- System requirements
- Profiler architecture
- Profiler installation
- Uninstall profiler
- Running the profiler
- Profiler activation
- Welcome screen
- Start profiling
- Profiling overhead
- Snapshots
- Solving performance problems
- CPU profiling
- Thread profiling
- Virtual threads support
- Object allocation profiling
- Memory profiling
- Monitor profiling
- Exception profiling
- Telemetry
- Probes: monitor events of various kinds
- Inspections: automatic recognition of typical problems
- Automatically trigger actions on event
- Automatic deobfuscation
- Summary
- Filters
- Profiler command line
- Export of profiling results to external formats
- Profiler Java API
- Profiler HTTP API
- Settings
- Troubleshooting and FAQ
Profiler HTTP API
YourKit profiler agent exposes language neutral HTTP API which allows to control profiling mode, capture snapshots and get JVM telemetry. The HTTP API is a RESTful in terms that agent's responses do not depend on previous request history.
API is based on HTTP requests and JSON responses. All endpoints use
POST methods and receive JSON object as a parameter in
a request body. The response is always JSON object and has
application/json as a Content-Type.
This API uses standard HTTP response codes to indicate whether a method
completed successfully.
A 200 response indicates success. A 400 type response indicates a failure,
and a 500 type response indicates an internal system error.
You can use any tool of your choice to send HTTP requests, but in the examples
below we will use
cURL tool.
We suppose that profiled application is running on host and
profiler agent listens port.
Profiler agent always opens encrypted SSL socket. If you do not provide the
SSL certificate, the agent creates a self-signed SSL certificate on the fly.
To skip certificate validation, please add -k or
--insecure to cURL options.
Requests
- advanceGeneration
- captureHprofSnapshot
- captureMemorySnapshot
- capturePerformanceSnapshot
- clearEventTables
- forceGc
- getJvmTelemetry
- getProbeActivityModes
- getStatus
- getTotalCreatedObjects
- getTriggers
- resetAllocationProfiling
- resetCpuProfiling
- resetExceptionProfiling
- resetMonitorProfiling
- resetTelemetry
- resetThreadProfiling
- setProbeActivityModes
- setTriggers
- startAllocationProfiling
- startAsyncSamplingCpu
- startCallCounting
- startExceptionProfiling
- startMonitorProfiling
- startSampling
- startTelemetry
- startThreadProfiling
- startTracing
- stopAllocationProfiling
- stopCpuProfiling
- stopExceptionProfiling
- stopMonitorProfiling
- stopTelemetry
- stopThreadProfiling
POST advanceGeneration
Advances object generation number.
Endpoint
https://host:port/yjp/api/v2/advanceGeneration
Parameters
description - Optional description associated with the generation.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/advanceGeneration \
-d '{"description" : "Hello, world"}'
POST captureHprofSnapshot
Captures snapshot with heap data in HPROF format.
Endpoint
https://host:port/yjp/api/v2/captureHprofSnapshot
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/captureHprofSnapshot
Response example
{
"path" : "/home/foobar/Snapshots/DemoApp-2021-11-16.hprof"
}
path - Absolute file path of the captured snapshot file.
If a remote application is being profiled, then
the path is in the file system of the remote host.
POST captureMemorySnapshot
Captures snapshot with heap data in YourKit format.
Endpoint
https://host:port/yjp/api/v2/captureMemorySnapshot
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/captureMemorySnapshot
Response example
{
"path" : "/home/foobar/Snapshots/DemoApp-2021-11-16.snapshot"
}
path - Absolute file path of the captured snapshot file.
If a remote application is being profiled, then
the path is in the file system of the remote host.
POST capturePerformanceSnapshot
Captures performance snapshot without heap data.
Endpoint
https://host:port/yjp/api/v2/capturePerformanceSnapshot
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/capturePerformanceSnapshot
Response example
{
"path" : "/home/foobar/Snapshots/DemoApp-2021-11-16.snapshot"
}
path - Absolute file path of the captured snapshot file.
If a remote application is being profiled, then
the path is in the file system of the remote host.
POST resetAllocationProfiling
Clears recorded allocations. When object allocation profiling starts, collected allocation data is cleared automatically, so you do not have to explicitly call this method in that case.
Endpoint
https://host:port/yjp/api/v2/resetAllocationProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/resetAllocationProfiling
POST resetCpuProfiling
Clears current results of CPU profiling in any mode, be it sampling, tracing or call counting. When CPU profiling starts, collected CPU profiling data is cleared automatically, so you do not have to explicitly call this method in that case.
Endpoint
https://host:port/yjp/api/v2/resetCpuProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/resetCpuProfiling
POST resetTelemetry
Clears all charts.
Endpoint
https://host:port/yjp/api/v2/resetTelemetry
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/resetTelemetry
POST resetThreadProfiling
Clears the collected thread profiling data and continues the thread profiling if it is active.
Endpoint
https://host:port/yjp/api/v2/resetThreadProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/resetThreadProfiling
POST clearEventTables
Clears event table(s) by name. If the specified tables have dependent tables, they will be cleared too.
Endpoint
https://host:port/yjp/api/v2/clearEventTables
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/clearEventTables \
-d '{"tables" : ["File", "Thread"]}'
POST resetExceptionProfiling
Clears recorded exceptions. When exception profiling starts, recorded exceptions are cleared automatically, so you do not have to explicitly call this method in that case.
Endpoint
https://host:port/yjp/api/v2/resetExceptionProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/resetExceptionProfiling
POST resetMonitorProfiling
Clears monitor profiling data. When monitor profiling starts, collected monitor profiling data is cleared automatically, so you do not have to explicitly call this method in that case.
Endpoint
https://host:port/yjp/api/v2/resetMonitorProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/resetMonitorProfiling
POST forceGc
Forces garbage collection in the profiled application.
Endpoint
https://host:port/yjp/api/v2/forceGc
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/forceGc
POST getJvmTelemetry
Returns current JVM telemetry.
Endpoint
https://host:port/yjp/api/v2/getJvmTelemetry
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/getJvmTelemetry
Response example
{
"totalHeapSize" : 31172040
}
totalHeapSize - Size of JVM heap in bytes.
POST getProbeActivityModes
The mapping of probe class names to the
probe activity mode.
Mode might be on, off or auto.
Endpoint
https://host:port/yjp/api/v2/getProbeActivityModes
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/getProbeActivityModes
Response example
{
"com.yourkit.probes.builtin.Sockets" : "auto",
"com.yourkit.probes.builtin.Sync" : "off",
"com.yourkit.probes.builtin.Threads" : "on"
}
POST getStatus
Returns the status of the profiler agent. The status describes currently running profiling modes.
Endpoint
https://host:port/yjp/api/v2/getStatus
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/getStatus
Response example
{
"allocationProfiling" : true,
"allocationProfilingSettings" : {
"mode" : "exactStacks",
"recordEach" : 10,
"sizeLimit" : 4096,
"heapSamplingInterval" : 0
},
"asyncSamplingCpu" : false,
"asyncSamplingPeriodic" : false,
"callCounting" : false,
"cpuProfiling" : false,
"exceptionProfiling" : true,
"monitorProfiling" : false,
"pid" : 37568,
"sampling" : false,
"appName" : "DemoApp",
"telemetry" : true,
"threadProfiling" : true,
"tracing" : false,
"agentVersion" : "YourKit Java Profiler 2024.9-b1"
}
POST getTotalCreatedObjects
Statistics of object allocation profiling.
Endpoint
https://host:port/yjp/api/v2/getTotalCreatedObjects
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/getTotalCreatedObjects
Response example
{
"count" : 25694429,
"size" : 1481721664
}
count - Number of created objects.
size - Size in bytes.
POST getTriggers
Obtains current trigger description. If there are no triggers, an empty string will be returned.
Endpoint
https://host:port/yjp/api/v2/getTriggers
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/getTriggers
POST setProbeActivityModes
Changes probe activity modes of the specified probes.
Endpoint
https://host:port/yjp/api/v2/setProbeActivityModes
Parameters
Mapping of probe class names to
probe activity mode.
It specifies the probes whose mode should be changed.
If a probe is not present in the mapping, its mode will remain unchanged.
Mode might be on, off or auto.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/setProbeActivityModes \
-d '{
"com.yourkit.probes.builtin.Sockets" : "off",
"com.yourkit.probes.builtin.Threads" : "on"
}'
POST setTriggers
Sets triggers.
Endpoint
https://host:port/yjp/api/v2/setTriggers
Parameters
triggers - Description of trigger(s).
append - If true, the triggers will be added to the
currently existing triggers. If false will be replaced.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/setTriggers \
-d '{
"triggers" : "TimerListener delay=1h maxTriggerCount=-1\n PrintMessage message=Hello output=stdout\n",
"append":false
}'
POST startAllocationProfiling
Starts object allocation profiling. The method clears previously recorded allocation data.
Endpoint
https://host:port/yjp/api/v2/startAllocationProfiling
Parameters
mode - Allocation profiling mode.
One of counting | exactStacks | heapSampling
sizeLimit - Applicable in the modes exactStacks.
Record all objects with at least the specified size in bytes.
If the parameter is missing, the default size 4096 (4 KiB) is applied.
recordEach - Applicable in the modes exactStacks.
Record every N-th object smaller than the sizeLimit.
If the parameter is missing, default value 10 is applied.
heapSamplingInterval - Applicable in the mode heapSampling.
Specify the heap sampling interval in bytes.
If the parameter is missing, default value 131072 (128 KiB) is applied.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/startAllocationProfiling \
-d '{ "mode" : "counting"}'
POST startAsyncSamplingCpu
Starts asynchronous CPU sampling.
Asynchronous sampling is a low overhead profiling mode that does not suffer from a Safepoint bias problem. It features HotSpot-specific APIs to collect stack traces. It works with OpenJDK, Oracle JDK and other Java runtimes based on the HotSpot JVM.
Endpoint
https://host:port/yjp/api/v2/startAsyncSamplingCpu
Parameters
settings - CPU sampling settings.
Absent parameter means the use of profiled application's settings.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/startAsyncSamplingCpu
POST startAsyncSamplingPeriodic
Starts asynchronous periodic sampling.
Asynchronous sampling is a low overhead profiling mode that does not suffer from a Safepoint bias problem. It features HotSpot-specific APIs to collect stack traces. It works with OpenJDK, Oracle JDK and other Java runtimes based on the HotSpot JVM.
Endpoint
https://host:port/yjp/api/v2/startAsyncSamplingPeriodic
Parameters
settings - CPU sampling settings.
Absent parameter means the use of profiled application's settings.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/startAsyncSamplingPeriodic
POST startCallCounting
Starts CPU call counting. Unlike other CPU profiling modes only method invocations are counted, neither call stacks nor times are gathered.
Endpoint
https://host:port/yjp/api/v2/startCallCounting
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/startCallCounting
POST startExceptionProfiling
Starts exception profiling. If exception profiling is not running when this method is called, previous exception profiling data is cleared. If exception profiling is already running, this method has no effect.
Endpoint
https://host:port/yjp/api/v2/startExceptionProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/startExceptionProfiling
POST startMonitorProfiling
Starts monitor profiling. If monitor profiling is not running when this method is called, previous monitor profiling data is cleared. If monitor profiling is already running, this method has no effect.
Endpoint
https://host:port/yjp/api/v2/startMonitorProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/startMonitorProfiling
POST startSampling
Starts CPU sampling. When sampling is used, the profiler periodically queries stacks and times of running threads to estimate the slowest parts of the code. In this mode method invocation counts are not available.
Endpoint
https://host:port/yjp/api/v2/startSampling
Parameters
settings - CPU sampling settings.
Absent parameter means the use of profiled application's settings.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/startSampling
POST startTelemetry
Starts telemetry collection. If a telemetry collection is already in progress, the method has no effect.
Endpoint
https://host:port/yjp/api/v2/startTelemetry
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/startTelemetry
POST startThreadProfiling
Starts thread profiling. If thread profiling is already in progress, the method has no effect.
Endpoint
https://host:port/yjp/api/v2/startThreadProfiling
Parameters
mode - Thread profiling mode.
One of full | states.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/startThreadProfiling \
-d '{ "mode" : "full"}'
POST startTracing
Starts CPU tracing. When tracing is used, the profiler instruments the bytecode of the profiled application for recording time spent inside each profiled method. Both times and invocation counts are available.
Endpoint
https://host:port/yjp/api/v2/startTracing
Parameters
settings - CPU tracing settings.
Absent parameter means the use of profiled application's settings.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/startTracing
POST stopAllocationProfiling
Stops allocation profiling. If allocation profiling is not running, this method has no effect.
Endpoint
https://host:port/yjp/api/v2/stopAllocationProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/stopAllocationProfiling
POST stopCpuProfiling
Stops CPU profiling in any mode, be it sampling, tracing or call counting. If CPU profiling is not running, this method has no effect.
Endpoint
https://host:port/yjp/api/v2/stopCpuProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/stopCpuProfiling
POST stopExceptionProfiling
Stops exception profiling. If exception profiling is not running, this method has no effect.
Endpoint
https://host:port/yjp/api/v2/stopExceptionProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/stopExceptionProfiling
POST stopMonitorProfiling
Stops monitor profiling. If monitor profiling is not running, this method has no effect.
Endpoint
https://host:port/yjp/api/v2/stopMonitorProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/stopMonitorProfiling
POST stopTelemetry
Stops telemetry collection. If a telemetry collection is already stopped, the method has no effect.
Endpoint
https://host:port/yjp/api/v2/stopTelemetry
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/stopTelemetry
POST stopThreadProfiling
Stops thread profiling. If thread profiling is off, the method has no effect.
Endpoint
https://host:port/yjp/api/v2/stopThreadProfiling
Parameters
No.
cURL example
curl -k -X POST https://host:port/yjp/api/v2/stopThreadProfiling