Object cache could not be flushed

Hi Till,

New WordPress installation here, it’s a MultiSite (subdirectories, not subdomains) with only one Site at the moment and a bunch of plugins, all of them very standard and well-known, so nothing special. Everything is last version.

The server is a Nginx standard installation and I have your Nginx Cache plugin working fine as well. It flushes, so no problems here. Also, I have no other caching plugins apart of your Nginx and Redis ones.

The Redis Object Cache plugin seems to work fine, it is connected but it does not flush anything. The message is just “Object cache could not be flushed.“. I’ve tried flushing from Redis itself with ‘flushall‘, it did it but the problem is not fixed.

The result is I can’t publish or save any post or page. If I disable the Object Cache, then I can.

Can you help, please?
Thanks in advance.

PS- There is another WordPress installation in that same server, almost the same but no MultiSite this time. The same problem happens.

My wp-config.php has this:

define( 'WP_REDIS_PREFIX', $table_prefix );
define( 'WP_REDIS_HOST', '127.0.0.1' );
define( 'WP_REDIS_PASSWORD', 'some_password' );
define( 'WP_REDIS_TIMEOUT', 1 );
define( 'WP_REDIS_READ_TIMEOUT', 1 );
// automatically delete cache keys after 7 days
define( 'WP_REDIS_MAXTTL', 60 * 60 * 24 * 7 );
define( 'WP_REDIS_DISABLE_BANNERS', true );

And Diagnostics says this:

Status: Connected
Client: PhpRedis (v5.3.2)
Drop-in: Valid
Disabled: No
Filesystem: Working
Ping: 1
Errors: []
PhpRedis: 5.3.2
Predis: Not loaded
Credis: Not loaded
PHP Version: 7.4.12
Plugin Version: 2.0.15
Redis Version: 6.0.8
Multisite: Yes
Global Prefix: ""
Blog Prefix: 1
WP_REDIS_HOST: "127.0.0.1"
WP_REDIS_TIMEOUT: 1
WP_REDIS_READ_TIMEOUT: 1
WP_REDIS_MAXTTL: 604800
WP_REDIS_PREFIX: "someprefix_"
WP_REDIS_PASSWORD: ••••••••
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",
    "themes"
]
Unflushable Groups: []
Drop-ins: [
    "Query Monitor Database Class v by ",
    "Redis Object Cache Drop-In v2.0.15 by Till Krüss"
]

• This topic was modified 5 years, 4 months ago by Goodvalley.
• This topic was modified 5 years, 4 months ago by Goodvalley.
• This topic was modified 5 years, 4 months ago by Goodvalley.
• This topic was modified 5 years, 4 months ago by Goodvalley.