marvel不出现数据，并报错

ES 1.7.6
ES 安装了head和marvel，在Hadoop上运行了一个Wordcount例子，marvel没能读取数据，并且报错，求大腿点拨一下~~谢谢

[2017-06-27 10:04:12,808][DEBUG][action.index ] [m1] [.marvel-kibana][3], node[Ckl9P8e1ToWtQ5hhRBiDLw], [P], s[STARTED]: Failed to execute [index {[.marvel-kibana][_gateway/snapshot][AVznSriF6yHP1vB3CMpu], source[_na_]}]
org.elasticsearch.indices.InvalidTypeNameException: mapping type name [_gateway/snapshot] can't start with '_'
at org.elasticsearch.index.mapper.MapperService.merge(MapperService.java:319)
at org.elasticsearch.index.mapper.MapperService.merge(MapperService.java:307)
at org.elasticsearch.index.mapper.MapperService.documentMapperWithAutoCreate(MapperService.java:482)
at org.elasticsearch.index.shard.IndexShard.prepareCreate(IndexShard.java:463)
at org.elasticsearch.action.index.TransportIndexAction.shardOperationOnPrimary(TransportIndexAction.java:201)
at org.elasticsearch.action.support.replication.TransportShardReplicationOperationAction$PrimaryPhase.performOnPrimary(TransportShardReplicationOperationAction.java:574)
at org.elasticsearch.action.support.replication.TransportShardReplicationOperationAction$PrimaryPhase$1.doRun(TransportShardReplicationOperationAction.java:440)
at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:36)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:748)