Network Error 207

Discussion of open issues, suggestions and bugs regarding ADO.NET provider for Oracle
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Posts: 2
Joined: Fri 30 Sep 2011 15:33

Network Error 207

Post by AGAZAGNES » Wed 19 Mar 2014 11:44

i am facing exceptions "Network Error 207" and sometimes "network error 204" using entity framework and devart dot connect for oracle. Those exceptions are sent "randomly", but quite often.

My application is a mvc 4 web site and runs on IIS 7 (windows server 2008 r2 - x64).

Here is a sample of stack trace (but origin call (here a firstOrDefault) is various) :

Network error: 207
at Devart.Data.Oracle.DirectUtils.b(Int32 A_0)
at Devart.Data.Oracle.b6.a(Byte& A_0)
at Devart.Data.Oracle.d.a(Byte[] A_0, Int32 A_1, Int32 A_2)
at Devart.Data.Oracle.d.h()
at Devart.Data.Oracle.dg.c()
at Devart.Data.Oracle.da.a(v A_0)
at Devart.Data.Oracle.j.j()
at Devart.Data.Oracle.OracleDataReader.Close()
at Devart.Common.Entity.bk.Close()
at System.Data.Common.DbDataReader.Dispose(Boolean disposing)
at System.Data.Common.DbDataReader.Dispose()
at System.Data.Common.Internal.Materialization.Shaper`1.Finally()
at System.Data.Common.Internal.Materialization.Shaper`1.SimpleEnumerator.Dispose()
at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)

would have an idea ? what can cause such exceptions ?

thank you

Posts: 2
Joined: Fri 30 Sep 2011 15:33

Re: Network Error 207

Post by AGAZAGNES » Wed 19 Mar 2014 12:50

I forgot to precise that i use .net framework 4.5, entity framework 5.0 and devart dotconnect for oracle 7.9.333

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Joined: Thu 14 Aug 2008 12:44

Re: Network Error 207

Post by Shalex » Fri 21 Mar 2014 15:05

You are using the Direct mode, aren't you?

"Network error" is an internal error of our provider which says "connection is not established" or "unexpected server response". Possible reasons:
a) code which tries to employ connection which was previously closed or being currently used in a different thread
b) server terminates the connection (server's problem)
c) bug of the provider

General recommendations:
1) avoid using the same OracleConnection in several threads at the same time because OracleConnection instance is not guaranteed to be thread safe
2) try using the "Validate Connection=true;" connection string parameter to validate connections that are being got from the pool;
3) upgrade to the latest (8.3.115) version of dotConnect for Oracle;
4) try using the OCI mode (via Oracle client).

We need to reproduce the problem in our environment to find out the true reason. If possible, try to localize the issue and send us a small test project with the corresponding DDL/DML script.

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