---
id: e2fcceb2-6481-11ee-8c99-0242ac120002
---

# Slow Elasticsearch Garbage Collection
---

This incident type refers to a problem that occurs when garbage collection takes a longer time than usual to complete in an Elasticsearch system. Garbage collection is a process used by Elasticsearch to free up memory occupied by unused objects and data structures. When this process takes longer than expected, it can slow down the overall performance of the system, causing delays and potential downtime. This issue can be caused by a variety of factors, including insufficient memory allocation or poor system resource management.

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

export ELASTICSEARCH_LOG_FILE_PATH="PLACEHOLDER"

export HEAP_SIZE="PLACEHOLDER"

export CONFIG_FILE="PLACEHOLDER"
```

## Debug

### Check Elasticsearch cluster health and node status
```shell
curl -s -XGET ${ELASTICSEARCH_ENDPOINT}/_cluster/health?pretty
```

### Check Elasticsearch cluster and node stats
```shell
curl -s -XGET ${ELASTICSEARCH_ENDPOINT}/_nodes/stats?pretty
```

### Check Elasticsearch garbage collection stats
```shell
curl -s -XGET ${ELASTICSEARCH_ENDPOINT}/_nodes/stats/jvm?pretty | grep gc
```

### Check Elasticsearch heap usage and garbage collection logs
```shell
curl -s -XGET ${ELASTICSEARCH_ENDPOINT}/_nodes/stats/jvm?pretty | grep -E 'jvm\.(max|mem|gc)\.'
```

### Check Elasticsearch garbage collection logs
```shell
tail -f ${ELASTICSEARCH_LOG_FILE_PATH} | grep --line-buffered 'gc\['
```

## Repair

### Increase the memory allocation for Elasticsearch to ensure that it has enough resources to complete garbage collection efficiently.
```shell


#!/bin/bash



# set variables

ELASTICSEARCH_HEAP_SIZE=${HEAP_SIZE}

ELASTICSEARCH_CONFIG_FILE=${CONFIG_FILE}



# backup existing config file

cp $ELASTICSEARCH_CONFIG_FILE $ELASTICSEARCH_CONFIG_FILE.bak



# update Elasticsearch heap size in config file

sed -i "s/-Xms[0-9]*m -Xmx[0-9]*m/-Xms${ELASTICSEARCH_HEAP_SIZE}m -Xmx${ELASTICSEARCH_HEAP_SIZE}m/g" $ELASTICSEARCH_CONFIG_FILE



# restart Elasticsearch service

systemctl restart elasticsearch.service


```


This incident type refers to a problem that occurs when garbage collection takes a longer time than usual to complete in an Elasticsearch system. Garbage collection is a process used by Elasticsearch to free up memory occupied by unused objects and data structures. When this process takes longer than expected, it can slow down the overall performance of the system, causing delays and potential downtime. This issue can be caused by a variety of factors, including insufficient memory allocation or poor system resource management.


```shell
export ELASTICSEARCH_ENDPOINT="PLACEHOLDER"

export ELASTICSEARCH_LOG_FILE_PATH="PLACEHOLDER"

export HEAP_SIZE="PLACEHOLDER"

export CONFIG_FILE="PLACEHOLDER"
```


### Check Elasticsearch cluster health and node status

```shell
curl -s -XGET ${ELASTICSEARCH_ENDPOINT}/_cluster/health?pretty
```

### Check Elasticsearch cluster and node stats

```shell
curl -s -XGET ${ELASTICSEARCH_ENDPOINT}/_nodes/stats?pretty
```

### Check Elasticsearch garbage collection stats

```shell
curl -s -XGET ${ELASTICSEARCH_ENDPOINT}/_nodes/stats/jvm?pretty | grep gc
```

### Check Elasticsearch heap usage and garbage collection logs

```shell
curl -s -XGET ${ELASTICSEARCH_ENDPOINT}/_nodes/stats/jvm?pretty | grep -E 'jvm\.(max|mem|gc)\.'
```

### Check Elasticsearch garbage collection logs

```shell
tail -f ${ELASTICSEARCH_LOG_FILE_PATH} | grep --line-buffered 'gc\['
```


### Increase the memory allocation for Elasticsearch to ensure that it has enough resources to complete garbage collection efficiently.

```shell


#!/bin/bash



# set variables

ELASTICSEARCH_HEAP_SIZE=${HEAP_SIZE}

ELASTICSEARCH_CONFIG_FILE=${CONFIG_FILE}



# backup existing config file

cp $ELASTICSEARCH_CONFIG_FILE $ELASTICSEARCH_CONFIG_FILE.bak



# update Elasticsearch heap size in config file

sed -i "s/-Xms[0-9]*m -Xmx[0-9]*m/-Xms${ELASTICSEARCH_HEAP_SIZE}m -Xmx${ELASTICSEARCH_HEAP_SIZE}m/g" $ELASTICSEARCH_CONFIG_FILE



# restart Elasticsearch service

systemctl restart elasticsearch.service


```


Slow Elasticsearch Garbage Collection

Overview

Parameters

Debug

Check Elasticsearch cluster health and node status

Check Elasticsearch cluster and node stats

Check Elasticsearch garbage collection stats

Check Elasticsearch heap usage and garbage collection logs

Check Elasticsearch garbage collection logs

Repair

Increase the memory allocation for Elasticsearch to ensure that it has enough resources to complete garbage collection efficiently.

Learn more

Related Runbooks

Support