Question

我们准备将许多SQL Server迁移到云端。我想找到一种在新虚拟服务器上重新分发数据库的逻辑方法。我想要考虑的一个因素是数据库的“繁忙”。我的想法是从dm_io_virtual_stats DMV获取信息，如下所示，以获得我可以在服务器之间进行比较的数字。本质上，它需要num_of_bytes_read和sum_of_bytes_written的总和除以sample_ms用于了解自上次启动系统以来每个数据库的平均I / O.我在几个服务器上运行此代码，因此除以sample_ms应该使它成为对不同机器的有效比较，I希望。我已经阅读了几篇关于这个DMV的文章，但没有一篇论述这个特定的用例。

BEGIN

declare @DatabaseId as int
declare @FileId as int
declare @DatabaseStart as datetime2
declare @BytesIn bigint
declare @BytesOut as bigint
declare @BytesOnDisk as bigint

create table #FileInfo (
  ServerName varchar(128),
  DatabaseName varchar(128),
  UpTime bigint,
  InputBytes float,
  OutputBytes float,
  BytesOnDisk bigint )

DECLARE FileCursor CURSOR FOR
select database_id, file_id
from sys.master_files

open FileCursor
FETCH NEXT FROM FileCursor into @DatabaseId, @FileId
WHILE @@FETCH_STATUS = 0
   BEGIN
      select @BytesIn = num_of_bytes_read, 
             @BytesOut = num_of_bytes_written, 
             @BytesOnDisk = size_on_disk_bytes, 
             @DatabaseStart = sqlserver_start_time
      from sys.dm_io_virtual_file_stats(@DatabaseId, @FileId),
           sys.dm_os_sys_info

      insert into #FileInfo values ( @@SERVERNAME, 
                                     db_name(@DatabaseId),  
                                     datediff(second, @DatabaseStart, getdate()), 
                                     @Bytesin, 
                                     @BytesOut, 
                                     @BytesOnDisk )
      FETCH NEXT FROM FileCursor into @DatabaseId, @FileId
   END;
CLOSE FileCursor
DEALLOCATE FileCursor

select ServerName, 
       DatabaseName, 
       (SUM((InputBytes + OutputBytes) / UpTime))[AvgBytesPerSec], 
       SUM(BytesOnDisk)[DatabaseSize]
from #FileInfo 
where UpTime > 0 
group by ServerName, DatabaseName
order by ServerName, DatabaseName

Drop table #FileInfo
END
GO

如何比较SQL Server上的数据库I / O负载

0 个答案: