所有池连接均在使用，并且达到了最大池大小。

SELECT [dec].client_net_address,
       [des].[program_name],
       [des].[host_name],
       Count([dec].session_id) AS connection_count
FROM   sys.dm_exec_sessions AS [des]
       INNER JOIN sys.dm_exec_connections AS [dec]
               ON [des].session_id = [dec].session_id
GROUP  BY [dec].client_net_address,
          [des].[program_name],
          [des].[host_name]
ORDER  BY [des].[program_name],
          [dec].[client_net_address];