I have DBconnect 3.1.3 running on a 7.0.1 instance with 3 DB Inputs, 2 of them work perfectly but the third one puts out the error below and then fails. Two of the connections are almost identical except they go to different DBs, but one works and one doesn't. I have tried restarting and reconfiguring the input.
2018-04-12 18:48:43.627 +0000 [QuartzScheduler_Worker-29] ERROR c.s.d.s.task.listeners.RecordWriterMetricsListener - action=unable_to_write_batch
java.io.IOException: HTTP Error 400: Bad Request
at com.splunk.dbx.server.dbinput.recordwriter.HttpEventCollector.uploadEventBatch(HttpEventCollector.java:112)
at com.splunk.dbx.server.dbinput.recordwriter.HttpEventCollector.uploadEvents(HttpEventCollector.java:89)
at com.splunk.dbx.server.dbinput.recordwriter.HecEventWriter.writeRecords(HecEventWriter.java:36)
at org.easybatch.core.job.BatchJob.writeBatch(BatchJob.java:203)
at org.easybatch.core.job.BatchJob.call(BatchJob.java:79)
at org.easybatch.extensions.quartz.Job.execute(Job.java:59)
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:573)
Found the problem, the HEC fails to write when a single event has 800000+ characters. Had 1 log message that was ~800x the size of a normal log message and that was causing the failure, when that message is skipped (by changing the rising column) everything goes back to working as intended.