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Building a Linux Virtual Server

Posted by Zonk on from the virtual-but-stable dept.

prostoalex writes "NewsForge (an OSTG site) has an article that discusses the details of building a cluster for a virtual server - an environment where one can add and remove machines as needed, to account for high-traffic Web site of intensive database application: 'The main advantage of using LVS is that unlike Microsoft network load-balancing clusters, the LVS allows you to add a node running any operating system that supports TCP/IP to the cluster.'"

2 of 93 comments (clear)

  1. Built one. by NovySan · · Score: 5, Insightful

    Great for http. Bad for nfs and smb/cifs.

  2. Lame Article ... Excellent Software by Anonymous Coward · · Score: 5, Informative

    Unlike most of the posters sharing their 'wisdom' on the merits (or lack thereof) of using PC's for networking ... I can say that I recently setup a load balancer using LVS in front of my Web cluster (of 6 dual Opteron's). It rocks!

    You can easily avoid it becoming a single point of failure by using 2 directors with realtime syncronization and failover. Keepalived works well in this regard, giving subsecond failover performance, and even uses VRRP, Cisco's own hot standby protocol.

    As for the level hardware that you need, a low end or older PC, such as a P3-700 for instance, can easily saturate a 100 mbit connection.

    I used 2 x P4 2.4G systems. So for less than a fraction of the cost of even 1 hardware based boxes, I get hot standby and should be good for way more throughput than I can afford to provide. :)

    The best feature that LVS brings to the table that the hardware based implementations miss out on, is flexibility. This software is being enhanced all the time and nothing is impossible with it. The same cannot be said for the hardware solutions.

    Unfortuneately the article does not touch on any of the nice add-ons, like keepalived, ldirectord, etc., that make LVS a manageable solution. I know that they are trying to keep the examples simple, but showing servers being configured using solely ipvsadm is not too realistic for the average person and make it look undeservedly complicated, which it is not.

    Give LVS a look an see if it might not give you the features you need without paying the big iron prices.

    DC