Multi Server with clustering

Discussion in 'General' started by ahnabil, Dec 13, 2017.

  1. ahnabil

    ahnabil New Member

    Hello,

    from what i understood that ISPconfig can run in 2 modes

    Multi-server: where 2 servers acts independt, but with 1 web managemnt server.
    Clustering: where 2 servers acts dependent and everything runs on Server1 and mirror to Server2, but also with 1 web managment server.

    i want to combine the 2 features, where i get mutli-servers with mirroring

    so if i have 6 servers i would then have 2 servers for web managment and 2 servers for websites, emails, dns etc. and the the other 2 servers would mirror the servers that are hosting the websites, emails, dns, etc.

    so:
    SERVER 1 & SERVER 2: Web administration with high availability
    SERVER 3 & SERVER 4: hosting websites, emails, dns, etc.
    SERVER 5 & SERVER 6: mirrors of SERVER 3 AND SERVER 4 & load balancing if applicable.

    if i can, then i want the 2 server that does the web management to be highly available in a cluster, where if one failed the other server should would provide web managment.

    is what i'm thinking of viable with ISPCONFIG?

    thanks guys and i really love ISPCONFIG
     
  2. nhybgtvfr

    nhybgtvfr Member

    yes, you can do that.

    there are instructions for doing it on debian
    https://www.howtoforge.com/tutorial...ase-cluster-on-debian-8.4-with-ispconfig-3/5/

    although the guide is assuming everything is running on that one cluster, but you can follow that guide for doing the web management part, your server1 & 2.
    you can add the other servers as normal additional servers in a multi-server setup, and mirror them as required.

    you'd need to install unison (as in the cluster guide) onto the additional servers and their mirrors, or provide shared storage to ensure that website files etc are kept in sync. and you'd probably want to think about a centralised db server/s (with replication or cluster) otherwise you could end up looking at maintaining a lot of different database replications.

    you may be able to combine eg server3 and server 5 as a cluster and just add that cluster as an additional server as per the normal multi-server setup, although I've never tried it that way, so can't confirm that.
     
  3. ahrasis

    ahrasis Active Member

    I guess the related reading in here should be the Multiserver Setup With Dedicated Web, Email, DNS & MySQL Database Servers On Debian Squeeze With ISPConfig 3 tutorial.

    In there the suggested dedicated servers are a web server (ISPConfig should be in here), a mail server, a database server and two dns servers (five servers altogether).

    But based on your plan, may be a web server + ISPConfig + dns server as #1 and its cluster in #2; and a mail server + database server in #3 and its cluster in #4. Or you can split the mail and database servers, so they stand on their own and each have its own cluster.

    2 cents only.
     
  4. till

    till Super Moderator Staff Member ISPConfig Developer

    As @nhybgtvfr and @ahrasis pointed out such a setup is possible by mixing the mirror and multiserver tutorial. In general, each server can mirror another server in a multiserver setup by setting his 'is mirror of' setting to the other server. What's happening then: When a server is a mirror, then he will not only fetch and process changes for the server_id of his master instead of his own server_id and he will not show up in the ISPConfig UI in the option fields for web, dns and web servers. Theoretically you can even have more than 2 servers to be mirrors of the same master, ISPConfig has no limit there. But practically you might get in trouble with mysql replication when you have 3, 4 or 5 masters, But technically it's possible. What ISPconfig mirroring does and what not: ISPConfig mirroring ensures that the same config changes get writen to all mirrored nodes (in the ispconfig database and in the config files) and that e.g. website folders get created on all nodes in case they don't exist. But mirroring the config is just one part, you need a shared filesystem for web and mail data and you need a technology to mirror the mysql database, for these two parts you are free to choose the technology, e.g. the mirror setup example uses unison for /var/www sync, but you can use e.g. a network file system here or mount the folder from a storage system. For /var/vmail, the latest mirror setup uses dovecot sync, but other solutions like shared filesystems are possible here as well. And for mysql, there we use the traditional mysql master/master mirror but there are other solutions available as well like a percona mysql cluster. Just to give you some ideas what's possible.
     
  5. ahnabil

    ahnabil New Member

    ok that is great, what's your recommendation for the server setup, i.e. how much web administration server and what they should hold and how much web hosting servers, etc.. etc..
     
  6. nhybgtvfr

    nhybgtvfr Member

    how long's a piece of string?

    how many websites? how big are the databases? are the sites heavy on db queries? how much traffic to each site? how much email? mass sending emails? large attachments? using a cdn for static files/images? nginx/apache2? if apache2, mpm_prefork / mpm_event / mpm_worker?

    the answers going to be different for everybody, and even once you know what you require for right now, it's going to change over time anyway.
     

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