Crossconnect MySQL connection drops

I've got 2 Windows 2003 servers, one IIS/PHP and another a dedicated MySQL machine crossconnected at theplanet.com.

For some reason, every day or so, my main site will timeout. The other static/php sites that don't use the external MySQL server still work fine on the IIS server. IISReset doesn't do anything to fix it. For some reason the MySQL connection over crossconnect just times out. (even though both servers appear fine)

The only way to fix this is to restart the IIS/PHP server. Strange eh? Nothing shows up in Event Viewer and both servers appear to be fine, except that the MySQL connection keeps timing out.

Does anyone have any ideas, as I have been battling with this for weeks. The Planet support are looking into it, but its fair to say that its hard for them to fix it without being able to see the problem in action.

Does anyone have any ideas or suggestions on how I can tackle this problem? :bawling:

Comments

  • primesuspectprimesuspect Beepin n' Boopin Detroit, MI Icrontian
    edited September 2005
    what versions of php/mysql?
  • edited September 2005
    MySQL 4.1.14nt
    PHP 4.4.0

    :thumbsup:
  • primesuspectprimesuspect Beepin n' Boopin Detroit, MI Icrontian
    edited September 2005
    Has it done this since launch? Or is this something that just happened one day?

    It could always be a code issue as well. What software are you running (php)? Who wrote it?
  • edited September 2005
    Has it done this since launch? Or is this something that just happened one day?

    It could always be a code issue as well. What software are you running (php)? Who wrote it?

    Yup, its PHP - but other sites are running fine that use PHP. Its just this one particular site that doesn't work, and its because of the external MySQL server. Its done it intermittently since the DB server was separated.

    Its mainly vbulletin code, so its quite robust :)
  • ShortyShorty Manchester, UK Icrontian
    edited September 2005
    Ian! :D

    Is there any way they can put performance monitoring on the MySQL host..? The only time I've had a problem with network MySQL is when the host was getting slammed. Im assuming here that this is a shared MySQL box & thus there are other DBs on it..?
  • primesuspectprimesuspect Beepin n' Boopin Detroit, MI Icrontian
    edited September 2005
    mainly vbulletin, but are there any custom written queries, say for your CMS or anything? Is VB the only php code running on the system?

    Also, shorty has a valid point. the db server might be getting hit too hard.
  • edited September 2005
    Sorry for the slow reply guys :) Both boxes are dedicated, and neither are under particular loads at the time (perhaps 25% of what they can be at peak).

    Its mainly vbulletin, but lots of custom things. It didn't cause a problem when they were all on the same box, only once they were split to a dedicated for IIS and another for MySQL.

    It seems asthough something just stops the IIS server from communicating with the MySQL box until the IIS server is reset. Just restarting the IIS service doesn't do it. Very very strange, and a royal pain in the bum!
  • edited October 2005
    An interesting development...

    I have tried "repairing" the crossconnect network connection from both servers to no avail... but I thought I might as well try to disable and re-enable it - and guess what, it worked?

    I know its only going to last for another day, but is there anything that would have symptoms like that?
  • RobRob Detroit, MI
    edited October 2005
    I wonder if there is a bad/poor connection on the interface or something between the two. Unfortunately, The Planet isn't the best place to have a problem, if you know what I mean. Tell them to unplug both ends, and jam it back in. Also, a cable check wouldn't be out of line.

    Also, try check the connection settings of the interfaces. They should both be auto, or the same setting. I have seen a few router, switch, and machine interface problems from negotiation. Could try forcing to 100-full on both ends. If they have a switch or other hardware somewhere in the middle it could be miss-configured as well. A fixed setting on one end and a auto on the other can get strange. The combinations that come up are long, something you need to take up with The Planet.

    Anyway you look at it, they _should_ be able to handle these questions. :thumbsup:
  • RobRob Detroit, MI
    edited October 2005
    I should mention that I am assuming that their hardware is known compatible and the correct software drivers are in place.

    I have had hardware that would shut down under heavy network load, the network adapter needed to be replaced. Sometimes things are just bad, it's not a perfect world and it's a pain to track down :)

    I would keep looking closer at the machine and not the services though. When I realized you were rebooting and not restarting IIS I start to lean away from a IIS/MySQL service problem. Then, restarting the network adapter reinforces it some. Confirm that all traffic between hosts is out, and not just a mysql connection loss.
  • edited October 2005
    Thanks Rob :)

    I've had them replace the cable, so thats been eliminated now. I guess the next step would be to replace the network adapters?

    It does seem to happen more often under load - but also sometimes when there is hardly any activity. Its definetly a total loss, as I can't ping the other machine or anything - although it doesnt detect a connection problem, everything just times out.

    Cheers,
    Ian
  • RobRob Detroit, MI
    edited October 2005
    The very last thing would be to replace the adapter. I would look at the negotiation settings, and also see if you are getting loss on the connection. Is this a crossover cable or a crossconnect? Ping across the two machines and look for loss and signs of bad connectivity when it is working. Try putting both machines as 100M full duplex and not auto. Also, see what ipconfig /all says when it's up and when it's down on both machines.

    Also, you should be beating The Planet up over this. There is no reason they shouldn't be able to work with you on this. They are in the right position to help, and from here I can only recommend what I've seen break before.
  • RobRob Detroit, MI
    edited October 2005
    Now that I think of it. I had a client that had the same problem, only it was his uplink and not his crossconnect. We swapped interfaces on the machine to track the problem. Plugged the uplink into the other port and the crossover to the first port. Just make sure you migrate all IP and firewall settings.

    This will tell you if there is a problem between the machines, or a problem with the adapter. If your uplink starts dropping, then you have isolated the problem to the adapter/drivers if the crossconnect keeps dropping you know to keep pushing for answers on that side.
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