Error while setting "exp_pager_stime" parameter on a bucket

The test is trying set the parameter "exp_pager_stime" but is failing with error :

[2015-07-08 00:59:09,395] - [cluster_helper:345] INFO - Setting flush param on server

{'username': 'Administrator', 'ip': u'172.23.107.212', 'password': 'password', 'port': u'8091'}

, exp_pager_stime to 10 on bucket0
setting param: exp_pager_stime 10
[2015-07-08 00:59:09,397] - [indexscans_2i:52] INFO - Got empty data (remote died?). from 172.23.107.212

The parameter is being set through memcached binary protocol. The test uses testrunner/lib/mc_bin_client.py to do this operation.

I did not see any activity in babysitter log around 2015-07-08 00:59

Server Logs:
https://s3-ap-southeast-1.amazonaws.com/indexing-test/Set2_Job3_Run41/collectinfo-2015-07-08T082802-ns_1%40172.23.107.210.zip
https://s3-ap-southeast-1.amazonaws.com/indexing-test/Set2_Job3_Run41/collectinfo-2015-07-08T082802-ns_1%40172.23.107.211.zip
https://s3-ap-southeast-1.amazonaws.com/indexing-test/Set2_Job3_Run41/collectinfo-2015-07-08T082802-ns_1%40172.23.107.212.zip
https://s3-ap-southeast-1.amazonaws.com/indexing-test/Set2_Job3_Run41/collectinfo-2015-07-08T082802-ns_1%40172.23.107.213.zip

Test Log: https://s3-ap-southeast-1.amazonaws.com/indexing-test/Set2_Job3_Run41/Set2_Job3_Run41_test11