Default sleep between polls (#182)

* Update java-connectors/kafka-connect-azure-servicebus/src/main/java/io/lenses/streamreactor/connect/azure/servicebus/config/AzureServiceBusConfigConstants.java

Co-authored-by: David Sloan <[email protected]>

* separates the code that cleans up the resources used by the Service Bus subscription and the async client

* Fix the usage of Option.of since the exception can be null.

* Change the default sleep time window when empty records are to be returned to 250 for higher throughput

---------

Co-authored-by: David Sloan <[email protected]>
Co-authored-by: stheppi <[email protected]>

Author: 3 people

java-connectors/kafka-connect-azure-servicebus/src/main/java/io/lenses/streamreactor/connect/azure/servicebus/config/AzureServiceBusConfigConstants.java

@@ -66,7 +66,7 @@ public class AzureServiceBusConfigConstants {
       "The duration in milliseconds to sleep when no records are returned from the poll. This avoids a tight loop in Connect.";
   public static final String SOURCE_SLEEP_ON_EMPTY_POLL_MS =
       SOURCE_CONNECTOR_PREFIX + DOT + "sleep.on.empty.poll.ms";
-  public static final int SOURCE_SLEEP_ON_EMPTY_POLL_MS_DEFAULT = 100;
+  public static final int SOURCE_SLEEP_ON_EMPTY_POLL_MS_DEFAULT = 250;
 
   public static final String MAX_NUMBER_OF_RETRIES = SINK_CONNECTOR_PREFIX + DOT + "retries.max";
   public static final String MAX_NUMBER_OF_RETRIES_DOC = "Maximum number of retries if message sending fails.";