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db2诊断�p�d��?--捕获sql执行情况

tacy lee — Sun, 25 Nov 2007 06:51:00 GMT

作者：tacy lee

在应用��用过�E�中�Q�我们经�怼��到应用响应旉��很慢�Q�甚��x��有响应，但是应用服务器可能�ƈ不是很繁忙，cpu利用率也非常低，引�v�q�种状况的原因有很多�U�，比如环境问题�Q�应用资源泄漏，数据库原因等�{�，本文主要是从一�ơ应用性能诊断�q�程来谈谈如何通过数据库诊断应用性能问题�?/p>

问题�Q?/p>

��试�q�程中发现应用中某个跌��{��面执行旉��比较长，�pȝ��压力不大�Q�cpu利用很低�Q�该��面需要从cache中取数据�Q�第一�ơ的时候加载cache�Q�从数据库中查询回数据�ƈcache�Q��?/p>

诊断�Q?/p>

��面逻辑比较��单，我们先用loadrunner模拟�q�发��试一下这个页面，然后再数据库端捕获sql执行情况�?/p>

1、打开db2监控开�?/p>

#db2 connect to eos

#db2 update monitor switches using statement on

#db2 reset monitor all

2、几分钟之后�Q�我们收集sql�l�计快照

#db2 get snapshot for dynamic sql on eos > dysqlstatus.out

现在�l�计信息已经存放在dysqlstatus.out中，你可以��用�Q意方便的文本处理工具查看�Q�我一般用windows上的gvim来处理，打开dysqlstatus.out

Number of executions               = 1

Number of compilations             = 1

Worst preparation time (ms)        = 2

Best preparation time (ms)         = 2

Internal rows deleted              = 0

Internal rows inserted             = 0

Rows read                          = 2

Internal rows updated              = 0

Rows written                       = 0

Statement sorts                    = 0

Statement sort overflows           = 0

Total sort time                    = 0

Buffer pool data logical reads     = Not Collected

Buffer pool data physical reads    = Not Collected

Buffer pool temporary data logical reads   = Not Collected

Buffer pool temporary data physical reads  = Not Collected

Buffer pool index logical reads    = Not Collected

Buffer pool index physical reads   = Not Collected

Buffer pool temporary index logical reads  = Not Collected

Buffer pool temporary index physical reads = Not Collected

Total execution time (sec.ms)      = 0.000377

Total user cpu time (sec.ms)       = 0.010000

Total system cpu time (sec.ms)     = 0.000000

Statement text                     = select ACTIVITYDEFID,ACTIVITYINSTID from wfworkitem  where 
PROCESSINSTID=104199 and CURRENTSTATE = 4


......

��单说一下vi中的处理

:g!/Total execution time/d

只保留文本中的sql执行旉����Q�我们要按照执行旉���来排�?br>


通过vim的visual功能选择执行旉���块（�{�号后面的数字）�Q�然后排�?br>
Total execution time (sec.ms)      = 0.050590

Total execution time (sec.ms)      = 0.000170

Total execution time (sec.ms)      = 0.000247

Total execution time (sec.ms)      = 0.000292

Total execution time (sec.ms)      = 0.000474

Total execution time (sec.ms)      = 0.000330

Total execution time (sec.ms)      = 0.000348

Total execution time (sec.ms)      = 0.000279

Total execution time (sec.ms)      = 0.000385

Total execution time (sec.ms)      = 0.000296

Total execution time (sec.ms)      = 0.000261

Total execution time (sec.ms)      = 0.000195

Total execution time (sec.ms)      = 0.000226

Total execution time (sec.ms)      = 0.000227

Total execution time (sec.ms)      = 0.000193

......

:'<,'>!sort



排序后的�l�果�Q�部分）

Total execution time (sec.ms)      = 2.027776

Total execution time (sec.ms)      = 2.203624

Total execution time (sec.ms)      = 2.504677

Total execution time (sec.ms)      = 2.951256

Total execution time (sec.ms)      = 3.119875

Total execution time (sec.ms)      = 3.303277

Total execution time (sec.ms)      = 3.303517

Total execution time (sec.ms)      = 4.017133

Total execution time (sec.ms)      = 4.043329

Total execution time (sec.ms)      = 4.252125

Total execution time (sec.ms)      = 4.400952

Total execution time (sec.ms)      = 4.606765

Total execution time (sec.ms)      = 5.208087

Total execution time (sec.ms)      = 5.778598

Total execution time (sec.ms)      = 8.117470

Total execution time (sec.ms)      = 9797.905136

可以看到最长时间的sql total执行旉��耗费�?797.905123s.

现在我们到dysqlstatus.out中去找这条语�?/p>

Number of executions               = 4602

Number of compilations             = 4294967295

Worst preparation time (ms)        = 2

Best preparation time (ms)         = 2

Internal rows deleted              = 0

Internal rows inserted             = 0

Rows read                          = 2963688

Internal rows updated              = 0

Rows written                       = 0

Statement sorts                    = 0

Statement sort overflows           = 0

Total sort time                    = 0

Buffer pool data logical reads     = Not Collected

Buffer pool data physical reads    = Not Collected

Buffer pool temporary data logical reads   = Not Collected

Buffer pool temporary data physical reads  = Not Collected

Buffer pool index logical reads    = Not Collected

Buffer pool index physical reads   = Not Collected

Buffer pool temporary index logical reads  = Not Collected

Buffer pool temporary index physical reads = Not Collected

Total execution time (sec.ms)      = 9797.905136

Total user cpu time (sec.ms)       = 9.290000

Total system cpu time (sec.ms)     = 1.230000

Statement text                     = select * from XXXX_T_CNFACTIVITYDEF

�q�条语句��d��执行�?602�ơ，�q�_��每次的执行时�?S�Q�而且�q�些数据应该是被cache��h��?nbsp; �Q�）

�ȝ��Q?/p>

上面的方法简单�ȝ��了从数据库层面对应用的性能问题诊断�Q�希望对大家有所帮助�Q�对于数据库快照诊断问题的思�\对于��L��数据库通用

补充一个unix上脚本处理方式：

sqlsort.sh

awk 'BEGIN{RS="";FS="\n";ORS="\n"};/Statement text/{print $1, $21, $24}' $1 | awk '$5 > 0 {print "AvgTime:", $11/$5, "\t", $0}'| sort -n | head -n $2|awk '{print $0, "\n"}'

使用�Q?sqlsort.sh dysqlstate.out 10�Q�显�C�Top ten�Q?/div>

del.icio.us Tags: db2,java,tuning,diagnostic

tacy lee 2007-11-25 14:51 发表评论

tacy lee — Sat, 24 Nov 2007 13:18:00 GMT

作者：tacy lee

在应用中�Q�我们经�怼��到sql执行很慢�Q�但是数据库cpu和内存��用率又不高的情况�Q�类似的问题基本上由于锁�Q�排序等原因造成�Q�本文主要描�q�如何去定位锁等待问题，谁在锁等待？�{�待谁持有的锁？锁在那个表？

一、测试准�?/p>

1、先在session1执行如下操作�Q�创建测试表

#db2 connect to eos
#export DB2OPTIONS=+C
#db2 "create table tacy_test (a int not null primary key,b varchar(10))"
#db2 "insert into tacy_test values(1,'a')"
#db2 "insert into tacy_test values(2,'a')"
#db2 "insert into tacy_test values(3,'a')"
#db2 "insert into tacy_test values(4,'a')"
#db2 commit

2、在session2执行如下操作

#db2 connect to eos
#export DB2OPTIONS=+C

二、��生一个lock wait

在session1做一个表更新�Q?/p>

#db2 "update tacy_test set b='b' where a=4"

sql执行成功

在session2做同��h��新操作：

#db2 "update tacy_test set b='c' where a=4"

�q�程被挂��L��?/p>

三、定位锁�{�待

1、先来看看应用的情况�Q?/p>

#db2pd -db eos -applications

Database Partition 0 -- Database EOS -- Active -- Up 0 days 07:37:37

Applications:
Address    AppHandl [nod-index] NumAgents  CoorPid    Status                  C-AnchID C-StmtUID  L-AnchID L-StmtUID  Appid                           
0x10140040 8        [000-00008] 1          8425       Lock-wait               80       2          66       1          *LOCAL.db2inst1.071124043739    
0x100CE540 7        [000-00007] 1          8358       UOW-Waiting             0        0          80       2          *LOCAL.db2inst1.071124043708

可以看到有一个应用的状态处于Lock-wait

2、现在我们来看看应用在等什�?/p>

#db2pd -db eos -locks showlock wait

Database Partition 0 -- Database EOS -- Active -- Up 0 days 07:42:56

Locks:
Address    TranHdl    Lockname                   Type       Mode Sts Owner      Dur HldCnt     Att Rlse
0x2C8E0760 3          02001806078066020000000052 Row        ..X  W   2          1   0          0   0x0  TbspaceID 2 TableID 1560 RecordID 0x2668007

锁的�c�d��为Row�Q�行锁）�Q�X锁（排他锁）�Q�下面是我们最兛_��的锁的位�|?/p>

TbspaceID 2 TableID 1560 RecordID 0x2668007

其中TbspaceID��I�间ID�Q�TableID��的ID�Q�RecordID代表具体位置�Q�全部应该是0x0266807,其中前面三个字节为page number�Q��ؓ0x02668�Q�后面一个字节代表solt identifier�Q��ؓ0x07

3、找到相应的�?/p>

#db2 "select tbspace,tabschema,tabname,tableid,tbspaceid from syscat.tables where tbspaceid=2 and tableid=1560"

TBSPACE       TABSCHEMA   TABNAME    TABLEID TBSPACEID
------------  ----------- ---------- ------- ---------
USERSPACE1    DB2INST1    TACY_TEST     1560         2

  1 record(s) selected.

4、根据RecordID扑ֈ�锁在哪行

db2提供了一个强大的数据分析工具db2dart�Q�可以dump出相应的page数据

#db2dart eos /dd /tsi 2 /oi 1560 /ps 157312p /np 1 /v y

Warning: The database state is not consistent.

Warning: Reorg rows MAY be due to the inconsistent state of the database.
                  DB2DART Processing completed with warning(s)!
                        Complete DB2DART report found in:
/home/db2inst1/sqllib/db2dump/DART0000/EOS.RPT

其中tsi��I�间id(2)�Q�oi��id(1560)�Q�ps为page number(0x0266807)�Q�需要�{换�ؓ十进�Ӟ��在结��ֿ��d��p�Q�np代表你要获取的页敎ͼ�v为是否详�l�输�?/p>

现在我们来看看EOS.RPT

______________________________________________________________________________

        _______                    DART                   _______ 

   D a t a b a s e   A n a l y s i s   a n d   R e p o r t i n g   T o o l

                           IBM    DB2    6000
______________________________________________________________________________

DART (V8.1.0)  Report:
2007-11-24-20.59.51.355893

            Database Name: EOS
            Report name: EOS.RPT
            Old report back-up: EOS.BAK
            Database Subdirectory: /opt/db2/db2inst1/NODE0000/SQL00001
            Operational Mode: Database Inspection Only (INSPECT)

______________________________________________________________________________
------------------------------------------------------------------------------


Action option: DD 
Table-object-ID: 1560; Tablespace-ID: 2; First-page: 157312p; Number-pages: 1; Verbose: y

Warning: The database state is not consistent.

Warning: Reorg rows MAY be due to the inconsistent state of the database.
Connecting to Buffer Pool Services...

   Table object report phase start.
   Dump format is verbose.

                           ______________________________________

         Page 0 of object 1560 from table space 2.

         BPS Page Header:

                     Page Data Offset = 48
                     Page Data Length = 4048
                             Page LSN = 0000 AE97 AE41
                   Object Page Number = 0
                     Pool Page Number = 157312
                            Object ID = 1560
                          Object Type = Data Object

               Data Page Header:

                           Slot Count = 8
                     Total Free Space = 2784
                  Total Reserve Space = 0
               Youngest Reserve Space = n/a
                         Youngest TID = n/a
                    Free Space Offset = 2799
                  Maximum Record Size = 23

               Data Records:


            Slot 0:

               Offset Location = 3996  (xF9C)
               Record Length = 32  (x20)

               Record Type = Data Object Header Control Record

                  Page count = 1
         Object Creation LSN = 0000 AE97 800C
                Object State = x0000
          UDI Since Runstats = 0
                  DART Field = x00000000

            Slot 1:

               Offset Location = 2992  (xBB0)
               Record Length = 1004  (x3EC)

               Record Type = Free Space Control Record

               Free space entries:
                 0:  2884 (x0B44),  4028 (x0FBC),  4028 (x0FBC),  4028 (x0FBC)
                 4:  4028 (x0FBC),  4028 (x0FBC),  4028 (x0FBC),  4028 (x0FBC)
                 8:  4028 (x0FBC),  4028 (x0FBC),  4028 (x0FBC),  4028 (x0FBC)
               省略。。�?
                  492:  4028 (x0FBC),  4028 (x0FBC),  4028 (x0FBC),  4028 (x0FBC)
                  496:  4028 (x0FBC),  4028 (x0FBC),  4028 (x0FBC),  4028 (x0FBC)

            Slot 2:

               Offset Location = 2916  (xB64)
               Record Length = 76  (x4C)

               Record Type = Table Directory Record

                  MetaIndex Root Page = 157377
                  Index Type = 2
                  Table Descriptor Pointer  --  Page 157312  Slot 3
                  Max Insert Search = 0
                  Flags = x02000200
                     bit representation = 00000010 00000000 00000010 00000000
                  Check pending info:
                     Constraint status    = x00
                     Constraint RID       = Page 0 Slot 0
                     last BID          = x00000000

            Slot 3:

               Offset Location = 2892  (xB4C)
               Record Length = 24  (x18)

               Record Type = Table Description Record

                  Number of Columns = 2


                  Column 1:
                  Type is Long Integer
                  Length = 4
                  Prohibits NULLs
                  Prohibits Default
            Fixed offset: 0

                  Column 2:
                  Type is Fixed Length Character String
                  Length = 10
                  Allows NULLs
                  Prohibits Default
            Fixed offset: 4

            Slot 4:

               Offset Location = 2869  (xB35)
               Record Length = 23  (x17)

               Record Type = Table Data Record (FIXEDVAR)

               Fixed part length value = 15

                  Column 1:
            Fixed offset: 0
                  Type is Long Integer
                  Value = 1

                  Column 2:
            Fixed offset: 4
                  Type is Fixed Length Character String
                      61202020 20202020 2020                 a               


            Slot 5:

               Offset Location = 2846  (xB1E)
               Record Length = 23  (x17)

               Record Type = Table Data Record (FIXEDVAR)

               Fixed part length value = 15

                  Column 1:
            Fixed offset: 0
                  Type is Long Integer
                  Value = 2

                  Column 2:
            Fixed offset: 4
                  Type is Fixed Length Character String
                      61202020 20202020 2020                 a               


            Slot 6:

               Offset Location = 2823  (xB07)
               Record Length = 23  (x17)

               Record Type = Table Data Record (FIXEDVAR)

               Fixed part length value = 15

                  Column 1:
            Fixed offset: 0
                  Type is Long Integer
                  Value = 3

                  Column 2:
            Fixed offset: 4
                  Type is Fixed Length Character String
                      61202020 20202020 2020                 a               


            Slot 7:

               Offset Location = 2800  (xAF0)
               Record Length = 23  (x17)

               Record Type = Table Data Record (FIXEDVAR)

               Fixed part length value = 15

                  Column 1:
            Fixed offset: 0
                  Type is Long Integer
                  Value = 4

                  Column 2:
            Fixed offset: 4
                  Type is Fixed Length Character String
                      61202020 20202020 2020                 a               


         Slots Summary:  Total=8,  In-use=8,  Deleted=0.

      
   Table object report phase end.
                     ______________________________________

                  DB2DART Processing completed with warning(s)!
                     Warning(s) detected during processing.
                     ______________________________________

                        Complete DB2DART report found in:
/home/db2inst1/sqllib/db2dump/DART0000/EOS.RPT
    _______    D A R T    P R O C E S S I N G    C O M P L E T E    _______

扑ֈ�Solt 7 (0x07)�Q�ok�Q�你现在可以清楚的知道应用等待的Row�?4,a)

�ȝ��

通过上面的方法，我们��单描�q�C��一个db2锁问题的定位�Ҏ��Q�希望能�l�大家在分析和定位应用性能问题的时候�v��C��定的帮助

del.icio.us Tags: db2,lock,tuning,diagnostic

tacy lee 2007-11-24 21:18 发表评论

tacy lee — Tue, 30 Oct 2007 04:59:00 GMT

先徏立一个监控器

db2 "create event monitor SQLCOST for statements write to file '/home/db2inst1'"

再设�|�事务状态�ؓ打开

db2 "set event monitor SQLCOST state=1"

注：1为打开�Q?为关闭，攉��数据之后�Q�记得关闭你的监控器�Q�否则。。�?/font>

跑你的测试后�Q�在你的/home/db2inst1目录下会生成一些evm文�g

用下面指令获取诊断信息：

db2evmon -db eos51 -evm SQLCOST>sqlcost1.txt

完成之后删除你的监控�?

db2 "drop event monitor SQLCOST"

生成的采样例子，从下面的例子中，你可以清除的看到SQL执行的时��_��CPU消耗情况，排序是否溢出�Q�BufferPool的��用情况，�Ҏ��q�些信息�Q�SQL的执行效率一目了�Ӟ��

26) Statement Event ...

Appl Handle: 336

Appl Id: C0A80421.O905.0ABDA5065446

Appl Seq number: 0657

Record is the result of a flush: FALSE

-------------------------------------------

Type : Dynamic

Operation: Execute

Section : 7

Creator : NULLID

Package : SYSSN300

Consistency Token : SYSLVL01

Package Version ID :

Cursor : SQL_CURSN300C7

Cursor was blocking: FALSE

Text : update WFProcessInst set relateData=? where processInstID= ?

-------------------------------------------

Start Time: 04/25/2007 14:57:19.402248

Stop Time: 04/25/2007 14:57:19.409622

Exec Time: 0.007374 seconds

Number of Agents created: 1

User CPU: 0.000000 seconds

System CPU: 0.000000 seconds [licl1]

Fetch Count: 0

Sorts: 0

Total sort time: 0

Sort overflows: 0 [licl2]

Rows read: 1

Rows written: 1

Internal rows deleted: 0

Internal rows updated: 0

Internal rows inserted: 0

Bufferpool data logical reads: 9

Bufferpool data physical reads: 0

Bufferpool temporary data logical reads: 0

Bufferpool temporary data physical reads: 0

Bufferpool index logical reads: 3

Bufferpool index physical reads: 0

Bufferpool temporary index logical reads: 0

Bufferpool temporary index physical reads: 0 [licl3]

SQLCA:

sqlcode: 0

sqlstate: 00000

[licl1]SQL执行旉��和CPU消耗情�?

[licl2]SQL的排序情况，可以看到�q�个SQL没有排序�Q�当然也没有排序溢出

[licl3]Bufferpool的��用情况，逻辑��d��物理�ȝ��Ҏ��

del.icio.us Tags: database , db2 , tuning

tacy lee 2007-10-30 12:59 发表评论

认识oracle数据�c�d��

tacy lee — Fri, 07 Sep 2007 09:10:00 GMT

摘要: 作者：tacy lee

在设计数据库的时候，选择正确的数据类型，往往可以避免很多的问题，正确理解数据库的�c�d��Q�对于存储空间规划，应用性能调整都会很有帮助�Q�下面是我个人的一�Ҏ�ȝ�� 阅读全文

tacy lee 2007-09-07 17:10 发表评论

3d成人动漫在线,精品av一区二区,久久亚洲精品成人

db2诊断�p�d���?--捕获sql执行情况

认识oracle数据�c�d��

db2诊断�p�d��?--捕获sql执行情况