Replace org.codehaus.jackson with FasterXML/jackson about helix

[brunnsbe]

I forked this repository and made a commit that replaces the old Jackson with the newer FasterXML/Jackson:
brunnsbe@ca36d5e
I however have problems running all the tests as quite many of them throws an OutOfMemoryException:

...
[ERROR]   TestZkHelixPropertyStore.testSet » OutOfMemory unable to create new native thr...
[ERROR]   TestZkHelixPropertyStore.testSetInvalidPath » OutOfMemory unable to create new...
[ERROR]   TestZkHelixPropertyStore.testZkClientMonitor » OutOfMemory unable to create ne...
[ERROR]   TestZkHelixPropertyStore.testZkTriggeredCallback » OutOfMemory unable to creat...
[ERROR]   TestZkManagerWithAutoFallbackStore.testBasic » OutOfMemory unable to create ne...
[INFO]
[ERROR] Tests run: 866, Failures: 177, Errors: 0, Skipped: 103
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary for Apache Helix 0.9.1-SNAPSHOT:
[INFO]
[INFO] Apache Helix ....................................... SUCCESS [  2.061 s]
[INFO] Apache Helix :: Core ............................... FAILURE [  01:00 h]
[INFO] Apache Helix :: Admin Webapp ....................... SKIPPED
[INFO] Apache Helix :: Restful Interface .................. SKIPPED
[INFO] Apache Helix :: HelixAgent ......................... SKIPPED
[INFO] Apache Helix :: Recipes ............................ SKIPPED
[INFO] Apache Helix :: Recipes :: Rabbitmq Consumer Group . SKIPPED
[INFO] Apache Helix :: Recipes :: Rsync Replicated File Store SKIPPED
[INFO] Apache Helix :: Recipes :: distributed lock manager  SKIPPED
[INFO] Apache Helix :: Recipes :: distributed task execution SKIPPED
[INFO] Apache Helix :: Recipes :: service discovery ....... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  01:00 h
[INFO] Finished at: 2019-08-13T09:23:19+03:00
[INFO] ------------------------------------------------------------------------
...

[narendly]

Will take a look.

[xyuanlu]

Hi @brunnsbe,

Thanks so much for working on Helix!
We did a performance experiment profile and find for a specific use case -- Helix controller leadership switch, using FasterXML/jackson along with some other performance improv changes, we get round around ~3x faster performance result.

Baseline profile:
The org.apache.helix.zookeeper.datamodel.serializer.ZNRecordSerializer.deserialize took ~60% of the time for org.apache.helix.manager.zk.DistributedLeaderElection.onControllerChange, where onControllerChange overall takes ~60s. This function call is CPU heavy.

After changing to FasterXML/jackson and made the ObjectMapper static, ZNRecordSerializer.deserialize only take ~10% of the total time, where onControllerChange overall takes ~20s. It becomes IO bounded.

It is another evidence that we should replace org.codehaus.jackson with FasterXML/jackson.

Do you want to continue the work and create a PR :D?

Xiaoyuan

[xyuanlu]

BTW, we improved our unit test and you won't see that much OutOfMemoryException now.