Support » Plugin: W3 Total Cache » W3TC with multiple WordPress sites using the same Memcached and Redis instance?

  • Resolved Fritex



    I am interested to using your plugin on my dedicated server.

    Currently using one instance of WordPress installation = one domain.

    Will it work if I add two more Websites – different domains – but on the same running Memcached (database cache) and Redis (object cache) instances?

    For example:
    1) – currently working perfect!
    2) – will be added
    3) – will be added

    All of them are separated in different, their own “public_html” and “www” folders, as well as the WordPress installations inside.

    So, I wonder if there is some special setup to use W3 Total Cache Plugin with multiple sites (different domains, separate installations, etc.) but on the same Memcached running instance and the same Redis instance running as well?

    Do I need to create another instances?
    Do I have to make Memcached/Redis running on different ports?
    Will the cache keys work?

    Moreover, the installation of all three WordPress databases has got different database names and different table prefixes as well.

    Do I have to add some prefix for the cache keys or anything else?
    If so, where should I add or modify existing .php files or configuration files of the dedicated server, maybe?

    I ask because I did not do that before and do not know the behaviour of the server and running different WordPress installations on the same Memcached (for database cache) and Redis (for object cache) within Page cache (disk enhanced).

    Thank you very much for any helpful information!

    Wish you the best on the holidays!

Viewing 3 replies - 1 through 3 (of 3 total)
  • In short, is it possible to use W3TC plugin with the:
    a) multiple WordPress websites that have:
    1. separated /home/www/domain-name/ folders
    2. installed in different databases
    2.1. different database names as well
    2.2. different table prefix as well

    b) while using a setup for each like:
    1. Memcached – database cache
    2. Redis – object cache

    NOTE: 1. and 2. – running on the same instance?!

    3. Page Cache – disk enhanced
    4. CloudFlare extension built inside W3TC
    5. AMP cache extension built inside W3TC

    Thank you very much!

    Plugin Support Marko Vasiljevic


    Hello @fritex

    Thank you for your inquiry and I am happy to help.
    As for Memcached, if you want to have multiple websites all using Memcached, then you need to have separate instances of Memcached running. It can just be bound to, for example, 3 different ports (one for reach site) or 3 different IP addresses.
    As for Redis, you can store data into an exclusive database for different apps. With the select command, you can switch between these databases. Redis allows you to have different databases, identified by a number. By default, you have 16 databases ( 0-15).
    Thank you!

    Thank you very much for provided information and help!

    I hope I will get it working.

    Basically if I understand it …
    From that, I can setup/configure on my dedicated server and use different ports for Memcached – for each of those 3 WordPress Websites.

    While also using, different Redis Databse ID – as I understand “max 15/16 databases per Redis instace” on the same port.

    Thank you for help and a bit of explanation!

    • This reply was modified 10 months, 1 week ago by Fritex.
    • This reply was modified 10 months, 1 week ago by Fritex.
Viewing 3 replies - 1 through 3 (of 3 total)
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