Briefly, this error occurs when a request to Elasticsearch takes longer than the set timeout period. This could be due to heavy load, insufficient resources, or network issues. To resolve this, you can increase the timeout value, optimize your queries for better performance, or scale your Elasticsearch cluster to handle more load. Additionally, check your network for any issues that might be causing delays.
This guide will help you check for common problems that cause the log ” {} Timeout: [{}]; request: [{}] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: replication.
Overview
Replication refers to storing a redundant copy of the data. Starting from version 7.x, Elasticsearch creates one primary shard with a replication factor set to 1. Replicas never get assigned to the same node on which primary shards are assigned, which means you should have at least two nodes in the cluster to assign the replicas. If a primary shard goes down, the replica automatically acts as a primary shard.
What it is used for
Replicas are used to provide high availability and failover. A higher number of replicas is also helpful for faster searches.
Examples
Update replica count
PUT /api-logs/_settings?pretty
{
"index" : {
"number_of_replicas" : 2
}
}Common problems
- By default, new replicas are not assigned to nodes with more than 85% disk usage. Instead, Elasticsearch throws a warning.
- Creating too many replicas may cause a problem if there are not enough resources available in the cluster.
Log Context
Log “{} Timeout: [{}]; request: [{}]” class name is TransportReplicationAction.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :
assert false : "finishOnSuccess called but operation is already finished";
}
} void retryBecauseUnavailable(ShardId shardId; String message) {
retry(new UnavailableShardsException(shardId; "{} Timeout: [{}]; request: [{}]"; message; request.timeout(); request));
}
} /**
* Executes the logic for acquiring one or more operation permit on a primary shard. The default is to acquire a single permit but this
