This demonstrates how a simple json data source can be used in Grafana to read the events of a JFR file.
For native image support, graalvm 21.3.0 (Java 17 version) is needed with path to it's directory set via environment variable GRAALVM_HOME
. This can be downloaded from:
https://github.com/graalvm/graalvm-ce-builds/releases
After downloading, run
/path/to/graal-install/bin/gu install native-image
libz.a
is also required to complete native image builds. On Fedora, dnf install zlib-devel
.
For containers, podman is needed. Installation instructions are here:
https://podman.io/getting-started/installation.html
This project uses Quarkus, which can produce a JAR to run in a JVM (JDK 17+), or an executable native image.
To build a JAR:
mvn clean verify
To build a native image instead:
mvn -Pnative clean verify
Native image builds may use more than 4G of RAM to complete.
To build a native image within a container, for a consistent environment:
mvn -Pnative -Dquarkus.native.container-build=true -Dquarkus.native.container-runtime=podman \
-Dquarkus.native.builder-image=quay.io/quarkus/ubi-quarkus-mandrel:21.3-java17 \
clean verify
If you built a JAR:
java -jar target/quarkus-app/quarkus-run.jar
If you built a native image:
./target/jfr-datasource-*-runner
- Install SimpleJson data source if not already installed via
grafana-cli --pluginsDir <path-to-your-plugins-directory> plugins install grafana-simple-json-datasource
- Add a SimpleJson data source
- Set the URL to the jfr-datasource (default:
http://localhost:8080
) - Create a panel that pulls from the data source and plots a timeseries
This project comes with a Dockerfile to produce a container image with the native image result.
podman build -f src/main/docker/Dockerfile.native -t quay.io/cryostat/jfr-datasource .
Responds with 200 OK. Used to verify server is available.
CURL Example
$ curl "localhost:8080/"
Expects a JFR file upload. Used to upload a JFR file to the server. Responds with the uploaded filename.
The webserver sets a default maximum file upload size of 10GB
(application.properties
: quarkus.http.limits.max-body-size=10G
).
This can be overridden on a deployed instance by setting the environment variable
QUARKUS_HTTP_LIMITS_MAX_BODY_SIZE
and restarting the instance.
CURL Example
$ curl -F "file=@/home/user/some-file.jfr" "localhost:8080/upload"
It is also possible to bypass this webserver HTTP body size limit by copying
the large JFR file directly into the webserver's filesystem storage location.
This location is defined as
(application.properties
: quarkus.http.body.uploads-directory=${java.io.tmpdir}${file.separator}jfr-file-uploads
),
or /tmp/jfr-file-uploads
. The following example assumes that the logged in
user has sufficient permissions and that the jfr-datasource
container has
an OpenShift Service and Route exposing it to traffic from outside the cluster.
oc
and CURL Example
$ oc cp my-large-file.jfr cryostat-sample-79cc897c8-smcrg:/tmp/jfr-file-uploads/my-large-file.jfr -c cryostat-sample-jfr-datasource
$ curl -X POST --data "my-large-file.jfr" "https://cryostat-sample-jfr-datasource-myproject.apps-crc.testing/set"
Sets a JFR file for querying requests. Expects file name specified via POST body.
CURL Example
$ curl -X POST --data "some-file" "localhost:8080/set"
Expects a JFR file upload. Performs Upload
and Set
in sequence. Responds with the uploaded and selected filename.
The webserver sets a default maximum file upload size. If the file to be
uploaded exceeds this size then either the limit can be raised or the /load
operation can be decomposed into two steps and the size limit worked around.
See the documentation for POST /upload
for further detail.
CURL Example
$ curl -F "file=@/home/user/some-file.jfr" "localhost:8080/load"
Lists files available for Set
.
If a file is currently Set
, it is highlighted with enclosing double asterisks **<filename>.jfr**
CURL Example
$ curl "localhost:8080/list"
file1.jfr
file2.jfr
**setFile.jfr**
Responds with the name of the currently Set
file.
CURL Example
$ curl "localhost:8080/current"
setFile.jfr
Deletes an individual JFR file. Expects file name specified via DELETE body.
If the specified file was Set
, then it is unset.
CURL Example
$ curl -X DELETE --data "some-file" "localhost:8080/delete"
Delete all JFR files.
CURL Example
$ curl -X DELETE "localhost:8080/delete_all"
These endpoints match those used by the Grafana Simple JSON datasource.
Responds with a JSON array containing selectable values of an event field (e.g. jdk.ObjectAllocationSample.objectClass
) specified in the JSON body's target
field. Used to define available selections for dashboard variables.
If target
is set to *
, responds with all selectable event fields.
CURL Example
$ curl -X POST --data '{ "target": "jdk.ObjectAllocationSample.objectClass" }' "localhost:8080/search"
Responds with a JSON array containing data points for a query. The query body format matches that of the Grafana Simple JSON datasource.
The target
field can have parameters to filter matching data points If there is no parameter, no matching is performed. If a parameter is specified with "*", matching is done for all possible value of that parameter.
CURL Example
$ curl -X POST --data '{ "target": "jdk.ObjectAllocationSample.weight?objectClass=java.util.HashSet", ...}' "localhost:8080/query"
This is a list of event attributes which work 'out-of-the-box' with this datasource. These are generally speaking any numerical timeseries-like event.
jdk.ActiveRecording.endTime
jdk.ActiveRecording.recordingDuration
jdk.ActiveRecording.recordingStart
jdk.BiasedLockClassRevocation.duration
jdk.BiasedLockRevocation.duration
jdk.BiasedLockSelfRevocation.duration
jdk.ClassLoaderStatistics.anonymousBlockSize
jdk.ClassLoaderStatistics.anonymousChunkSize
jdk.ClassLoaderStatistics.anonymousClassCount
jdk.ClassLoaderStatistics.blockSize
jdk.ClassLoaderStatistics.chunkSize
jdk.ClassLoaderStatistics.classCount
jdk.ClassLoadingStatistics.loadedClassCount
jdk.CodeCacheConfiguration.expansionSize
jdk.CodeCacheConfiguration.initialSize
jdk.CodeCacheConfiguration.minBlockLength
jdk.CodeCacheConfiguration.nonNMethodSize
jdk.CodeCacheConfiguration.nonProfiledSize
jdk.CodeCacheConfiguration.profiledSize
jdk.CodeCacheConfiguration.reservedSize
jdk.CodeSweeperStatistics.methodReclaimedCount
jdk.CodeSweeperStatistics.peakFractionTime
jdk.CodeSweeperStatistics.peakSweepTime
jdk.CodeSweeperStatistics.sweepCount
jdk.CodeSweeperStatistics.totalSweepTime
jdk.CompilerConfiguration.threadCount
jdk.CompilerStatistics.compileCount
jdk.CompilerStatistics.bailoutCount
jdk.CompilerStatistics.invalidatedCount
jdk.CompilerStatistics.osrCompileCount
jdk.CompilerStatistics.standardCompileCount
jdk.CompilerStatistics.osrBytesCompiled
jdk.CompilerStatistics.standardBytesCompiled
jdk.CompilerStatistics.nmetodsSize
jdk.CompilerStatistics.nmetodCodeSize
jdk.CompilerStatistics.peakTimeSpent
jdk.CompilerStatistics.totalTimeSpent
jdk.CPUInformation.sockets
jdk.CPUInformation.cores
jdk.CPUInformation.hwThreads
jdk.CPULoad.jvmSystem
jdk.CPULoad.jvmUser
jdk.CPULoad.machineTotal
jdk.CPUTimestampCounter.osFrequency
jdk.CPUTimestampCounter.fastTimeFrequency
jdk.DataLoss.amount
jdk.DataLoss.total
jdk.ExceptionStatistics.throwables
jdk.GCConfiguration
jdk.GCHeapConfiguration
jdk.GCSurvivorConfiguration
jdk.GCTLABConfiguration
jdk.G1EvacuationOldStatistics
jdk.G1EvacuationYoungStatistics
jdk.JavaThreadStatistics.accumulatedCount
jdk.JavaThreadStatistics.activeCount
jdk.JavaThreadStatistics.daemonCount
jdk.JavaThreadStatistics.peakCount
jdk.YoungGenerationConfiguration
jdk.MetaspaceGCThreshold
jdk.JVMInformation
jdk.PhysicalMemory
jdk.ThreadContextSwitchRate
jdk.ObjectAllocationSample.eventThread
jdk.ObjectAllocationSample.stackTrace
jdk.ObjectAllocationSample.objectClass
jdk.ObjectAllocationSample.weight
This is a list of events which have no attributes that work out-of-the-box or no relevant attributes when visualized in Grafana.
jdk.ActiveSetting
jdk.AllocationRequiringGC
jdk.BooleanFlag
jdk.BooleanFlagChanged
jdk.ClassDefine
jdk.ClassLoad
jdk.ClassUnload
jdk.CodeCacheFull
jdk.CodeCacheStatistics
jdk.CodeSweeperConfiguration
** jdk.Compilation
jdk.CompilationFailure
** jdk.CompilerInlining
jdk.CompilerPhase
jdk.ConcurrentModeFailure
jdk.DoubleFlag
jdk.DoubleFlagChanged