consumption message delay

[orange-jacky]

hi,anyone
I create a consumergroup to consumer some topics, and I print offset of each topic, and find some topic consumption delay.
Meanwhile, i create a consumergroup with "github.com/Shopify/sarama", and find topic is normal consumption.
Anyone can help me fix the issue?

tips:

**normal consumption source code**

kafka.go.zip

**consumption delay source code**
kafka_0.8.2_group.go.zip
delay_log.txt