TCP Keep Alive

Interesting Finds: December 12, 2007

Jason Haley — Wed, 12 Dec 2007 18:11:22 GMT

re: TCP Keep Alive

Yair Zadik — Wed, 12 Dec 2007 20:20:42 GMT

Is there any easy way to get to the underlying TCP stream and change the keep-alive to something shorter like 1 minute, assuming you're willing to pay for the extra network traffic and processing time?

Is this something that could be done in a custom binding?

re: TCP Keep Alive

Sean — Wed, 12 Dec 2007 22:25:41 GMT

Shy Cohen at MSFT suggested to use reliable session:

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=289842&SiteID=1

Are there problems with this solution?

Thanks.

re: TCP Keep Alive

Nicholas Allen — Thu, 13 Dec 2007 00:02:12 GMT

Hi Yair,

Controlling the keep-alive is a socket option and there's no way to get at the socket held by the TCP transport.

re: TCP Keep Alive

Nicholas Allen — Thu, 13 Dec 2007 00:06:09 GMT

Hi Sean,

There are a couple ways to get keep alives with just the components that ship in the box but you generally have to pay something in return for the convenience. Reliable messaging is a very heavy protocol if you just want a heartbeat so you'll pay in terms of latency and throughput for the extra features you're not using.

re: TCP Keep Alive

Michael Swart — Thu, 13 Dec 2007 05:55:17 GMT

Interestingly enough, I implemented the heartbeat model for a project based on WCF. We were tasked with creating a seemless offline system. Luckily, in my scenario, we have a series of services so creating a new service with required heartbeat contract was very simple. A background manager is used to handle subscriptions and send out call backs. That said, there seem to be many corner cases to watch out for when implementing this method.

Maybe there is a better way to implement this model, but the code we have written works just fine.

Resolving Conflicts in Serialization

Nicholas Allen's Indigo Blog — Thu, 13 Dec 2007 06:43:58 GMT

DataContractSerializer supports multiple serialization mechanisms. If more than one serialization mechanism

re: TCP Keep Alive

Sean — Fri, 14 Dec 2007 06:24:24 GMT

Thanks Nicholas for quick reply!

You mentioned there are a couple ways to get keep alives with just the components that ship in the box. It seems to me in a duplex connection, channel faults when the other side is down or throws an exception. Is this an alternative to get keep alive?

Thanks.

re: TCP Keep Alive

Nicholas Allen — Thu, 20 Dec 2007 19:47:14 GMT

Hi Sean,

Any configuration that keeps a continuously pending IO will allow you to detect a disconnection. An ordinary duplex connection won't do this but if you have a callback contract so that there is a local listener, then you'll be able to detect when the connection is dropped.