Sqlserver 账号同步问题
使用alwayson架构的sqlserver数据库，在主备切换时可能会出现以下与账号有关的问题：
1. 账号密码不对，导致无法登陆。
2. 账号权限出现丢失，没法正常打开数据库。
第一个问题，很大的可能是用户创建账号时只在当时的主节点上创建了，另外一个节点没有创建。
第二个问题，是因为主备节点都使用了普通的方式创建了相同名称的账户。sqlserver的alwayson集群下，其账号不是以名称来识别是否是同一个账户的，而是以sid来识别。使用普通方式分别创建的账号，其SID是不同的，这就是导致两边权限出现不一致的根源。
sqlserver 账号正确的创建方式
alwasyon架构下的sqlserver，如果要创建新账号，以下是正确的创建方法：
1. 当前主节点以普通方式创建账号。
2. 在主节点创建以下存储过程
USE [master]
GO
IF OBJECT_ID ('sp_hexadecimal') IS NOT NULL
DROP PROCEDURE sp_hexadecimal
GO
CREATE PROCEDURE [dbo].[sp_hexadecimal]
(
@binvalue varbinary(256),
@hexvalue varchar (514) OUTPUT
)
AS
BEGIN
DECLARE @charvalue varchar (514)
DECLARE @i int
DECLARE @length int
DECLARE @hexstring char(16)
SELECT @charvalue = '0x'
SELECT @i = 1
SELECT @length = DATALENGTH (@binvalue)
SELECT @hexstring = '0123456789ABCDEF'
WHILE (@i <= @length)
BEGIN
DECLARE @tempint int
DECLARE @firstint int
DECLARE @secondint int
SELECT @tempint = CONVERT(int, SUBSTRING(@binvalue,@i,1))
SELECT @firstint = FLOOR(@tempint/16)
SELECT @secondint = @tempint - (@firstint*16)
SELECT @charvalue = @charvalue + SUBSTRING(@hexstring, @firstint+1, 1) + SUBSTRING(@hexstring, @secondint+1, 1)
SELECT @i = @i + 1
END
SELECT @hexvalue = @charvalue
END
go
IF OBJECT_ID ('sp_help_revlogin') IS NOT NULL
DROP PROCEDURE sp_help_revlogin
GO
CREATE PROCEDURE [dbo].[sp_help_revlogin]
(
@login_name sysname = NULL
)
AS
BEGIN
DECLARE @name SYSNAME
DECLARE @type VARCHAR (1)
DECLARE @hasaccess INT
DECLARE @denylogin INT
DECLARE @is_disabled INT
DECLARE @PWD_varbinary VARBINARY (256)
DECLARE @PWD_string VARCHAR (514)
DECLARE @SID_varbinary VARBINARY (85)
DECLARE @SID_string VARCHAR (514)
DECLARE @tmpstr VARCHAR (1024)
DECLARE @is_policy_checked VARCHAR (3)
DECLARE @is_expiration_checked VARCHAR (3)
Declare @Prefix VARCHAR(255)
DECLARE @defaultdb SYSNAME
DECLARE @defaultlanguage SYSNAME
DECLARE @tmpstrRole VARCHAR (1024)
IF (@login_name IS NULL)
BEGIN
DECLARE login_curs CURSOR
FOR
SELECT p.sid, p.name, p.type, p.is_disabled, p.default_database_name, l.hasaccess, l.denylogin, p.default_language_name
FROM sys.server_principals p
LEFT JOIN sys.syslogins l ON ( l.name = p.name )
WHERE p.type IN ( 'S', 'G', 'U' )
AND p.name <> 'sa'
AND p.name not like '##%'
ORDER BY p.name
END
ELSE
DECLARE login_curs CURSOR
FOR
SELECT p.sid, p.name, p.type, p.is_disabled, p.default_database_name, l.hasaccess, l.denylogin, p.default_language_name
FROM sys.server_principals p
LEFT JOIN sys.syslogins l ON ( l.name = p.name )
WHERE p.type IN ( 'S', 'G', 'U' )
AND p.name = @login_name
ORDER BY p.name
OPEN login_curs
FETCH NEXT FROM login_curs INTO @SID_varbinary, @name, @type, @is_disabled, @defaultdb, @hasaccess, @denylogin, @defaultlanguage
IF (@@fetch_status = -1)
BEGIN
PRINT 'No login(s) found.'
CLOSE login_curs
DEALLOCATE login_curs
RETURN -1
END
SET @tmpstr = '/* sp_help_revlogin script '
PRINT @tmpstr
SET @tmpstr = '** Generated ' + CONVERT (varchar, GETDATE()) + ' on ' + @@SERVERNAME + ' */'
PRINT @tmpstr
PRINT ''
WHILE (@@fetch_status <> -1)
BEGIN
IF (@@fetch_status <> -2)
BEGIN
PRINT ''
SET @tmpstr = '-- Login: ' + @name
PRINT @tmpstr
SET @tmpstr='IF NOT EXISTS (SELECT * FROM sys.server_principals WHERE name = N'''+@name+''')
BEGIN'
Print @tmpstr
IF (@type IN ( 'G', 'U'))
BEGIN -- NT authenticated account/group
SET @tmpstr = 'CREATE LOGIN ' + QUOTENAME( @name ) + ' FROM WINDOWS WITH DEFAULT_DATABASE = [' + @defaultdb + ']' + ', DEFAULT_LANGUAGE = [' + @defaultlanguage + ']'
END
ELSE
BEGIN -- SQL Server authentication
-- obtain password and sid
SET @PWD_varbinary = CAST( LOGINPROPERTY( @name, 'PasswordHash' ) AS varbinary (256) )
EXEC sp_hexadecimal @PWD_varbinary, @PWD_string OUT
EXEC sp_hexadecimal @SID_varbinary,@SID_string OUT
-- obtain password policy state
SELECT @is_policy_checked = CASE is_policy_checked WHEN 1 THEN 'ON' WHEN 0 THEN 'OFF' ELSE NULL END
FROM sys.sql_logins
WHERE name = @name
SELECT @is_expiration_checked = CASE is_expiration_checked WHEN 1 THEN 'ON' WHEN 0 THEN 'OFF' ELSE NULL END
FROM sys.sql_logins
WHERE name = @name
SET @tmpstr = 'CREATE LOGIN ' + QUOTENAME( @name ) + ' WITH PASSWORD = ' + @PWD_string + ' HASHED, SID = '
+ @SID_string + ', DEFAULT_DATABASE = [' + @defaultdb + ']' + ', DEFAULT_LANGUAGE = [' + @defaultlanguage + ']'
IF ( @is_policy_checked IS NOT NULL )
BEGIN
SET @tmpstr = @tmpstr + ', CHECK_POLICY = ' + @is_policy_checked
END
IF ( @is_expiration_checked IS NOT NULL )
BEGIN
SET @tmpstr = @tmpstr + ', CHECK_EXPIRATION = ' + @is_expiration_checked
END
END
IF (@denylogin = 1)
BEGIN -- login is denied access
SET @tmpstr = @tmpstr + '; DENY CONNECT SQL TO ' + QUOTENAME( @name )
END
ELSE IF (@hasaccess = 0)
BEGIN -- login exists but does not have access
SET @tmpstr = @tmpstr + '; REVOKE CONNECT SQL TO ' + QUOTENAME( @name )
END
IF (@is_disabled = 1)
BEGIN -- login is disabled
SET @tmpstr = @tmpstr + '; ALTER LOGIN ' + QUOTENAME( @name ) + ' DISABLE'
END
SET @Prefix = '
EXEC master.dbo.sp_addsrvrolemember @loginame='''
SET @tmpstrRole=''
SELECT @tmpstrRole = @tmpstrRole
+ CASE WHEN sysadmin = 1 THEN @Prefix + [LoginName] + ''', @rolename=''sysadmin''' ELSE '' END
+ CASE WHEN securityadmin = 1 THEN @Prefix + [LoginName] + ''', @rolename=''securityadmin''' ELSE '' END
+ CASE WHEN serveradmin = 1 THEN @Prefix + [LoginName] + ''', @rolename=''serveradmin''' ELSE '' END
+ CASE WHEN setupadmin = 1 THEN @Prefix + [LoginName] + ''', @rolename=''setupadmin''' ELSE '' END
+ CASE WHEN processadmin = 1 THEN @Prefix + [LoginName] + ''', @rolename=''processadmin''' ELSE '' END
+ CASE WHEN diskadmin = 1 THEN @Prefix + [LoginName] + ''', @rolename=''diskadmin''' ELSE '' END
+ CASE WHEN dbcreator = 1 THEN @Prefix + [LoginName] + ''', @rolename=''dbcreator''' ELSE '' END
+ CASE WHEN bulkadmin = 1 THEN @Prefix + [LoginName] + ''', @rolename=''bulkadmin''' ELSE '' END
FROM (
SELECT CONVERT(VARCHAR(100),SUSER_SNAME(sid)) AS [LoginName],
sysadmin,
securityadmin,
serveradmin,
setupadmin,
processadmin,
diskadmin,
dbcreator,
bulkadmin
FROM sys.syslogins
WHERE ( sysadmin<>0
OR securityadmin<>0
OR serveradmin<>0
OR setupadmin <>0
OR processadmin <>0
OR diskadmin<>0
OR dbcreator<>0
OR bulkadmin<>0
)
AND name=@name
) L
PRINT @tmpstr
PRINT @tmpstrRole
PRINT 'END'
END
FETCH NEXT FROM login_curs INTO @SID_varbinary, @name, @type, @is_disabled, @defaultdb, @hasaccess, @denylogin, @defaultlanguage
END
CLOSE login_curs
DEALLOCATE login_curs
RETURN 0
END
3. 运行这个存储过程
EXEC sp_help_revlogin
4. 根据生成的sql，复制我们刚刚创建的账号相关的sql到从节点运行。例如我测试的testread这个账户的同步sql：
-- Login: testread
IF NOT EXISTS (SELECT * FROM sys.server_principals WHERE name = N'testread')
BEGIN
CREATE LOGIN [testread] WITH PASSWORD = 0x0200B3D5539562DEA6B8Axxxxxxxxxxx0790C7745338AA0E63B071CDF72DE245AC8DF9CF868D533E07661E3509080DA3D56696F55A94961C11041FF37F271C8AD7DA HASHED, SID = 0x489550Exxxxxx498FE000B5DB5A4CB3, DEFAULT_DATABASE = [master], DEFAULT_LANGUAGE = [简体中文], CHECK_POLICY = ON, CHECK_EXPIRATION = ON
END
5. 从节点执行完上面sql后，就能看到这个账号，而且权限都和主节点一致。
6. 后续如果该账号有新的赋权，也会正常同步到从节点。
已存在问题的修复
如果已经两边都创建了，然后主从切换后发现问题，那么可以按下面步骤解决：
1. 先切换回原来的主节点（如果暂时没法切换的话，那就比较难处理了，还没研究。。。。）
2. 确认账号权限是否以正常的主节点上的权限为准，否则应和业务确认清楚权限，并添加上缺失的权限。
3. 把异常节点上的账号删除。
4. 跑 sp_help_revlogin 存储过程，把异常账号涉及的sql复制到异常节点上跑一遍。这样同步完成后，就可以解决了。
官方参考文档
[在 SQL Server 实例之间传输登录名和密码](https://learn.microsoft.com/zh-cn/troubleshoot/sql/database-engine/security/transfer-logins-passwords-between-instances?source=recommendations)
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