Running Pinot with an invalid zookeeper service name seems to error during clean-up (in addition to connection error)

Running with an invalid zookeeper service name seems to have an error during clean-up in addition to the main error, eg: `bin/pinot-admin.sh StartController -clusterName PinotCluster -controllerHost null -controllerPort 9000 -dataDir /tmp/PinotController -zkAddress pinotzookeeper.service:2181`

It appears that not only did it error on `java.net.UnknownHostException: pinotzookeeper.service: Name or service not known`, but it also error'd on afterwards (or during recovery).
```
java.lang.NullPointerException: null
at org.apache.helix.manager.zk.client.ZkConnectionManager.cleanupInactiveWatchers(ZkConnectionManager.java:112)
```

Looks like it just may not be skipping cleanup when no connection was established?

Here's the full stack trace.

```
Initiating client connection, connectString=pinotzookeeper.service:2181 sessionTimeout=30000 watcher=org.apache.helix.manager.zk.client.ZkConnectionManager@432038ec
Unable to connect to server: pinotzookeeper:2181
java.net.UnknownHostException: pinotzookeeper.service: Name or service not known
at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method) ~[?:1.8.0_252]
at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:929) ~[?:1.8.0_252]
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1324) ~[?:1.8.0_252]
at java.net.InetAddress.getAllByName0(InetAddress.java:1277) ~[?:1.8.0_252]
at java.net.InetAddress.getAllByName(InetAddress.java:1193) ~[?:1.8.0_252]
at java.net.InetAddress.getAllByName(InetAddress.java:1127) ~[?:1.8.0_252]
at org.apache.zookeeper.client.StaticHostProvider.(StaticHostProvider.java:62) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.zookeeper.ZooKeeper.(ZooKeeper.java:449) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.zookeeper.ZooKeeper.(ZooKeeper.java:383) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.zookeeper.ZkConnection.connect(ZkConnection.java:63) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.zookeeper.ZkClient.connect(ZkClient.java:1565) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.zookeeper.ZkClient.(ZkClient.java:179) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.ZkClient.(ZkClient.java:87) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.client.ZkConnectionManager.(ZkConnectionManager.java:41) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.client.SharedZkClientFactory.getOrCreateZkConnectionNamanger(SharedZkClientFactory.java:60) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.client.SharedZkClientFactory.buildZkClient(SharedZkClientFactory.java:40) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.ZKHelixAdmin.(ZKHelixAdmin.java:107) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.controller.helix.core.util.HelixSetupUtils.setupHelixClusterIfNeeded(HelixSetupUtils.java:69) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.controller.helix.core.util.HelixSetupUtils.setupHelixController(HelixSetupUtils.java:63) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.controller.ControllerStarter.setUpHelixController(ControllerStarter.java:310) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.controller.ControllerStarter.start(ControllerStarter.java:289) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.service.PinotServiceManager.startController(PinotServiceManager.java:113) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.service.PinotServiceManager.startRole(PinotServiceManager.java:90) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.command.StartServiceManagerCommand.startPinotService(StartServiceManagerCommand.java:200) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.command.StartServiceManagerCommand.startPinotService(StartServiceManagerCommand.java:195) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.command.StartServiceManagerCommand.execute(StartServiceManagerCommand.java:166) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.command.StartControllerCommand.execute(StartControllerCommand.java:130) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.PinotAdministrator.execute(PinotAdministrator.java:156) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.PinotAdministrator.main(PinotAdministrator.java:168) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
Failed to start a [ CONTROLLER ] Service
java.lang.NullPointerException: null
at org.apache.helix.manager.zk.client.ZkConnectionManager.cleanupInactiveWatchers(ZkConnectionManager.java:112) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.client.ZkConnectionManager.close(ZkConnectionManager.java:95) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.client.ZkConnectionManager.close(ZkConnectionManager.java:91) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.zookeeper.ZkClient.connect(ZkClient.java:1591) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.zookeeper.ZkClient.(ZkClient.java:179) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.ZkClient.(ZkClient.java:87) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.client.ZkConnectionManager.(ZkConnectionManager.java:41) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.client.SharedZkClientFactory.getOrCreateZkConnectionNamanger(SharedZkClientFactory.java:60) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.client.SharedZkClientFactory.buildZkClient(SharedZkClientFactory.java:40) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.helix.manager.zk.ZKHelixAdmin.(ZKHelixAdmin.java:107) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.controller.helix.core.util.HelixSetupUtils.setupHelixClusterIfNeeded(HelixSetupUtils.java:69) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.controller.helix.core.util.HelixSetupUtils.setupHelixController(HelixSetupUtils.java:63) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.controller.ControllerStarter.setUpHelixController(ControllerStarter.java:310) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.controller.ControllerStarter.start(ControllerStarter.java:289) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.service.PinotServiceManager.startController(PinotServiceManager.java:113) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.service.PinotServiceManager.startRole(PinotServiceManager.java:90) ~[pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.command.StartServiceManagerCommand.startPinotService(StartServiceManagerCommand.java:200) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.command.StartServiceManagerCommand.startPinotService(StartServiceManagerCommand.java:195) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.command.StartServiceManagerCommand.execute(StartServiceManagerCommand.java:166) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.command.StartControllerCommand.execute(StartControllerCommand.java:130) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.PinotAdministrator.execute(PinotAdministrator.java:156) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
at org.apache.pinot.tools.admin.PinotAdministrator.main(PinotAdministrator.java:168) [pinot-all-0.5.0-SNAPSHOT-jar-with-dependencies.jar:0.5.0-SNAPSHOT-a8fbdaeffaf99c1df4258f60ecbbab1f553d7696]
```

Start with the ZkConnectionManager cleanupInactiveWatchers() and close() frames in the stack trace, then follow the connection setup from HelixSetupUtils.setupHelixClusterIfNeeded() and ControllerStarter.setUpHelixController(). Reproduce the controller start with the invalid -zkAddress shown in the issue. Done means the original connection failure remains clear without a secondary cleanup NullPointerException.

Written by the indexing model from the issue text.