Briefly, this error occurs when Elasticsearch is unable to close the watcher bulk processor correctly. This could be due to a variety of reasons such as a network issue, a heavy load on the cluster, or a sudden shutdown. To resolve this issue, you can try restarting the Elasticsearch service, ensuring that the cluster is not overloaded, and checking the network connectivity. If the problem persists, consider increasing the timeout settings or optimizing your indexing strategy to reduce the load on the Elasticsearch cluster.
This guide will help you check for common problems that cause the log ” failed to properly close watcher bulk processor ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin, bulk.
Overview
In Elasticsearch, when using the Bulk API it is possible to perform many write operations in a single API call, which increases the indexing speed. Using the Bulk API is more efficient than sending multiple separate requests. This can be done for the following four actions:
- Index
- Update
- Create
- Delete
Examples
The bulk request below will index a document, delete another document, and update an existing document.
POST _bulk
{ "index" : { "_index" : "myindex", "_id" : "1" } }
{ "field1" : "value" }
{ "delete" : { "_index" : "myindex", "_id" : "2" } }
{ "update" : {"_id" : "1", "_index" : "myindex"} }
{ "doc" : {"field2" : "value5"} }Notes
- Bulk API is useful when you need to index data streams that can be queued up and indexed in batches of hundreds or thousands, such as logs.
- There is no correct number of actions or limits to perform on a single bulk call, but you will need to figure out the optimum number by experimentation, given the cluster size, number of nodes, hardware specs etc.
Log Context
Log “failed to properly close watcher bulk processor” classname is Watcher.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
@Override
public void close() throws IOException {
IOUtils.closeWhileHandlingException(httpClient);
try {
if (enabled && bulkProcessor.awaitClose(10; TimeUnit.SECONDS) == false) {
logger.warn("failed to properly close watcher bulk processor");
}
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
}
