@jun Rao about this question，can you give me some suggestion？
> 在 2016年6月18日，上午11:26，Kafka <kafka...@126.com> 写道： > > hello，I have done a series of tests on kafka 0.9.0，and one of the results > confused me. > > test enviroment: > kafka cluster: 3 brokers，8core cpu ／ 8g mem ／1g netcard > client：4core cpu／4g mem > topic：6 partitions，2 replica > > total messages：10000 > singal message size：1024byte > fetch.min.bytes:1 > fetch.wait.max.ms:100ms > > all send tests are under the enviroment of using scala sync interface， > > when I set ack to 0，the producer’s delay is 0.3ms，the consumer’s delay is > 7.7ms > when I set ack to 1，the producer's delay is 1.6ms, the consumer’s delay is > 3.7ms > when I set ack to -1，the produce's delay is 3.5ms, the consumer’s delay is > 4.2ms > > but why consumer’s delay is decreased when I set ack from 0 to 1，its confused > me。 >
