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Creating a Sampling Profiling Task

The tool collects internal activities and performance events of the JVM through data sampling, and performs offline analysis through data recording and playback. This method requires only a small overhead and has little impact on services, making it suitable for large Java programs. For details, see Table 1.

Prerequisites

  • A target environment has been added and is online.
  • The JDK that runs the Java process must be BiSheng JDK 8.302 or later or OpenJDK 9 or later.

    If the Java Profiler was deployed by an OS administrator and you want to perform sampling analysis on a Java process that was not created by an OS administrator, ensure that the JDK running the Java process is BiSheng JDK 8.302 or later or OpenJDK 9 or later, and configure the JAVA_HOME environment variable in the non-interactive shell. For details, see Configuring the JDK.

Procedure

  1. On the left area of the Java Profiler, select the target environment in the Target Environments list. Under Java Processes on the right, select the target Java process. See Figure 1.
    Figure 1 Selecting a Java process
    Figure 2 Selecting a container process

    You can click to import a downloaded report and perform verification during the import.

    • Java processes in containers can be analyzed, and Java applications in pods can be analyzed remotely (when Kubernetes compute nodes are not connected).
    • Container processes can be filtered by namespace. If the namespace value is - -, there is no namespace. If the pod value is - -, there is no pod.
  2. Click Sampling Profiling.

    The Add Sampling Analysis page is displayed, as shown in Figure 3. For details about the parameters, see Table 1.

    Figure 3 Adding a sampling analysis task
    Table 1 Parameters for adding a sampling analysis task

    Parameter

    Description

    Recording Mode

    Recording mode. The options are:

    • Specified duration: You can specify the sampling duration.
    • Continue until manual stop: The sampling duration cannot be customized.
      NOTE:

      The maximum sampling data size for continuous recording is 250 MB. If the sampling data size exceeds 250 MB, the system analyzes only the last collected 250 MB data.

    Duration (s)

    Recording duration. The default value is 60. The value range is 1 to 300.

    Method Sampling

    Indicates whether to enable method sampling. This function is enabled by default.

    Java Method Sampling Interval (ms)

    Interval at which the Java method sampling is performed. The default value is 1. The value range is 1 to 1000.

    NOTE:

    This parameter is unavailable if Method Sampling is disabled.

    Native Method Sampling Interval (ms)

    Interval at which the Native method sampling is performed. The default value is 1. The value range is 1 to 1000.

    NOTE:

    This parameter is unavailable if Method Sampling is disabled.

    Thread Dump

    Indicates whether to enable thread dump. This function is enabled by default.

    Dump Interval (s)

    Interval at which the thread dump is performed. The default value is 1. The value range is 1 to 300.

    NOTE:
    • This parameter is unavailable if Thread Dump is disabled.
    • The value of Dump Interval must be less than or equal to the value of Duration. You are advised to set Dump Interval to 1, 5, 10, 20, 30, or 60.

    File I/O Sampling

    Indicates whether to enable file I/O sampling. This function is disabled by default.

    Threshold (μs)

    File I/O sampling threshold. The default value is 500. The value range is 0 to 1,000,000.

    This parameter is displayed only when File I/O Sampling is enabled.

    NOTE:

    The tool captures only the file I/Os that exceed the threshold for analysis.

    Socket I/O Sampling

    Indicates whether to enable socket I/O sampling. This function is disabled by default.

    Threshold (μs)

    Socket I/O sampling threshold. The default value is 1000. The value range is 0 to 1,000,000.

    This parameter is displayed only when Socket I/O Sampling is enabled.

    NOTE:

    The tool captures only the socket I/Os that exceed the threshold for analysis.

    Old-Generation Object Sampling

    Indicates whether to enable old-generation object sampling. This function is enabled by default.
  3. Set parameters according to Table 1 and click OK.

    The task process is displayed. See Figure 4.

    • You can click Stop or Cancel to stop or cancel the sampling analysis task respectively.
    • After the sampling analysis task is complete, you can click View Details on the upper left of the report page to view the tuning suggestions on all tab pages.
    • Deleting a sampling analysis report will delete all historical data of the analysis task. Exercise caution when performing this operation.
    • If you delete a sampling analysis report that is opened on the current tab page, the tab page is reserved temporarily. After you close or refresh the tab page, the report data is deleted.
    Figure 4 Task process
Parent topic: Sampling Profiling