Retry group joins on CoordinatorLoadInProgress error

This is a temporary error, so can be safely retried.

Author: dasch

lib/kafka/consumer_group.rb

@@ -161,6 +161,12 @@ def join_group
       @member_id = ""
       sleep 1
 
+      retry
+    rescue CoordinatorLoadInProgress
+      @logger.error "Coordinator broker still loading, retrying in 1s..."
+
+      sleep 1
+
       retry
     end