---
id: ea13a64e-6481-11ee-8c99-0242ac120002
---

# Frequent Garbage Collection in Elasticsearch
---

This incident type refers to a situation where the Elasticsearch cluster is experiencing frequent garbage collection. Garbage collection is a process that frees up memory occupied by objects that are no longer in use. In Elasticsearch, garbage collection is a critical process that ensures that the cluster runs smoothly and efficiently. However, if garbage collection occurs too frequently, it can cause performance issues and impact the overall health of the Elasticsearch cluster. This incident requires investigation to determine the root cause of the frequent garbage collection and implement a solution to prevent it from happening again in the future.

### Parameters
```shell
export ELASTICSEARCH_NODE_NAME="PLACEHOLDER"

export ELASTICSEARCH_NODE_IP="PLACEHOLDER"

export HEAP_SIZE="PLACEHOLDER"
```

## Debug

### Check Elasticsearch logs for GC activity
```shell
grep "gc" /var/log/elasticsearch/${ELASTICSEARCH_NODE_NAME}/elasticsearch.log
```

### Check Elasticsearch JVM heap usage
```shell
curl -s -XGET "http://${ELASTICSEARCH_NODE_IP}:9200/_nodes/stats/jvm?pretty=true" | grep -A 2 heap_used_in_bytes
```

### Check Elasticsearch cluster health
```shell
curl -s -XGET "http://${ELASTICSEARCH_NODE_IP}:9200/_cluster/health?pretty=true"
```

### Check Elasticsearch node stats
```shell
curl -s -XGET "http://${ELASTICSEARCH_NODE_IP}:9200/_nodes/stats?pretty=true"
```

### Check Elasticsearch index stats
```shell
curl -s -XGET "http://${ELASTICSEARCH_NODE_IP}:9200/_stats?pretty=true"
```

## Repair

### Increase heap space allocated to Elasticsearch to prevent frequent garbage collection.
```shell


#!/bin/bash



# Set the Elasticsearch heap size to ${HEAP_SIZE}

sed -i 's/-Xms.*/-Xms${HEAP_SIZE}/g' /etc/elasticsearch/jvm.options

sed -i 's/-Xmx.*/-Xmx${HEAP_SIZE}/g' /etc/elasticsearch/jvm.options



# Restart Elasticsearch

systemctl restart elasticsearch.service


```


This incident type refers to a situation where the Elasticsearch cluster is experiencing frequent garbage collection. Garbage collection is a process that frees up memory occupied by objects that are no longer in use. In Elasticsearch, garbage collection is a critical process that ensures that the cluster runs smoothly and efficiently. However, if garbage collection occurs too frequently, it can cause performance issues and impact the overall health of the Elasticsearch cluster. This incident requires investigation to determine the root cause of the frequent garbage collection and implement a solution to prevent it from happening again in the future.


```shell
export ELASTICSEARCH_NODE_NAME="PLACEHOLDER"

export ELASTICSEARCH_NODE_IP="PLACEHOLDER"

export HEAP_SIZE="PLACEHOLDER"
```


### Check Elasticsearch logs for GC activity

```shell
grep "gc" /var/log/elasticsearch/${ELASTICSEARCH_NODE_NAME}/elasticsearch.log
```

### Check Elasticsearch JVM heap usage

```shell
curl -s -XGET "http://${ELASTICSEARCH_NODE_IP}:9200/_nodes/stats/jvm?pretty=true" | grep -A 2 heap_used_in_bytes
```

### Check Elasticsearch cluster health

```shell
curl -s -XGET "http://${ELASTICSEARCH_NODE_IP}:9200/_cluster/health?pretty=true"
```

### Check Elasticsearch node stats

```shell
curl -s -XGET "http://${ELASTICSEARCH_NODE_IP}:9200/_nodes/stats?pretty=true"
```

### Check Elasticsearch index stats

```shell
curl -s -XGET "http://${ELASTICSEARCH_NODE_IP}:9200/_stats?pretty=true"
```


### Increase heap space allocated to Elasticsearch to prevent frequent garbage collection.

```shell


#!/bin/bash



# Set the Elasticsearch heap size to ${HEAP_SIZE}

sed -i 's/-Xms.*/-Xms${HEAP_SIZE}/g' /etc/elasticsearch/jvm.options

sed -i 's/-Xmx.*/-Xmx${HEAP_SIZE}/g' /etc/elasticsearch/jvm.options



# Restart Elasticsearch

systemctl restart elasticsearch.service


```


Frequent Garbage Collection in Elasticsearch

Overview

Parameters

Debug

Check Elasticsearch logs for GC activity

Check Elasticsearch JVM heap usage

Check Elasticsearch cluster health

Check Elasticsearch node stats

Check Elasticsearch index stats

Repair

Increase heap space allocated to Elasticsearch to prevent frequent garbage collection.

Learn more

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