使用alwayson后如何收缩数据库日志的方法详解

--- YOU MUST EXECUTE THE FOLLOWING SCRIPT IN SQLCMD MODE.
:Connect DBSERVER1 -U sa -P abc@123 
 
USE [master]
 
GO
 
ALTER AVAILABILITY GROUP [syncdb] REMOVE DATABASE [test];
GO

:Connect DBSERVER3 -U sa -P abc@123 
 
USE [master]
GO
 
DROP DATABASE [test]
GO

--- YOU MUST EXECUTE THE FOLLOWING SCRIPT IN SQLCMD MODE.
:Connect DBSERVER1 -U sa -P abc@123 
 
USE [master]
 
GO
 
 
BACKUP LOG [test] TO DISK='NUL:'with STATS = 10
go
use [test]
go
DBCC SHRINKFILE (N'test_log' , 20480)
GO
 
USE [master]
 
GO
 
ALTER AVAILABILITY GROUP [test]
ADD DATABASE [test];
 
GO
 
:Connect DBSERVER1 -U sa -P test@123 
 
BACKUP DATABASE [test] TO DISK = N'\\dbserver3\e$\share\test.bak' WITH COPY_ONLY, FORMAT, INIT, SKIP, REWIND, NOUNLOAD, COMPRESSION, STATS = 5
 
GO
 
:Connect DBSERVER3 -U sa -P test@123 
 
RESTORE DATABASE [test] FROM DISK = N'\\dbserver3\e$\share\test.bak' WITH NORECOVERY, NOUNLOAD, STATS = 5
 
GO
 
:Connect DBSERVER1 -U sa -P test@123 
 
BACKUP LOG [test] TO DISK = N'\\dbserver3\e$\share\test.trn' WITH NOFORMAT, NOINIT, NOSKIP, REWIND, NOUNLOAD, COMPRESSION, STATS = 5
 
GO
 
:Connect DBSERVER3 -U sa -P test@123 
 
RESTORE LOG [test] FROM DISK = N'\\dbserver3\e$\share\test.trn' WITH NORECOVERY, NOUNLOAD, STATS = 5
 
GO
 
:Connect DBSERVER3 -U sa -P test@123 
 
 
-- Wait for the replica to start communicating
begin try
declare @conn bit
declare @count int
declare @replica_id uniqueidentifier 
declare @group_id uniqueidentifier
set @conn = 0
set @count = 30 -- wait for 5 minutes 
 
if (serverproperty('IsHadrEnabled') = 1)
	and (isnull((select member_state from master.sys.dm_hadr_cluster_members where upper(member_name COLLATE Latin1_General_CI_AS) = upper(cast(serverproperty('ComputerNamePhysicalNetBIOS') as nvarchar(256)) COLLATE Latin1_General_CI_AS)), 0) > 0)
	and (isnull((select state from master.sys.database_mirroring_endpoints), 1) = 0)
begin
  select @group_id = ags.group_id from master.sys.availability_groups as ags where name = N'yorkdb'
	select @replica_id = replicas.replica_id from master.sys.availability_replicas as replicas where upper(replicas.replica_server_name COLLATE Latin1_General_CI_AS) = upper(@@SERVERNAME COLLATE Latin1_General_CI_AS) and group_id = @group_id
	while @conn > 1 and @count > 0
	begin
		set @conn = isnull((select connected_state from master.sys.dm_hadr_availability_replica_states as states where states.replica_id = @replica_id), 1)
		if @conn = 1
		begin
			-- exit loop when the replica is connected, or if the query cannot find the replica status
			break
		end
		waitfor delay '00:00:10'
		set @count = @count - 1
	end
end
end try
begin catch
	-- If the wait loop fails, do not stop execution of the alter database statement
end catch
ALTER DATABASE [test] SET HADR AVAILABILITY GROUP = [syncdb];

GO

GO