consumer on 0.11 very slow compared to 0.10

[xhbpiao]

Sarama Version: 1.14.0
Kafka Version: 0.11
Go Version: 1.9

When I consumed kafka 0.11, it was only 2,000 more

The following is a 0.11 test data
config.Version=sarama.V0_11_0_0
2017/11/16 18:04:52 Authenticated: id=171052472662687789, timeout=4000
2017/11/16 18:04:52 Re-submitting 0 credentials after reconnect
num is 1595
num is 3815
num is 6065
num is 8305
num is 10515
num is 12865
num is 15115
num is 17315
num is 19595
num is 21855
num is 24135

The following is a 0.10 test data
2017/11/16 18:10:15 Authenticated: id=171049895100416379, timeout=4000
2017/11/16 18:10:15 Re-submitting 0 credentials after reconnect
num is 17945
num is 98631
num is 247405
num is 422190
num is 597477
num is 768666
num is 945612
num is 1128327
num is 1313118
num is 1491429
num is 1670132
num is 1840736
num is 2015498
num is 2195034
num is 2370444
num is 2540082