* Add pattern logger to replace the easy logger.
* Doc update
* Support console log 

change `agent.span_limit_per_segment` default value to match the default value of `SPAN_LIMIT_PER_SEGMENT` in https://github.com/apache/skywalking/blob/master/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/Config.java

* improve auto connect

* add config

* use int instread of atomic

* update format

* update doc

* update var name and doc

* fix

* support elasticsearch address configuration with http scheme.

* update logical.

* Update backend-storage.md

* Update backend-storage.md

* Update ES-Server-FAQ.md

* add http

* update plugin

* Add StaticMethodsAroundInterceptor to be injected.

* move to options plugin

* move folder

* update pom

* support https

* add witness class

* Make JDK9-11 available for bootstrap instrumentation

* Remove temp folder of old bootstrap instrumentation requirement.

* remove witness ,work for jdk6,7,8,9,10,11

* Make JDK 12 works.

* move jdk-http-plugin to bootstrap-plugins folder

* add httpsclient

* update README.md

* Support upgrade backend w/o rebooting agents

* Make JDK9-11 available for bootstrap instrumentation

* Remove temp folder of old bootstrap instrumentation requirement.

* correct 3rd default alarm rule description

* unit change: 1000ms -> 1s

* Remove javassist dependency

*   Finish the PR.

* Change doc title level.

* Remove the duplicated codes.

* POC: Intercept successfully.

* Refactor codes

* Build the new core

* Setup the new core.

* Push the javassist version to 3.23.2-GA, as it is the last version supports JDK 1.6 compile, according to https://github.com/jboss-javassist/javassist/blob/rel_3_23_2_ga/pom.xml#L149-L160

* Finish the all codes.

* Document updated for bootstrap instrumentation.

* Add a notice to document.

* Remove unexpected file.

* Set javassist version right. Add judge in core interceptors

* Fixe no log bridge implementation

* First commit

* Fix e2e test and some nits

* Documenting so11y and setting default values of it in dev env

* Fix 3096

* spring_async_plugin

* fix

* fix

* fix

* fix

* format fix

* rename

* fix

* fix version

* Update SWCallable.java

* Update Supported-list.md

* Update Supported-list.md

* AsyncAppender

* improve performance

* fix mdc issue

* fix mdc

* add Async demo

* Support bootstrap class enhance and fix OOM by empty stack of exception.

* Agent document update

* Remove a word.

* Fix wrong cause exception search.

* Fix the condition

* Revert bootstrap class loader enhance.

* Remove import.

* no message

Change go2sky repo. Tetrate.io donated it to SkyAPM

* Remove login permanently.

* Sync UI change.

* Delete `org.apache.skywalking.apm.webapp.security`

* Delete tests.

* Add config to control tracing sql parameters

* configration-zookeeper

* restore solrj-plugin

* restore solrj-plugin

* Provide Apollo dynamic configuration center implementation. fixes #2825

* Update backend-alarm.md

* Update backend-alarm.md

* Revert SolrJ plugin.

* Remove an unexpected test case.

* Revert "Remove an unexpected test case."

This reverts commit 359990e18b0c0ae1a6e1005ff985bf237ec05619.

* Clear context.

* Fix a leak.

* Provide Nacos dynamic configuration center implementation. fixes #2816

* Add unit tests

* Sync

* Replace pull-mode with watch-mode

* Fix ci

* Unify dependency management

* Add integration tests

* Revert unexpected changes

* Add more test cases

* Revert unexpected changes

* Suppress IDE warning

* Correctify volumes position

* Add license header

* Remove Chinese comments

* Sync

* Sync

* Sync

* Sync

* Revert unexpected changes

* Rebase on refactored code and add missing config to docker

* Fix unit test

* Revert unnecessary changes

* new branch for solrj-plugin

* rollback and add module solrj-plugin

* preparing to pr

* to resolve reviewers' suggestions

* remove unused code

* remove unused code

* remove unused comments

* To avoid NPE

* fix typo

* Change to JRE6

* fix pom.xml merge incorrectly. and java.net.URL instead of Regex

* Using RuntimeContext instead of ThreadLocal

* To reduce unnecessary tags

* add test cases

* fix validation fail

* add solrj-plugin into component-libraries & Supported-list

* to trace all patch to avoid recheck status of span

* remove unnecessary properites

* remove unnecessary tags

* Add the config to document of setup

* Implement the base of config API module.

* Finish configuration module codebases w/o tests, revert some changes.

* Finish mock tests.

* Add new gRPC service for configuration.

* Make gRPC configuration sync provider works.

* Add database slow statement dynamic setting.

* Finish the dynamic configuration service.

* Fix version.

* The new feature of Elasticsearch storage with the time series implementation.

* Time bucket util improve.

* Fixed some Gramma error.

* Update ttl.md

Polish English a little.

* Update ttl.md

Add more explicit description of TTL

* Update ttl.md

* Update StorageModuleElasticsearchConfig.java

Set otherMetricsDataTTL = 0 as default, make user more clear.

* Rename the timeSeriesAble to capableOfTimeSeries

* Fixed a test case failure.

* merge

* merge

* Provide plugin for ShardingSphere (#2699)

* Provide plugin for ShardingSphere (#2699)

* Provide plugin for ShardingSphere (#2699)

* adjust package name (#2699)

* fix mvnw (#2699)

* revert files access permission from 644 to 755

* change the access permission from 644 to 755

* change files access permission from 644 to 755

* revert all no changes files

* feat(agent sdk): resteasy plugin

* fix(agent sdk): fix component define

* fix(agent sdk): fix file license

* fix(agent sdk): fix file license

* docs(agent sdk): add supported list

* fix(agent sdk): fix file license

* fix(agent sdk): fix response error tag

* fix(agent sdk): fix

* fix(agent sdk): adapter 3.5+

* fix(agent sdk): remove unreasonable async handling

* spring cloud gateways plugin

* Add ALS proto and receiver in envoy

* Link Go agent project in main repo.

* Fix link.

* Provide plugin for ShardingSphere (#1933)