ongoing since wp7.0

Sporadic disconnect from Redis that eventually returns
meanwhile, larger websites overload the _db_ on max
reported to core track 4 weeks ago with no resolve…

https://core.trac.wordpress.org/ticket/65626

//THANKS

Update WordPress

Downloading update from https://downloads.wordpress.org/release/wordpress-7.0.3-no-content.zip...

Unpacking the update...

Verifying the unpacked files...

Preparing to install the latest version...

Enabling Maintenance mode...

Copying the required files...

Disabling Maintenance mode...

Upgrading database... Error establishing a Redis connection

Error while reading line from the server. [tcp://127.0.0.1:6379]

WordPress is unable to establish a connection to Redis. This means that the connection information in your wp-config.php file are incorrect, or that the Redis server is not reachable.

Is the correct Redis host and port set?

Is the Redis server running?

If you need help, please read the installation instructions.

To disable Redis, delete the object-cache.php file in the /wp-content/ directory.