Redis and CentOS 7

Redis is a feature-packed cache that’s easy to install and work with. Here’s some notes on installing and using Redis with CentOS 7.

Install available redis package from your available yum repos:

# yum install redis
# systemctl enable redis
# systemctl start redis

By default, Redis is configured at installation to bind to localhost with no password in /etc/redis.conf.

See status of redis and redis services:

# systemctl list-unit-files 'redis*'

Setup for programming with some Perl modules:

# cpan Redis Redis::Fast Redis::List

Perl code snippet for a web page performance footer:

use strict;
use diagnostics;

use Redis::Fast;

my $r_cache = cache_info();

my $cache_info = '';

$cache_info = "Redis $r_cache->{'redis_version'} \
up $r_cache->{'uptime_in_seconds'} s \
$r_cache->{'keyspace_hits'}h/$r_cache->{'keyspace_misses'}m \
/$r_cache->{'expired_keys'}e last write: \
$r_cache->{'aof_last_write_status'}" if defined $r_cache;

print $cache_info;

sub cache_info {
   my $h = Redis::Fast->new;

   if ($h) {
      my $r_hash = $h->info();
      $h->quit();
      return $r_hash;
   }

   return undef;
}

will output a useful message like:

Redis 3.2.10 up 414908 s 1146h/301m/141e last write: ok