* Fix #2546

* Change the stackdepth type

* Fix bug

* Fix CI failed

* fix #2599

* fix ci

* add license

* add ActiveTag error methods

* fix

* fix

* nacos

* nacos

* nacos

* nacos

* fix ci

* support nacos cluster

* fix yml

* fix license

* fix ci

* remove optional

* update license

* update license and doc

* fix

* Rename metric to metrics.

* Fixed test case execute failure issues.

2. Add unit tests for cluster-zookeeper-plugin;
3. Add unit tests for cluster-kubernetes-plugin;

* Move submodule plugin.

* Always auto-submodule

* [maven-release-plugin] prepare release v6.1.0

* [maven-release-plugin] prepare for next development iteration

* Change keys location.

* Make k8s-Coordinator back in role mode.

* Start query API server after the core started.

* Do lock when port has been intialized.

* Rename service.

* Fix text cases.

* Declare ConfigService.class in core module.

* Implement in an easier way.

* Envoy print whole metric, now in debug.

* Forcedly fix envoy timestamp issue.

* Support to register different host/port at cluster coordinator. Only for Zookeeper and Consul

* Provide document for internalComHost and internalComPort

* Reset port to default.

* [maven-release-plugin] prepare release v6.0.0-GA

* [maven-release-plugin] prepare for next development iteration

* Finish the basic codes of telemetry.

* Add many telemetry in oap.

* Fix a test case.

* Finish all telemetry metric.

* Fix format.

* Make telemetry works.

* Support JVM metrics.

* Add doc for telemetry.

* Fix typo.

* Fix #2135

* modify code style

* ci

* Provide consul cluster plugin.

* Change log and application config file.

* Add consul's config item into the docker's application.yml.

* Fixed bug.

* Add consul description into  readme.

* Add okhttp component license.

2. Zookeeper implementation of the cluster module using name space to support using same zookeeper cluster by different OAP clusters.

* Close the clients which are unreachable.
Remote client manager test case and comments.

* Test the GRPCRemote client.

* 1. Catch the throwable for onComplete method cause of it will throw exception when connection lost.
2. Check the gRPC channel state, send message when state is ready, wait 5 second when state is not ready.

Notice: gRPC channel getState with true parameter will trigger reconnect operation.

* gRPC client will reconnect to the server when network recorvered.

* Recovery application.yml

* Recovery proto module commit id.

* no message

* Fixed compile error.

* OAP server testing module.

#1930

* #Missing delete code.

* Lock oracle and resin plugins version.

* Move resin and oracle plugin to openskywalking

* Restore submodule active.

* Add another submodule active command.

* Remove the wrong test cases in release and fix some doc issues.

* [maven-release-plugin] prepare release v6.0.0-alpha

* [maven-release-plugin] prepare for next development iteration

* Fix some doc

* Update submodule skywalking-ui

* Fix k8s api bugs

* Fix api connection leak

* 1. Fixed the bug of the cluster node sync failure cause by curator instance cache is null.
2. Fixed the bug of the collection in remote data builder is not initialized.

* 1. Re-generate indicator.

* Fixed the bug of the collection in remote data builder is not initialized.

* Fixed the bug of the remote client created but not  initialize.

* Update submodule skywalking-ui

* Fix k8s api bugs

* Sample operator code.

* Indicator aggregator framework.

* Provide some annotation for OAL.

* Remote module.

* Register service.

* Add apache license header.

* Ignore comments when load definition files.

# 1447
Use `GET /api/v1/watch/namespaces/{namespace}/pods` api to watch pod's
containerIp which help collector containers to discovery each other.

* Receiver, aggregate, server finished.

* Cluster module implementation finished.