The application monitoring function of Application Real-Time Monitoring Service (ARMS) provides the memory snapshot feature. After creating the memory snapshot, you can view specific information of multiple memory metrics within the specified time range through detailed logs. This topic describes the scenarios and methods for using memory snapshots.

Scenarios

ARMS provides JVM monitoring to give you a clear view of multiple memory metrics within the specified time range. Although the chart can show you that the memory is overused, it cannot provide detailed information for you to identify the root cause. You can create a memory snapshot and view detailed memory usage through the log.

Procedure

  1. Log on to the ARMS console. In the left-side navigation pane, choose Application Monitoring > Applications.
  2. On the Applications page, click the name of the target application.

  3. On the Application Details page, select the target node and click the JVM Monitoring tab on the right side of the page.

  4. In the upper-right corner of the JVM Monitoring tab, click Create Memory Snapshot.
    Note When you click Create Memory Snapshot, if the previous snapshot job is still running, you will get an error message. Wait until the previous snapshot job is finished. Currently, you can only create memory snapshots for Linux systems.
  5. In the Create Memory Snapshot dialog box, select an IP address from the IP drop-down list and click OK.
    Note If you create a snapshot at the machine level under an application, then the IP address of this machine is selected by default in the IP field.
    Notice The running time of a snapshot job varies from a few minutes to half an hour. When a snapshot job is running, you may experience brief freezing. Be cautious in using this function.

    The created snapshot is displayed in the snapshot job list of Snapshot History.

    The information of a snapshot job includes:

    • IP address
    • Creation time of snapshot
    • Running time of snapshot job
    • Delete: Used to delete a snapshot
    • Detail: Used to view details of a memory snapshot

    Green indicates a successful snapshot job, and red indicates a failed one.

  6. Click Detail to open the Snapshot Details dialog box and view the details.
    • Dominator Tree: Lists the top 5 objects that use the most memory, in descending order.

      The indentation of lines represents the dominance relation between objects. If the Number 1 object on the list takes up a small portion or uses little memory, it means no object is overusing memory. Otherwise, modify the memory object to shrink it or quickly release it.

    • Histogram: Lists the top 20 classes that use the most memory, in descending order.