如何監視 SQL Server 2000 阻塞
251004 (http://support.microsoft.com/kb/251004/) 如何監視 SQL Server 7.0 阻塞
本文提供可用于診斷阻塞和性能問題的存儲過程的用法和設計。有關如何了解和解決阻塞問題的說明,請參閱以下 Microsoft 知識庫文章:
224453 (http://support.microsoft.com/kb/224453/) 了解和解決 SQL Server 7.0 或 2000 阻塞問題
更多信息
對 sp_blocker_pss80 存儲過程的下列描述可捕獲此信息: • 開始時間(視運行 SQL Server 的計算機而定),以便此阻塞采樣在時間上可以與其他性能信息(如 Windows NT 性能監視器日志或 SQL 事件探查器日志)一致。
• 有關與 SQL Server 的連接的信息,通過查詢 sysprocesses 系統表獲取。
• 有關鎖定資源的信息,通過查詢 syslockinfo 系統表獲取。
• 有關資源等待的信息,通過運行 DBCC SQLPERF(WAITSTATS) 獲取。
• 用于連接(被其他連接阻塞或者阻塞其他連接)的當前正在運行的 SQL Server 批處理,通過運行 DBCC INPUTBUFFER 語句獲取。
• 結束時間,視運行 SQL Server 的計算機而定。
創建該存儲過程時使用了下列優化,從而降低了運行該存儲過程對性能和阻塞的影響: • 除非至少有一個連接在等待資源,否則不生成輸出。
• 直接查詢 master 數據庫中的 sysprocesses 和 syslockinfo 系統表,以提高性能并防止該存儲過程被阻塞。因此,該存儲過程是特定于 Microsoft SQL Server 2000 的。
• 使用光標創建一個小工作表來獲取 DBCC INPUTBUFFER 輸出,這對在 tempdb 數據庫中的使用應沒有太大影響。
• 由于收集信息時阻塞可以更改,因此存在一種快速模式,該模式可將所得到的結果降至 sysprocesses 和 syslockinfo 系統表的相關行,從而提高了性能。
• 如果您試圖跟蹤非鎖定資源等待,則存在一種鎖存模式,該模式可導致鎖定輸出被忽略。
該存儲過程從任何查詢工具運行,都十分有用。但是,Microsoft 建議您按照下列步驟來執行阻塞分析: 1. 當使用對計劃要監視的 SQL Server 服務器或 SQL Server 實例具有 sysadmin 特權的登錄信息進行連接時,從任何查詢工具創建存儲過程 sp_blocker_pss80(在本文末尾提供)。
2. 創建一個包含以下查詢的腳本文件以循環運行該存儲過程。請注意,延遲應在 5 秒和 60 秒之間:WHILE 1=1
BEGIN
EXEC master.dbo.sp_blocker_pss80
-- Or for fast mode
-- EXEC master.dbo.sp_blocker_pss80 @fast=1
-- Or for latch mode
-- EXEC master.dbo.sp_blocker_pss80 @latch=1
WAITFOR DELAY '00:00:15'
END
GO
3. 該輸出在與 Microsoft Windows NT 性能監視器日志和 SQL 事件探查器日志結合時非常有用,因此建議同時創建這兩種日志。有關要捕獲哪些事件探查器和性能監視器事件的信息,以及有關如何解釋結果的信息,請參閱下面的 Microsoft 知識庫文章:
224453 (http://support.microsoft.com/kb/224453/) 了解和解決 SQL Server 7.0 或 2000 阻塞問題
4. 在運行 SQL Server 的計算機(您要對其進行監視以防止網絡問題導致查詢工具斷開連接)上,在 Windows 命令提示符處從 Isql.exe 或 Osql.exe 查詢工具運行在第 2 步創建的腳本文件。下面是可用于啟動 Osql.exe 的示例命令行,它假定客戶端從運行 SQL Server 的計算機運行,并且腳本文件名為 Checkblk.sql。請務必更正 -S 參數,并將“server”替換為 SQL Server 服務器的名稱(或“servername\instance”,如果您監視的是已命名實例)。此外,還必須更正 -i 參數,并將“checkblk.sql”替換為在第 2 步中創建的腳本文件的路徑和名稱。 osql -E -Sserver -icheckblk.sql -ocheckblk.out -w2000
請注意,由于下列原因,您必須使用其他命令行開關:
• 為了防止輸出文件中出現換行(換行可使輸出文件更易于閱讀)。
• 為了將輸出發送到使用 -o 參數指定的文件,而不是發送到屏幕,以便在查詢工具出現問題時,在查詢工具失敗之前仍得到輸出。
下面是用于創建 sp_blocker_pss80 存儲過程的腳本: /*
Note: This is meant to have 2 creations of the same stored procedure and one of them will fail
with either 207 errors or a 2714 error.
*/
use master
GO
if exists (select * from sysobjects where id = object_id('dbo.sp_blocker_pss80') and sysstat & 0xf = 4)
drop procedure dbo.sp_blocker_pss80
GO
create procedure sp_blocker_pss80 (@latch int = 0, @fast int = 1)
as
--version 15SP3
set nocount on
declare @spid varchar(6)
declare @blocked varchar(6)
declare @time datetime
declare @time2 datetime
declare @dbname nvarchar(128)
declare @status sql_variant
declare @useraccess sql_variant
set @time = getdate()
declare @probclients table(spid smallint, ecid smallint, blocked smallint, waittype binary(2), dbid smallint,
ignore_app tinyint, primary key (blocked, spid, ecid))
insert @probclients select spid, ecid, blocked, waittype, dbid,
case when convert(varchar(128),hostname) = 'PSSDIAG' then 1 else 0 end
from sysprocesses where blocked!=0 or waittype != 0x0000
if exists (select spid from @probclients where ignore_app != 1 or waittype != 0x020B)
begin
set @time2 = getdate()
print ''
print '8.2 Start time: ' + convert(varchar(26), @time, 121) + ' ' + convert(varchar(12), datediff(ms,@time,@time2))
insert @probclients select distinct blocked, 0, 0, 0x0000, 0, 0 from @probclients
where blocked not in (select spid from @probclients) and blocked != 0
if (@fast = 1)
begin
print ''
print 'SYSPROCESSES ' + ISNULL (@@servername,'(null)') + ' ' + str(@@microsoftversion)
select spid, status, blocked, open_tran, waitresource, waittype,
waittime, cmd, lastwaittype, cpu, physical_io,
memusage, last_batch=convert(varchar(26), last_batch,121),
login_time=convert(varchar(26), login_time,121),net_address,
net_library, dbid, ecid, kpid, hostname, hostprocess,
loginame, program_name, nt_domain, nt_username, uid, sid,
sql_handle, stmt_start, stmt_end
from master..sysprocesses
where blocked!=0 or waittype != 0x0000
or spid in (select blocked from @probclients where blocked != 0)
or spid in (select spid from @probclients where blocked != 0)
print 'ESP ' + convert(varchar(12), datediff(ms,@time2,getdate()))
print ''
print 'SYSPROC FIRST PASS'
select spid, ecid, waittype from @probclients where waittype != 0x0000
if exists(select blocked from @probclients where blocked != 0)
begin
print 'Blocking via locks at ' + convert(varchar(26), @time, 121)
print ''
print 'SPIDs at the head of blocking chains'
select spid from @probclients
where blocked = 0 and spid in (select blocked from @probclients where spid != 0)
if @latch = 0
begin
print 'SYSLOCKINFO'
select @time2 = getdate()
select spid = convert (smallint, req_spid),
ecid = convert (smallint, req_ecid),
rsc_dbid As dbid,
rsc_objid As ObjId,
rsc_indid As IndId,
Type = case rsc_type when 1 then 'NUL'
when 2 then 'DB'
when 3 then 'FIL'
when 4 then 'IDX'
when 5 then 'TAB'
when 6 then 'PAG'
when 7 then 'KEY'
when 8 then 'EXT'
when 9 then 'RID'
when 10 then 'APP' end,
Resource = substring (rsc_text, 1, 16),
Mode = case req_mode + 1 when 1 then NULL
when 2 then 'Sch-S'
when 3 then 'Sch-M'
when 4 then 'S'
when 5 then 'U'
when 6 then 'X'
when 7 then 'IS'
when 8 then 'IU'
when 9 then 'IX'
when 10 then 'SIU'
when 11 then 'SIX'
when 12 then 'UIX'
when 13 then 'BU'
when 14 then 'RangeS-S'
when 15 then 'RangeS-U'
when 16 then 'RangeIn-Null'
when 17 then 'RangeIn-S'
when 18 then 'RangeIn-U'
when 19 then 'RangeIn-X'
when 20 then 'RangeX-S'
when 21 then 'RangeX-U'
when 22 then 'RangeX-X'end,
Status = case req_status when 1 then 'GRANT'
when 2 then 'CNVT'
when 3 then 'WAIT' end,
req_transactionID As TransID, req_transactionUOW As TransUOW
from master.dbo.syslockinfo s,
@probclients p
where p.spid = s.req_spid
print 'ESL ' + convert(varchar(12), datediff(ms,@time2,getdate()))
end -- latch not set
end
else
print 'No blocking via locks at ' + convert(varchar(26), @time, 121)
print ''
end -- fast set
else
begin -- Fast not set
print ''
print 'SYSPROCESSES ' + ISNULL (@@servername,'(null)') + ' ' + str(@@microsoftversion)
select spid, status, blocked, open_tran, waitresource, waittype,
waittime, cmd, lastwaittype, cpu, physical_io,
memusage, last_batch=convert(varchar(26), last_batch,121),
login_time=convert(varchar(26), login_time,121),net_address,
net_library, dbid, ecid, kpid, hostname, hostprocess,
loginame, program_name, nt_domain, nt_username, uid, sid,
sql_handle, stmt_start, stmt_end
from master..sysprocesses
print 'ESP ' + convert(varchar(12), datediff(ms,@time2,getdate()))
print ''
print 'SYSPROC FIRST PASS'
select spid, ecid, waittype from @probclients where waittype != 0x0000
if exists(select blocked from @probclients where blocked != 0)
begin
print 'Blocking via locks at ' + convert(varchar(26), @time, 121)
print ''
print 'SPIDs at the head of blocking chains'
select spid from @probclients
where blocked = 0 and spid in (select blocked from @probclients where spid != 0)
if @latch = 0
begin
print 'SYSLOCKINFO'
select @time2 = getdate()
select spid = convert (smallint, req_spid),
ecid = convert (smallint, req_ecid),
rsc_dbid As dbid,
rsc_objid As ObjId,
rsc_indid As IndId,
Type = case rsc_type when 1 then 'NUL'
when 2 then 'DB'
when 3 then 'FIL'
when 4 then 'IDX'
when 5 then 'TAB'
when 6 then 'PAG'
when 7 then 'KEY'
when 8 then 'EXT'
when 9 then 'RID'
when 10 then 'APP' end,
Resource = substring (rsc_text, 1, 16),
Mode = case req_mode + 1 when 1 then NULL
when 2 then 'Sch-S'
when 3 then 'Sch-M'
when 4 then 'S'
when 5 then 'U'
when 6 then 'X'
when 7 then 'IS'
when 8 then 'IU'
when 9 then 'IX'
when 10 then 'SIU'
when 11 then 'SIX'
when 12 then 'UIX'
when 13 then 'BU'
when 14 then 'RangeS-S'
when 15 then 'RangeS-U'
when 16 then 'RangeIn-Null'
when 17 then 'RangeIn-S'
when 18 then 'RangeIn-U'
when 19 then 'RangeIn-X'
when 20 then 'RangeX-S'
when 21 then 'RangeX-U'
when 22 then 'RangeX-X'end,
Status = case req_status when 1 then 'GRANT'
when 2 then 'CNVT'
when 3 then 'WAIT' end,
req_transactionID As TransID, req_transactionUOW As TransUOW
from master.dbo.syslockinfo
print 'ESL ' + convert(varchar(12), datediff(ms,@time2,getdate()))
end -- latch not set
end
else
print 'No blocking via locks at ' + convert(varchar(26), @time, 121)
print ''
end -- Fast not set
print 'DBCC SQLPERF(WAITSTATS)'
dbcc sqlperf(waitstats)
Print ''
Print '*********************************************************************'
Print 'Print out DBCC Input buffer for all blocked or blocking spids.'
Print '*********************************************************************'
declare ibuffer cursor fast_forward for
select cast (spid as varchar(6)) as spid, cast (blocked as varchar(6)) as blocked
from @probclients
where (spid <> @@spid) and
((blocked!=0 or (waittype != 0x0000 and ignore_app = 0))
or spid in (select blocked from @probclients where blocked != 0))
open ibuffer
fetch next from ibuffer into @spid, @blocked
while (@@fetch_status != -1)
begin
print ''
print 'DBCC INPUTBUFFER FOR SPID ' + @spid
exec ('dbcc inputbuffer (' + @spid + ')')
fetch next from ibuffer into @spid, @blocked
end
deallocate ibuffer
Print ''
Print '*******************************************************************************'
Print 'Print out DBCC OPENTRAN for active databases for all blocked or blocking spids.'
Print '*******************************************************************************'
declare ibuffer cursor fast_forward for
select distinct cast (dbid as varchar(6)) from @probclients
where dbid != 0
open ibuffer
fetch next from ibuffer into @spid
while (@@fetch_status != -1)
begin
print ''
set @dbname = db_name(@spid)
set @status = DATABASEPROPERTYEX(@dbname,'Status')
set @useraccess = DATABASEPROPERTYEX(@dbname,'UserAccess')
print 'DBCC OPENTRAN FOR DBID ' + @spid + ' ['+ @dbname + ']'
if @Status = N'ONLINE' and @UserAccess != N'SINGLE_USER'
dbcc opentran(@dbname)
else
print 'Skipped: Status=' + convert(nvarchar(128),@status)
+ ' UserAccess=' + convert(nvarchar(128),@useraccess)
print ''
if @spid = '2' select @blocked = 'Y'
fetch next from ibuffer into @spid
end
deallocate ibuffer
if @blocked != 'Y'
begin
print ''
print 'DBCC OPENTRAN FOR DBID 2 [tempdb]'
dbcc opentran ('tempdb')
end
print 'End time: ' + convert(varchar(26), getdate(), 121)
end -- All
else
print '8 No Waittypes: ' + convert(varchar(26), @time, 121) + ' '
+ convert(varchar(12), datediff(ms,@time,getdate())) + ' ' + ISNULL (@@servername,'(null)')
GO
create proc sp_blocker_pss80 (@latch int = 0, @fast int = 1)
as
--version 15
set nocount on
declare @spid varchar(6)
declare @blocked varchar(6)
declare @time datetime
declare @time2 datetime
declare @dbname nvarchar(128)
declare @status sql_variant
declare @useraccess sql_variant
set @time = getdate()
declare @probclients table(spid smallint, ecid smallint, blocked smallint, waittype binary(2), dbid smallint,
ignore_app tinyint, primary key (blocked, spid, ecid))
insert @probclients select spid, ecid, blocked, waittype, dbid,
case when convert(varchar(128),hostname) = 'PSSDIAG' then 1 else 0 end
from sysprocesses where blocked!=0 or waittype != 0x0000
if exists (select spid from @probclients where ignore_app != 1 or waittype != 0x020B)
begin
set @time2 = getdate()
print ''
print '8 Start time: ' + convert(varchar(26), @time, 121) + ' ' + convert(varchar(12), datediff(ms,@time,@time2))
insert @probclients select distinct blocked, 0, 0, 0x0000, 0, 0 from @probclients
where blocked not in (select spid from @probclients) and blocked != 0
if (@fast = 1)
begin
print ''
print 'SYSPROCESSES ' + ISNULL (@@servername,'(null)') + ' ' + str(@@microsoftversion)
select spid, status, blocked, open_tran, waitresource, waittype,
waittime, cmd, lastwaittype, cpu, physical_io,
memusage,last_batch=convert(varchar(26), last_batch,121),
login_time=convert(varchar(26), login_time,121), net_address,
net_library, dbid, ecid, kpid, hostname, hostprocess,
loginame, program_name, nt_domain, nt_username, uid, sid
from master..sysprocesses
where blocked!=0 or waittype != 0x0000
or spid in (select blocked from @probclients where blocked != 0)
or spid in (select spid from @probclients where waittype != 0x0000)
print 'ESP ' + convert(varchar(12), datediff(ms,@time2,getdate()))
print ''
print 'SYSPROC FIRST PASS'
select spid, ecid, waittype from @probclients where waittype != 0x0000
if exists(select blocked from @probclients where blocked != 0)
begin
print 'Blocking via locks at ' + convert(varchar(26), @time, 121)
print ''
print 'SPIDs at the head of blocking chains'
select spid from @probclients
where blocked = 0 and spid in (select blocked from @probclients where spid != 0)
if @latch = 0
begin
print 'SYSLOCKINFO'
select @time2 = getdate()
select spid = convert (smallint, req_spid),
ecid = convert (smallint, req_ecid),
rsc_dbid As dbid,
rsc_objid As ObjId,
rsc_indid As IndId,
Type = case rsc_type when 1 then 'NUL'
when 2 then 'DB'
when 3 then 'FIL'
when 4 then 'IDX'
when 5 then 'TAB'
when 6 then 'PAG'
when 7 then 'KEY'
when 8 then 'EXT'
when 9 then 'RID'
when 10 then 'APP' end,
Resource = substring (rsc_text, 1, 16),
Mode = case req_mode + 1 when 1 then NULL
when 2 then 'Sch-S'
when 3 then 'Sch-M'
when 4 then 'S'
when 5 then 'U'
when 6 then 'X'
when 7 then 'IS'
when 8 then 'IU'
when 9 then 'IX'
when 10 then 'SIU'
when 11 then 'SIX'
when 12 then 'UIX'
when 13 then 'BU'
when 14 then 'RangeS-S'
when 15 then 'RangeS-U'
when 16 then 'RangeIn-Null'
when 17 then 'RangeIn-S'
when 18 then 'RangeIn-U'
when 19 then 'RangeIn-X'
when 20 then 'RangeX-S'
when 21 then 'RangeX-U'
when 22 then 'RangeX-X'end,
Status = case req_status when 1 then 'GRANT'
when 2 then 'CNVT'
when 3 then 'WAIT' end,
req_transactionID As TransID, req_transactionUOW As TransUOW
from master.dbo.syslockinfo s,
@probclients p
where p.spid = s.req_spid
print 'ESL ' + convert(varchar(12), datediff(ms,@time2,getdate()))
end -- latch not set
end
else
print 'No blocking via locks at ' + convert(varchar(26), @time, 121)
print ''
end -- fast set
else
begin -- Fast not set
print ''
print 'SYSPROCESSES ' + ISNULL (@@servername,'(null)') + ' ' + str(@@microsoftversion)
select spid, status, blocked, open_tran, waitresource, waittype,
waittime, cmd, lastwaittype, cpu, physical_io,
memusage,last_batch=convert(varchar(26), last_batch,121),
login_time=convert(varchar(26), login_time,121), net_address,
net_library, dbid, ecid, kpid, hostname, hostprocess,
loginame, program_name, nt_domain, nt_username, uid, sid
from master..sysprocesses
print 'ESP ' + convert(varchar(12), datediff(ms,@time2,getdate()))
print ''
print 'SYSPROC FIRST PASS'
select spid, ecid, waittype from @probclients where waittype != 0x0000
if exists(select blocked from @probclients where blocked != 0)
begin
print 'Blocking via locks at ' + convert(varchar(26), @time, 121)
print ''
print 'SPIDs at the head of blocking chains'
select spid from @probclients
where blocked = 0 and spid in (select blocked from @probclients where spid != 0)
if @latch = 0
begin
print 'SYSLOCKINFO'
select @time2 = getdate()
select spid = convert (smallint, req_spid),
ecid = convert (smallint, req_ecid),
rsc_dbid As dbid,
rsc_objid As ObjId,
rsc_indid As IndId,
Type = case rsc_type when 1 then 'NUL'
when 2 then 'DB'
when 3 then 'FIL'
when 4 then 'IDX'
when 5 then 'TAB'
when 6 then 'PAG'
when 7 then 'KEY'
when 8 then 'EXT'
when 9 then 'RID'
when 10 then 'APP' end,
Resource = substring (rsc_text, 1, 16),
Mode = case req_mode + 1 when 1 then NULL
when 2 then 'Sch-S'
when 3 then 'Sch-M'
when 4 then 'S'
when 5 then 'U'
when 6 then 'X'
when 7 then 'IS'
when 8 then 'IU'
when 9 then 'IX'
when 10 then 'SIU'
when 11 then 'SIX'
when 12 then 'UIX'
when 13 then 'BU'
when 14 then 'RangeS-S'
when 15 then 'RangeS-U'
when 16 then 'RangeIn-Null'
when 17 then 'RangeIn-S'
when 18 then 'RangeIn-U'
when 19 then 'RangeIn-X'
when 20 then 'RangeX-S'
when 21 then 'RangeX-U'
when 22 then 'RangeX-X'end,
Status = case req_status when 1 then 'GRANT'
when 2 then 'CNVT'
when 3 then 'WAIT' end,
req_transactionID As TransID, req_transactionUOW As TransUOW
from master.dbo.syslockinfo
print 'ESL ' + convert(varchar(12), datediff(ms,@time2,getdate()))
end -- latch not set
end
else
print 'No blocking via locks at ' + convert(varchar(26), @time, 121)
print ''
end -- Fast not set
print 'DBCC SQLPERF(WAITSTATS)'
dbcc sqlperf(waitstats)
Print ''
Print '*********************************************************************'
Print 'Print out DBCC Input buffer for all blocked or blocking spids.'
Print '*********************************************************************'
declare ibuffer cursor fast_forward for
select cast (spid as varchar(6)) as spid, cast (blocked as varchar(6)) as blocked
from @probclients
where (spid <> @@spid) and
((blocked!=0 or (waittype != 0x0000 and ignore_app = 0))
or spid in (select blocked from @probclients where blocked != 0))
open ibuffer
fetch next from ibuffer into @spid, @blocked
while (@@fetch_status != -1)
begin
print ''
print 'DBCC INPUTBUFFER FOR SPID ' + @spid
exec ('dbcc inputbuffer (' + @spid + ')')
fetch next from ibuffer into @spid, @blocked
end
deallocate ibuffer
Print ''
Print '*******************************************************************************'
Print 'Print out DBCC OPENTRAN for active databases for all blocked or blocking spids.'
Print '*******************************************************************************'
declare ibuffer cursor fast_forward for
select distinct cast (dbid as varchar(6)) from @probclients
where dbid != 0
open ibuffer
fetch next from ibuffer into @spid
while (@@fetch_status != -1)
begin
print ''
set @dbname = db_name(@spid)
set @status = DATABASEPROPERTYEX(@dbname,'Status')
set @useraccess = DATABASEPROPERTYEX(@dbname,'UserAccess')
print 'DBCC OPENTRAN FOR DBID ' + @spid + ' ['+ @dbname + ']'
if @Status = N'ONLINE' and @UserAccess != N'SINGLE_USER'
dbcc opentran(@dbname)
else
print 'Skipped: Status=' + convert(nvarchar(128),@status)
+ ' UserAccess=' + convert(nvarchar(128),@useraccess)
print ''
if @spid = '2' select @blocked = 'Y'
fetch next from ibuffer into @spid
end
deallocate ibuffer
if @blocked != 'Y'
begin
print ''
print 'DBCC OPENTRAN FOR DBID 2 [tempdb]'
dbcc opentran ('tempdb')
end
print 'End time: ' + convert(varchar(26), getdate(), 121)
end -- All
else
print '8 No Waittypes: ' + convert(varchar(26), @time, 121) + ' '
+ convert(varchar(12), datediff(ms,@time,getdate())) + ' ' + ISNULL (@@servername,'(null)')
GO
------------------------
這篇文章中的信息適用于:
• Microsoft SQL Server 2000 Desktop Engine (Windows)
• Microsoft SQL Server 2000 Developer Edition
• Microsoft SQL Server 2000 Enterprise Edition
• Microsoft SQL Server 2000 Enterprise Edition
• Microsoft SQL Server 2000 Personal Edition Service Pack 3
• Microsoft SQL Server 2000 標準版
關鍵字:SQL Server、服務器、網絡
新文章:
- CentOS7下圖形配置網絡的方法
- CentOS 7如何添加刪除用戶
- 如何解決centos7雙系統后丟失windows啟動項
- CentOS單網卡如何批量添加不同IP段
- CentOS下iconv命令的介紹
- Centos7 SSH密鑰登陸及密碼密鑰雙重驗證詳解
- CentOS 7.1添加刪除用戶的方法
- CentOS查找/掃描局域網打印機IP講解
- CentOS7使用hostapd實現無AP模式的詳解
- su命令不能切換root的解決方法
- 解決VMware下CentOS7網絡重啟出錯
- 解決Centos7雙系統后丟失windows啟動項
- CentOS下如何避免文件覆蓋
- CentOS7和CentOS6系統有什么不同呢
- Centos 6.6默認iptable規則詳解