Why it is necessary to understand the underlying infrastructure even though you’re a DBA

I keep highlighting that it is necessary for DBAs to understand the underlying infrastructure as it helps when it comes to resolving issues. I was having connectivity issues with my SQL Server 2008 instance as sqlcmd and osql are both throwing this error

HResult 0xFFFFFFFF, Level 16, State 1SQL Network Interfaces: Error Locating Server/Instance Specified [xFFFFFFFF].Sqlcmd: Error: Microsoft SQL Native Client : An error has occurred while establishing a connection to the server. When connecting to SQL Server 2008, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections..Sqlcmd: Error: Microsoft SQL Native Client : Login timeout expired.

This blog post highlights how to troubleshoot connectivity issues with SQL Server and gave me an idea why I am getting the issue. The first thing I did was to run an ipconfig /flushdns to make sure I was looking at the correct IP-hostname resolution from my DNS server. Then, I tried to PING the IP address of the SQL Server instance and it worked just fine (I usually add the -a switch on my PING command to include the hostname if it is indeed correct). I tried the reverse – PING the hostname – but my DNS server is returning a different IP for the same hostname. Lokks like the DNS entry for my SQL Server box is a bit screwed up. I logged on to the DNS server to validate and I was right. I modified the IP address of the A record pointing to my SQL Server box, ran another ipconfig /flushdns before doing another PING test to validate the change. Once everything is ok, I was able to connect to my SQL Server instance using sqlcmd and osql.

Now, you might be wondering, “Why do I have to know?” If you’ve read some of my previous blog posts, you’ll know that I’m an advocate of knowing who’s on the team responsible for keeping the infrastructure highly available. It doesn’t matter if your database server is online and available from your perspective. If your applications could not connect to it, it’s as good as it being offline. In fact, I sometimes tell DBAs that my personal measure of availability is the number of phone calls I get from end users regarding the specific application. I shift my focus from being a DBA to being a service delivery manager to properly manage expectations.

It pays to understand a bit about something not directly related to your work sometimes. If we know the underlying infrastructure that our databases are a part of, it makes it easy for us to resolve issues, meet expectations and achieve availability goals.




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2 thoughts on “Why it is necessary to understand the underlying infrastructure even though you’re a DBA

  1. Great article! Unfortunately very large group of DBA’s (Developers too) are total ignorants. They want to administer databases or create applications based on the infrastructure but they don’t have no idea what’s going on there. Many time I saw such “experts” facing trivial issues with Database or Apps related to OS, network, hardware and they looked like a stupid child. For example some of those “DBAs” or “Developers” want to configure network settings for DB or create network application but they don’t know how basic IPv4 addresation and network mask works. They said we are “DBAs” or “Devbelopers”!! We don’t need to know such things 😀 Sorry but what a ignorant lames.

    • Hi Tom,

      I totally understand your sentiments. I’ve been in those environments before and, sadly, sometimes it’s a result of silo-ed organizational structure that has to meet compliance and regulatory requirements. I remember not being able to do anything other than what’s assigned to me even though I am qualified to do so.

      This reminded me of the time when a friend of mine asked if I’ve ever seen (or heard) of a barking kitten. I couldn’t believe what he said: “a barking kitten.” It turned out that the kitten grew up with a bunch of other dogs that it started to think like one. And my friend showed me that it was indeed a kitten that barked like a dog.

      I don’t want to call them ignorant nor stupid. Maybe they were forced into one of those organizations who strictly enforce segregation of duties. And because they were there for so long, they started to think that they don’t need to know more than what they have to work with.

      And, that’s my goal for writing such blog posts: to help IT professionals grow and develop their fullest potential by encouraging them to think big.

      Thanks, Tom, for your comment.