can you share a  screenshot of the Storm UI for your spout?

On Wed, Feb 4, 2015 at 9:58 PM, clay teahouse <> wrote:
 I have this issue with any amount of load. Different max spout pendings do not seem to make much a difference. I've lowered this parameter to 100, still a little difference . At this point the bolt consuming the data does no processing.

On Wed, Feb 4, 2015 at 3:26 PM, Haralds Ulmanis <> wrote:
I'm not sure, that i understand your problem .. but here is few points:
If you have large pending spout size and slow processing - you will see large latency at kafka spout probably. Spout emits message .. it stays in queue for long time (that will add latency) .. and finally is processed and ack received. You will see queue time + processing time in kafka spout latency.
Take a look at load factors of your bolts - are they close to 1 or more ? and load factor of kafka spout.

On 4 February 2015 at 21:19, Andrey Yegorov <> wrote:
have you tried increasing max spout pending parameter for the spout?

                       new KafkaSpout(spoutConfig),
          //the maximum parallelism you can have on a KafkaSpout is the number of partitions

Andrey Yegorov

On Tue, Feb 3, 2015 at 4:03 AM, clay teahouse <> wrote:
Hi all,

In my topology,  kafka spout is responsible for over 85% of the latency. I have tried different spout max pending and played with the buffer size and fetch size, still no luck. Any hint on how to optimize the spout? The issue doesn't seem to be with the kafka side, as I see high throughput with the simple kafka consumer.

thank you for your feedback