Redis Client and Site Health

Can you post your diagnostics from Settings => Redis?

Here it is

Status: Connected
Client: Predis (v1.1.6)
Drop-in: Valid
Disabled: No
Filesystem: Working
Ping: PONG
Errors: []
PhpRedis: 5.3.1
Predis: 1.1.6
Credis: Not loaded
PHP Version: 7.4.11
Plugin Version: 2.0.15
Redis Version: 6.0.8
Multisite: Yes
Global Prefix: ""
Blog Prefix: 1
WP_REDIS_DISABLED: ""
WP_REDIS_CLIENT: ""
WP_REDIS_SCHEME: "unix"
WP_REDIS_PATH: "/server/redis/var/run/redis.sock"
WP_REDIS_HOST: "localhost"
WP_REDIS_PORT: "6379"
WP_REDIS_DATABASE: "10"
WP_REDIS_TIMEOUT: "5"
WP_REDIS_READ_TIMEOUT: "5"
WP_REDIS_RETRY_INTERVAL: ""
WP_REDIS_IGBINARY: "true"
WP_REDIS_SERIALIZER: ""
WP_REDIS_MAXTTL: "0"
WP_REDIS_PREFIX: "gd_"
WP_REDIS_IGNORED_GROUPS: ["counts","plugins"]
WP_REDIS_UNFLUSHABLE_GROUPS: ""
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",
    "blog_meta"
]
Ignored Groups: [
    "counts",
    "plugins",
    "wordfence-ls"
]
Unflushable Groups: []
Drop-ins: [
    "Redis Object Cache Drop-In v2.0.15 by Till Krüss"
]

If you add this to your config, what error are you seeing?

define( 'WP_REDIS_CLIENT', 'phpredis' );
define( 'WP_DEBUG', true );
define( 'WP_DEBUG_DISPLAY', true );

Blog page shows this error

There has been a critical error on your website.

Learn more about debugging in WordPress.

WP Admin shows

There has been a critical error on your website. Please check your site admin email inbox for instructions.

Learn more about debugging in WordPress.

And no debug message.

What does your error log show?

Sorry, error page did show debug info. I forget a line define debug false around.

This is the debug message

Warning: Redis::connect() expects parameter 5 to be int, string given in /server/www/site/wp-content/object-cache.php on line 582

Fatal error: Uncaught RedisException: Redis server went away in /server/www/site/wp-content/object-cache.php:597 Stack trace: #0 /server/www/site/wp-content/object-cache.php(597): Redis->select() #1 /server/www/site/wp-content/object-cache.php(427): WP_Object_Cache->connect_using_phpredis() #2 /server/www/site/wp-content/object-cache.php(173): WP_Object_Cache->__construct() #3 /server/www/site/wp-includes/load.php(638): wp_cache_init() #4 /server/www/site/wp-settings.php(131): wp_start_object_cache() #5 /server/www/site/wp-config.php(146): require_once(‘/server/www/gio…’) #6 /server/www/site/wp-load.php(37): require_once(‘/server/www/gio…’) #7 /server/www/site/wp-blog-header.php(13): require_once(‘/server/www/gio…’) #8 /server/www/site/index.php(17): require(‘/server/www/gio…’) #9 {main} thrown in /server/www/site/wp-content/object-cache.php on line 597
There has been a critical error on your website.

Learn more about debugging in WordPress.

You set WP_REDIS_RETRY_INTERVAL to an empty string. Comment that out.

Yes, that seems exactly the problem. Now Client is PhpRedis and I can see Host value is Redis socket location instead of localhost like before. I only feel strange while Plugin still works without proper client driver.

And for Site Health problem, do you have any recommendation?

Are you referring to the dashboard widget, or Tools > Site Health?

Both of them are not working property and show “No information yet…” / “Results are still loading…”. They only work if I disable the plugin / or Disable Object Cache.

Please try disabling all other plugins, one by one, to narrow down which plugin is causing an incompatibility with Redis Object Cache.

I can try to reproduce it after that ????

I’ve found the problem. It does not come from your plugin but truly from a plugin function that incompatible with Redis Object Cache.

If “Disable Heartbeat” option from “Perfmatters” is set to value other than “Default” then Site Health problem happens. I just write it down here so anyone having the same issue with same situation may find the answer. Now everything is working flawlessly.

Thank you for your nice support.

Great. I’m glad you resolved this!