Cannot generate dynamic mappings of type [_id] for [_id]]

[SjonHortensius]

I keep gettting this error while attempting to reindex a few indexes. Since the index contains data from graylog, the generated _mappings are quite long; but nothing obviously wrong. Full message:

[2016-11-01 16:57:20,897][DEBUG][action.bulk              ] [NODE] [graylog2_0-2.4.0][0] failed to execute bulk item (index) index {[graylog2_0-2.4.0][message][1ea85f90-xxx00cbcdbb], source[{"gl2_source_node":"713372bd-x","line":0,"Boot_id":"942dxa08711e856d4ca3d","version":"1.0","timestamp":"2014-03-11 18:01:07.000","message":"Starting Session 100 of user git.","level":6,"facility":"systemd","_id":"1ea85f90-xxx00cbcdbb","streams":[],"Pid":"1","Uid":"0"}]}
MapperParsingException[Cannot generate dynamic mappings of type [_id] for [_id]]
        at org.elasticsearch.index.mapper.DocumentParser.createBuilderFromFieldType(DocumentParser.java:506)
        at org.elasticsearch.index.mapper.DocumentParser.parseDynamicValue(DocumentParser.java:616)
        at org.elasticsearch.index.mapper.DocumentParser.parseValue(DocumentParser.java:444)
        at org.elasticsearch.index.mapper.DocumentParser.parseObject(DocumentParser.java:264)
        at org.elasticsearch.index.mapper.DocumentParser.parseDocument(DocumentParser.java:124)
        at org.elasticsearch.index.mapper.DocumentMapper.parse(DocumentMapper.java:309)
        at org.elasticsearch.index.shard.IndexShard.prepareIndex(IndexShard.java:580)
        at org.elasticsearch.index.shard.IndexShard.prepareIndexOnPrimary(IndexShard.java:559)
        at org.elasticsearch.action.index.TransportIndexAction.prepareIndexOperationOnPrimary(TransportIndexAction.java:211)
        at org.elasticsearch.action.index.TransportIndexAction.executeIndexRequestOnPrimary(TransportIndexAction.java:223)
        at org.elasticsearch.action.bulk.TransportShardBulkAction.shardIndexOperation(TransportShardBulkAction.java:327)
        at org.elasticsearch.action.bulk.TransportShardBulkAction.shardOperationOnPrimary(TransportShardBulkAction.java:120)
        at org.elasticsearch.action.bulk.TransportShardBulkAction.shardOperationOnPrimary(TransportShardBulkAction.java:68)
        at org.elasticsearch.action.support.replication.TransportReplicationAction$PrimaryPhase.doRun(TransportReplicationAction.java:648)

Document from the error-message

{
   "gl2_source_node":"713372bd-x",
   "line":0,
   "Boot_id":"942dxa08711e856d4ca3d",
   "version":"1.0",
   "timestamp":"2014-03-11 18:01:07.000",
   "message":"Starting Session 100 of user x.",
   "level":6,
   "facility":"systemd",
   "_id":"1ea85f90-xxx00cbcdbb",
   "streams":[],
   "Pid":"1",
   "Uid":"0"
}

Is there anything wrong with these documents? It seems to me META fields should not be mapped? What does this error-message indicate?

[clintongormley]

Hi @SjonHortensius

Yes, you can't have an _id field inside the document _source any more, as of 2.0. You'll need to reindex these documents manually including a script to delete the _id field during reindexing.

[SjonHortensius]

Thanks, I missed that. After setting script.engine.groovy.inline.update: true I added this to my reindex parameters:

  "script": {
    "inline": "ctx._id = ctx._source.remove(\"_id\")"
  }

and that does indeed seem to fix it