Module jdk.management.jfr
Package jdk.management.jfr

## Interface FlightRecorderMXBean

- All Superinterfaces:
    `PlatformManagedObject`

      public interface FlightRecorderMXBean
      extends PlatformManagedObject

  Management interface for controlling Flight Recorder.

  The object name for identifying the MXBean in the platform MBean server is:

  > `jdk.management.jfr:type=FlightRecorder`

  Flight Recorder can be configured in the following ways:

  - Recording options
    Specify how long a recording should last, and where and when data should be dumped.
  - Settings
    Specify which events should be enabled and what kind information each event should capture.
  - Configurations
    Predefined sets of settings, typically derived from a settings file, that specify the configuration of multiple events simultaneously.

  See the package `jdk.jfr` documentation for descriptions of the settings syntax and the `ConfigurationInfo` class documentation for configuration information.

  ### Recording options

  The following table shows the options names to use with `setRecordingOptions(long, Map)` and `getRecordingOptions(long)`.

  Recording options
  Name | Descripion | Default value | Format | Example values
  --- | --- | --- | --- | ---
  `name` | Sets a human-readable recording name | String representation of the recording id | `String` | `"My Recording"`, `"profiling"`
  `maxAge` | Specify the length of time that the data is kept in the disk repository until the oldest data may be deleted. Only works if `disk=true`, otherwise this parameter is ignored. | `"0"` (no limit) | `"0"` if no limit is imposed, otherwise a string representation of a positive `Long` value followed by an empty space and one of the following units, `"ns"` (nanoseconds) `"us"` (microseconds) `"ms"` (milliseconds) `"s"` (seconds) `"m"` (minutes) `"h"` (hours) `"d"` (days) | `"2 h"`, `"24 h"`, `"2 d"`, `"0"`
  `maxSize` | Specifies the size, measured in bytes, at which data is kept in disk repository. Only works if `disk=true`, otherwise this parameter is ignored. | `"0"` (no limit) | String representation of a `Long` value, must be positive | `"0"`, `"1000000000"`
  `dumpOnExit` | Dumps recording data to disk on Java Virtual Machine (JVM) exit | `"false"` | String representation of a `Boolean` value, `"true"` or `"false"` | `"true"`, `"false"`
  `destination` | Specifies the path where recording data is written when the recording stops. | `"false"` | See `Paths#getPath` for format. If this method is invoked from another process, the data is written on the machine where the target JVM is running. If destination is a relative path, it is relative to the working directory where the target JVM was started.} | `"c:\recording\recotding.jfr"`, `"/recordings/recording.jfr"`, `"recording.jfr"`
  `disk` | Stores recorded data as it is recorded | `"false"` | String representation of a `Boolean` value, `"true"` or `"false"` | `"true"`, `"false"`
  `duration` | Sets how long the recording should be running | `"0"` (no limit, continuous) | `"0"` if no limit should be imposed, otherwise a string representation of a positive `Long` followed by an empty space and one of the following units: `"ns"` (nanoseconds) `"us"` (microseconds) `"ms"` (milliseconds) `"s"` (seconds) `"m"` (minutes) `"h"` (hours) `"d"` (days) | `"60 s"`, `"10 m"`, `"4 h"`, `"0"`

  Since:
    9

- - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `static String` | `MXBEAN_NAME` | String representation of the `ObjectName` for the `FlightRecorderMXBean`.

  - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `long` | `cloneRecording​(long recordingId, boolean stop)` | Creates a copy of an existing recording, useful for extracting parts of a recording.
    `void` | `closeRecording​(long recordingId)` | Closes the recording with the specified ID and releases any system resources that are associated with the recording.
    `void` | `closeStream​(long streamId)` | Closes the recording stream with the specified ID and releases any system resources that are associated with the stream.
    `void` | `copyTo​(long recordingId, String outputFile)` | Writes recording data to the specified file.
    `List<ConfigurationInfo>` | `getConfigurations()` | Returns the list of predefined configurations for this Java Virtual Machine (JVM).
    `List<EventTypeInfo>` | `getEventTypes()` | Returns the list of currently registered event types.
    `Map<String,​String>` | `getRecordingOptions​(long recordingId)` | Returns a map that contains the options for the recording with the specified ID (for example, the destination file or time span to keep recorded data).
    `List<RecordingInfo>` | `getRecordings()` | Returns the list of the available recordings, not necessarily running.
    `Map<String,​String>` | `getRecordingSettings​(long recordingId)` | Returns a `Map` that contains the settings for the recording with the specified ID, (for example, the event thresholds)
    `long` | `newRecording()` | Creates a recording, but doesn't start it.
    `long` | `openStream​(long recordingId, Map<String,​String> streamOptions)` | Opens a data stream for the recording with the specified ID, or `0` to get data irrespective of recording.
    `byte[]` | `readStream​(long streamId)` | Reads a portion of data from the stream with the specified ID, or returns `null` if no more data is available.
    `void` | `setConfiguration​(long recordingId, String contents)` | Sets a configuration as a string representation for the recording with the specified ID.
    `void` | `setPredefinedConfiguration​(long recordingId, String configurationName)` | Sets a predefined configuration for the recording with the specified ID.
    `void` | `setRecordingOptions​(long recordingId, Map<String,​String> options)` | Configures the recording options (for example, destination file and time span to keep data).
    `void` | `setRecordingSettings​(long recordingId, Map<String,​String> settings)` | Sets and replaces all previous settings for the specified recording.
    `void` | `startRecording​(long recordingId)` | Starts the recording with the specified ID.
    `boolean` | `stopRecording​(long recordingId)` | Stops the running recording with the specified ID.
    `long` | `takeSnapshot()` | Creates a snapshot recording of all available recorded data.

    - ### Methods declared in interface java.lang.management.PlatformManagedObject

      `getObjectName`

- - ### Field Detail

    - #### MXBEAN_NAME

          static final String MXBEAN_NAME

      String representation of the `ObjectName` for the `FlightRecorderMXBean`.
      See Also:
        Constant Field Values

  - ### Method Detail

    - #### newRecording

          long newRecording()
                     throws IllegalStateException,
                            SecurityException

      Creates a recording, but doesn't start it.
      Returns:
        a unique ID that can be used to start, stop, close and configure the recording
      Throws:
        `IllegalStateException` - if Flight Recorder can't be created (for example, if the Java Virtual Machine (JVM) lacks Flight Recorder support, or if the file repository can't be created or accessed)
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`
      See Also:
        `Recording`

    - #### takeSnapshot

          long takeSnapshot()

      Creates a snapshot recording of all available recorded data.

      A snapshot is a synthesized recording in a stopped state. If no data is available, a recording with size `0` is returned.

      A snapshot provides stable access to data for later operations (for example, operations to change the time interval or to reduce the data size).

      The caller must close the recording when access to the data is no longer needed.

      Returns:
        a snapshot of all available recording data, not `null`
      Throws:
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`
      See Also:
        `Recording`

    - #### cloneRecording

          long cloneRecording​(long recordingId,
                              boolean stop)
                       throws IllegalArgumentException,
                              SecurityException

      Creates a copy of an existing recording, useful for extracting parts of a recording.

      The cloned recording contains the same recording data as the original, but it has a new ID and a name prefixed with `"Clone of recording"`. If the original recording is running, then the clone is also running.

      Parameters:
        `recordingId` - the recording ID of the recording to create a clone from
        `stop` - if the newly created clone is stopped before returning.
      Returns:
        a unique ID that can be used to start, stop, close and configure the recording
      Throws:
        `IllegalArgumentException` - if a recording with the specified ID doesn't exist
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`
      See Also:
        `Recording`

    - #### startRecording

          void startRecording​(long recordingId)
                       throws IllegalStateException,
                              SecurityException

      Starts the recording with the specified ID.

      A recording that is stopped can't be restarted.

      Parameters:
        `recordingId` - ID of the recording to start
      Throws:
        `IllegalArgumentException` - if a recording with the specified ID doesn't exist
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`
        `IllegalStateException`
      See Also:
        `Recording`

    - #### stopRecording

          boolean stopRecording​(long recordingId)
                         throws IllegalArgumentException,
                                IllegalStateException,
                                SecurityException

      Stops the running recording with the specified ID.
      Parameters:
        `recordingId` - the ID of the recording to stop
      Returns:
        `true` if the recording is stopped, `false` otherwise
      Throws:
        `IllegalArgumentException` - if a recording with the specified ID doesn't exist
        `IllegalStateException` - if the recording is not running
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`
      See Also:
        `newRecording()`

    - #### closeRecording

          void closeRecording​(long recordingId)
                       throws IOException

      Closes the recording with the specified ID and releases any system resources that are associated with the recording.

      If the recording is already closed, invoking this method has no effect.

      Parameters:
        `recordingId` - the ID of the recording to close
      Throws:
        `IllegalArgumentException` - if a recording with the specified ID doesn't exist
        `IOException` - if an I/O error occurs
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`
      See Also:
        `newRecording()`

    - #### openStream

          long openStream​(long recordingId,
                          Map<String,​String> streamOptions)
                   throws IOException

      Opens a data stream for the recording with the specified ID, or `0` to get data irrespective of recording.

      Recording stream options
      Name | Descripion | Default value | Format | Example values
      --- | --- | --- | --- | ---
      `startTime` | Specifies the point in time to start a recording stream. Due to how data is stored, some events that start or end prior to the start time may be included. | `Instant.MIN_VALUE.toString()` | ISO-8601. See `Instant.toString()` or milliseconds since epoch | `"2015-11-03T00:00"`, `"1446508800000"`
      `endTime` | Specifies the point in time to end a recording stream. Due to how data is stored, some events that start or end after the end time may be included. | `Instant.MAX_VALUE.toString()` | ISO-8601. See `Instant.toString()` or milliseconds since epoch | `"2015-11-03T01:00"`, `"1446512400000"`
      `blockSize` | Specifies the maximum number of bytes to read with a call to `readStream` | `"50000"` | A positive `long` value. Setting `blockSize` to a very high value may result in `OutOfMemoryError` or an `IllegalArgumentException`, if the Java Virtual Machine (JVM) deems the value too large to handle. | `"50000"`, `"1000000"`,

      If an option is omitted from the map the default value is used.

      The recording with the specified ID must be stopped before a stream can be opened. This restriction might be lifted in future releases.

      Parameters:
        `recordingId` - ID of the recording to open the stream for
        `streamOptions` - a map that contains the options that controls the amount of data and how it is read, or `null` to get all data for the recording with the default block size
      Returns:
        a unique ID for the stream.
      Throws:
        `IllegalArgumentException` - if a recording with the iD doesn't exist, or if `options` contains invalid values
        `IOException` - if the recording is closed, an I/O error occurs, or no data is available for the specified recording or interval
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`

    - #### closeStream

          void closeStream​(long streamId)
                    throws IOException

      Closes the recording stream with the specified ID and releases any system resources that are associated with the stream.

      If the stream is already closed, invoking this method has no effect.

      Parameters:
        `streamId` - the ID of the stream
      Throws:
        `IllegalArgumentException` - if a stream with the specified ID doesn't exist
        `IOException` - if an I/O error occurs while trying to close the stream
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`
      See Also:
        `openStream(long, Map)`

    - #### readStream

          byte[] readStream​(long streamId)
                     throws IOException

      Reads a portion of data from the stream with the specified ID, or returns `null` if no more data is available.

      To read all data for a recording, invoke this method repeatedly until `null` is returned.

      Parameters:
        `streamId` - the ID of the stream
      Returns:
        byte array that contains recording data, or `null` when no more data is available
      Throws:
        `IOException` - if the stream is closed, or an I/O error occurred while trying to read the stream
        `IllegalArgumentException` - if no recording with the stream ID exists
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("monitor")`

    - #### getRecordingOptions

          Map<String,​String> getRecordingOptions​(long recordingId)
                                                throws IllegalArgumentException

      Returns a map that contains the options for the recording with the specified ID (for example, the destination file or time span to keep recorded data).

      See `FlightRecorderMXBean` for available option names.

      Parameters:
        `recordingId` - the ID of the recording to get options for
      Returns:
        a map describing the recording options, not `null`
      Throws:
        `IllegalArgumentException` - if no recording with the specified ID exists
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("monitor")`

    - #### getRecordingSettings

          Map<String,​String> getRecordingSettings​(long recordingId)
                                                 throws IllegalArgumentException

      Returns a `Map` that contains the settings for the recording with the specified ID, (for example, the event thresholds)

      If multiple recordings are running at the same time, more data could be recorded than what is specified in the `Map` object.

      The name in the `Map` is the event name and the setting name separated by `"#"` (for example, `"jdk.VMInfo#period"`). The value is a textual representation of the settings value (for example, `"60 s"`).

      Parameters:
        `recordingId` - the ID of the recordings to get settings for
      Returns:
        a map that describes the recording settings, not `null`
      Throws:
        `IllegalArgumentException` - if no recording with the specified ID exists
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("monitor")`

    - #### setConfiguration

          void setConfiguration​(long recordingId,
                                String contents)
                         throws IllegalArgumentException

      Sets a configuration as a string representation for the recording with the specified ID.
      Parameters:
        `recordingId` - ID of the recording
        `contents` - a string representation of the configuration file to use, not `null`
      Throws:
        `IllegalArgumentException` - if no recording with the specified ID exists or if the configuration could not be parsed.
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`
      See Also:
        `Configuration.getContents()`

    - #### setPredefinedConfiguration

          void setPredefinedConfiguration​(long recordingId,
                                          String configurationName)
                                   throws IllegalArgumentException

      Sets a predefined configuration for the recording with the specified ID.
      Parameters:
        `recordingId` - ID of the recording to set the configuration for
        `configurationName` - the name of the configuration (for example, `"profile"` or `"default"`), not `null`
      Throws:
        `IllegalArgumentException` - if no recording with the specified ID exists
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`
      See Also:
        `getConfigurations()`

    - #### setRecordingSettings

          void setRecordingSettings​(long recordingId,
                                    Map<String,​String> settings)
                             throws IllegalArgumentException

      Sets and replaces all previous settings for the specified recording.

      A setting consists of a name/value pair, where name specifies the event and setting to configure, and the value specifies what to set it to.

      The name can be formed in the following ways:

      `<event-name> + "#" + <setting-name>`

      or

      `<event-id> + "#" + <setting-name>`

      For example, to set the sample interval of the CPU Load event to once every second, use the name `"jdk.CPULoad#period"` and the value `"1 s"`. If multiple events use the same name, for example if an event class is loaded in multiple class loaders, and differentiation is needed between them, then the name is `"56#period"`. The ID for an event is obtained by invoking `EventType.getId()` method and is valid for the Java Virtual Machine (JVM) instance that the event is registered in.

      A list of available event names is retrieved by invoking `FlightRecorder.getEventTypes()` and `EventType.getName()`. A list of available settings for an event type is obtained by invoking `EventType.getSettingDescriptors()` and `ValueDescriptor.getName()`.

      Parameters:
        `recordingId` - ID of the recording
        `settings` - name value map of the settings to set, not `null`
      Throws:
        `IllegalArgumentException` - if no recording with the specified ID exists
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("control")`
      See Also:
        `Recording.getId()`

    - #### setRecordingOptions

          void setRecordingOptions​(long recordingId,
                                   Map<String,​String> options)
                            throws IllegalArgumentException

      Configures the recording options (for example, destination file and time span to keep data).

      See `FlightRecorderMXBean` for a description of the options and values that can be used. Setting a value to `null` restores the value to the default value.

      Parameters:
        `recordingId` - the ID of the recording to set options for
        `options` - name/value map of the settings to set, not `null`
      Throws:
        `IllegalArgumentException` - if no recording with the specified ID exists
        `SecurityException` - if a security manager exists, and the caller does not have `ManagementPermission("control")` or an option contains a file that the caller does not have permission to operate on.
      See Also:
        `Recording.getId()`

    - #### getRecordings

          List<RecordingInfo> getRecordings()

      Returns the list of the available recordings, not necessarily running.

      MBeanServer access:
      The mapped type of `RecordingInfo` is `CompositeData` with attributes as specified in the `RecordingInfo.from` method.

      Returns:
        list of recordings, not `null`
      Throws:
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("monitor")`
      See Also:
        `RecordingInfo`, `Recording`

    - #### getConfigurations

          List<ConfigurationInfo> getConfigurations()

      Returns the list of predefined configurations for this Java Virtual Machine (JVM).

      MBeanServer access:
      The mapped type of `ConfigurationInfo` is `CompositeData` with attributes as specified in the `ConfigurationInfo.from` method.

      Returns:
        the list of predefined configurations, not `null`
      Throws:
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("monitor")`
      See Also:
        `ConfigurationInfo`, `Configuration`

    - #### getEventTypes

          List<EventTypeInfo> getEventTypes()

      Returns the list of currently registered event types.

      MBeanServer access:
      The mapped type of `EventTypeInfo` is `CompositeData` with attributes as specified in the `EventTypeInfo.from` method.

      Returns:
        the list of registered event types, not `null`
      Throws:
        `SecurityException` - if a security manager exists and the caller does not have `ManagementPermission("monitor")`
      See Also:
        `EventTypeInfo`, `EventType`

    - #### copyTo

          void copyTo​(long recordingId,
                      String outputFile)
               throws IOException,
                      SecurityException

      Writes recording data to the specified file.

      If this method is invoked remotely from another process, the data is written to a file named `outputFile` on the machine where the target Java Virtual Machine (JVM) is running. If the file location is a relative path, it is relative to the working directory where the target JVM was started.

      Parameters:
        `recordingId` - the ID of the recording to dump data for
        `outputFile` - the system-dependent file name where data is written, not `null`
      Throws:
        `IOException` - if the recording can't be dumped due to an I/O error (for example, an invalid path)
        `IllegalArgumentException` - if a recording with the specified ID doesn't exist
        `IllegalStateException` - if the recording is not yet started or if it is already closed
        `SecurityException` - if a security manager exists and its `SecurityManager.checkWrite(java.lang.String)` method denies write access to the named file or the caller does not have `ManagmentPermission("control")`
      See Also:
        `Path.toString()`, `Recording.dump(java.nio.file.Path)`