failed to flush export bulks

[wh211212]

Elasticsearch version:Elasticsearch 5.1.1

Plugins installed: []x-pack

JVM version:1.8.0_111

OS version:CentOS 7.3 CentOS 6.8

Description of the problem including expected versus actual behavior:
after install x-pack ,restart Elasticsearch faild,export some error
Steps to reproduce:

1. I remove data path all file,then restart Elasticsearch still failed

Provide logs (if relevant):
[2017-01-10T12:03:32,508][ERROR][o.e.x.m.AgentService ] [elastic-2] exception when exporting documents
org.elasticsearch.xpack.monitoring.exporter.ExportException: failed to flush export bulks
at org.elasticsearch.xpack.monitoring.exporter.ExportBulk$Compound.doFlush(ExportBulk.java:148) ~[x-pack-5.1.1.jar:5.1.1]
at org.elasticsearch.xpack.monitoring.exporter.ExportBulk.close(ExportBulk.java:77) ~[x-pack-5.1.1.jar:5.1.1]
at org.elasticsearch.xpack.monitoring.exporter.Exporters.export(Exporters.java:194) ~[x-pack-5.1.1.jar:5.1.1]
at org.elasticsearch.xpack.monitoring.AgentService$ExportingWorker.run(AgentService.java:208) [x-pack-5.1.1.jar:5.1.1]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_111]

Describe the feature:

[clintongormley]

Please consult the Elasticsearch logs to find out the problem.
Please ask questions like these in the forum instead: https://discuss.elastic.co/

The github issues list is reserved for bug reports and feature requests only.

thanks

[rprots]

Related: https://discuss.elastic.co/t/errors-after-installing-x-pack/64210