Briefly, this error occurs when Elasticsearch’s Machine Learning (ML) feature fails to update its memory tracker. This could be due to insufficient memory, a configuration issue, or a problem with the ML job. To resolve this, you can try increasing the memory allocation for Elasticsearch, checking the configuration of the ML job for any errors, or restarting the ML job. If the problem persists, consider checking the Elasticsearch logs for more detailed error messages that can help pinpoint the issue.
This guide will help you check for common problems that cause the log ” ML memory tracker last update failed and listeners called ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin, listeners, memory.
Log Context
Log “ML memory tracker last update failed and listeners called” classname is MlMemoryTracker.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
synchronized (fullRefreshCompletionListeners) {
assert fullRefreshCompletionListeners.isEmpty() == false;
for (ActionListener listener : fullRefreshCompletionListeners) {
listener.onFailure(e);
}
logIfNecessary(() -> logger.warn("ML memory tracker last update failed and listeners called"; e));
// It's critical that we empty out the current listener list on
// error otherwise subsequent retries to refresh will be ignored
fullRefreshCompletionListeners.clear();
}
});
