Fatal error: Class 'Redis' not found

Question

I've installed Redis on my ubuntu 14 server with phpredis extension. Im using Nginx server. I have php testing script

$redis=new Redis() or die("Cannot load Redis module.");
$redis->connect('localhost');
$redis->set('random', rand(5000,6000));
echo $redis->get('random');

which is working fine from command-line but not from web browser.

Nginx error log:

[info] 31102#0: Using 32768KiB of shared memory for push module in /etc/nginx/nginx.conf:82
[error] 31108#0: *21 FastCGI sent in stderr: "PHP message: PHP Fatal error:  Class 'Redis' not found in...

i can't see it even in phpinfo()

all installed with apt-get install

all other modules (mysql, imagemagick...) are working fine

i've spent few hours on google but haven't found nothing useful

Solution 1

You have installed redis but not php-redis. you can simply run the command below to install php-redis

sudo apt-get install php-redis

Solution 2

TLDR;
On Ubuntu 16.04 using NGINX with PHP 7 I found that PHP-FPM was not restarted. A simple restart of the service worked for me:

sudo service php-fpm restart
OR
sudo service php7.0-fpm restart
OR
sudo service php5-fpm restart

You may need to need to search "restart PHP-FPM" in case any of the above commands don't work for you.

To give some context, I had installed phpredis using the standard sudo apt-get install php-redis and I restarted nginx using sudo systemctl restart nginx but whenever trying to use new Redis() in PHP I received the same error as in the question (... Class 'Redis' not found...).

When running phpinfo(); in a PHP file on the NGINX server I could see the PHP-FPM was loading additional configuration from /etc/php/7.0/fpm/conf.d ("Scan this dir for additional .ini files" section). Looking in that directory with a simple ls -al /etc/php/7.0/fpm/conf.d I can see there is a symlink named 20-redis.ini but that file was not being loaded in the phpinfo section "Additional .ini files parsed".

The problem as I see it now is that restarting NGINX did not restart PHP-FPM. Using ps aux | grep php-fpm to see if there were any PHP-FPM processes running when I had stopped NGINX confirmed my suspicions. Because a restart is required to reload the PHP modules the PHP-FPM restart was required in addition to the NGINX restart.

Solution 3

Manual instalation of PhpRedis solved this problem

git clone git://github.com/nicolasff/phpredis.git
cd phpredis
phpize
./configure
make
sudo -s make install

sudo -s
echo "extension=redis.so">/etc/php5/conf.d/redis.ini
ln -s /etc/php5/conf.d/redis.ini /etc/php5/fpm/conf.d/20-redis.ini
exit

copied from Rico's Tech Memo

Solution 4

composer require predis/predis

Then add "predis" in app/config/database.php :

'redis' => [

    'client' => env('REDIS_CLIENT', 'predis'),

    'options' => [
        'cluster' => env('REDIS_CLUSTER', 'redis'),
        'prefix' => env('REDIS_PREFIX', Str::slug(env('APP_NAME', 
                    'laravel'), '_').'_database_'),
    ],
]

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Comments

[naomi]

...and then restart php-fpm, as suggested below.

[abbood]

this is what fixed it for me, but what's the difference between redis and php-redis?

[Kareem]

@abbood redis installs redis on your server. php-redis allows you to pull and manipulate redis data using php. You can run redis on the command line without php-redis.

[Pat Gilmour]

On Ubuntu 18, use this to restart php-fpm sudo systemctl restart php7.2-fpm.service replacing "7.2" with your version of php. The above solution worked on my server after hours of head-scratching. Restarting nginx was not enough.

[Serhii Popov]

For googlers, as mention in this issues: PHP5 is not supported anymore. 4.3.0 was the last release which works with older versions of PHP. Use next command for clone correct branch git clone -b 4.3.0 --single-branch https://github.com/phpredis/phpredis.git

[famas23]

Do you need to enable redis php extension in some way ?

[Kareem]

This Fatal Error barely means that php can't execute commands the same way you do on the console. To enable the bridge between php and redis, install php-redis. If redis works in the console, it will work through php without any extra configuration.

[Qumber]

This did it. Also, I was running Lumen's development server. I killed it and started again after installing php-redia and bingo.