According to the Cisco AppDynamics Professional Implementer (CAPI) documents, the two recommendations for servers in an Events Service Cluster are:

Should be on the same local network : This is a valid recommendation because the Events Service Cluster is based on Apache Cassandra, which is a distributed database that relies on network communication between the nodes. Having the servers on the same local network reduces the network latency and improves the performance and reliability of the cluster.The network bandwidth should be at least 1 Gbps, and the network firewall should allow the required ports for the Events Service Cluster12.

Should have identical hardware specifications (D): This is a valid recommendation because the Events Service Cluster is horizontally scalable, which means that the nodes share the data storage and processing load equally. Having identical hardware specifications for the servers ensures that the cluster is balanced and efficient, and avoids performance bottlenecks or failures due to hardware differences.The hardware specifications should meet the minimum requirements for the Events Service Cluster, such as CPU cores, RAM, disk space, and disk type12.

The incorrect options are:

Should be installed using the same user account (A): This is not a valid recommendation because the Events Service Cluster does not require the same user account for installation. The user account that is used to install the Events Service Cluster should have sudo privileges on the target hosts, but it does not have to be the same for all the hosts.The user account that is used to run the Events Service Cluster should have read and write permissions on the installation directory, but it does not have to be the same for all the hosts either12.

Should have eight or more CPU cores (B): This is not a valid recommendation because the Events Service Cluster does not require eight or more CPU cores for the servers. The minimum requirement for the CPU cores is four, and the recommended requirement is six.Having more CPU cores may improve the performance of the cluster, but it is not a mandatory recommendation12.

Should be running the same operating system version (E): This is not a valid recommendation because the Events Service Cluster does not require the same operating system version for the servers. The Events Service Cluster supports various Linux operating systems, such as CentOS, Red Hat, Ubuntu, and SUSE.The operating system version should be compatible with the Events Service version, but it does not have to be the same for all the hosts12.

1: Events Service Requirements - AppDynamics

2: Events Service Deployment - AppDynamics

According to the Cisco AppDynamics Professional Implementer (CAPI) documents, the recommended way to add capacity to the Events Service cluster is to add nodes running on machines with identical hardware matching the existing nodes12. This will increase the data storage, replication, and redundancy of the cluster, as well as the processing power for queries.The Events Service cluster is horizontally scalable, so nodes can be added as your data storage requirements grow32.The Events Service must run on dedicated machines with identical directory structures, user account profiles, and hardware profiles1.For heap space allocation, AppDynamics recommends allocating half of the available RAM to the Events Service process, with a minimum of 7 GB up to 31 GB1.Solid-state drives (SSD) can significantly outperform hard disk drives (HDD), and are therefore recommended for production deployments1.

The incorrect options are:

Add a new Events Service cluster to share the load. (A) This is not recommended because it will create additional complexity and overhead for managing multiple clusters and routing data and queries to the appropriate cluster. It will also require more license units to enable analytics on multiple clusters.

Add more storage to the master nodes of the cluster. This is not recommended because it will not increase the data replication and redundancy of the cluster, nor the processing power for queries. It will also create an imbalance in the cluster, as the master nodes will have more storage than the worker nodes, which may affect the performance and stability of the cluster.

Add more storage to as many of the existing nodes as possible. (D) This is not recommended because it will not increase the data replication and redundancy of the cluster, nor the processing power for queries. It will also create an imbalance in the cluster, as some nodes will have more storage than others, which may affect the performance and stability of the cluster.

1: Cisco AppDynamics Professional Implementer (500-430)

2: Events Service Requirements - AppDynamics

3: Events Service Deployment - AppDynamics

4: Events Service Deployment - AppDynamics

According to the Cisco AppDynamics Professional Implementer (CAPI) documents, the two valid ways to confirm that the upgraded Java Agent is running successfully are:

Verify that the node within the Controller UI indicates the app agent is reporting. (B) This is a valid way because the Controller UI is a web-based application that allows users to monitor and manage the performance of the applications, tiers, nodes, and other entities that are instrumented by the AppDynamics agents. The Controller UI displays the status of the nodes within each tier, and indicates whether the app agent is reporting or not. If the app agent is reporting, the node icon is green and shows the agent version. If the app agent is not reporting, the node icon is gray and shows the last time the agent reported. The user can also hover over the node icon to see more details, such as the agent type, the agent version, the agent runtime directory, and the agent properties file.The user can verify that the upgraded Java Agent is running successfully by checking that the node icon is green and shows the latest agent version12.

Verify the Java Agent Version metric for that node in the Metric Browser. This is a valid way because the Metric Browser is a feature of the Controller UI that allows users to view and analyze the metrics collected by the AppDynamics agents. The Metric Browser displays the metrics in a hierarchical tree structure, where each node represents a metric category, a metric name, or a metric value. The user can expand or collapse the nodes, and select or deselect the metrics to view them in a chart. The user can also apply filters, time ranges, baselines, and other options to customize the chart. The user can verify that the upgraded Java Agent is running successfully by navigating to the Java Agent Version metric for that node in the Metric Browser. The Java Agent Version metric shows the version number of the Java Agent that is running on the node.The user can compare the metric value with the expected agent version, and check that the metric is updated after the upgrade34.

The incorrect options are:

Verify that the application log contains a message indicating success. (A) This is not a valid way because the application log does not contain any message indicating the success of the Java Agent upgrade. The application log is a file that records the events and messages that occur in the application server, such as the startup, shutdown, errors, warnings, and debug information. The application log does not record the events and messages that occur in the Java Agent, such as the installation, upgrade, configuration, or reporting. The Java Agent has its own log file, which is located in the /logs directory, and which contains the messages indicating the success or failure of the Java Agent upgrade .

Verify that the Java Agent log contains a message indicating the agent started successfully. (D) This is not a valid way because the Java Agent log does not contain any message indicating the agent started successfully after the upgrade. The Java Agent log is a file that records the events and messages that occur in the Java Agent, such as the installation, upgrade, configuration, or reporting. The Java Agent log contains a message indicating the agent started successfully when the application server is started, not when the Java Agent is upgraded. The Java Agent log does not contain any message indicating the success or failure of the Java Agent upgrade. The Java Agent log is located in the /logs directory, and the message indicating the agent started successfully is ''Agent Startup Complete'' .

1: Tiers and Nodes - AppDynamics

2: Tier Dashboard - AppDynamics

3: Metric Browser - AppDynamics

4: Java Agent Metrics - AppDynamics

[5]: Java Agent Logs - AppDynamics

[6]: Troubleshoot the Java Agent - AppDynamics

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-host>:/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-host>:/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-host>:/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.Reference:Application Model API,Metric and Snapshot API

The AppDynamics REST API to retrieve metrics allows you to get values generated for metrics by specifying the path of the metric and the time frame for the data1.Some of the valid reasons to use this API are12:

To archive 1-minute granularity data. The AppDynamics Controller stores metric data at different levels of granularity depending on the retention period. For example, it stores 1-minute granularity data for 8 days, 10-minute granularity data for 32 days, and 1-hour granularity data for 365 days. If you want to archive the 1-minute granularity data for longer than 8 days, you can use the API to retrieve and store the data in an external database or file system.

To calculate a new metric based on two existing metrics. The AppDynamics Controller provides some built-in metrics such as average response time, calls per minute, errors per minute, etc. However, you may want to calculate a new metric that is not available in the Controller, such as the ratio of errors to calls, or the percentage of slow transactions. You can use the API to retrieve the values of the existing metrics and perform the calculation using your own logic or formula.

To retrieve health rule violations. Health rules are the rules that define the performance and availability thresholds for your application components. When a health rule is violated, the AppDynamics Controller generates an event and optionally triggers a policy action. You can use the API to retrieve the list of health rule violations for a given application, time range, and severity level. This can help you monitor and troubleshoot the health of your application and take corrective actions if needed.Reference:Retrieve Metric Data,Health Rule API