enabling Redis cache to wordpress

[ruihildt]

I just installed a fresh manager WP, and Redis cache plugin was not installed by default. (I thought it was?)

I installed it and enabled it, restarted the app, but there are still some errors in the logs:

RedisException: Connection refused in /app/data/wp-content/object-cache.php:574\nStack trace:\n#0 /app/data/wp-content/object-cache.php(574): Redis->connect('127.0.0.1', 6379, 1, NULL, NULL, 1)\n#1 /app/data/wp-content/object-cache.php(419): WP_Object_Cache->connect_using_phpredis(Array)\n#2 /app/data/wp-content/object-cache.php(165): WP_Object_Cache->__construct(true)\n#3 /app/code/wp-includes/load.php(632): wp_cache_init()\n#4 /app/code/wp-settings.php(131): wp_start_object_cache()\n#5 /app/data/wp-config.php(70): require_once('/app/code/wp-se...')\n#6 /app/code/wp-load.php(37): require_once('/app/data/wp-co...')\n#7 /app/code/wp-admin/admin-ajax.php(22): require_once('/app/code/wp-lo...')\n#8 {main}, referer: https://managed.llm.be/wp-admin/options-general.php?page=redis-cache

And on the redis plugin itself:

Status: Not connected
Client: PhpRedis (v5.2.1)
Drop-in: Valid
Disabled: No
Filesystem: Working
Ping: 
Connection Exception: Connection refused (RedisException)
Errors: [
    "Connection refused"
]
PhpRedis: 5.2.1
Predis: Not loaded
Credis: Not loaded
PHP Version: 7.3.17-1+ubuntu18.04.1+deb.sury.org+1
Plugin Version: 2.0.13
Redis Version: Unknown
Multisite: No
Global Prefix: null
Blog Prefix: null
Global Groups: [
    "blog-details",
    "blog-id-cache",
    "blog-lookup",
    "global-posts",
    "networks",
    "rss",
    "sites",
    "site-details",
    "site-lookup",
    "site-options",
    "site-transient",
    "users",
    "useremail",
    "userlogins",
    "usermeta",
    "user_meta",
    "userslugs",
    "redis-cache"
]
Ignored Groups: [
    "counts",
    "plugins",
    "themes",
    "blog-details",
    "blog-id-cache",
    "blog-lookup",
    "global-posts",
    "networks",
    "rss",
    "sites",
    "site-details",
    "site-lookup",
    "site-options",
    "site-transient",
    "users",
    "useremail",
    "userlogins",
    "usermeta",
    "user_meta",
    "userslugs",
    "redis-cache",
    "blog_meta"
]
Unflushable Groups: []
Drop-ins: [
    "Redis Object Cache Drop-In v2.0.13 by Till Krüss"
]

How can I enable it? (and is Opcode caching still on by default?)

[girish]

@ruihildt redis is only available in the unmanaged WP app. opcache is enabled in both the WP apps.

[rmdes]

@girish Ohhh, I just learned something, thanks !

[rmdes]

@girish does it mean on managed WP it is still best to install totalcache or similar to handle cache in a proper way ?

[girish]

@rmdes Yes, I have been doing some load tests with Cloudron app vs Vanilla WP vs OpenLite Speed. Generally, having redis is not much of a difference. What makes the big difference is static page caches like W3 Total Cache. It's also the reason OLS on first run appears so fast (it has a cache plugin enabled by default). Redis cache is for objects and dynamic pages, it's not going to make things much fast.

Note that one pain of these static cache plugins is that you have to clear the cache manually (or set some timer to re-generate the cache).