On Tue, Dec 04, 2018 at 02:35:39PM +0200, Mutsikiwa Admire wrote:
Just wondering if it is possible to have a Koha implementation in which we have a front-end Load Balancer such as NGINX or HAProxy, several Koha web server instances powered by one database server running on a separate server with balancing from source with stick-table in the case of HAProxy.
Yep! I'm currently handling the sysadmin side of an installation which runs the koha web interface on two mirrored web servers behind an F5 BIG-IP load balancer, with a third non-web server to handle cron jobs, outgoing mail, etc. All three servers talk to a three-node mariadb/galera cluster (although they only actually talk to a single node because koha doesn't play well with multi-master database configurations) for data storage and a five-node elasticsearch cluster for indexing. On each individual web server (after passing through the load balancer), the request path is nginx => apache => starman/plack. nginx serves static files, apache handles shibboleth authentication, and starman runs the koha scripts. I opted to go with the F5 device instead of nginx for the front-end load balancing because it was already available through the campus data center and I didn't want to deal with setting up failover on an IP address myself, but I can't see any reason that it wouldn't work just as well (from koha's perspective) with nginx or haproxy as the load balancer instead of a dedicated device. -- Dave Sherohman