concurrency - RavenDB keeps throwing a ConcurrencyException -

i keep getting concurrencyexception trying update same document multiple times in succession. put attempted on document '<id>' using non current etag message.

on every save our ui publish event using masstransit. event sent subscriberqueues, put eventhandlers offline (testing offline subscribers). once eventhandler comes online queue read , messages processed intended.

however since same object in queue multiple times first write succeeds, next doesn't , throws concurrencyexception.

i use factory class have consistent idocumentstore , idocumentsession in applications. set useoptimisticconcurrency = false in getsession() method.

public static class ravenfactory {     public static idocumentstore createdocumentstore()     {         var store = new documentstore() { connectionstringname = "ravendb" };          // setting conventions         store.conventions.registeridconvention<mytype>((db, cmd, e) => e.myproperty.tostring());         store.conventions.registerasyncidconvention<mytype>((db, cmd, e) => new completedtask<string>(e.myproperty.tostring()));          // registering listeners         store             .registerlistener(new takenewestconflictresolutionlistener())             .registerlistener(new documentconversionlistener())             .registerlistener(new documentstorelistener());          // initialize , return         store.initialize();         return store;     }      public static idocumentsession getsession(idocumentstore store)     {         var session = store.opensession();         session.advanced.useoptimisticconcurrency = false;         return session;     } } 

the eventhandler looks this. idocumentsession gets injected using dependency injection. here logic instance of idocumentsession.

private static void initializeravendb(iunitycontainer container) {     container.registerinstance<idocumentstore>(ravenfactory.createdocumentstore(), new containercontrolledlifetimemanager());     container.registertype<idocumentsession, documentsession>(new perresolvelifetimemanager(), new injectionfactory(c => ravenfactory.getsession(c.resolve<idocumentstore>()))); } 

and here actual eventhandler has concurrencyexception.

public class myeventhandler:consumes<myevent>.all, iconsumer {     private readonly idocumentsession _session;      public myeventhandler(idocumentsession session)     {         if (session == null) throw new argumentnullexception("session");          _session = session;     }      public void consume(myevent message)     {         console.writeline("myevent received: id = '{0}'", message.myproperty);          try         {         _session.store(message);     _session.savechanges();         }         catch (exception ex)         {             var exc = ex.tostring();             // deal concurrent writes ...             throw;         }     } } 

i want ignore concurrencyexception until can sort out business on how tackle concurrency.

so, ideas why concurrencyexception? want save happen no matter whether document has been updated before or not.

i unfamiliar configuring unity, want singleton of idocumentstore. below, have coded singleton out manually, i'm sure unity support it:

public static class ravenfactory {     private static idocumentstore store;     private static object synclock = new object();      public static idocumentstore createdocumentstore()     {         if(ravenfactory.store != null)             return ravenfactory.store;          lock(synclock)         {            if(ravenfactory.store != null)                return ravenfactory.store;             var localstore = new documentstore() { connectionstringname = "ravendb" };             // setting conventions            localstore .conventions.registeridconvention<mytype>((db, cmd, e) => e.myproperty.tostring());            localstore .conventions.registerasyncidconvention<mytype>((db, cmd, e) => new completedtask<string>(e.myproperty.tostring()));             // registering listeners            localstore                .registerlistener(new takenewestconflictresolutionlistener())               .registerlistener(new documentconversionlistener())               .registerlistener(new documentstorelistener());             // initialize , return            localstore.initialize();            ravenfactory.store = localstore;            return ravenfactory.store;        }     }      //      before     //     public static idocumentsession getsession(idocumentstore store)     // }