Embed Size (px)
Citation preview
db2pd in a Nutshell
Phil GunningPrincipal Consultant, Gunning Technology Solutions, LLC
Session: D0425 October 20050830 – 0930
Platform: DB2 for Linux, UNIX, and Windows
2
db2pd Background
• Developed based on OnStat utility from Informix• Problem determination and monitoring tool• Integrated into DB2 V8.2 (Stinger)
• Does not yet contain all options from OnStat
• Documented in the Command Reference
• Low monitoring overhead (latch free), preferred where possible over snapshots or event monitors
• Command line driven which makes it excellent for use with scripts
• Not dependent on monitor switches
3
db2pd Background
• db2pd returns information without acquiring any locks or use of DB2 engine resources
• Since no locks are obtained, data returned by dbp2d may not be completely current or accurate • Zero use of database engine resources however is a good trade-off
• It is important to become familiar with db2pd as there is much information provided by db2pd that cannot be obtained through snapshot or event monitoring
• db2pd contains 34 options• We will cover these new monitoring and problem
determination information elements in this presentation
4
Using db2pd
• Command line tool• Requires SYSADM authority and on UNIX/Linux must be
instance owner• No required connection or instance attachment• For database level information to be retrieved, database must
be active • Standard options are:
• -c command, read commands from input file• -r repeat, num sec count• -i interactive• -file, specifies output file
5
db2pd Option Categories• db2pd options can be divided into three categories in
terms of information provided• Administrative/Status
• OS Info• DBM and DB Configuration Information• DB2 and OS Version, virtual and physical memory
• Monitoring and Tuning• Problem Determination/Troubleshooting
6
-osinfo option• db2pd –osinfoOperating System Information:OSName: WIN32_NT NodeName: GTSLT1 Version: 5.1 Release: Service Pack 2 Machine: x86 Family 6, model 10, stepping 0
CPU Information:TotalCPU OnlineCPU ConfigCPU Speed(MHz) HMTDegree Cores/Socket1 1 1 1856 1 1
Physical Memory and Swap (Megabytes):TotalMem FreeMem AvailMem TotalSwap FreeSwap 703 326 326 1016 1159
Virtual Memory (Megabytes):Total Reserved Available Free 1719 n/a n/a 1485
7
Instance and Database Scope• db2pd options are further broken down by Instance
and Database scope• Instance scope options return information at the
Instance level• -agents, -fcm, -mempools, -memsets, -dbmcfg, -sysplex
-utilities
8
Database Scope Options1. –storagepaths 2. –transactions *
• Returns detailed information on transactions 3. –locks*
• Returns detailed lock information4. –tablespaces*
• Returns detailed tablespace information5. –dynamic*
• Returns detailed information about dynamic SQL 6. –static
• Returns information about static SQL
9
Database Scope Options
7. –mempools
• Returns information about memory pools
8. –memsets
• Returns information about memory sets
9. -catalogcache
• Returns detailed information about catalog table activity
10. –tcbstats*
• Returns detailed information about tables and indexes
11. –activestatements*
10
Database Scope Options
12. –applications*
13. –bufferpools
14. -logs
15. –hadr
16. – reorgs
17. -reopts
18. –recovery
19. –dbcfg*
20. –dbmcfg*
11
-inst option
• Returns all instance-scope information
• db2pd -inst• Version, level, bitness, fixpak information• Operating System Information• CPU Information, including hardware multithreading• Physical Memory, Swap and Virtual Memory Configuration and usage• Agent Information – Idle, Active, Coordinator• Memory Pool information – Actual physical size, upper bound, high water
mark• Memory Set Summary• Database Manager Configuration Settings – In memory and on disk• Utility status and progress
12
-dbmcfg option
• Command: db2pd –dbmcfg file=/tmp/dbmcfg.txtDatabase Partition 0 -- Active -- Up 0 days 18:36:03
Database Manager Configuration Settings:
Description Memory Value Disk Value
RELEASE 0xa00 0xa00
CPUSPEED 1.141499e-006 1.141499e-006
COMM_BANDWIDTH 1.000000e+002 1.000000e+002
NUMDB 8 8
DATALINKS NO NO
13
-dbcfg option
• Command: db2pd –db GTSTST3 –dbcfg• Returns Database Configuration information
• DB CFG parameter settings in memory and on disk
14
-database option
• Command: >db2pd -db sample -file c:\dbase.txt
Sending all options output to c:\dbase.txt
• Returns database information• Automatic storage status• Storage path information• HADR status• Table and index activity
• Active table scans• Index splits
• Active statement list
• Without options specified, runs all database scope options• -alldbs runs all options for all databases
15
-database ExampleC:>db2pd -db sample -file c:\dbase.txtSending all options output to c:\dbase.txtDatabase Partition 0 -- Database SAMPLE -- Active -- Up 0 days 00:42:21
Applications:
Address AppHandl [nod-index] NumAgents CoorTid Status C-AnchID C-StmtUID L-AnchID L-StmtUID Appid
0x003FBEA0 448 [000-00448] 1 5376 ConnectCompleted 0 0 0 0 *LOCAL.DB2.050901015508
Database Partition 0 -- Database SAMPLE -- Active -- Up 0 days 00:42:21
Transactions:
Address AppHandl [nod-index] TranHdl Locks State Tflag Tflag2 Firstlsn Lastlsn LogSpace SpaceReserved TID AxRegCnt GXID
0x04531580 448 [000-00448] 2 0 READ 0x00000000 0x00000000 0x000000000000 0x000000000000 0 0 0x000000000BFE 1 0
Database Partition 0 -- Database SAMPLE -- Active -- Up 0 days 00:42:21
BufferPools:
First Active Pool ID 1
Max Bufferpool ID 1
Max Bufferpool ID on Disk 1
Num Bufferpools 5
Address Id Name PageSz PA-NumPgs BA-NumPgs BlkSize ES NumTbsp PgsLeft CurrentSz PostAlter SuspndTSCt
0x0448C980 1 IBMDEFAULTBP 4096 250 0 0 N 4 0 250 250 0
0x04483D60 4096 IBMHIDDENBP4K 4096 16 0 0 N 0 0 16 16 0
0x0448C200 4097 IBMHIDDENBP8K 8192 16 0 0 N 0 0 16 16 0
0x0448C480 4098 IBMHIDDENBP16K 16384 16 0 0 N 0 0 16 16 0
16
-transactions option
• Command: db2pd –db db2mon –trans
Database Partition 0 -- Database DB2MON -- Active -- Up 1 days 04:27:09
Transactions:Address AppHandl [nod-index] TranHdl Locks State Tflag Tflag2 Firstlsn Lastlsn
LogSpace SpaceReserved TID AxRegCnt GXID 0x027D1000 599 [000-00599] 99 0 READ 0x00000000 0x00000000
0x000000000000 0x000000000000 0 0 0x000000009016 1 0 0x027D1A80 591 [000-00591] 100 0 READ 0x00000000 0x00000000
0x000000000000 0x000000000000 0 0 0x000000008FF6 1 0 0x027D2500 589 [000-00589] 101 0 READ 0x00000000 0x00000000
0x000000000000 0x000000000000 0 0 0x000000008FFD 1 0 0x027D2F80 588 [000-00588] 102 0 READ 0x00000000 0x00000000
0x000000000000 0x000000000000 0 0 0x000000009012 1 0 0x027D3A00 9 [000-00009] 103 2 READ 0x00000000 0x00000000
0x000000000000 0x000000000000 0 0 0x0000000003FA 1 0 0x027D4480 8 [000-00008] 104 0 READ 0x00000000 0x00000000
0x000000000000 0x000000000000 0 0 0x000000009014 1 0
17
-locks option
• Command: db2pd –db db2mon –locksDatabase Partition 0 -- Database DB2MON -- Active -- Up 1 days 04:44:50
Locks:
Address TranHdl Lockname Type Mode Sts Owner Dur HldCnt Att ReleaseFlg
0x032DE790 103 4442324143434553BBCB10EC41 Internal P ..S G 103 1 0 0x0000 0x40000000
0x032DE740 103 53514C4445464C5428DD630641 Internal P ..S G 103 1 0 0x0000 0x40000000
Snippet from previous –trans output:
0x027D3A00 9 [000-00009] 103 2 READ 0x00000000 0x00000000 0x000000000000 0x000000000000 0 0 0x0000000003FA 1 0
0x027D4480 8 [000-00008] 104 0 READ 0x00000000 0x00000000 0x000000000000 0x000000000000 0 0 0x000000009014 1 0
18
Resolving Lock Contention with db2pd
Database Partition 0 -- Database SAMPLE -- Active -- Up 0 days 16:39:33
db2pd –db GTSTST1 –locks –file /tmp/lockc.txtLocks:
Address TranHdl Lockname Type Mode Sts Owner Dur HldCnt Att ReleaseFlg
0x0459C510 2 53514C4332453036BD4A32C841 Internal P .. S G 2 1 0 0x0000 0x40000000
0x0459CA10 3 53514C4332453036BD4A32C841 Internal P .. S G 3 1 0 0x0000 0x40000000
0x0459CA60 3 010000000100000001007B0056 Internal V . S G 3 1 0 0x0000 0x40000000
0x0459C9E8 3 53514C4445464C5428DD630641 Internal P . S G 3 1 0 0x0000 0x40000000
0x0459EF90 2 02000300270000000000000052 Row . X G 2 1 0 0x0008 0x40000002
0x0459CAB0 3 02000300270000000000000052 Row .NS W 2 1 0 0x0000 0x00000001
0x0459C8F8 2 02000300000000000000000054 Table .IX G 2 1 0 0x0000 0x40000002
0x0459CA88 3 02000300000000000000000054 Table .IS G 3 1 0 0x0000 0x00000001
Type of lock
Lock mode
TranHdl 2 has an X lock on
this row
TranHdl 3 is waiting on a lock held by TranHdl 2
19
-locks showlocks option
Locks:Address TranHdl Lockname Type Mode Sts Owner Dur HldCnt Att ReleaseFlg0x0459C510 2 53514C4332453036BD4A32C841 Internal P ..S G 2 1 0 0x0000
0x40000000 Pkg UniqueID 434c5153 36304532 Name c8324abd Loading = 00x0459CA10 3 53514C4332453036BD4A32C841 Internal P ..S G 3 1 0 0x0000
0x40000000 Pkg UniqueID 434c5153 36304532 Name c8324abd Loading = 00x0459CA60 3 010000000100000001007B0056 Internal V ..S G 3 1 0 0x0000 0x40000000
Anchor 123 Stmt 1 Env 1 Var 1 Loading 00x0459C9E8 3 53514C4445464C5428DD630641 Internal P ..S G 3 1 0 0x0000
0x40000000 Pkg UniqueID 444c5153 544c4645 Name 0663dd28 Loading = 00x0459EF90 2 02000300270000000000000052 Row ..X G 2 1 0 0x0008 0x40000002
TbspaceID 2 TableID 3 RecordID 0x270x0459CAB0 3 02000300270000000000000052 Row .NS W 2 1 0 0x0000
0x00000001 TbspaceID 2 TableID 3 RecordID 0x270x0459C8F8 2 02000300000000000000000054 Table .IX G 2 1 0 0x0000 0x40000002
TbspaceID 2 TableID 30x0459CA88 3 02000300000000000000000054 Table .IS G 3 1 0 0x0000 0x00000001
TbspaceID 2 TableID 3
20
-applications option
• Command: db2pd –db db2mon –applicationsApplications:Address AppHandl [nod-index] NumAgents CoorTid Status C-AnchID C-StmtUID
L-AnchID L-StmtUID Appid 0x02B9B120 1086 [000-01086] 1 3148 UOW-Waiting 0 0 79 180
*LOCAL.DB2.050901041938 0x01B686D0 599 [000-00599] 1 1664 UOW-Waiting 0 0 84 216
*LOCAL.DB2.050901022803 0x0196FB80 591 [000-00591] 1 1984 UOW-Waiting 0 0 0 0
*LOCAL.DB2.050901022720 0x003FBF30 589 [000-00589] 1 2928 UOW-Waiting 0 0 0 0
*LOCAL.DB2.050901022718 0x01B6BD70 588 [000-00588] 1 2520 UOW-Waiting 0 0 0 0
*LOCAL.DB2.050901022717 0x003FB490 9 [000-00009] 1 2172 UOW-Waiting 0 0 0 0
*LOCAL.DB2.050830232506 0x0196F520 8 [000-00008] 1 2244 UOW-Waiting 0 0 0 0
*LOCAL.DB2.050830232351
21
-tcbstats option
• Contains over 21 output data elements that report on previously unavailable table, index, and table space information
• One of the most important db2pd options• Command: db2pd –db db2mon -tcbstats
22
-tcbstats Example
TbspaceID TableID TableNameScans UDI DataSize IndexSize PgReorgs NoChgUpdtsReads FscrUpdatesInserts Updates Deletes OvFlReadsOvFlCrtes LfSize LobSize0 1 SYSBOOT 1 0 1 0 0 0 0 0 0 0 0 0 0 0 00 2 SYSTABLES 54 499 51 24 0 0 3819 2 17 15 0 0 0 0 5760 3 SYSCOLUMNS 0 6820 358 176 0 0 20 24 247 1 0 0 0 0 03 2 HMON_ATM_INFO196 2507 15 5 56 7225 3802 135 156 2507 0 21581 100 0 00 4 SYSINDEXES 0 206 20 12 0 0 0 1 4 0 0 0 0 0 13 3 POLICY 0 5 1 3 0 0 4 0 5 0 0 0 0 0 640 5 SYSCOLPROPERTIES0 0 1 0 0 0 0 0 0 0 0 0 0 0 03 4 HMON_COLLECTION0 0 1 3 0 0 0 0 0 0 0 0 0 0 00 6 SYSINDEXCOLUSE0 560 8 12 0 0 0 1 10 0 0 0 0 0 03 5 STMG_DBSIZE_INFO0 1 1 0 0 0 0 0 1 0 0 0 0 0 00 8 SYSVIEWDEP 0 794 21 34 0 0 0 0 0 0 0 0 0 0 00 9 SYSPLAN 0 77 9 5 0 0 154 2 1 0 0 0 0 0 3200 10 SYSPLANDEP 0 117 5 8 1 0 0 36 16 0 0 0 0 0 640 11 SYSSECTION 0 302 11 10 0 0 1448 2 32 0 0 0 0 0 29440 12 SYSSTMT 0 323 11 10 0 0 0 2 32 0 0 0 0 0 1280 13 SYSDBAUTH 0 0 1 3 0 0 0 0 0 0 0 0 0 0 00 14 SYSPLANAUTH0 110 3 8 0 0 0 1 1 0 0 0 0 0 00 15 SYSTABAUTH 0 372 10 25 0 0 0 2 17 0 0 0 0 0 0
23
-tcbstats index option
• Command: db2pd –db db2mon –tcbstats index
Address TbspaceID TableID TableNameIID EmpPgDel RootSplits BndrySpltsPseuEmptPgScans KeyUpdatesInclUpdats NonBndSptsPgAllocs Merges PseuDels DelClean IntNodSpl0x03CF4B18 0 2 SYSTABLES 6 0 0 0 0 55 0 0 0 0 0 0 0 00x03CF4B18 0 2 SYSTABLES 5 0 0 0 0 0 0 0 0 0 0 0 0 00x03CF4B18 0 2 SYSTABLES 4 0 0 0 0 0 0 0 0 0 0 0 0 00x03CF4B18 0 2 SYSTABLES 3 0 0 0 0 0 0 0 0 0 0 0 0 00x03CF4B18 0 2 SYSTABLES 2 0 0 0 0 0 0 0 0 0 0 0 0 00x03CF4B18 0 2 SYSTABLES 1 0 0 0 0 2592 0 0 1 1 0 0 0 00x03CF4B18 0 2 SYSTABLES 0 0 0 0 0 0 0 0 0 0 0 0 0 00x03D21398 0 3 SYSCOLUMNS 2 0 0 0 0 0 0 0 1 1 0 0 0 00x03D21398 0 3 SYSCOLUMNS 1 0 0 1 0 51 0 0 6 7 0 0 0 00x03D21398 0 3 SYSCOLUMNS 0 0 0 0 0 0 0 0 0 0 0 0 0 00x02D22218 3 2 HMON_ATM_INFO 1 0 1 0 0 6693 0 0 1 3 0 0 0 00x02D22218 3 2 HMON_ATM_INFO 0 0 0 0 0 0 0 0 0 1 0 0 0 00x02F9B298 0 4 SYSINDEXES 3 0 0 0 0 0 0 0 0 0 0 0 0 00x02F9B298 0 4 SYSINDEXES 2 0 0 0 0 0 0 0 0 0 0 0 0 00x02F9B298 0 4 SYSINDEXES 1 0 0 0 0 0 0 0 0 0 0 0 0 00x02F9B298 0 4 SYSINDEXES 0 0 0 0 0 0 0 0 0 0 0 0 0 00x02D22E18 3 3 POLICY 1 0 0 0 0 49 0 0 0 1 0 0 0 0
24
-tablespaces option
Command and output: db2pd -db db2mon -tablespaces tablespace=2 file=c:\tsid.txt Sending -tablespaces output to c:\tsid.txt.
Database Partition 0 -- Database DB2MON -- Active -- Up 1 days 21:28:46
Tablespace 2 Configuration:Address Type Content PageSz ExtentSz Prefetch BufID BufIDDisk FSC NumCntrs MaxStripe LastConsecPg Name0x03ADE9D0 SMS Any 4096 32 0 1 1 On 1 0 31 USERSPACE1
Tablespace 2 Statistics:Address TotPages UsablePgs UsedPgs PndFreePgs FreePgs HWM State MinRecTime NQuiescers0x03ADE9D0 37403 37403 37403 0 0 0 0x00000000 0 0
Tablespace 2 Autoresize Statistics:Address AS AR Auto InitSize IncSize IIP MaxSize LastResize LRF0x03ADE9D0 No No Yes 0 0 No 0 None No
Containers:Address ContainNum Type TotalPages UseablePgs StripeSet Container 0x03ADEFD0 0 Path 37403 37403 0 C:\DB2\NODE0000\SQL00003\SQLT0002.0
25
-activestatements option
• Command: db2pd –db db2mon –activestatementsDatabase Partition 0 -- Database DB2MON -- Active -- Up 1 days 04:56:27
Active Statement List:
Address AppHandl [nod-index] UOW-ID StmtID AnchID StmtUID EffISO EffLockTOut EffDegree StartTime LastRefTime
0x02D279E0 1086 [000-01086] 3 1 79 180 1 -2 0 Thu Sep 01 00:19:54 2005 Thu Sep 01 00:19:54 2005
Snippet from –dynamic option
Dynamic SQL Statements:
Address AnchID StmtUID NumEnv NumVar NumRef NumExe Text
x03F2D9B0 79 180 0 0 1 1 select * from
sysibm.systables
26
Putting it All TogetherLocks:Address TranHdl Lockname Type Mode Sts Owner Dur HldCnt Att ReleaseFlg
0x0485E3B0 3 02000300270000000000000052 Row .NS W 2 1 0 0x0000 0x00000001 0x0485C998 2 02000300000000000000000054 Table .IX G 2 1 0 0x0000 0x40000000
TransactionsAddress AppHandl [nod-index] TranHdl Locks State Tflag Tflag2 Firstlsn Lastlsn LogSpace SpaceReserved TID AxRegCnt GXID 0x045B1580 236 [000-00236] 2 8 WRITE 0x00000000 0x00000000 0x000003A9800C 0x000003AA27B6 234 572 0x0000000014DD 1 0
0x045B2000 425 [000-00425] 3 5 READ 0x00000000 0x00000000 0x000000000000 0x000000000000 0 0 0x000000001716 1 0
0x045B2A80 339 [000-00339] 4 0 READ 0x00000000 0x00000000 0x000000000000 0x000000000000 0 0 0x00000000168C 1 0
Applications:Address AppHandl [nod-index] NumAgents CoorTid Status C-AnchID C-StmtUID L-AnchID L-StmtUID Appid
0x01B19950 425 [000-00425] 1 3652 Lock-wait 123 1 0 0 *LOCAL.DB2.050920034220
0x0090BE70 236 [000-00236] 1 2452 UOW-Waiting 0 0 149 1 *LOCAL.DB2.050920021447
Dynamic SQL Statements:Address AnchID StmtUID NumEnv NumVar NumRef NumExe Text
0x05E289C0 123 1 1 1 1 1 select * from staff0x05E26FB0 129 1 1 1 1 1 SELECT SCHEMA, NAME, STATS_DETAIL, STATS_STATE, STATS_TIME FROM SYSTOOLS.HMON_ATM_INFO WHERE (STATS_STATE = 2 OR STATS_STATE = 6) AND STATS_FLAG = 'Y'
0x05E27E60 149 1 1 1 1 1 insert into department values('1b', 'Gunning','4', 'C00', NULL)
27
-bufferpools option
• Command: db2pd –database sample –bufferpools• Returns bufferpool activity such as size in pages, post alter
size in pages, number of blocks being used for block-based bufferpools
• Element of interest is table spaces suspended for I/O• Indicated by non-zero value
• NOT as good as bufferpool snapshot
28
db2pd Problem Determination
• -catch option• Can be used to catch any sqlcode, ZRC code, or ecf code and
capture information needed to help solve the problem• Can be used in conjunction with the db2cos callout script
which can be called to run any db2pd or OS command
29
db2cos
• The DB2 callout script, db2cos is shipped with DB2 and is located in the sqllib/cfg directory and must be moved to the DB2 /bin directory before it can be used
• db2cos default template provided
30
db2pd Problem Determination Scenarios
• Command: db2pd –catch -911,68 db2cos• Output:Error Catch #2
Sqlcode: -911ReasonCode: 68ZRC: 0ECF: 0Component ID: 0LockName: Not SetLockType: Not SetCurrent Count: 0Max Count: 255Bitmap: 0x261Action: Error code catch flag enabledAction: Execute sqllib/db2cos callout script
31
db2pd Problem Determination Scenarios
• db2diag.log entry:2005-09-01-17.49.59.065000-240 I2998718H296 LEVEL: Event
PID : 220 TID : 6024 PROC : db2syscs.exe
INSTANCE: DB2 NODE : 000
FUNCTION: DB2 UDB, RAS/PD component, pdErrorCatch, probe:30
START : Error catch set for sqlCode -911 reasonCode 68
• Lock timeout received:C:\Documents and Settings\Phil Gunning>db2 "select * from department"
SQL0911N The current transaction has been rolled back because of a deadlock
or timeout. Reason code "68". SQLSTATE=40001
• Reset catch flags as follows: db2pd –catch clear all
32
Stack Trace
• The stack trace has been incorporated in db2pd as of V8.2.2 • Issue the following command to produce a stack trace for a
process or thread • db2pd –stack 2632
• Command response:>db2pd -stack 2632
Attempting to dump stack trace for pid 2632.
See current DIAGPATH for trapfile.
33
Summary
• db2pd is a lightweight monitoring tool that provides information that is not available through other means
• Use it with the understanding that output may not be exact due to changing data
• Best used via a script that formats the output into a more readable format
• Run on a regular schedule, save to a file or insert into DB2 tables and review and make tuning adjustments as necessary
• Familiarize yourself with the extensive options and look for continued improvements via Fixpaks and new releases
34
Summary
• What db2pd is not:• As of DB2 V8.2.3, it is not a replacement for snapshot monitoring or
event monitoring
• First version of it goes a long way in providing new monitoring and problem determination capabilities
35
References
• DB2 UDB Command Reference V8.2, SC09-4828-01• http://publib.boulder.ibm.com/infocenter/db2help/index.jsp?
topic=/com.ibm.db2.udb.doc/core/r0011729.htm
36
db2pd in a NutshellSession: D04
THANK YOU!
Phil GunningGunning Technology Solutions, LLC
