on them. When things slow down or don’t happen we get frustrated. And when we get really frustrated, we complain.

If your application today has SOA design principles, is heavily distributed and relies on 3rd party service providers, then you’ve probably become frustrated at some point when your application slows down or crashes, and so have your end users. The problem is this: your end user experience and quality of service (QoS) are only as good as the QoS of your service providers. So, unless you monitor QoS you can’t measure QoS – and if you can’t measure QoS, you can’t manage your service providers and your end user experience. Let’s take for example an e-commerce application that has 7 JVMs, 1 database and 7 external web service providers.

This customer recently had a slowdown with their e-commerce ...
... production application. They used a java profiling tool to identify performance problems in dev and test, but could not use it in their production environment. Because the problem was a slow web service call to a remote application this tool was unable to identify the problem. After a few hours searching on Google for possible issues (“code deadlock java,” “slow sql reason” etc.) they finally found an application monitoring tool that could help. They installed this tool and soon discovered the root cause of their latency issues: long running 3rd party service calls. They called their service provider, and sure enough the service provider admitted to having issues. A few hours later the service provider called back and said “we fixed the problem, everything should be back to normal” – and yet the customer could clearly see latency issues still occurring
in their monitoring tool. So they sent their service provider a screenshot showing the evidence. The service provider then checked again, and called back a few minutes later saying, “Yes, sorry a few customers are still being impacted.” Without this level of visibility, many organizations are simply blind to how external service providers impact their end user experience and business.

If your application relies on one or more 3rd party web services, you should periodically check and report what level of service you are receiving each week. That way, you can truly understand your service provider QoS and its impact on your end user experience and application performance. You can also keep your service providers honest, with complete visibility of whether QoS is improving or degrading over time as service outages occur and are fixed.

The next time you experience a slow down or outage in your application, you should first check external web services before you start to troubleshoot your own. The last thing you want to be doing is debugging your own code, when it could be someone else’s service and code that is causing the issue. Using AppDynamics it’s possible to monitor, measure, and manage the QoS from each of your web service providers. You can get started right now with a free Java download for a single JVM or IIS web server.