* Fix Finagle plugin bug, in processing Noop Span.
* Make `CommandService` daemon to avoid blocking target application shutting down gracefully.
#### OAP-Backend
* Support InfluxDB as a new storage option.
* Add `selector` in the `application.yml`. Make the provider activation more flexible through System ENV.
* Support sub-topology map query.
* Support gRPC SSL.
* Support HTTP protocol for agent.
* Support Nginx LUA agent.
* Support skip the instance relationship analysis if some agents doesn't have upstream address, currently for LUA agent.
* Support metrics entity name in the storage. Optional, default OFF.
* Merge the HOUR and DAY metrics into MINUTE in the ElasticSearch storage implementation. Reduce the payload for ElasticSearch server.
* Support change detection mechanism in DCS.
* Support Daily step in the ElasticSearch storage implementation for low traffic system.
* Provide profile export tool.
* Support alarm gRPC hook.
* Fix PHP language doesn't show up on the instance page.
* Add more comments in the source codes.
* Add a new metrics type, multiple linears.
* Fix thread concurrency issue in the alarm core.
* Support meter system for Prometheus adoption. In future releases, we will add native meter APIs and MicroMeter(Sleuth) system.
* Support endpoint grouping.
* Add **SuperDataSet** annotation for storage entity.
* Add **superDatasetIndexShardsFactor** in the ElasticSearch storage, to provide more shards for @SuperDataSet annotated entites. Typically TraceSegment.
* Support alarm settings for relationship of service, instance, and endpoint level metrics.
* Support alarm settings for database(conjecture node in tracing scenario).
* Data Model could be added in the runtime, don't depend on the bootstrap sequence anymore.
* Reduce the memory cost, due to no inventory caches.
* No buffer files in tracing and service mesh cases.
* New ReadWriteSafe cache implementation. Simplify codes.
* Provide default way for metrics query, even the metrics doesn't exist.
* New GraphQL query protocol is provided. Support the metrics type query.
* Set up length rule of service, instance, and endpoint.
* Adjust the default jks for ElasticSearch to empty.
* Fix Apdex function integer overflow issue.
* Fix profile storage issue.
* Fix TTL issue.
* Fix H2 column type bug.
* Add JRE 8-14 test for the backend.
#### UI
* Support custom topology definition.
* UI dashboard is 100% configurable to adopt new metrics definited in the backend.
#### Document
* Add FAQ about `python2` command required in the compiling.
* Add doc about new e2e framework.
* Add doc about the new profile feature.
* Powered-by page updated.
* Add v8 upgrade document.
* Make the coverage accurate including UT and e2e tests.
* Add miss doc about collecting parameters in the profiled traces.
#### CVE
* Fix SQL Injection vulnerability in H2/MySQL implementation.
* Upgrade Nacos to avoid the FastJson CVE in high frequency.
* Upgrade jasckson-databind to 2.9.10.
All issues and pull requests are [here](https://github.com/apache/skywalking/milestone/37?closed=1)
All issues and pull requests are [here](https://github.com/apache/skywalking/milestone/45?closed=1)
7.0.0 release
------------------
You could find all CHANGES of 7.0.0 at [here](https://github.com/apache/skywalking/blob/v7.0.0/CHANGES.md)
