CODEWITHSUNDEEP
wcflinqentity-framework-5
Muhammad Imran Khan
Muhammad Imran Khan

Reputation: 325

WCF : An item with the same key has already been added

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

Upvotes: 0

Views: 1248

Answers (2)

Tiago Nunes
Tiago Nunes

Reputation: 61

Actually it looks like there's a concurrency issue in .Select(). See http://www.webr2.com/system-linq-dynamic-select-new-does-not-appear-to-be-thread-safe/

Easiest fix is to put some locking in your code around calls to Select

Upvotes: 2

Reed Copsey
Reed Copsey

Reputation: 564851

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.

Upvotes: 2

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