SQL Server 环形缓冲区（Ring Buffer） -- RING_BUFFER_SECURITY_ERROR 诊断安全相
SQL Server 环形缓冲区（Ring Buffer） -- RING_BUFFER_SECURITY_ERROR 诊断安全相关错误
环形缓冲存储了大量的在过去一段时间段内的安全错误信息，有助于分析SQL Server安全问题。
例如，当你尝试创建一个SQL登录账号，并启用密码策略，但是提供的密码不匹配密码策略。然后，你将会收到一个错误消息说明密码不匹配。这个错误将会存储在环形缓冲区。当你执行下面的查询，你将会导致错误的SPID以及导致失败的API名称。如上面示例描述的，你会找到NetValidatePwdPolicy错误。
如果你转换ErrorCode的值 0x8C5（=2245）为数值型，然后使用命令行命令NET HELPMSG <number>，你将会看到导致错误发生的原因。
![clip_image001[4]](http://s3.51cto.com/wyfs02/M00/54/1C/wKiom1R4KaPTc-1FAACY92HeGMg587.jpg "clip_image001[4]")
调用的API的名称对于判断域帐号相关的安全错误是非常有用的，因为它将会调用活动目录服务相关的函数，这些文档很容易找到，对于定位问题更为容易。
![clip_image002[4]](http://s3.51cto.com/wyfs02/M01/54/1C/wKiom1R4KaThyzPiAASTOdcm6iM910.jpg "clip_image002[4]")
对于SQL Server 2005：
SELECT CONVERT (varchar(30), GETDATE(), 121) as runtime,
DATEADD (ms, -1 * ((sys.cpu_ticks / sys.cpu_ticks_in_ms) - a.[Record Time]), GETDATE()) AS Notification_time,
a.* , sys.ms_ticks AS [Current Time]
FROM
(SELECT
x.value('(//Record/Error/ErrorCode)[1]', 'varchar(30)') AS [ErrorCode],
x.value('(//Record/Error/CallingAPIName)[1]', 'varchar(255)') AS [CallingAPIName],
x.value('(//Record/Error/APIName)[1]', 'varchar(255)') AS [APIName],
x.value('(//Record/Error/SPID)[1]', 'int') AS [SPID],
x.value('(//Record/@id)[1]', 'bigint') AS [Record Id],
x.value('(//Record/@type)[1]', 'varchar(30)') AS [Type],
x.value('(//Record/@time)[1]', 'bigint') AS [Record Time]
FROM (SELECT CAST (record as xml) FROM sys.dm_os_ring_buffers
WHERE ring_buffer_type = 'RING_BUFFER_SECURITY_ERROR') AS R(x)) a
CROSS JOIN sys.dm_os_sys_info sys
ORDER BY a.[Record Time] ASC
对于SQL Server 2008：
SELECT CONVERT (varchar(30), GETDATE(), 121) as runtime,
dateadd (ms, (a.[Record Time] - sys.ms_ticks), GETDATE()) as [Notification_Time],
a.* , sys.ms_ticks AS [Current Time]
FROM
(SELECT
x.value('(//Record/Error/ErrorCode)[1]', 'varchar(30)') AS [ErrorCode],
x.value('(//Record/Error/CallingAPIName)[1]', 'varchar(255)') AS [CallingAPIName],
x.value('(//Record/Error/APIName)[1]', 'varchar(255)') AS [APIName],
x.value('(//Record/Error/SPID)[1]', 'int') AS [SPID],
x.value('(//Record/@id)[1]', 'bigint') AS [Record Id],
x.value('(//Record/@type)[1]', 'varchar(30)') AS [Type],
x.value('(//Record/@time)[1]', 'bigint') AS [Record Time]
FROM (SELECT CAST (record as xml) FROM sys.dm_os_ring_buffers
WHERE ring_buffer_type = 'RING_BUFFER_SECURITY_ERROR') AS R(x)) a
CROSS JOIN sys.dm_os_sys_info sys
ORDER BY a.[Record Time] ASC