* add heart beat handler to jetty

* add heart beat handler to jetty

* Change version 

* #1202

1. Determine the log is enabled for the DEBUG level before printing message.
2. Make the columns initialize to be static attribute.
3. Topology build optimize: Cache query result to avoid repeating queries.

* #1202

Add elasticsearch batch process setting into application.yml.

* #1202

Fixed check style error.

* #1202

Use XContentFactory to build source to insert into elasticsearch.

* #1206

1. Support list data type attribute in streaming data.
2. Support multiple service names in segment duration index.

* Fixed the conflict.

* #1206

Add TODO description to notify linjiaqi.

* #1206

Remove @NotNull

* Add Zipkin receiver

Module class rename to ModuleDefine, Module is the JDK9 class. It is conflict with our Module class. (#1168)

* init test

* update

* agent-grpc-test

* part

* fix based on org.apache.skywalking.apm.agent.core.context.trace.AbstractTracingSpan.logs

* Fix Code Bug

* Add Test

* Fix Text

* add SegmentCounterTest

* fix based on org.apache.skywalking.apm.agent.core.context.trace.AbstractTracingSpan.logs

* Fix Code Bug

* Fix Doc

* Add non-merge persistence worker for segment, segment_duration, global_trace persistence.

* omitted class.

* Disable _all field.

* no message

* Refactor tps to cpm

* Change the implementation for new graphql protocol.

* Add aggregate column named duration in GC metric table.

* getGCTrend query finished.

* Change between seconds to between minutes.

* Provide short database column name.

* Compile successful

* Attribute name change from source to target.

* Provide highPerformanceMode setting for short column name speciality.

* Fixed a bug that persistent timer started multiple times.
Running about 10 minute, the result of collector performance test is above 1w TPS when using MacBook 2017.

* Refactor the collector configuration initialization.

#1047

Add contains point method instead instance of for decide span listener class type.
Transform minute time bucket just once.

#1032

* 1. Add the performance collection point.
2. Report formatter.

#1032

* Add a new cache implementation by caffeine.

#1032

* Performance optimization:
Make all the loggers class variable to have the static modifier.

#1009

* Add client side token.

* Fix ci.

* Fix most codes of token auth at both sides.

* Add settings in config files.

* Make auth interceptor doesn't throw expcetion.

* Update AuthenticationSimpleChecker.java

* Update AuthenticationActivator.java

* Revert "Update AuthenticationActivator.java"

This reverts commit 0935f18fd6802ab84c12e0609c21ef753ff51be3.

* Merge branch 'feature/token-auth' of https://github.com/apache/incubator-skywalking into feature/token-auth

# Conflicts:
#	apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/main/java/org/apache/skywalking/apm/collector/agent/grpc/provider/AuthenticationSimpleChecker.java

* Fix Auhentication token works incorrect (#1001)

* Fix Auhentication token works incorrect

* Change way to build GRPC Channel

* Response an empty header when auth fails.

* Finish the prototype of TLS of gRPC between agent and server.

* Fix for rat check.

* Update GRPCChannelManager.java

* Update AgentModuleGRPCProvider.java

* Upgrade netty version (#971)

* Make sure end user can't start gRPC server with and without SSL in the same port.

* [maven-release-plugin] prepare release apm-5.0.0-alpha

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

* Get the MQ server address id from reference.

* Fixed the remote exception bug when running cluster mode collector.
How: Register remote data entity into remote module.

2. Setting the src span type when agent register service name.
3. Revert the topology build logic.

2. Add column named service_name_keyword into service_name elastic search table by the type of keyword.

Fix assmbly for mvn clean install -Papache-release and update version to SNAPSHOT for SNAPSHOT release.