---
id: afbebef9-3d9f-4196-935f-afa288197fa5
---

# Redis Cluster Resharding Delays.
---
Redis Cluster Resharding Delays occur when the process of redistributing data across Redis cluster nodes takes longer than expected. This can lead to slow resharding operations and may cause performance issues for applications that rely on the Redis database. In such instances, it is important to investigate the root cause of the delays and take necessary actions to restore normal performance.

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

export REDIS_PORT="PLACEHOLDER"

export PATH_TO_REDIS_CONFIG_FILE="PLACEHOLDER"
```

## Debug

### Check Redis cluster status and get the node IDs
```shell
redis-cli -h ${REDIS_HOST} -p ${REDIS_PORT} cluster nodes
```

### Check CPU usage of Redis nodes
```shell
redis-cli -h ${REDIS_HOST} -p ${REDIS_PORT} info cpu
```

### Check memory usage of Redis nodes
```shell
redis-cli -h ${REDIS_HOST} -p ${REDIS_PORT} info memory
```

### Check network latency between Redis nodes
```shell
redis-cli --latency -h ${REDIS_HOST} -p ${REDIS_PORT}
```

### Check for slow Redis commands
```shell
redis-cli -h ${REDIS_HOST} -p ${REDIS_PORT} slowlog get
```

## Repair

### Optimize the resharding algorithm: Redis provides various resharding algorithms that can be used to optimize the resharding process. Choosing the right algorithm based on the cluster's specific needs may help to improve performance.
```shell


#!/bin/bash



REDIS_CONFIG_FILE=${PATH_TO_REDIS_CONFIG_FILE}



# Check if Redis config file exists

if [ ! -f "$REDIS_CONFIG_FILE" ]; then

    echo "Redis config file not found at $REDIS_CONFIG_FILE"

    exit 1

fi



# Check if Redis server is running

REDIS_PID=$(pidof redis-server)

if [ -z "$REDIS_PID" ]; then

    echo "Redis server is not running"

    exit 1

fi



# Stop Redis server

sudo systemctl stop redis



# Edit Redis config file to set resharding algorithm

sudo sed -i 's/redis.resharding.algorithm =.*$/redis.resharding.algorithm = optimized/' $REDIS_CONFIG_FILE



# Start Redis server

sudo systemctl start redis



echo "Redis resharding algorithm has been optimized"


```

Redis Cluster Resharding Delays occur when the process of redistributing data across Redis cluster nodes takes longer than expected. This can lead to slow resharding operations and may cause performance issues for applications that rely on the Redis database. In such instances, it is important to investigate the root cause of the delays and take necessary actions to restore normal performance.


```shell
export REDIS_HOST="PLACEHOLDER"

export REDIS_PORT="PLACEHOLDER"

export PATH_TO_REDIS_CONFIG_FILE="PLACEHOLDER"
```


### Check Redis cluster status and get the node IDs

```shell
redis-cli -h ${REDIS_HOST} -p ${REDIS_PORT} cluster nodes
```

### Check CPU usage of Redis nodes

```shell
redis-cli -h ${REDIS_HOST} -p ${REDIS_PORT} info cpu
```

### Check memory usage of Redis nodes

```shell
redis-cli -h ${REDIS_HOST} -p ${REDIS_PORT} info memory
```

### Check network latency between Redis nodes

```shell
redis-cli --latency -h ${REDIS_HOST} -p ${REDIS_PORT}
```

### Check for slow Redis commands

```shell
redis-cli -h ${REDIS_HOST} -p ${REDIS_PORT} slowlog get
```


### Optimize the resharding algorithm: Redis provides various resharding algorithms that can be used to optimize the resharding process. Choosing the right algorithm based on the cluster's specific needs may help to improve performance.

```shell


#!/bin/bash



REDIS_CONFIG_FILE=${PATH_TO_REDIS_CONFIG_FILE}



# Check if Redis config file exists

if [ ! -f "$REDIS_CONFIG_FILE" ]; then

    echo "Redis config file not found at $REDIS_CONFIG_FILE"

    exit 1

fi



# Check if Redis server is running

REDIS_PID=$(pidof redis-server)

if [ -z "$REDIS_PID" ]; then

    echo "Redis server is not running"

    exit 1

fi



# Stop Redis server

sudo systemctl stop redis



# Edit Redis config file to set resharding algorithm

sudo sed -i 's/redis.resharding.algorithm =.*$/redis.resharding.algorithm = optimized/' $REDIS_CONFIG_FILE



# Start Redis server

sudo systemctl start redis



echo "Redis resharding algorithm has been optimized"


```


Redis Cluster Resharding Delays.

Overview

Parameters

Debug

Check Redis cluster status and get the node IDs

Check CPU usage of Redis nodes

Check memory usage of Redis nodes

Check network latency between Redis nodes

Check for slow Redis commands

Repair

Optimize the resharding algorithm: Redis provides various resharding algorithms that can be used to optimize the resharding process. Choosing the right algorithm based on the cluster's specific needs may help to improve performance.

Learn more

Related Runbooks

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