Squid and the Virtualization: Tuning Software Configurations to Obtain the Best Performance on High Demand Proxy Servers. 97 p.

This work presents a case study of performance improvement in network proxy services using the free software Squid and free operating systems, such as Linux, FreeBSD and NetBSD, using full machine virtualization or machine paravirtualization with Xen or KVM. The studied performance improvement relates to various operating systems properties, file systems, the Squid itself or the network. The disk cache performance is tested throughout comparative tests made under Linux with XFS and ReiserFS file systems. The correct choice of a DNS or name resolution service, considering its geographical or network location, is shown as a strong alternative for the response time reduction not only for a proxy service but also for any network server that needs domain name resolution. SquidGuard utilization also aims to reduce the response time, but through the reduction of machine processing time of access control lists. The use of various operating systems reflects the difference that the same service or application may suffer due to constructive properties of those operating systems. The whole study is done using total virtualization or paravirtualization techniques on the machines where the proxy service is executed.

Keywords: Performance. Free Software. Squid. Proxy. Virtualization.