BlockingBatchedESOutput Error

[pbrocker]

Running ES 5.6.1

2017-11-21T16:01:25.902Z ERROR [BlockingBatchedESOutput] Unable to flush message buffer
java.lang.ClassCastException: Cannot cast java.lang.String to org.joda.time.DateTime
        at java.lang.Class.cast(Class.java:3369) ~[?:1.8.0_111]
        at org.graylog2.plugin.Message.getFieldAs(Message.java:384) ~[graylog.jar:?]
        at org.graylog2.plugin.Message.getTimestamp(Message.java:189) ~[graylog.jar:?]
        at org.graylog2.indexer.messages.Messages.propagateFailure(Messages.java:181) ~[graylog.jar:?]
        at org.graylog2.indexer.messages.Messages.bulkIndex(Messages.java:145) ~[graylog.jar:?]
        at org.graylog2.outputs.ElasticSearchOutput.writeMessageEntries(ElasticSearchOutput.java:111) ~[graylog.jar:?]
        at org.graylog2.outputs.BlockingBatchedESOutput.flush(BlockingBatchedESOutput.java:129) [graylog.jar:?]
        at org.graylog2.outputs.BlockingBatchedESOutput.writeMessageEntry(BlockingBatchedESOutput.java:110) [graylog.jar:?]
        at org.graylog2.outputs.BlockingBatchedESOutput.write(BlockingBatchedESOutput.java:92) [graylog.jar:?]
        at org.graylog2.buffers.processors.OutputBufferProcessor$1.run(OutputBufferProcessor.java:191) [graylog.jar:?]
        at com.codahale.metrics.InstrumentedExecutorService$InstrumentedRunnable.run(InstrumentedExecutorService.java:176) [graylog.jar:?]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_111]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_111]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_111]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_111]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_111]

[jochen]

You have one or more messages which have a string in the “timestamp” field instead of a proper date/time object.

[pbrocker]

Fixed the issue… ES was not indexing fields properly after updating ES. Some of the indices had no mapped fields. After creating a template in ES for the fields. All the errors went away in GL.