ServiceStack Ormlite transaction between services - sql-server

Question

I'm having trouble with a rather complex save operation inside a ServiceStack service.
To simplify the explanation the service starts an Ormlite transaction and within it calls another service through ResolveService:
public ApplicationModel Post(ApplicationModel request)
{
using (IDbTransaction tr = Db.OpenTransaction())
{
using (var cases = ResolveService<CaseService>())
{
request.Case = cases.Post(request.Case);
}
}
Db.Save<Application>(request.Application, true);
}
The other service (CaseService) uses also a transaction to perform its logic:
public CaseModel Post(CaseModel request)
{
using (IDbTransaction tr = Db.OpenTransaction())
{
Db.Insert<Case>(request);
Db.SaveAllReferences<CaseModel>(request);
}
}
In a similar situation with higher hierarchy of services calling other services a "Timeout expired" error is thrown, and so far I've not been able to resolve, although I closely monitored the SQL Server for deadlocks.
My question is whether this is the right way of using/sharing Ormlite transactions across services or there is another mechanism?
Thanks in advance.

Answer 1

You shouldn't have nested transactions, rather than calling across services to perform DB operations you should extract shared logic out either using a separate shared Repository or re-usable extension methods:
public static class DbExtensions
{
public static void SaveCaseModel(this IDbConnection db,
CaseModel case)
{
db.Insert<Case>(case);
db.SaveAllReferences<CaseModel>(case);
}
}
Then your Services can maintain their own transactions whilst being able to share logic, e.g:
public ApplicationModel Post(ApplicationModel request)
{
using (var trans = Db.OpenTransaction())
{
Db.SaveCaseModel(request.Case);
Db.Save<Application>(request.Application, true);
trans.Commit();
}
}
public CaseModel Post(CaseModel request)
{
using (var trans = Db.OpenTransaction())
{
Db.SaveCaseModel(request);
trans.Commit();
}
}