microsoft/gctoolkit
Publicmirrored from https://github.com/microsoft/gctoolkitAvailable
sample/README.md
47lines · modecode
| 1 | # GCToolKit introductory sample |
| 2 | |
| 3 | This sample shows how to use [GCToolKit](../README.md) to analyze a GC log file and report on total heap occupancy after a GC cycle has been completed. For more details on how GCToolKit and this sample work, visit [Introducing Microsoft GCToolKit](https://devblogs.microsoft.com/java/introducing-microsoft-gctoolkit/). |
| 4 | |
| 5 | ## To run the sample |
| 6 | |
| 7 | ### From Maven |
| 8 | |
| 9 | Compile the sample with `mvn compile`, then use `mvn exec:exec` to run the sample. |
| 10 | |
| 11 | ```shell |
| 12 | $ mvn clean compile |
| 13 | $ mvn exec:exec |
| 14 | ``` |
| 15 | |
| 16 | By default, the sample analyzes `../gclogs/preunified/cms/defnew/details/defnew.log`. Set the parameter `gcLogPath` to analyze a different GC log file. |
| 17 | |
| 18 | ```shell |
| 19 | mvn exec:exec -DgcLogFile=../gclogs/unified/parallel/parallelgc.log |
| 20 | ``` |
| 21 | |
| 22 | ### From the command line |
| 23 | |
| 24 | The sample can also be run from the command line with Java 11 or higher. Compile the sample with `mvn compile dependency:copy-dependencies`, |
| 25 | then run `java` with `--module-path` and give it the path to a GC log file as an argument. |
| 26 | |
| 27 | ```shell |
| 28 | $ mvn clean compile dependency:copy-dependencies |
| 29 | $ java java --module-path target/classes:target/lib --module gctoolkit.sample/com.microsoft.gctoolkit.sample.Main ../gclogs/preunified/cms/defnew/details/defnew.log |
| 30 | ``` |
| 31 | |
| 32 | ## Troubleshooting |
| 33 | |
| 34 | ### `mvn exec:java` fails |
| 35 | |
| 36 | If you try to run the `exec:java` goal, you may see the following error: |
| 37 | |
| 38 | `Unable to parse configuration of mojo org.codehaus.mojo:exec-maven-plugin:3.0.0:java for parameter arguments: Cannot store value into array` |
| 39 | |
| 40 | This has something to do with the [Exec Maven Plugin](https://www.mojohaus.org/exec-maven-plugin/), which automatically builds the command line from the project dependencies. But it is unclear exactly what the cause of this issue is. The solution is to use the `exec:exec` goal. |
| 41 | |
| 42 | ### java.nio.file.NoSuchFileException: ../gclogs/preunified/cms/defnew/details/defnew.log |
| 43 | |
| 44 | There are two possible issues here. |
| 45 | |
| 46 | 1. There is no `gclogs` directory in the _top-level_ directory. The sample uses `unit-test` data from building GCToolKit. Either run `mvn test` from the _top-level_ directory, or use `-DgcLogFile=<path-to-gc-log-file>` argument to specify a log file. |
| 47 | 1. The sample is not being run from the `sample` directory. Please ensure you are in the sample directory before executing `mvn exec:exec`. |