WCF PerSession service and AutoMapper

where should I put the code for configuring AutoMapper mapping between DTO and EntityFramework Entities for WCF PerSession services?

If in the default constructor, does that mean every session will create an individual mapping and causes lots of ov开发者_开发问答erhead on the server side?

Thanks

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Configuration of AutoMapper is global for the whole application so your service should not do any configuration itself. AutoMapper should be configured in your application bootstraper (when the application starts). For example in WCF service hosted in IIS (over HTTP) you can use standard Global.asax and Application_Start.