A good travel tale? Thanks Avis. UnSpun un-spun?
Nov 27

Why did my MySQL connections suddently take 30 seconds?

Tech Add comments

After a MySQL upgrade, connections to our DB from our Web tier were taking ~30 seconds. It was infuriating.

We weren’t the first to see this:

After three years of running flawlessly, out MySQL database started experiencing problems handling connections. We soon discovered that MySQL by default does a reverse DNS lookup as part of its security process. We discovered that the reverse DNS lookups performed by MySQL were either timing out or were taking a very long time (5-10 seconds). We also discovered that another peice of software- a socket service listening on port 211 began to fail as well. This was a third party product so we are not sure, but the presumption is that it must also use reverse DNS lookups.

We added valid reverses via /etc/hosts and the connections happened immediately again.

Thanks to Contegix on this one. If your company has its servers hanging out in the office, please call contegix right away and get serious (Yes, I am talking to you :).

2 Responses to “Why did my MySQL connections suddently take 30 seconds?”

  1. Rob Sanheim Says:

    Hmm…I have no idea who you are talking about. Maybe they are too busy doing “smack” to take notice….

  2. edisern Says:

    “Player friend:come here to experience the pouring , thrilling and lightsome

    online game, please register the following website ,they will provide the high-

    speed game agency to every player, the speed and service must be the top-grade

    absolutely .”
    game

Leave a Reply

Spam is a pain, I am sorry to have to do this to you, but can you answer the question below?

Q: Type in the word 'ajax'