Add: ElasticSearch backend listener

[anthonygauthier]

Description

After 3 years of developing and maintaining the ElasticSearch Backend Listener plugin for JMeter, I believe it's time for it to be integrated to the main codebase.

• Added org.apache.jmeter.visualizers.backend.elasticsearch package
• Added the following classes:
  • ElasticsearchBackendClient.java
  • ElasticsearchMetric.java
  • ElasticsearchMetricSender.java
  • ElasticsearchRequests.java
• Added unit tests
  • TestElasticsearchBackend.java

Motivation and Context

As I mentioned above, after 3 years of developing, publishing and maintaining the plugin "Elasticsearch Backend Listener", I believe it is time for it to be added to the main codebase. As a result of this, Elasticsearch would officially be supported by JMeter and would evolve nicely with it.

It is clearly a used and needed integration since, as it stands, there are over 2500 users installing the plugin (source).

How Has This Been Tested?

The plugin itself has been tested through and through for over 3 years. As for how it's been tested in the main codebase; I've changed all the packages names, added the necessary dependencies in the build.gradle.kts of the components workspace. I have applied the necessary coding styles, corrected and adjusted if necessary.

My testing environment consisted of the following:

• locally built JMeter (5.3.1-SNAPSHOT + my code modifications)
• ElasticSearch 7.9.0
• Kibana 7.9.0

To test, I built JMeter using gw runGui. I then added a sample Thread Group as well as Debug samplers and a Backend Listener to which I setup the config to point to my local ElasticSearch engine.
I executed the test and verified that samples showed up.

Screenshots

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist:

• My code follows the code style of this project.
• I have updated the documentation accordingly.

[anthonygauthier]

Hey there @pmouawad , anything to change in your opinion?

[pmouawad]

Hello @delirius325 ,
Thanks a lot for your contribution.
Can you open a discussion on dev mailing list for this PR ?

Thanks
Regards

[vlsi]

Just in case, here's dependency impact.
+5MiB is not that very expensive, however, it would be great if there was a brief explanation of why the dependency is needed and why existing classes are not enough.

For instance, we already have jackson-*, so do we really need gson?
Do we need guava?
Do we need AWS clients?

    55421535 => 60544843 bytes (+5123308 bytes)
    98 => 108 files (+10)
  
  + 1013903 aws-java-sdk-core-1.11.851.jar
  +  272295 aws-java-sdk-secretsmanager-1.11.851.jar
  +   12691 aws-signing-request-interceptor-0.0.22.jar
  +   64552 elasticsearch-rest-client-7.9.0.jar
  +  240255 gson-2.8.6.jar
  + 2256213 guava-18.0.jar
  +  565410 ion-java-1.0.2.jar
  +   48468 jackson-dataformat-cbor-2.6.7.jar
  +   27590 jmespath-java-1.11.851.jar
  +  621931 joda-time-2.8.1.jar

[anthonygauthier]

@vlsi Thanks for the feedback! I've added comments concerning AWS and I've switched from Gson to Jackson, therefore avoiding the need to add a new dependency.

[pmouawad]

Hello @delirius325 ,
The drawbacks I see currently are:

• For signing on AWS ElasticSearch, It introduces a dependency on aws-java-sdk and google guava which might not be acceptable. This should be available as a pluggable thing instead
• We need to maintain in core a dependency on a 3rd party (Elastic Search) that has a faster pace in terms of releases
• is there a reason for not keeping the plugin as is and contributing it to JMeter core ?

The addition looks really useful, but I am wondering if it's not better that this one remains as a plugin, as its pace of release can be faster than JMeter one.

What's your thoughts ?
Regards

[anthonygauthier]

Hey @pmouawad ,

You bring up some good points; including the plugin's JAR probably would be the more logical and flexible approach to this. Otherwise, I agree that I would have to cut back on some of the features to remove certain dependencies (i.e. for AWS). Honestly, it's a good thing you brought this up, I hadn't even thought about doing it like that.

I'll look into making that happen instead of having an "official" implementation.

Thanks for the feedback!

[pmouawad]

Thanks for your answer.
I'll close this PR for now.
Thanks