Here is an article by Theresa Miller on how to diagnose the root cause of Citrix slowness. It's not always a Citrix issue that makes Citrix slow. A problem in the underlying infrastructure also affects Citrix performance. This original article by Theresa is posted here: https://24x7itconnection.com/2018/04/24/citrix-is-slow-how-to-uncover-the-real-cause-and-prove-its-not-citrix/.
As a Citrix administrator you are supporting architecture that can be complex, distributed and includes many interdependencies between the Citrix tiers and the supporting infrastructure. It is also extremely likely that you are supporting an environment with many different versions of the Citrix software. Citrix is typically a performance-sensitive application. A problem anywhere in the Citrix delivery infrastructure can impact performance, and in turn, end user experience. And, when a user calls and reports that Citrix is Slow, your troubleshooting process can become complex.
Today, let's assess how to understand how even though a user makes a simple statement that Citrix is Slow, it really may not be a problem with Citrix at all. We will also discuss how monitoring your Citrix environment can help expedite identification of problems, and their root cause.
Understanding the Real Issue
When a user calls to report an issue, it's not always clear where the real problem exists – especially in a complex and inter-dependent architecture like Citrix has. To deliver Citrix services, many infrastructure tiers may be involved, including Active Directory, storage, drive mappings, hypervisor and more. Asking the right questions when a user call comes in is very important and having a very good understanding of the environment is invaluable for rapid problem resolution. Let's look at some problems, and then discover some of dependencies that could be resulting in the problem the user is experiencing.
- User calls indicating they are experiencing slow logon to the main Citrix web URL for employee access to the farm. First check the Citrix Storefront server for performance issues, but if the server is ok then consider the fact that there could be an authentication issue to Active Directory, slow group policy (GPO) processing, a DNS problem, or even a potential network issue.
- Support desk takes a call where a user is reporting slow access to a specific application. First evaluate the Citrix server that the user is connected too, but if that is not the cause then non-Citrix interdependencies should be evaluated. For example, external storage could be experiencing an IOPS bottleneck. Also keep in mind that there could also be a problem in the application backend causing latencies (For example, a human resources application database server is down or running slow).
- A coworker stops by your desk and reports that when they launch their virtual desktop its opening very slow. Always analyze the Citrix environment first, but when you have disproved Citrix as the root cause consider other interdependencies. For example, investigate the services and scripts that run when the VM boots up, evaluate the operations that happen when group policy (GPO) is applied, check if there could be a DNS problem, or even a network issue. There could also be a resource contention issue within the hypervisor that hosts your virtual machines, or the storage that it uses.
- The helpdesk receives a call that a group of users at a certain worksite cannot connect to Citrix. For this one I would not start with Citrix, but I would first determine if there are issues with other corporate resources on these machines. If other resources cannot be accessed there could be a problem with the networking equipment at that location, or internet provider problem that could be impacting connectivity.
Keep in in mind that these are places to start your troubleshooting process, but the real resolution may not be limited to what I have shared here today. It's technology, so there are more things that could be factors. This list provides you with the foundation you need to get the troubleshooting process started when the problem doesn't appear to be related to your Citrix deployment.
Monitoring is Necessary
When considering your Citrix environment alone, one may argue that they can manually troubleshoot their deployment related problems. Although I would never recommend this approach because it's slow and time consuming. We have discussed some examples of interdependencies that can impact common troubleshooting scenarios within Citrix environments. There is a lot of value in having end-to-end visibility across your Citrix tiers and their interdependent tiers with a monitoring tool. Not only will you be able to resolve real issues more quickly, you can also engage other teams only when needed and with specific insights that can enable you to resolve problems quickly and keep your users happy.