static final String MXBEAN_NAME

String representation of the ObjectName for the FlightRecorderMXBean.

long newRecording() throws IllegalStateException, SecurityException

Creates a recording, but doesn't start it.

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.

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.

void startRecording(long recordingId) throws IllegalStateException, SecurityException

Starts the recording with the specified ID.

A recording that is stopped can't be restarted.

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

Stops the running recording with the specified ID.

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.

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.

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.

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.

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.

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").

void setConfiguration(long recordingId, String contents) throws IllegalArgumentException

Sets a configuration as a string representation for the recording with the specified ID.

void setPredefinedConfiguration(long recordingId, String configurationName) throws IllegalArgumentException

Sets a predefined configuration for the recording with the specified ID.

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().

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.

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.

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.

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.

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.