Operations

Cluster Concurrent Rebalance High / Low

The cluster concurrent rebalance setting determines the maximum number of shards the cluster can move to rebalance the distribution of...

Flood Stage Disk Watermark

When the “disk flood stage” threshold is passed on an Elasticsearch cluster, it will start to block core actions. To resolve this issue...

Heavy Merges Were Detected

Heavy merges use CPU, memory and disk resources, which can slow down the cluster’s response speed. In order to fix...

High Cluster Pending Tasks

Cluster pending tasks are updates to the cluster state which may have been initiated directly by a user or by the cluster itself. When...

High CPU

High CPU is often a symptom of other underlying issues. It should be fixed because a distressed node will slow query response time and...

High Disk Watermark

The high disk watermark is one of the various thresholds on your ES cluster. It's important to understand what it means and how to handle...

High Management Queue

A high number of tasks in management queue can cause Elasticsearch cluster instability which could result in data loss. To resolve...

How to Handle Circuit Breakers in Elasticsearch

Circuit breaker exceptions are thrown to alert us that something needs to be fixed in Elasticsearch in order to reduce memory usage. To fix...

Index Queue Size Is High

Once an indexing queue exceeds the maximum size, the Elasticsearch node will start rejecting index requests. To resolve this, check the...

Loaded Client Nodes

A saturated coordinating node could cause an increase in search or indexing response latency. This can be fixed by putting a load balancer...

Loaded Data Nodes

Sometimes you can observe that the CPU and load on some of your data nodes is higher than on others. This can occasionally be caused by...

Loaded Master Nodes

An overloaded master node may cause instability in the cluster. There are 3 ways to fix loaded master nodes: (1) Checking for...

Low Disk Watermark

Low disk watermark is one of the various thresholds on your Elasticsearch cluster. Here are possible actions you can take to resolve...

Master Node Not Discovered

An Elasticsearch cluster requires a master node to be identified in the cluster in order for it to start properly. If the cluster lacks a...

Max Shards Per Node Exceeded

If the max of shards per node is exceeded in Elasticsearch, shards can't be allocated. It is crucial to check if the limit is set at a...

Node Disconnected

It's important to realize that node disconnection is often a symptom of underlying problems which must be found and solved - learn how to...

Oversharding

A large number of shards on an Elasticsearch cluster requires extra resources. Learn key ways to avoid and correct oversharding...

Rejected Search Requests in Elasticsearch - Causes and Solutions

There are a number of reasons why a search request can be rejected by the Elasticsearch cluster. To resolve the issue, you need to...

Search Rejected Queue

If the Elasticsearch cluster starts to reject search requests, there could be a number of causes. Generally it indicates that...

Shard Allocation is Unbalanced

Elasticsearch usually balances index shards evenly across all of the active data nodes in the cluster. If this isn't happening it's because..

Shards Too Large

It is a best practice that Elasticsearch shard size should not go above 50GB for a single shard. If you go above this limit...

Slow Indexing in Nodes

If the indexing queue is high or produces time outs, it indicates that one or more Elasticsearch nodes cannot keep up with the rate of...

Status Red

Elasticsearch red status indicates not only that the primary shard has been lost, but also that a replica has not been promoted...

Status Yellow

Yellow status indicates that one or more of the replica shards on the Elasticsearch cluster are not allocated to a node. This could occur...