Before you begin reading this guide, we recommend you try running the Elasticsearch Error Check-Up which can resolve issues causing many log errors (free and no installation required)
This guide will help you check for common problems that cause the log “Actual Exception” to appear. It’s important to understand the issues related to the log, so to get started, read the general overview on common issues and tips related to the Elasticsearch concepts: replication.
Advanced users might want to skip right to the common problems section in each concept or try running the Check-Up which analyses ES to discover the cause of many errors and provides suitable actionable recommendations.
Replication in Elasticsearch
What it is
Replication refers to storing the 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 on 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 replication count
PUT /api-logs/_settings?pretty
{
"index" : {
"number_of_replicas" : 2
}
}
Common problems
- By default, If free disk space usage reaches 85%, the replicas of newly created indices are not assigned on that node and 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”actual Exception” classname is TransportReplicationAction.java
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
Releasables.close(indexShardReference);
try {
channel.sendResponse(t);
} catch (IOException responseException) {
logger.warn("failed to send error message back to client for action [{}]"; responseException; transportReplicaAction);
logger.warn("actual Exception"; t);
}
}
}
private void doFinish() {
Related issues to this log
We have gathered selected Q&A from the community and issues from Github, that can help fix related issues please review the following for further information :
1 Elasticsearch Net 7 1 0 Issue
2 Querying Elasticsearch With Nest Er
About Opster
Opster line of products and support services detects, prevents, optimizes and automates everything needed to manage mission-critical Elasticsearch.
