The AppDynamics Rest API allows you to retrieve information and perform operations on the AppDynamics platform using HTTP requests. To retrieve all AppDynamics business applications from an AppDynamics Controller using the AppDynamics Rest API, you need to use the following URL format:

http(s)://:/controller/rest/applications

This URL returns the business application names and internal numeric identifiers for all the applications that are monitored by the Controller. You can use the application name or ID as a parameter for other API methods that require the application context. You can also specify the output format as XML (default) or JSON by adding the output query parameter. For example:

http(s)://:/controller/rest/applications?output=JSON

This URL returns the same information as the previous one, but in JSON format. You can also filter the applications by their status (alive or not) by adding the time-range-type query parameter. For example:

http(s)://:/controller/rest/applications?time-range-type=BEFORE_NOW&duration-in-mins=60

This URL returns only the applications that are alive in the last 60 minutes. An alive application is an application with at least one node that submits at least one metric to the Controller in the provided time range12. References: Application Model API, Metric and Snapshot API

According to the Cisco AppDynamics Professional Implementer (CAPI) documents, the minimum recommended number of nodes for a redundant Events Service is three ©. The Events Service is a distributed database that stores and processes the analytics data collected by the AppDynamics platform. The Events Service cluster consists of multiple nodes that share the data load and provide fault tolerance and high availability. The minimum number of nodes for a functional Events Service cluster is one, but this is not recommended for production environments, as it does not provide any redundancy or resilience. The minimum number of nodes for a redundant Events Service cluster is three, as this allows the cluster to tolerate the failure of one node without losing any data or availability. The recommended number of nodes for a redundant Events Service cluster is five or more, as this provides better performance and scalability12.

The incorrect options are:

• 1 (A): This is not a valid option because a single-node Events Service cluster does not provide any redundancy or resilience. If the node fails, the cluster becomes unavailable and the data is lost. A single-node Events Service cluster is only suitable for testing or development purposes, not for production environments12.
• 2 (B): This is not a valid option because a two-node Events Service cluster does not provide sufficient redundancy or resilience. If one node fails, the cluster becomes unstable and may lose data or availability. A two-node Events Service cluster is not recommended for production environments12.
• 4 (D): This is not a valid option because a four-node Events Service cluster is not optimal for redundancy or resilience. A four-node Events Service cluster has an even number of nodes, which may cause a split-brain scenario, where the cluster is divided into two equal partitions that cannot communicate with each other. This may result in data inconsistency or unavailability. A four-node Events Service cluster can be improved by adding a fifth node to avoid the split-brain scenario12.

References:

• 1: Events Service Deployment - AppDynamics
• 2: Events Service Requirements - AppDynamics

The directory contains the EUM Server installation files, configuration files, and data files. It is recommended to back up this directory as a precaution before upgrading or migrating the EUM Server. The default location of this directory is /AppDynamics/EUM, where is the directory where you installed the Controller. You can also use the backup-eum.sh script to back up the EUM Server data12. References: Upgrade the Production EUM Server, Configure the EUM Server

The AppDynamics Controller Admin Console lets you configure certain global settings for the Controller, such as metric retention periods, UI notification triggers, tenancy mode, and accounts in multi-tenancy mode1. Two of the settings that an administrator can configure from the AppDynamics Controller Admin Console are:

• License allocation: This setting allows you to view and manage the license usage and availability for your Controller. You can see the total number of licenses, the number of licenses in use, the number of licenses available, and the license expiration date for each agent type. You can also allocate licenses to specific applications or accounts, and set license limits and alerts2.
• Retention periods: This setting allows you to specify how long the Controller retains the metric data and the event data for your monitored applications. You can configure the retention periods for different types of data, such as minute-level metrics, hour-level metrics, day-level metrics, transaction snapshots, and events. You can also configure the data purge schedule and the data backup schedule3.

References: Access the Administration Console, License Rules, Data Retention

According to the Cisco AppDynamics Professional Implementer (CAPI) documents, the two reasons that would require an administrator to install the Events Service cluster manually are:

• Security concerns with passwordless SSH (B): This is a valid reason because the automated installation of the Events Service cluster requires passwordless SSH access to the target hosts. Passwordless SSH allows the Enterprise Console to execute commands on the remote hosts without prompting for a password. However, some organizations may have security policies that prohibit passwordless SSH access, as it may pose a risk of unauthorized access or malicious attacks. In such cases, the administrator can install the Events Service cluster manually, by following the steps described in the Manual Installation of the Events Service Cluster document1.
• Security requirements to install using a non-root user account ©: This is a valid reason because the automated installation of the Events Service cluster requires root privileges on the target hosts. Root privileges allow the Enterprise Console to create directories, change permissions, and install packages on the remote hosts. However, some organizations may have security policies that restrict root access, as it may pose a risk of accidental or intentional damage to the system. In such cases, the administrator can install the Events Service cluster manually, by following the steps described in the Manual Installation of the Events Service Cluster document1. The administrator can use a non-root user account that has sudo privileges to perform the manual installation.

The incorrect options are:

• Installation on SUSE Linux (A): This is not a valid reason for manual installation, because the automated installation of the Events Service cluster supports SUSE Linux as one of the compatible operating systems. The Enterprise Console can install the Events Service cluster on SUSE Linux hosts using the automated installation process, as long as the hosts meet the prerequisites described in the Events Service Requirements document2.
• Installation on Windows (D): This is not a valid reason for manual installation, because the Events Service cluster does not support Windows as an operating system. The Events Service cluster can only run on Linux hosts, as it is based on Apache Cassandra, which is a Linux-based distributed database. The Events Service cluster cannot be installed on Windows hosts, either manually or automatically2.

References:

• 1: Manual Installation of the Events Service Cluster - AppDynamics
• 2: Events Service Requirements - AppDynamics

The AppDynamics Controller properties that govern how long metric data is retained in the database are1:

• metrics.ten.min.retention.period: This property specifies the number of days to retain metric data at 10-minute granularity. The default value is 32 days.
• metrics.retention.period: This property specifies the number of days to retain metric data at 1-hour granularity. The default value is 365 days.
• metrics.min.retention.period: This property specifies the number of hours to retain metric data at 1-minute granularity. The default value is 4 hours.

The other options are incorrect because1:

• metrics.ten.sec.retention.period: This property does not exist in the AppDynamics Controller. The finest granularity for metric data is 1 minute.
• metrics.day.retention.period: This property does not exist in the AppDynamics Controller. The coarsest granularity for metric data is 1 hour.
• metrics.week.retention.period: This property does not exist in the AppDynamics Controller. The metric data retention is based on days, not weeks. References: Database Size and Data Retention

According to the Cisco AppDynamics Professional Implementer (CAPI) documents, the two reasons for the missing correlated server-side snapshots are:

• Server has set the HttpOnly flag on all cookies. (A) This is a valid reason because the HttpOnly flag is a security feature that prevents client-side scripts from accessing the cookies. However, the AppDynamics JavaScript Agent relies on the cookies to correlate the browser snapshots with the server-side snapshots. The JavaScript Agent injects a cookie named _appdyn_browser into the browser requests, which contains the correlation information. If the server sets the HttpOnly flag on all cookies, including the _appdyn_browser cookie, the JavaScript Agent cannot read or modify the cookie, and the correlation fails. To enable the correlation, the server should not set the HttpOnly flag on the _appdyn_browser cookie12.
• Server-side application is not instrumented with server agent. (E) This is a valid reason because the server-side snapshots are collected by the AppDynamics app agents that instrument the application servers. The app agents monitor the business transactions that are executed by the server-side application, and capture the execution context, call graphs, errors, and metrics. If the server-side application is not instrumented with the app agent, the server-side snapshots are not available, and the correlation fails. To enable the correlation, the server-side application should be instrumented with the app agent that is compatible with the application server and the Controller34.

The incorrect options are:

• Correlated server-side snapshots work only for .NET Applications. (B) This is not a valid reason because the correlated server-side snapshots work for any application server that is instrumented with the AppDynamics app agent, not only for .NET applications. The AppDynamics platform supports various application servers, such as Java, .NET, PHP, Node.js, Python, and C/C++. The app agents collect the server-side snapshots for the business transactions that are executed by the application server, regardless of the programming language or framework34.
• Correlated snapshots are visible only if the injection mechanism is Automatic. © This is not a valid reason because the correlated snapshots are visible regardless of the injection mechanism. The injection mechanism refers to the way the AppDynamics JavaScript Agent is inserted into the web pages. There are two injection mechanisms: Automatic and Manual. The Automatic injection mechanism uses the app agent to inject the JavaScript Agent into the web pages that are served by the application server. The Manual injection mechanism requires the user to manually insert the JavaScript Agent into the web pages. Both injection mechanisms support the correlation of the browser snapshots and the server-side snapshots, as long as the JavaScript Agent and the app agent are configured correctly .
• Correlated snapshots are visible only if browser is Chrome. (D) This is not a valid reason because the correlated snapshots are visible regardless of the browser. The AppDynamics JavaScript Agent supports various browsers, such as Chrome, Firefox, Safari, Edge, and Internet Explorer. The JavaScript Agent collects the browser snapshots for the web pages that are loaded by the browser, and correlates them with the server-side snapshots, regardless of the browser type or version .
• Correlated server-side snapshots are visible only if Java version is 1.7+. (F) This is not a valid reason because the correlated server-side snapshots are visible regardless of the Java version. The AppDynamics Java Agent supports various Java versions, such as 1.5, 1.6, 1.7, 1.8, and 11. The Java Agent collects the server-side snapshots for the business transactions that are executed by the Java application server, and correlates them with the browser snapshots, regardless of the Java version or vendor .

References:

• 1: Browser Snapshots - AppDynamics
• 2: Troubleshoot Browser RUM - AppDynamics
• 3: Transaction Snapshots - AppDynamics
• 4: Supported Environments and Versions - AppDynamics
• [5]: Browser Real User Monitoring - AppDynamics
• [6]: Set Up and Configure Web EUM - AppDynamics
• [7]: Browser Support - AppDynamics
• [8]: Java Agent - AppDynamics
• [9]: Java Supported Environments - AppDynamics