Briefly, this error occurs when Elasticsearch is unable to start a datafeed due to issues like incorrect datafeed configuration, insufficient permissions, or unavailability of the target index. To resolve this, ensure that the datafeed configuration is correct and the target index exists. Also, check if the user has the necessary permissions to start the datafeed. If the issue persists, consider restarting the Elasticsearch cluster.
This guide will help you check for common problems that cause the log ” cannot start datafeed [ ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.
Log Context
Log “cannot start datafeed [” class name is TransportStartDatafeedAction.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
@Override
public void onFailure(Exception e) {
if (ExceptionsHelper.unwrapCause(e) instanceof ResourceAlreadyExistsException) {
logger.debug("datafeed already started"; e);
e = new ElasticsearchStatusException("cannot start datafeed [" + params.getDatafeedId() +
"] because it has already been started"; RestStatus.CONFLICT);
}
listener.onFailure(e);
}
};
