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 final String
    MXBEAN_NAME
    String representation of the ObjectName for the FlightRecorderMXBean.

  • Method Summary

    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 Details

    • MXBEAN_NAME

      static final String MXBEAN_NAME
      String representation of the ObjectName for the FlightRecorderMXBean.
      See Also:

  • Method Details

    • newRecording

      long newRecording() throws IllegalStateException
      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)
      See Also:

    • 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 unique ID that can be used for reading recording data
      See Also:

    • cloneRecording

      long cloneRecording(long recordingId, boolean stop) throws IllegalArgumentException
      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
      See Also:

    • startRecording

      void startRecording(long recordingId) throws IllegalStateException
      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
      IllegalStateException
      See Also:

    • stopRecording

      boolean stopRecording(long recordingId) throws IllegalArgumentException, IllegalStateException
      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
      See Also:

    • 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
      See Also:

    • 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",
      streamVersion Specifies format to use when reading data from a running recording "1.0" A version number with a major and minor.

      To be able to read from a running recording the value must be set      		 "1.0"
      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, unless the option "streamVersion" is specified.

      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

    • 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
      See Also:

    • 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

    • 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

    • 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

    • 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.
      See Also:

    • 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
      See Also:

    • 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
      See Also:

    • 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
      See Also:

    • 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
      See Also:

    • 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
      See Also:

    • 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
      See Also:

    • copyTo

      void copyTo(long recordingId, String outputFile) throws IOException
      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
      See Also: