LAPI application hangs on a socket

We spent a lot of time to improve our LAPI wrapper class written in Java. Using a retry mechanism we solved problems which come with a LLIOExceptions like

Could not access server
Server did not accept open request
Could not read router packet from socket

In a network with good performance our tools using this wrapper class may run for several days without any problem. But accessing a Livelink system over a bad network sometimes we got a locked situation where the LAPI application seems to hang on a socket. One way to get out of this state is to deactivate/activate the network interface but we want to have an automatic solution. Does anybody know a way to solve this? Is there a way to close the socket programmatically or to set a timeout on the socket?

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Comments

Ferdinand Prantl

Basically, you can help yourself either by asynchronous network connection methods or by spawning another thread. Then you original thread can wait either for the connection or for the timeout. If the timeout occurs you can close the socket which  makes the the system stop trying and discards the system resource.

I haven't worked with Java for a long time; this is the solution I use in .NET - maybe it will help you to look for a similar pattern in JDK:

// HTTP client class has built-in support for the connection timeout
HttpWebRequest.Timeout // connection timeout HttpWebRequest.ReadWriteTimeout // further communication timeout
 // TCP client has no built-in support for the connection timeout but can work// asynchronously and you can set a manual event in the connection callback// to let the main thread know that the connection has been establishedTcpClient.BeginConnect + WaitHandle.WaitOne(...) + TcpClient.EndConnectTcpClient.ReceiveTimeout + TcpClient.SendTimeout // further communication timeout   --- Ferda

eLink User

Afaik there is no way. The Java LAPI stubs library does _not_ provide you any control over the socket it uses.You _may_ try to workaround this by implementing your own java.net.SocketImplFactory and set this by java.net.Socket. setSocketImplFactory ... could be a challenging task, I think.Since LAPI is heading end of life you may consider to switch to the Content Web Services instead.

Ferdinand Prantl

The worker-thread-spawning-and-waiting-for approach can be applied to the whole LAPI call. The finalizer of LLSession closes the underlying socket. I'd probably want to close it immediately without relying on the finalizer - to replenish the system resources quicker. You'd be able to figure out how.

--- Ferda