MSQL_XP is the  wait type that occurs when a task is executing an extended stored procedure - XP. SQL Server does not have control over an XP even though it is executing within the SQL Server process. Investigation of these waits requires investigating the execution of the extended stored procedure code—the vendor may have provided diagnostic tools for the XP. If such tools are not available and the source code of the XP is not available and the documentation does not provide other troubleshooting information, contacting the vendor may be the only option.

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