Here is an optional plugin `apm-customize-enhance-plugin`
## Introduce
SkyWalking has provided [Java agent plugin development guide](https://github.com/apache/incubator-skywalking/blob/master/docs/en/guides/Java-Plugin-Development-Guide.md) to help developers to build new plugin.
This plugin is not designed for replacement but for user convenience. The behaviour is very similar with [@Trace toolkit](Application-toolkit-trace.md), but without code change requirement, and more powerful, such as provide tag and log.
## How to configure
Implementing enhancements to custom classes requires two steps.
1. Active the plugin, move the `optional-plugins/apm-customize-enhance-plugin.jar` to `plugin/apm-customize-enhance-plugin.jar`.
2. Set `plugin.customize.enhance_file` in agent.config, which targets to rule file, such as `/absolute/path/to/customize_enhance.xml`.
3. Set enhancement rules in `customize_enhance.xml`.
@@ -94,6 +94,7 @@ Now, we have the following known optional plugins.
* Gson serialization lib in optional plugin folder
* Lettuce 5.x(JRE1.8+) in optional plugin folder
* Zookeeper 3.4.x in optional plugin folder. The reason of being optional plugin is, many business irrelevant traces are generated, which cause extra payload to agents and backends. At the same time, those traces may be just heartbeat(s).
*[Customize enhance](Customize-enhance-trace.md) Trace methods based on description files, rather than write plugin or change source codes.
## Advanced Features
* Set the settings through system properties for config file override. Read [setting override](Setting-override.md).