Fix Redis After Reboot on Ubuntu

After my server rebooted, my Laravel app suddenly crashed, and upon checking the logs, I discovered that the app couldn’t connect to the Redis server.

production.ERROR: Connection refused [tcp://127.0.0.1:6379]
[object] (Predis\\Connection\\ConnectionException(code: 111)

It’s worth noting that the app was installed on a bare-metal server, not a Docker container, and Redis was installed using apt install redis.

To confirm Redis installation, I ran apt-cache policy redis:

redis:
  Installed: 6:7.2.3-1rl1~bionic1
  Candidate: 6:7.2.3-1rl1~bionic1

As seen, Redis is installed. However, running systemctl status redis returned:

Unit redis.service could not be found.

After researching, I found this post that mentioned:

The problem is that symlink redis-server.service to redis.service was deleted.

So the solution is running the command below:

$ systemctl enable redis-server
Synchronizing state of redis-server.service with SysV service script with /lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install enable redis-server
Created symlink /etc/systemd/system/redis.service → /lib/systemd/system/redis-server.service.

This created a symlink. Despite this, Redis still didn’t start:

$ service redis status
● redis-server.service - Advanced key-value store
   Loaded: loaded (/lib/systemd/system/redis-server.service; enabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: http://redis.io/documentation,
           man:redis-server(1)

To resolve this, a simple start was needed:

$ service redis start

After restarting, checking the status showed that everything was running smoothly:

$ service redis status
 
● redis-server.service - Advanced key-value store
   Loaded: loaded (/lib/systemd/system/redis-server.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2024-01-08 12:02:13 WIB; 1s ago
     Docs: http://redis.io/documentation,
           man:redis-server(1)
 Main PID: 29254 (redis-server)
   Status: "Ready to accept connections"
    Tasks: 6 (limit: 4654)
   CGroup: /system.slice/redis-server.service
           └─29254 /usr/bin/redis-server 127.0.0.1:6379