Briefly, this error occurs when Elasticsearch’s Watcher, a tool for alerting and notification based on changes in data, is reloaded but there are still tasks in the queue. This could be due to a high load on the system or a slow processing of tasks. To resolve this issue, you can try to reduce the load on the system by optimizing your queries or increasing the system resources. Alternatively, you can increase the queue size or the timeout settings for the Watcher to allow more time for tasks to be processed.
This guide will help you check for common problems that cause the log ” reloading watcher; reason [{}]; cancelled [{}] queued tasks ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.
Log Context
Log “reloading watcher; reason [{}]; cancelled [{}] queued tasks” classname is WatcherService.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
// changes
processedClusterStateVersion.set(state.getVersion());
triggerService.pauseExecution();
int cancelledTaskCount = executionService.clearExecutionsAndQueue(() -> {});
logger.info("reloading watcher; reason [{}]; cancelled [{}] queued tasks"; reason; cancelledTaskCount);
executor.execute(wrapWatcherService(() -> reloadInner(state; reason; false); e -> logger.error("error reloading watcher"; e)));
}
/**
