horizon: ERROR: A non-numeric value encountered

• Horizon Version: 3.2.1
• Laravel Version: 5.7.28
• PHP Version: 7.1.26
• Redis Driver & Version: predis 1.1.1
• Database Driver & Version: mysql 5.7

Description:

When launching php artisan horizon, after the installation steps listed in the documentation, the system works but keeps throwing this Exception every second or so:

{
   "class": "ErrorException",
   "message": "A non-numeric value encountered",
   "code": 0,
   "file": "\/var\/www\/vendor\/laravel\/framework\/src\/Illuminate\/Support\/Collection.php:1682",
   "trace": [
       "\/var\/www\/vendor\/laravel\/framework\/src\/Illuminate\/Support\/Collection.php:1682",
       "{\"function\":\"Illuminate\\\\Support\\\\{closure}\",\"class\":\"Illuminate\\\\Support\\\\Collection\",\"type\":\"->\",\"args\":[0,{\"cpu\":0.47,\"mem\":\"www\"}]}",
       "\/var\/www\/vendor\/laravel\/framework\/src\/Illuminate\/Support\/Collection.php:1415",
       "\/var\/www\/vendor\/laravel\/framework\/src\/Illuminate\/Support\/Collection.php:1683",
       "\/var\/www\/vendor\/laravel\/horizon\/src\/Repositories\/RedisSupervisorRepository.php:129",
       "{\"function\":\"Laravel\\\\Horizon\\\\Repositories\\\\{closure}\",\"class\":\"Laravel\\\\Horizon\\\\Repositories\\\\RedisSupervisorRepository\",\"type\":\"->\",\"args\":[\"[object] (Predis\\\\Pipeline\\\\Pipeline)\"]}",
       "\/var\/www\/vendor\/predis\/predis\/src\/Pipeline\/Pipeline.php:211",
       "\/var\/www\/vendor\/predis\/predis\/src\/Client.php:445",
       "\/var\/www\/vendor\/predis\/predis\/src\/Client.php:396",
       "\/var\/www\/vendor\/predis\/predis\/src\/Client.php:418",
       "\/var\/www\/vendor\/laravel\/framework\/src\/Illuminate\/Redis\/Connections\/Connection.php:114",
       "\/var\/www\/vendor\/laravel\/framework\/src\/Illuminate\/Redis\/Connections\/Connection.php:214",
       "\/var\/www\/vendor\/laravel\/horizon\/src\/Repositories\/RedisSupervisorRepository.php:138",
       "\/var\/www\/vendor\/laravel\/horizon\/src\/Supervisor.php:354",
       "\/var\/www\/vendor\/laravel\/horizon\/src\/Supervisor.php:308",
       "\/var\/www\/vendor\/laravel\/horizon\/src\/Supervisor.php:267",
       "\/var\/www\/vendor\/laravel\/horizon\/src\/Console\/SupervisorCommand.php:92",
       "\/var\/www\/vendor\/laravel\/horizon\/src\/Console\/SupervisorComman…

I was able to fix it temporarily by updating vendor/laravel/horizon/src/SystemProcessCounter.php at line 33:

return ['cpu' => $row->first() / 100, 'mem' => $row->last()];

to

return ['cpu' => $row->first() / 100, 'mem' => (float)$row->last()];

It probably can be fixed in a better way, but that’s the spot where it was breaking, by sending 0.00 instead of “0.00”. Looking forward to an update to avoid having to manually change my vendor files. O_o 😄

Steps To Reproduce:

• Install Redis
• Install Horizon
• Launch php artisan horizon