Data Center
Building things: cubicle analogy time
Jan 4th
This week, I’ve been building (actually, rebuilding) cubicle desks in our new office space and comparisons were naturally drawn to building virtual machines a few weeks ago.
Setting up a LogicMonitor Agent
Dec 30th
LogicMonitor is a really cool server and network monitoring and measurement system which we’ve been working with. It uses a lightweight monitoring agent installed on your local network which collects data from your systems and passes it over SSL to an external aggregator. It’s capable of auto-discovery and is mostly self-configuring though you can adjust many of the metrics. After many years of working with patchwork monitoring and alert systems we’re pretty excited about it. Call us if you’re interested.
Setting up a monitoring agent on your local network is easy. The server hosting the agent just needs a JRE (Java Runtime Environment) installed using version 1.6 or greater and must be able to make an outgoing SSL connection. To monitor Windows systems, you’ll need to install the agent on a Windows server.
comparing software load balancers
Dec 1st
now that i have three different software load balancers installed (Balance, Crossroads, and Pen), i want to evaluate their relative performance. benchmarking a single web server isn’t difficult using tools like ab, but trying to benchmark a load balanced cluster is somewhat different. since most load balancers support stickiness, all the requests from a single source will be directed to a single back-end server. thus, i’ll need to run the benchmarker from several different sources simultaneously, or i’m really just testing one server with something in the way. fortunately, i have three machines on different IP addresses sitting idle.
software load balancing
Nov 29th
load balancing is a common technique for distributing a workload, such as handling a web site, across multiple servers. a pool of several smaller servers can be more efficient than a single large server, since the size and capability of the “server” can be changed just by adding or eliminating servers from the pool. a pool of servers can also be more responsive than a single server, and more fault-tolerant.
one of the simplest forms of load balancing is round-robin DNS, where a single hostname is pointed at multiple IP addresses, each of an individual server. this is very easy to set up, but changes to the pool are limited by DNS caching and TTL. on the other end of the spectrum are dedicated hardware load balancers, such as the F5 Big-IP we use, which monitor the status of each server in the pool and intelligently route incoming requests. these are awesome machines, but come with equally awesome price tags. between these two extremes lie some network firewalls with load balancing, and software load balancers, which run on a front-end server.
i’ve been looking at a few software load balancers for a small virtual server project; Balance, Crossroads, and Pen.
Colocation is so 1990s…
Oct 11th
Yep, I said it.
Today, organizations need more agility and elasticity in their computing services. Sounds cloudy, huh?
I’m not a fan of the term ‘cloud’, with the vague meanings and weird marketing tricks. We banter around at the office and come up with silly & new terms like ‘fog’ (because it isn’t clear) or ‘to the clown!’ (a play on words in reference to the Microsoft advertisements).
What I am a fan of is the change in operation for how we (all of us) use computing facilities.
Not long ago we were all buying servers for either a single use (front-end web server, a database server, etc) or a larger edition to combine services onto (perhaps a web/database server with email services planned). This is great from the hardware manufacturer point of view but isn’t the best use of the business’ cash flow, creates inflexible hardware configurations, and isn’t very green.
Enter the concept of the virtual data center (or VDC), something we rolled out on October 1st, 2011 after months of testing.
