Four (additional) things to consider when moving applications to the cloud
Organizations across Globe are adopting Cloud at a staggering rate, consuming various flavors of cloud such as Software-as-a-Service (SaaS) ,Platform-as-a-Service( PaaS ) and Infrastructure-as-a-service (IaaS). As a result, traditional applications hosted at in-house datacenters are getting converted into to cloud applications. Typically performance testing has lowest priority before go-live of application because of various reasons e.g.. Project deadline, costs etc. But when applications are moved into cloud, there are additional layer of unknowns that stakeholders should test out before go-live, the performance of the application being one of them.
There are two main reasons why organizations should think of performance testing when moving their application into cloud:
- Validation of application performance from cloud
- Uncover any potential issues caused by cloud move
During similar moves in the past, performance testing didn't see any changes except putting Load generators in the new location and continue with the testing. With the cloud move, its different and there four additional factors to think about:
- Location of performance testing infrastructure
- Impact of performance testing on your internet pipe
- Timeline: on time testing completion
- Ability (license + infrastructure) to scale users for short term
1. Location:
Historically, the load generators are installed within the internal network where applications are hosted. But with application moving into cloud, where should the load generators be located? If an organization has different locations from where end users will access the application, they may be accessing application directly from the cloud. In the past they would have accessed it within their own network.
Many cloud vendors provide redundancy by offering applications hosted in multiple datacenters in case one goes down. Having load generators spread across various locations helps you in validation of even load distribution between multiple hosting locations.
2. Impact of performance testing on Internet Pipe:
Think about a scenario where an organization decides to use existing load generators that are hosted in their network and hitting an application that is located in the cloud. The virtual users will end up clogging the production network instead of a lab where historically performance testing is done. This could create company-wide bandwidth shortages. To avoid impacting other users, performance testing should be done during off hours. But this can impact the timeline of project and may end up increasing overall costs.
3. Timeline, how much time you get for the application move and will the application testing end up delaying the project?
If you think about the previous factors and decide to plan accordingly, chances are that performance testing will need additional time when compared to your previous projects. Performance testing cloud application adds additional steps to your timeline like procuring new hardware for load generators in new location, network and firewall changes approval
4. Do you have the ability (license + infrastructure) to scale users?
For application move to cloud, you may need to go beyond your normal load testing levels and consider stressing the entire system. The goal is not only to ensure performance at the existing load, but also simulate a worst case scenario. Depending upon your current licenses for HP Loadrunner or HP Performance Center, you may require simulating additional load. Then you may need additional infrastructure but only for small duration.
So how can you address above concerns and continue with the application move into cloud? The short answer is, move the load testing into cloud too!! HP Performance Center on SaaS can help you with your move to cloud and address above concerns.
Below is high level architecture diagram of Performance Center on SaaS.
Location of Load Generators & impact on your production network:
HP Performance Center SaaS Load generators are scattered across globe in HP datacenters and other infrastructure providers such as Amazon and can simulate realistic user load from multiple locations. You can perform testing at any given time without impacting your production network because the load will be generated from outside your network.
Timeline:
There is immediate availability of performance testing infrastructure through HP Performance Center on SaaS. There are no delays caused due to infrastructure procurement, installation or configuration because it'ss ready to use turnkey solution.
Use of existing Loadrunner/Performance Center scripts:
Existing scripts that you may have from previous loadtest can be re-used if the application remains the same. If you think of other performance testing solutions from cloud, you cannot leverage your existing assets and instead may end up creating scripts from scratch using different a tool set which may be uknown to your internal testing team members
Flexibility to increase virtual users licenses and infrastructure:
HP SaaS offers very flexible licensing model where you can easily increase or decrease your virtual users footprint. You can sign up for terms ranging from one month, three months or a year, based on your performance testing needs.
In the end, it should be emphasized that performance testing applications are a must when moving from in-house to cloud. You should think of minimizing the impact on your existing user base and finishing your cloud move under the allocated time.
For more details on complete IT Performance Suite & HP SaaS offerings, go to HP SaaS
