This topic describes Application Live View in Tanzu Application Platform GUI.
The Application Live View features of the Tanzu Application Platform include sophisticated components to give developers and operators a view into their running workloads on Kubernetes.
Application Live View shows an individual running process, for example, a Spring Boot application deployed as a workload resulting in a JVM process running inside of a pod. This is an important concept of Application Live View: only running processes are recognized by Application Live View. If there is not a running process inside of a running pod, Application Live View does not show anything.
Under the hood, Application Live View uses the concept of Spring Boot Actuators to gather data from those running processes. It visualizes them in a semantically meaningful way and allows users to interact with the inner workings of the running processes within limited boundaries.
The actuator data serves as the source of truth. Application Live View provides a live view of the data from inside of the running processes only. Application Live View does not store any of that data for further analysis or historical views. This easy-to-use interface provides ways to troubleshoot, learn, and maintain an overview of certain aspects of the running processes. It gives a level of control to the users to change some parameters, such as environment properties, without a restart (where the Spring Boot application, for example, supports that).
The Application Live View UI plug-in is part of Tanzu Application Platform GUI. To use the Application Live View plug-in:
The following sections describe Application Live View pages.
This is the default page loaded in the Live View section. This page gives a tabular overview containing the following information:
The user can navigate between Information Categories by selecting from the drop-down menu on the top right corner of the page.
To navigate to the health page, the user can select the Health option from the Information Category drop-down menu. The health page provides detailed information about the health of the application. It lists all the components that make up the health of the application such as readiness, liveness, and disk space. It displays the status, details associated with each of the components.
To navigate to the Environment page, the user can select the Environment option from the Information Category drop-down menu. The Environment page contains details of the applications’ environment. It contains properties including, but not limited to, system properties, environment variables, and configuration properties (such as application.properties) in a Spring Boot application.
The page includes the following features:
The management.endpoint.env.post.enabled=true has to be set in the application config properties of the application and a corresponding, editable Environment has to be present in the application.
To navigate to the Log Levels page, the user can select the Log Levels option from the Information Category drop-down menu. The log levels page provides access to the application’s loggers and the configuration of their levels.
The user can configure the log levels such as INFO, DEBUG, and TRACE in real time from the UI. The user can search for a package and edit its respective log level. The user can configure the log levels at a specific class and package. They can deactivate all the log levels by modifying the log level of root logger to OFF.
The toggle Changes Only displays the changed log levels. The search feature enables the user to search by logger name. The Reset resets the log levels to the original state. The Reset All on top right corner of the page resets all the loggers to default state.
To navigate to the Threads page, the user can select the Threads option from the Information Category drop-down menu.
This page displays all details related to JVM threads and running processes of the application. This tracks live threads and daemon threads real-time. It is a snapshot of different thread states. Navigating to a thread state displays all the information about a particular thread and its stack trace.
The search feature enables the user to search for threads by thread ID or state. The refresh icon refreshes to the latest state of the threads. The user can view more thread details by clicking on the Thread ID. The page also has a feature to download thread dump for analysis purposes.
To navigate to the Memory page, the user can select the Memory option from the Information Category drop-down menu.
This graphical visualization happens in real time and shows real-time data only. As mentioned at the top, the Application Live View features do not store any information. That means the graphs visualize the data over time only for as long as you stay on that page.
To navigate to the Request Mappings page, the user should select the Request Mappings option from the Information Category drop-down menu.
This page provides information about the application’s request mappings. For each of the mapping, it displays the request handler method. The user can view more details of the request mapping such as header metadata of the application. That is, it produces, consumes and HTTP method by clicking on the mapping.
The search feature enables the user to search on the request mapping or the method. The toggle /actuator/** Request Mappings displays the actuator related mappings of the application.
When the application actuator endpoint is exposed on management.server.port, the application does not return any actuator request mappings data in the context. The application displays a message when the actuator toggle is enabled.
To navigate to the HTTP Requests page, the user should select the HTTP Requests option from the Information Category drop-down menu. The HTTP Requests page provides information about HTTP request-response exchanges to the application.
The graph visualizes the requests per second indicating the response status of all the requests. The user can filter on the response statuses which include info, success, redirects, client-errors, server-errors. The trace data is captured in detail in a tabular format with metrics such as timestamp, method, path, status, content-type, length, time.
The search feature on the table filters the traces based on the search field value. The user can view more details of the request such as method, headers, response of the application by clicking on the timestamp. The refresh icon above the graph loads the latest traces of the application. The toggle /actuator/** on the top right corner of the page displays the actuator related traces of the application.
When the application actuator endpoint is exposed on management.server.port, no actuator HTTP Traces data is returned for the application. In this case, a message is displayed when the actuator toggle is enabled.
To navigate to the Caches page, the user can select the Caches option from the Information Category drop-down menu.
The Caches page provides access to the application’s caches. It gives the details of the cache managers associated with the application including the fully qualified name of the native cache.
The search feature in the Caches Page enables the user to search for a specific cache/cache manager. The user can clear individual caches by clicking Evict. The user can clear all the caches completely by clicking Evict All. If there are no cache managers for the application, the message No cache managers available for the application is displayed.
To navigate to the Configuration Properties page, the user can select the Configuration Properties option from the Information Category drop-down menu.
The configuration properties page provides information about the configuration properties of the application. In case of Spring Boot, it displays application’s @ConfigurationProperties beans. It gives a snapshot of all the beans and their associated configuration properties. The search feature allows the user to look up for property’s key/value or the bean name.
To navigate to the Conditions page, the user can select the Conditions option from the Information Category drop-down menu. The conditions evaluation report provides information about the evaluation of conditions on configuration and auto-configuration classes.
In case of Spring Boot, this gives the user a view of all the beans configured in the application. When the user clicks on the bean name, the conditions and the reason for the conditional match is displayed.
In case of not configured beans, it shows both the matched and unmatched conditions of the bean if any. In addition to this, it also displays names of unconditional auto configuration classes if any. The user can filter out on the beans and the conditions using the search feature.
To navigate to the Scheduled Tasks page, the user can select the Scheduled Tasks option from the Information Category drop-down menu.
The scheduled tasks page provides information about the application’s scheduled tasks. It includes cron tasks, fixed delay tasks and fixed rate tasks, custom tasks and the properties associated with them.
The user can search for a particular property or a task in the search bar to retrieve the task or property details.
To navigate to the Beans page, the user can select the Beans option from the Information Category drop-down menu. The beans page provides information about a list of all application beans and its dependencies. It displays the information about the bean type, dependencies, and its resource. The user can search by the bean name or its corresponding fields.
To navigate to the Metrics page, the user can select the Metrics option from the Information Category drop-down menu.
The metrics page provides access to application metrics information. The user can choose from the list of various metrics available for the application such as jvm.memory.used, jvm.memory.max, http.server.request, and so on.
After the metric is chosen, the user can view the associated tags. The user can choose the value of each of the tags based on filtering criteria. Clicking Add Metric adds the metric to the page which is refreshed every 5 seconds by default.
The user can pause the auto refresh feature by deactivating the Auto Refresh toggle. The user can also refresh the metrics manually by clicking Refresh All. The format of the metric value can be changed according to the user’s needs. They can delete a particular metric by clicking the minus symbol in the same row.
To navigate to the Actuator page, the user can select the Actuator option from the Information Category drop-down menu. The actuator page provides a tree view of the actuator data. The user can choose from a list of actuator endpoints and parse through the raw actuator data.
You might run into cases where a workload running on your cluster does not show up in the Application Live View overview, the detail pages do not load any information while running, or similar issues. See Troubleshooting in the Application Live View documentation.
