If I open some DB connection in some global viable in one call of the web service's method and if concurrently at second call of this method will it see this instance in this global viable ? Are this resources shared or each call has it's own resources ?
Thanks
Global variables tend to be just that, global. If your global variable is a C# static, it will be shared by webservice methods in the AppDomain. This is obviously error-prone - It is better, if each webservice method obtains a new connection when needed, and close it before the method finishes.
static ? Does it have rules for opening/closing connections, etc. Depending on that, you may or might not have a severe concurrency problem. If you add some more info to your question, I will do my best to elaborate.Usually Web service use Http request. In this case it's possible that each call you have to define the object, because the service are stateless...
For services it is better to use some kind of database connection management. Usually you can adapt Open/Close new connection on per-request basis. Note, most likely you will be working with logical connections and connection pool. Those are helpful to significantly reduce load to open physical connection. Physical connection is created without your direct control and is really heavy weight operation.
Do not put connection in a shared static variable, because connection is typically a disposable resource, which means you must dispose it. If something goes wrong and your connection to the database is corrupted then all your subsequent calls are deemed in doom.
