Here are the basic and simple usages of the MeterSystem APIs.
## Meter Creation
New meter could be created based on metrics name, function, scope and data type.
1. Metrics name is still the storage entity name.
2. Functions are every similar with the OAL function, just accepting different input.
```java
final MeterSystem meterSystem = MeterSystem.meterSystem(getManager());
meterSystem.create("test_long_metrics", "avg", ScopeType.SERVICE, Long.class);
```
NOTICE, this creation should only be called in the `module#prepare` stage, otherwise, `Can't create new metrics anymore` exception will be raised after the **CORE** module `start` stage finished. You may find out, there is a chance `create` could be executed successfully in your own `module#start` stage, but it it just because of the sequence of provider loaded by the class loader, **no guarantee, so please don't do that**.
## Runtime Calculation
`AcceptableValue` is the object created at the runtime to accept new metrics value.
```java
final MeterSystem service = getManager().find(CoreModule.NAME).provider().getService(MeterSystem.class);
Executors.newSingleThreadScheduledExecutor().scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
final AcceptableValue<Long> value = service.buildMetrics("test_long_metrics", Long.class);
value.accept(MeterEntity.newService("abc"), 5L);
value.setTimeBucket(TimeBucket.getMinuteTimeBucket(System.currentTimeMillis()));
service.doStreamingCalculation(value);
}
}, 2, 2, TimeUnit.SECONDS);
```
## Meter Functions
Right now, only `avg` function has been implemented. I submit this PR as soon as possible to get your feedback. I will add more functions.
## Notice
1. Make slow trace query available in the sampled record. Logically, they are the same thing. The UI doesn't need to concern about the trace as a special case.
2. Endpoint dependency will be removed from the dashboard. Because no query available for it. We will provide a new page for that in 8.1
3. Comparison page will be removed due to dashboard is powerful enough to replace it.
Motivation:
Review code styles with some bots automatically.
Modifications:
Set up ReviewDog in GitHub Action to review code style.
Add more check rules to checkstyle plugin.
Result:
Obvious code styles can be reviewed and commented automatically.
* Change OAL generator tool to runtime.
Step 1. change project structure. API links and maven pom.
* Part of metrics class generation
* Metrcis class generated.
* Set up the basic structure of new OAL engine.
* Finish metrics generation.
* Support dispatcher generation.
* Format codes.
* Generate dispatcher all methods.
* Implement disable in hardcode.
* Clear up
* Fix compile startup.
* Update license and document of new OAL engine.
* Fix rat.
* Disable class output in default
* Copy from @kezhenxu94 's test PR, https://github.com/apache/skywalking/pull/3110
* Wait for the mount command to finish
吴晟 Wu Sheng
kezhenxu94