What speeds I should expect

Does Redis Server sit on the same machine as WordPress?

It should be on the same server, but based on your reply, it’s clearly slower than expected so I’ve sent a message to my hosts to ask for details. Will let you know the outcome.

Thanks

It looks like it’s on 127.0.0.1. What’s the hosting company?

Hey, sorry for the delay – was hoping to get it all sorted with the hosting company first rather than having to bother you but sorry – here I am!

My hosts are a small but nice and responsive company here in the UK – you wont have heard of them.

You were spot-on before, I was connecting to a Redis server that had been setup for me on a different server (within the same hosts). I don’t think that was supposed to be possible though, so they’ve stopped that from working now ??

They’ve now added Redis on this server (my dev server) but I’m unable to connect using the details they think should work, and they’re not sure why. Details they’ve recommended are:

define( 'WP_REDIS_SCHEME', 'unix');
define( 'WP_REDIS_PATH ', "/home/<myusername>/redis/redis.sock");
define( 'WP_REDIS_DATABASE', 0 );

(I have updated <myusername>!)

Message I get in diagnostics:

Connection Exception: php_network_getaddresses: getaddrinfo failed: Name or service not known (RedisException)
Errors: [
    "php_network_getaddresses: getaddrinfo failed: Name or service not known"
]

Do you have any advice for what I should try / ask the hosts?

Many thanks

Does the file /home/<myusername>/redis/redis.sock exist on your server’s filesystem?

Yeah, my hosts say it’s there and they can connect to it. I haven’t delved deep enough to know the details so can’t confirm that myself, but can either pass direct questions to them, or can get my hands dirty and SSH in if required! Not sure what I’d be looking at yet though.

What does this print?

<?php

$redis = new Redis();

try {
    if ($redis->connect("/home/<myusername>/redis/redis.sock")) {
        echo "Connected!";
    }

} catch (Exception $e) {
    echo $e->getMessage();
}

Connected!

Can you post your wp-config.php with all secrets redacted?

... (comments) ...

define( 'WP_MEMORY_LIMIT', '512M' );
define( 'WP_MAX_MEMORY_LIMIT', '512M' );

... (db settings) ...

// Get details for the current environment.
$environment = <redacted>

define('WP_HOME', $environment['wp_home']);
define('WP_SITEURL', $environment['wp_site_url']);

define('DB_NAME', $environment['db_name']);
define('DB_USER', $environment['db_user']);
define('DB_PASSWORD', $environment['db_password']);
define('DB_HOST', $environment['db_host']);

/**
 * Authentication Unique Keys and Salts.
....
*/

define('WP_REDIS_SCHEME', 'unix');
define( 'WP_REDIS_PATH ', "/home/<redacted>/redis/redis.sock");
define( 'WP_REDIS_DATABASE', 0 );
define( 'WP_REDIS_PORT', 0 );

/**
 * WordPress Database Table prefix.
 *
 * You can have multiple installations in one database if you give each
 * a unique prefix. Only numbers, letters, and underscores please!
 */
$table_prefix = 'wp_';

define('WP_DEBUG', false);

/* That's all, stop editing! Happy blogging. */

/** Absolute path to the WordPress directory. */
if ( ! defined( 'ABSPATH' ) )
	define( 'ABSPATH', dirname( __FILE__ ) . '/' );

/** Sets up WordPress vars and included files. */
require_once ABSPATH . 'wp-settings.php';

Hey, here’s something that might help:

Line 700 of wp-content/object-cache.php. I’ve added a print_r($args):

Array
(
    [host] => 127.0.0.1
    [port] => 6379
    [timeout] => 1
    [0] => 
    [retry_interval] => 0
    [read_timeout] => 1
)

So it hasn’t got the .sock details

Oh no! There was a space in my config ??

define( 'WP_REDIS_PATH ' );

I think we’re working! Will report back when I’ve tested.

You have a space in your WP_REDIS_PATH definition.

If that doesn’t fix it, try:

define('WP_REDIS_HOST', "/home/<redacted>/redis/redis.sock");
define('WP_REDIS_PORT', -1);
define('WP_REDIS_DATABASE', 0);

I wish I could rub out the last 10 messages! (thanks).

So we are up and running again. My hosts have told me that Redis is on the same server – that path implies that it’s in my user account. But my metrics are still 60ms during low server load, and doubling when I give the server some traffic.

https://ibb.co/ynwJh0Y

Does this look like my Redis installation is rubbish?

That’s 60ms total in Redis wait times. Not bad ??