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

The AppDynamics Controller is a Java web application that runs on a GlassFish application server and uses a MySQL database. During the installation of the Controller, two user accounts are created by default:

• The GlassFish asadmin user is the administrative user for the GlassFish server. This user has the authority to start, stop, and configure the GlassFish server and its domains. The default username for this user is admin and the default password is appdynamics. You can change the password for this user after the installation by using the asadmin command-line tool1.
• The customer-specified Controller administrator account is the user account that you provide during the installation wizard. This is the account that you use to access the AppDynamics User Interface (UI) for the first time and perform various tasks such as creating applications, configuring agents, managing users and groups, and so on. You can choose any username and password for this account, but AppDynamics recommends using only ASCII characters. You can also create additional user accounts in the Controller UI after the installation2.

The other options are not user accounts that are created by the Controller installation. The Elastic search root user, the REST API user, and the MySQL appd admin user are user accounts that are used internally by the Controller components and are not exposed to the end user. The OS user that will run the controller is a user account that you need to create on the host machine before the installation, and it is not created by the Controller installation3. References: Controller Installation, Manage Users and Groups, and Update the Root User and Glassfish Admin Passwords in the AppDynamics documentation.

According to the Cisco AppDynamics Professional Implementer (CAPI) documents, the REST API for health rule violations allows you to retrieve information about the health rule violations that occurred in a specified time range for a given application1. You can use the REST API for health rule violations for the following valid reasons:

• For determining which actions have been executed (B): The REST API response includes the details of the actions that were triggered by the health rule violation, such as email, SMS, HTTP request, or custom action1. You can use this information to verify if the actions were executed successfully, or to troubleshoot any issues with the action execution.
• When searching for historical events ©: The REST API allows you to specify a custom time range for retrieving the health rule violations, such as BEFORE_TIME, AFTER_TIME, BETWEEN_TIMES, or BEFORE_NOW1. You can use this feature to search for historical events that occurred in the past, or to analyze the trends and patterns of the health rule violations over time.

The incorrect options are:

• For updating an AppDynamics dashboard (A): This is not a valid reason for using the REST API for health rule violations, because the AppDynamics dashboards already display the health rule violations that occurred in the selected time frame, along with the severity, status, affected entities, and actions2. You do not need to use the REST API to update the dashboard, as the dashboard is automatically refreshed with the latest data from the Controller.
• For sending emails (D): This is not a valid reason for using the REST API for health rule violations, because the REST API does not send emails directly. The REST API only returns the information about the health rule violations, and the actions that were triggered by them. If you want to send emails based on the health rule violations, you need to configure an email action in the health rule configuration, or use a custom action that invokes an external email service3.
• When pushing events to the Event Management System is NOT possible (E): This is not a valid reason for using the REST API for health rule violations, because the REST API does not push events to the Event Management System. The REST API only returns the information about the health rule violations, and the actions that were triggered by them. If you want to push events to the Event Management System, you need to configure an HTTP request action in the health rule configuration, or use a custom action that invokes an external API3.

References:

• 1: Health Rule Violations API - AppDynamics
• 2: Health Rule Violations - AppDynamics
• 3: Actions - AppDynamics

To upgrade an EUM Server that is currently in production, the administrator should follow these steps:

• Stop the EUM Server before the upgrade. This ensures that the EUM Server does not process any incoming data from the EUM agents during the upgrade process. The administrator can use the eum.sh or eum.bat script to stop the EUM Server gracefully1.
• Run the new installer on the EUM host machine. The installer will detect the existing EUM Server installation and prompt the administrator to upgrade it to the latest version. The installer will also migrate the EUM data from the old version to the new version, if needed. The administrator should follow the instructions on the installer wizard to complete the upgrade2.

The other options are not necessary or correct for upgrading the EUM Server. The administrator does not need to stop or upgrade the EUM agents, as they are compatible with the new version of the EUM Server. The administrator does not need to update the EUM Server access key, as it remains the same after the upgrade. The administrator does not need to install MySQL, as it is bundled with the EUM Server installation package2. References: Upgrade the Production EUM Server and Start and Stop the EUM Server in the AppDynamics documentation.

AppDynamics recommends that you terminate SSL connections from agents at a reverse proxy or a load balancer in front of the Controller, rather than at the Controller itself. This improves the performance and scalability of the Controller by offloading the SSL processing to the proxy or load balancer. It also simplifies the configuration and management of SSL certificates and truststores. To enable this option, you need to configure the proxy or load balancer to accept SSL connections from agents and forward them to the Controller using HTTP. You also need to configure the agents to use SSL and point to the proxy or load balancer host and port. See Enable SSL for the Java Agent for an example. References: Agent-to-Controller Connections and Enable SSL and SSH for Database Agent Communications in the AppDynamics documentation.

The REST query that could be used to verify the availability of an AppDynamics Controller is1:

• http://:/controller/rest/ping

This query returns a simple text response of “pong” if the Controller is up and running, or an error message if the Controller is down or unreachable1. This query does not require any authentication or parameters, and can be used as a quick and easy way to check the Controller status1. References: Ping the Controller