# Redis
Plugin: go.d.plugin
Module: redis
## Overview
This collector monitors the health and performance of Redis servers and collects general statistics, CPU and memory consumption, replication information, command statistics, and more.
It connects to the Redis instance via a TCP or UNIX socket and executes the following commands:
- [INFO ALL](https://redis.io/commands/info)
- [PING](https://redis.io/commands/ping/)
This collector is supported on all platforms.
This collector supports collecting metrics from multiple instances of this integration, including remote instances.
### Default Behavior
#### Auto-Detection
By default, it detects instances running on localhost by attempting to connect using known Redis TCP and UNIX sockets:
- 127.0.0.1:6379
- /tmp/redis.sock
- /var/run/redis/redis.sock
- /var/lib/redis/redis.sock
#### Limits
The default configuration for this integration does not impose any limits on data collection.
#### Performance Impact
The default configuration for this integration is not expected to impose a significant performance impact on the system.
## Metrics
Metrics grouped by *scope*.
The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.
### Per Redis instance
These metrics refer to the entire monitored application.
This scope has no labels.
Metrics:
| Metric | Dimensions | Unit |
|:------|:----------|:----|
| redis.connections | accepted, rejected | connections/s |
| redis.clients | connected, blocked, tracking, in_timeout_table | clients |
| redis.ping_latency | min, max, avg | seconds |
| redis.commands | processes | commands/s |
| redis.keyspace_lookup_hit_rate | lookup_hit_rate | percentage |
| redis.memory | max, used, rss, peak, dataset, lua, scripts | bytes |
| redis.mem_fragmentation_ratio | mem_fragmentation | ratio |
| redis.key_eviction_events | evicted | keys/s |
| redis.net | received, sent | kilobits/s |
| redis.rdb_changes | changes | operations |
| redis.bgsave_now | current_bgsave_time | seconds |
| redis.bgsave_health | last_bgsave | status |
| redis.bgsave_last_rdb_save_since_time | last_bgsave_time | seconds |
| redis.aof_file_size | current, base | bytes |
| redis.commands_calls | a dimension per command | calls |
| redis.commands_usec | a dimension per command | microseconds |
| redis.commands_usec_per_sec | a dimension per command | microseconds/s |
| redis.key_expiration_events | expired | keys/s |
| redis.database_keys | a dimension per database | keys |
| redis.database_expires_keys | a dimension per database | keys |
| redis.connected_replicas | connected | replicas |
| redis.master_link_status | up, down | status |
| redis.master_last_io_since_time | time | seconds |
| redis.master_link_down_since_time | time | seconds |
| redis.uptime | uptime | seconds |
## Alerts
The following alerts are available:
| Alert name | On metric | Description |
|:------------|:----------|:------------|
| [ redis_connections_rejected ](https://github.com/netdata/netdata/blob/master/src/health/health.d/redis.conf) | redis.connections | connections rejected because of maxclients limit in the last minute |
| [ redis_bgsave_slow ](https://github.com/netdata/netdata/blob/master/src/health/health.d/redis.conf) | redis.bgsave_now | duration of the on-going RDB save operation |
| [ redis_bgsave_broken ](https://github.com/netdata/netdata/blob/master/src/health/health.d/redis.conf) | redis.bgsave_health | status of the last RDB save operation (0: ok, 1: error) |
| [ redis_master_link_down ](https://github.com/netdata/netdata/blob/master/src/health/health.d/redis.conf) | redis.master_link_down_since_time | time elapsed since the link between master and slave is down |
## Setup
### Prerequisites
No action required.
### Configuration
#### File
The configuration file name for this integration is `go.d/redis.conf`.
You can edit the configuration file using the `edit-config` script from the
Netdata [config directory](https://github.com/netdata/netdata/blob/master/docs/netdata-agent/configuration.md#the-netdata-config-directory).
```bash
cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config go.d/redis.conf
```
#### Options
The following options can be defined globally: update_every, autodetection_retry.
Config options
| Name | Description | Default | Required |
|:----|:-----------|:-------|:--------:|
| update_every | Data collection frequency. | 5 | no |
| autodetection_retry | Recheck interval in seconds. Zero means no recheck will be scheduled. | 0 | no |
| address | Redis server address. | redis://@localhost:6379 | yes |
| timeout | Dial (establishing new connections), read (socket reads) and write (socket writes) timeout in seconds. | 1 | no |
| username | Username used for authentication. | | no |
| password | Password used for authentication. | | no |
| tls_skip_verify | Server certificate chain and hostname validation policy. Controls whether the client performs this check. | no | no |
| tls_ca | Certificate authority that client use when verifying server certificates. | | no |
| tls_cert | Client tls certificate. | | no |
| tls_key | Client tls key. | | no |
#### Examples
##### TCP socket
An example configuration.
Config
```yaml
jobs:
- name: local
address: 'redis://@127.0.0.1:6379'
```
##### Unix socket
An example configuration.
Config
```yaml
jobs:
- name: local
address: 'unix://@/tmp/redis.sock'
```
##### TCP socket with password
An example configuration.
Config
```yaml
jobs:
- name: local
address: 'redis://:password@127.0.0.1:6379'
```
##### Multi-instance
> **Note**: When you define multiple jobs, their names must be unique.
Local and remote instances.
Config
```yaml
jobs:
- name: local
address: 'redis://:password@127.0.0.1:6379'
- name: remote
address: 'redis://user:password@203.0.113.0:6379'
```
## Troubleshooting
### Debug Mode
To troubleshoot issues with the `redis` collector, run the `go.d.plugin` with the debug option enabled. The output
should give you clues as to why the collector isn't working.
- Navigate to the `plugins.d` directory, usually at `/usr/libexec/netdata/plugins.d/`. If that's not the case on
your system, open `netdata.conf` and look for the `plugins` setting under `[directories]`.
```bash
cd /usr/libexec/netdata/plugins.d/
```
- Switch to the `netdata` user.
```bash
sudo -u netdata -s
```
- Run the `go.d.plugin` to debug the collector:
```bash
./go.d.plugin -d -m redis
```