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Memory snapshot

Last Updated: Jun 29, 2018

This topic explains the memory snapshot function of Application Monitoring.

What it does

With the JVM monitoring of ARMS, you can see multiple memory metrics within specified time span, for example memory usage. Although the chart can show you that the memory is overused, it cannot provide detailed information for you to identify the root cause. In this case, by creating a memory snapshot, you can clearly see what is overusing the memory in the detailed log.

How to use

  1. Log on to the ARMS Console, and choose Application Monitoring > Application List in the left-side navigation pane.
  2. On the Application Monitoring instance list page, click the name of a target application.
  3. In the left-side navigation pane, click Application Details, and click JVM Monitoring tab on the right side.

  4. Click New Snapshot in the upper-right corner of the page. Create Snapshot dialog box is displayed.

    Note:

    When you click New Snapshot, if the previous snapshot job is still running, you will get an error message. Please wait until the previous snapshot job is finished. Currently, you can only create memory snapshots for Linux system.

  5. Select an IP in the dialog box, and click OK. The created snapshot is displayed in the Snapshot Task list.

    Tip: 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.

    Note:

    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. Please be cautious.

    The information of a snapshot job includes:

    • IP
    • Creation time of snapshot
    • Duration of snapshot job
    • Delete: deletes a snapshot
    • View Details: shows the details of a memory snapshotGreen indicates a successful snapshot job, while red indicates a failed one.
  6. Click View Details to open the Snapshot Details dialog box and view the details.

    • Dominator Tree: Lists the top five objects that use the most memory in descending order.

      The indentation of lines represents the dominance relation. If the object on the top of the list takes up a small portion or use little memory, it means no object is overusing memory. Otherwise, please modify the memory object to shrink it or quick-release it.

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