Some things to try;
Check the php-info
php -i | grep -i redis
From Installing emoncms - redis problem on openSUSE system - #27 by pb66 - the small script below will prove if PHP is able to connect to Redis on a basic level.
<?php
$redis = new Redis();
$redis->connect('127.0.0.1', 6379);
if ($redis->ping() === "+PONG") {
echo "Successfully connected to Redis!".PHP_EOL;
} else {
echo "Failed to get response from Redis!".PHP_EOL;
}
?>
Save the above code to a file called test_redis.php and run from the command line
pb66@test2:~$ php test_redis.php
Successfully connected to Redis!
Final thing to check (if the above were unsuccessful) - from Installing emoncms - redis problem on openSUSE system - #4 by Greebo - test redis from the command line… Try this:
$ redis-cli
127.0.0.1:6379> lpush test "hello"
(integer) 1
127.0.0.1:6379> lpop test
"hello"
127.0.0.1:6379> exit
$
If that all works, we can confirm that redis is actually working and rule that out.
This is an odd one as it just worked for me.