Making the case for a virtualized hardware appliance

As Data Center infrastructures become more virtualized, the desire for virtualized network services increases. We see 2 types of offerings:

1. virtual appliances delivered in a VM image, such as the Netscaler VPX from Citrix
2. hardware appliances that can be virtualized, such as Cisco ACE or ASA

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application availability monitoring

The availability of any enterprise application is only as good as the monitoring solutions utilized. The reason being that a well thought out / well deployed monitoring solution not only detects when an application has failed to respond to requests, it can also take steps to being remedy the problem without involving human intervention. The last thing any admin wants to be waken up at 3a only to hit the restart button for the downed service. (more…)

packet capture repository

Ever asked yourself the question of “I wonder what a trace of my favorite application protocol looks like”? I did that today and found myself browsing through the collection of sample packet captures on wireshark.org. The collection is quite impressive. There are nearly 50 categories of packet captures available, from HTTP to NTP to SQL to IPSec to Kerberos. You can even check out a capture of a slammer worm! Anyway, I thought this is a great resource and want to pass it on.

local & global load balancing on the cheap

Not many people know what LVS is. I ran World Health Organization’s public website (www.who.int) using a pair of Compaq DL360 servers running Linux Virtual Server, which is an open-source load-balancer. And guess what, during SARS, we saw over 14 million hits a day at the peak. While I don’t have the specific cps / concurrent conn numbers (we didn’t measure those), the boxes did just fine. (more…)