The call to BeginSession() in RelationalSyncProvider is not valid. A session is already in progress.

Question

I have two syncOrchestrator configured for same peers but for different scopes as shown below:

  SyncOrchestrator scopeA=new syncorchestrator();

  SyncOrchestrator scopeB=new syncorchestrator();

two scopes don't share any common database table.

When I initiate the two synchronize() on the two syncOrchestrator's in two different threads , I was getting following error message:

The call to BeginSession() in RelationalSyncProvider is not valid. A session is already in progress.

Cant we have two syncorchestrator on same peers running the synchronization?

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ess

Answer 1

are you assigning different sync providers for each one?

Answer 2

yes.

This is N-Tier sync. I hosted my remote provider on wcf(remote machine) and made the service behaviour available to multiple requests by having configuration as

[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession,ConcurrencyMode=ConcurrencyMode.Multiple)]

Now window service on client machine have two threads running.

Each thread will have separate syncorchestrator object, and proxy to wcf service to call methods (beginsession,getknowledge...............endsession) on remoteprovider. 

this is how i designed my app.

is there anything wrong with design. plz let me know if u need additional info.

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ess

Answer 3

plz let me know if u need any additional info. sync framework methods are not thread safe?

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ess

Answer 4

afaik, they're not.

Answer 5

Would you have any idea of how we can handle sync of two different scopes on same peers at same time(by putting in two different threads).

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ess

Answer 6

can you try enabling sync framework tracing so we can figure out which provider it's failing?

or try changing you concurrency mode in wcf

Answer 7

in my wcf service, concurrency mode is multiple.

Yesterday I tried few things and below are my findings:

If I have to two client windows service for each scope accessing single wcf service hosted - sync is working.

If I run two threads in one window service, its throwing error.

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ess

Answer 8

I suggest you focus on how you're instantiating the local provider in your app and how you're attaching it to the corresponding syncorchestrator.

Answer 9

Hi JuneT,

Its started working. I am using wshttpbinding. the problems is with in-efficient handling of sessions.

I remember it started working after making few changes related to sessions (don't remember what exactly) in wcf service web.config file

following is one among them:

 <reliableSession enabled = "true"/>

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ess