Question

While testing WCF services with 150 Users, i got this exception.

Note : I am using MS Test Project for loadtesting of WCF Service. When load test is run for 100users, there is no exception.

at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) at System.Collections.Generic.Dictionary2.Insert(TKey key, TValue value, Boolean add) at System.Linq.Dynamic.ClassFactory.GetDynamicClass(IEnumerable1 properties) at System.Linq.Dynamic.DynamicExpression.CreateClass(IEnumerable`1 properties) at System.Linq.Dynamic.ExpressionParser.ParseNew() at System.Linq.Dynamic.ExpressionParser.ParseIdentifier() at System.Linq.Dynamic.ExpressionParser.ParsePrimaryStart() at System.Linq.Dynamic.ExpressionParser.ParsePrimary() at System.Linq.Dynamic.ExpressionParser.ParseUnary() at System.Linq.Dynamic.ExpressionParser.ParseMultiplicative() at System.Linq.Dynamic.ExpressionParser.ParseAdditive() at System.Linq.Dynamic.ExpressionParser.ParseComparison() at System.Linq.Dynamic.ExpressionParser.ParseLogicalAnd() at System.Linq.Dynamic.ExpressionParser.ParseLogicalOr() at System.Linq.Dynamic.ExpressionParser.ParseExpression() at System.Linq.Dynamic.ExpressionParser.Parse(Type resultType) at System.Linq.Dynamic.DynamicExpression.ParseLambda(ParameterExpression[] parameters, Type resultType, String expression, Object[] values) at System.Linq.Dynamic.DynamicExpression.ParseLambda(Type itType, Type resultType, String expression, Object[] values) at System.Linq.Dynamic.DynamicQueryable.Select(IQueryable source, String selector, Object[] values) at CustomEntities.Data.Repository.CustomEntitiesDataRepository.GetCustomEntityData(CriteriaDto criteriaDto) in d:\Projects\SRM\Services\Data\CustomEntities\CustomEntities.Data.Repository\CustomEntitiesDataRepository.cs:line 131 at CustomEntities.Data.Manager.CustomEntitiesDataManager.GetCustomEntityData(CriteriaDto criteriaDto) in d:\Projects\SRM\Services\Data\CustomEntities\CustomEntities.Data.Manager\CustomEntitiesDataManager.cs:line 69

Answer 1

If you look at your code, in CustomEntitiesDataRepository.cs at line 131, this line is triggering the issue. The custom entity you are returning is, at some level, trying to insert a value into a Dictionary<T,U>, but the key its using already exists.