- All Superinterfaces:
PlatformManagedObject
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).
| 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
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Field Summary
FieldsModifier and TypeFieldDescriptionstatic final StringString representation of theObjectNamefor theFlightRecorderMXBean. -
Method Summary
Modifier and TypeMethodDescriptionlongcloneRecording(long recordingId, boolean stop) Creates a copy of an existing recording, useful for extracting parts of a recording.voidcloseRecording(long recordingId) Closes the recording with the specified ID and releases any system resources that are associated with the recording.voidcloseStream(long streamId) Closes the recording stream with the specified ID and releases any system resources that are associated with the stream.voidWrites recording data to the specified file.Returns the list of predefined configurations for this Java Virtual Machine (JVM).Returns the list of currently registered event types.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).Returns the list of the available recordings, not necessarily running.getRecordingSettings(long recordingId) Returns aMapthat contains the settings for the recording with the specified ID, (for example, the event thresholds)longCreates a recording, but doesn't start it.longopenStream(long recordingId, Map<String, String> streamOptions) Opens a data stream for the recording with the specified ID, or0to get data irrespective of recording.byte[]readStream(long streamId) Reads a portion of data from the stream with the specified ID, or returnsnullif no more data is available.voidsetConfiguration(long recordingId, String contents) Sets a configuration as a string representation for the recording with the specified ID.voidsetPredefinedConfiguration(long recordingId, String configurationName) Sets a predefined configuration for the recording with the specified ID.voidsetRecordingOptions(long recordingId, Map<String, String> options) Configures the recording options (for example, destination file and time span to keep data).voidsetRecordingSettings(long recordingId, Map<String, String> settings) Sets and replaces all previous settings for the specified recording.voidstartRecording(long recordingId) Starts the recording with the specified ID.booleanstopRecording(long recordingId) Stops the running recording with the specified ID.longCreates a snapshot recording of all available recorded data.Methods declared in interface java.lang.management.PlatformManagedObject
getObjectName
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Field Details
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MXBEAN_NAME
String representation of theObjectNamefor theFlightRecorderMXBean.- See Also:
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Method Details
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newRecording
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 haveManagementPermission("control")- See Also:
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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
0is 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
- Throws:
SecurityException- if a security manager exists and the caller does not haveManagementPermission("control")- See Also:
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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 fromstop- 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 existSecurityException- if a security manager exists and the caller does not haveManagementPermission("control")- See Also:
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startRecording
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 existSecurityException- if a security manager exists and the caller does not haveManagementPermission("control")IllegalStateException- See Also:
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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:
trueif the recording is stopped,falseotherwise- Throws:
IllegalArgumentException- if a recording with the specified ID doesn't existIllegalStateException- if the recording is not runningSecurityException- if a security manager exists and the caller does not haveManagementPermission("control")- See Also:
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closeRecording
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 existIOException- if an I/O error occursSecurityException- if a security manager exists and the caller does not haveManagementPermission("control")- See Also:
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openStream
Opens a data stream for the recording with the specified ID, or0to get data irrespective of recording.
If an option is omitted from the map the default value is used.Recording stream options Name Descripion Default value Format Example values startTimeSpecifies 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"endTimeSpecifies 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"blockSizeSpecifies the maximum number of bytes to read with a call to readStream"50000"A positive longvalue.
SettingblockSizeto a very high value may result inOutOfMemoryErroror anIllegalArgumentException, if the Java Virtual Machine (JVM) deems the value too large to handle."50000",
"1000000",
streamVersionSpecifies 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"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 forstreamOptions- a map that contains the options that controls the amount of data and how it is read, ornullto 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 ifoptionscontains invalid valuesIOException- if the recording is closed, an I/O error occurs, or no data is available for the specified recording or intervalSecurityException- if a security manager exists and the caller does not haveManagementPermission("control")
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closeStream
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 existIOException- if an I/O error occurs while trying to close the streamSecurityException- if a security manager exists and the caller does not haveManagementPermission("control")- See Also:
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readStream
Reads a portion of data from the stream with the specified ID, or returnsnullif no more data is available.To read all data for a recording, invoke this method repeatedly until
nullis returned.- Parameters:
streamId- the ID of the stream- Returns:
- byte array that contains recording data, or
nullwhen no more data is available - Throws:
IOException- if the stream is closed, or an I/O error occurred while trying to read the streamIllegalArgumentException- if no recording with the stream ID existsSecurityException- if a security manager exists and the caller does not haveManagementPermission("monitor")
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getRecordingOptions
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
FlightRecorderMXBeanfor 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 existsSecurityException- if a security manager exists and the caller does not haveManagementPermission("monitor")
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getRecordingSettings
Returns aMapthat 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
Mapobject.The name in the
Mapis 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 existsSecurityException- if a security manager exists and the caller does not haveManagementPermission("monitor")
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setConfiguration
Sets a configuration as a string representation for the recording with the specified ID.- Parameters:
recordingId- ID of the recordingcontents- a string representation of the configuration file to use, notnull- 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 haveManagementPermission("control")- See Also:
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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 forconfigurationName- the name of the configuration (for example,"profile"or"default"), notnull- Throws:
IllegalArgumentException- if no recording with the specified ID existsSecurityException- if a security manager exists and the caller does not haveManagementPermission("control")- See Also:
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setRecordingSettings
void setRecordingSettings(long recordingId, Map<String, String> settings) throws IllegalArgumentExceptionSets 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 invokingEventType.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()andEventType.getName(). A list of available settings for an event type is obtained by invokingEventType.getSettingDescriptors()andValueDescriptor.getName().- Parameters:
recordingId- ID of the recordingsettings- name value map of the settings to set, notnull- Throws:
IllegalArgumentException- if no recording with the specified ID existsSecurityException- if a security manager exists and the caller does not haveManagementPermission("control")- See Also:
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setRecordingOptions
void setRecordingOptions(long recordingId, Map<String, String> options) throws IllegalArgumentExceptionConfigures the recording options (for example, destination file and time span to keep data).See
FlightRecorderMXBeanfor a description of the options and values that can be used. Setting a value tonullrestores the value to the default value.- Parameters:
recordingId- the ID of the recording to set options foroptions- name/value map of the settings to set, notnull- Throws:
IllegalArgumentException- if no recording with the specified ID existsSecurityException- if a security manager exists, and the caller does not haveManagementPermission("control")or an option contains a file that the caller does not have permission to operate on.- See Also:
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getRecordings
List<RecordingInfo> getRecordings()Returns the list of the available recordings, not necessarily running.MBeanServer access:
The mapped type ofRecordingInfoisCompositeDatawith attributes as specified in theRecordingInfo.frommethod.- Returns:
- list of recordings, not
null - Throws:
SecurityException- if a security manager exists and the caller does not haveManagementPermission("monitor")- See Also:
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getConfigurations
List<ConfigurationInfo> getConfigurations()Returns the list of predefined configurations for this Java Virtual Machine (JVM).MBeanServer access:
The mapped type ofConfigurationInfoisCompositeDatawith attributes as specified in theConfigurationInfo.frommethod.- Returns:
- the list of predefined configurations, not
null - Throws:
SecurityException- if a security manager exists and the caller does not haveManagementPermission("monitor")- See Also:
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getEventTypes
List<EventTypeInfo> getEventTypes()Returns the list of currently registered event types.MBeanServer access:
The mapped type ofEventTypeInfoisCompositeDatawith attributes as specified in theEventTypeInfo.frommethod.- Returns:
- the list of registered event types, not
null - Throws:
SecurityException- if a security manager exists and the caller does not haveManagementPermission("monitor")- See Also:
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copyTo
Writes recording data to the specified file.If this method is invoked remotely from another process, the data is written to a file named
outputFileon 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 foroutputFile- the system-dependent file name where data is written, notnull- 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 existIllegalStateException- if the recording is not yet started or if it is already closedSecurityException- if a security manager exists and itsSecurityManager.checkWrite(java.lang.String)method denies write access to the named file or the caller does not haveManagmentPermission("control")- See Also:
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