Why I still like Service Indicator Lights

My business partner loves to tell people I can always find something with an error light illuminated in a data center.

You know the light….the one basically saying “I need attention.”  They vary in color…some may be red, some amber.  They are meant to draw attention to them.

Well, please don’t tell him….but I’m actually not omniscient.  The law of averages begins to come into play.  In a large data center holding thousands of devices, with a mean time between failures measured in years, something is always failing.

Sometimes the “I need attention” light comes on because a dual power corded device only has one power cord plugged in.  All the computer knows is one side of power isn’t working…so someone should know about it.  Sometimes the light comes on for more serious reasons….such as a fan failing or a processor check.

Some might argue the external service indicators are a thing of the past.  In an era of systems being able to report on a large variety of health measures, most servers are already communicating to a variety of monitoring systems so “looking at a light” may be considered old fashioned.  And while I wouldn’t argue that, I don’t use the service indicator lights that way.

I use them as a simple way to consider how an organization is servicing their environment.

For example, year ago I walked into the data center of a financial services firm and noticed an service indicator was “on” with a key processor.  I made a mental note.

A week later, the same light was still on.  I got the manager and asked him about it.  “Our people are aware and taking care of it.”

Another week goes by…and the same light is still on.  Admittedly, someone could have repaired the machine and another failure ensured.  Such was not the case.  This company simply wasn’t taking their systems servicing seriously.  This time, the manager did get the machine repaired before there was a serious issue.

This same data center also had a large number of dual power corded devices with indicator lights illuminated.  The company quickly discovered one side of the power distribution unit had a tripped breaker and they didn’t realize it.

So clearly systems monitoring and power monitoring was an issue.

Do I run my shop based on the lights?  No.  Automated tools properly configured will provide better instrumentation.

That said, these “dummy lights” painstakingly added to systems by thoughtful engineers provide a litmus test for me…a simple litmus test I can administer solely by walking around a data center without touching anything. 

So, the truth is I always do find lights on, as can you.  It’s how your organization deals with the lights that differentiates.

How do you react to service indicator lights?