Requirements

Asterisell instance

Linux CentOS 7 x86_64
1 CPU core minimum, 4 CPU cores are optimals in case of millions of monthly calls
1GB of RAM minimum
consider additional 200MB of RAM for every additional instance you install on the same host
for optimal performances /var directory with Ext4, XFS file-system or other DBMS friendly file-system
for optimal performances an SSD disk, but it works rather good also on a traditional HDD disk, thanks to TokuDB engine
it is not important a distinct /home partition, because all data is saved on /var partition
it must be completely dedicated to Asterisell, because many operating-system configurations will be overwritten by Instances configuration tool

Some benchmarks to use as reference

8500 CDRS/s on dedicated fast host: 4 cores, 8GB RAM, 2xSSD
4300 CDRS/s on shared cloud host: 1 core, 2GB RAM, SSD
2600 CDRS/s on host with slow HDD

Management utility instance

Linux CentOS x86_64
3GB of RAM, required during the compilation of the Haskell rating engine
an SSH connection to Asterisell host running the Asterisell instance

In case you install the Instances configuration tool on the same host containing Asterisell instance, do not allocate too much RAM to the DBMS, because during compilation/upgrading of the application 2-3GB will be used. At the end of the upgrade, the free RAM will be used from Linux for buffering the files with TokuDB engine, so it will be not wasted. You can enable also swap disk space, because code compilation is an one-time operation done only during application upgrade.

Why using a distinct host for Asterisell management tool?

Normal users use the same host for managing and running Asterisell instances.

It makes sense using different hosts in case:

you are managing a lot of Asterisell hosts/instances
you are an Asterisell developer, and you develop on your main host, and test on distinct VM
you want use a cheap Asterisell host with 1-2GB of RAM, and so you offload RAM-hungry operations on the local management host