First of all, a Call Center is a very specific use case of a FIFO queue. Any respectable call center business must have some kind of implementation for their own use or for their users.
People do not like to wait while listening to your music on hold. Depending on the nature of your business, people could switch to another business or just wait. Because of this, itis very common these days that call centers to offer a call back feature. A call center feature is the one that allows users to hang out without losing its turn in the queue. When it is their turn (or about to be their turn), the system callbacks them.
In my last article, I wrote how to use the tmpfs from Linux to speed up the local SQLite databases that FreeSWITCHtmpfsuse the tmpfs from Linux to speed up the local SQLite databases that FreeSWITCH uses for operation.
What happens when you are not using SQLite? As a cluster, Is there a way? The short answer is yes. This is more a database specific speed up, but because the nature of the use case, it is very specific for FreeSWITCH and FusionPBX.
Today I have published in OKay's RPM repository RPMs for MCRouter. Mcrouter is a Memcached protocol router for scaling Memcached (http://memcached.org/) deployments. It's a core component of cache infrastructure at Facebook and Instagram where mcrouter handles almost 5 billion requests per second at peak.
RPM's are available for Centos 7 on x86_64 only. Sadly, Boost 1.66 does not compile under CentOS 6 (I guess it is possible, but I am not spending more time making this work). This RPM is already with a systemd unit. You can find it if you type yum search mcrouter.