Cisco Specialist Certification 500-430 Cisco Study Notes

The AppDynamics Controller is instrumented by an internal, out-of-the-box, AppDynamics Java agent that monitors the performance and health of the Controller itself1. To access the information provided by the internal agent, you need to log in to the Controller UI with the following credentials2:

• Account = system
• Username = root
• Password =

The system account is a special account that is used only for internal monitoring and troubleshooting purposes. It is not visible in the normal Controller UI and requires a special URL to access it2. The root user is the default administrator user for the system account and has the same password as the admin user for the customer1 account3. References: Controller Self-Monitoring, Monitoring a Controller Using the Internal Monitoring Agent, Controller Accounts

The EUM Server is the on-premises version of the EUM Cloud that receives, processes, and stores data from EUM agents. For production installation, AppDynamics recommends that the EUM Server and the Controller sit on different hosts, and the EUM Server hosts its own MySQL instance. This improves the scalability and performance of both components. Moreover, AppDynamics strongly recommends that SSL traffic from agents to the EUM Server is terminated at a reverse proxy that sits in front of the EUM Server in the network path, and forwards connections to the EUM Server using HTTP. This relieves the SSL processing load from the EUM Server, simplifies the certificate management, and enhances the security by isolating the EUM Server from the external Internet. Therefore, the best implementation mode for deploying an EUM Server with reverse proxy in a production environment is option D. References: EUM Server Deployment, Install a Production EUMServer, Reverse Proxy configuration for EUM, and Browser EUM installation in the AppDynamics documentation and community.

To prepare a Linux environment for the installation of an AppDynamics Controller with a Large performance profile, which is suitable for monitoring up to 1000 agents, you need to perform the following steps:

• Install libaio on the host machine if it does not already have it installed. This library facilitates asynchronous I/O operations on the system, which are required by the Controller. You can use the package manager of your Linux distribution to install libaio, such as yum or apt-get. For example, on CentOS, you can run yum install libaio1.
• Verify the open file descriptor limit on the system. The file descriptor limit determines how many files a process can open at a time. The Controller requires a high file descriptor limit to handle the large number of connections and transactions. AppDynamics recommends setting the file descriptor limit to at least 65535 for the user account that runs the Controller. You can check the current file descriptor limit by running ulimit -n and modify it by editing the /etc/security/limits.conf file2.
• Verify the process limit on the system. The process limit determines how many processes a user can run at a time. The Controller requires a high process limit to handle the large number of threads and subprocesses. AppDynamics recommends setting the process limit to at least 65535 for the user account that runs the Controller. You can check the current process limit by running ulimit -u and modify it by editing the /etc/security/limits.conf file2.

Other steps that are not required but recommended for the Controller installation are verifying the user account permissions, configuring the virus scanners, installing the netstat network utility, and setting the NUMA configuration2. You do not need to install MySQL or Java separately, as they are included in the Controller installation package3. References: Prepare Linux for the Controller, Install the Controller on Linux, and Controller System Requirements in the AppDynamics documentation.

Custom correlation is needed when the default detection mechanisms of AppDynamics are not capable of auto-correlating transactions across tiers or across parent-child threads in complex multithreaded applications. Custom correlation enables the user to configure AppDynamics to propagate a unique correlation key by using the extension points of the distributed protocol or by decorating the payload. Among the four options, a custom TCP concurrent server is the most likely to require the implementation of custom correlation, as it is an unsupported framework and protocol that may not have easily-defined method calls or payload objects to configure as exit points or entry points. The other options, such as SOAP, JMS, and WCF, are supported by AppDynamics and can be automatically correlated by the agents without the need for custom configuration. References: Custom Correlation for Java Applications and Configure Custom Correlation for .NET Applications in the AppDynamics community.