Could not start datafeed; allocation explanation – How to solve this Elasticsearch error

Opster Team

July-20, Version: 1.7-8.0

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This guide will help you check for common problems that cause the log ” Could not start datafeed; allocation explanation ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: allocation and plugin.

Log Context

Log “Could not start datafeed; allocation explanation [“classname  is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

if (assignment.equals(DatafeedNodeSelector.AWAITING_JOB_ASSIGNMENT)) {
 return true;
 if (assignment.equals(PersistentTasksCustomMetadata.INITIAL_ASSIGNMENT) == false && assignment.isAssigned() == false) {
 // Assignment has failed despite passing our "fast fail" validation
 exception = new ElasticsearchStatusException("Could not start datafeed; allocation explanation [" +
 assignment.getExplanation() + "]"; RestStatus.TOO_MANY_REQUESTS);
 return true;
 DatafeedState datafeedState = (DatafeedState) persistentTask.getState();


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