Art, thanks for your reply.
I Change DS_NONPDQ_QUERY_MEM too 51240, also run dostats. And there is
no change, all our queries that have to access a lot of rows takes too
much time.
Now I'm going to install Informix 11.5FC5 in my old server, and check if
there's a problem with my OS or hardware.
Thanks again for your help, and any other ideas are welcome :)
# onstat -g mgm
Memory Grant Manager (MGM)
--------------------------
MAX_PDQPRIORITY: 100
DS_MAX_QUERIES: 400
DS_MAX_SCANS: 1048576
DS_NONPDQ_QUERY_MEM: 51240 KB
DS_TOTAL_MEMORY: 204960 KB
Queries: Active Ready Maximum
0 0 400
Memory: Total Free Quantum
(KB) 204960 204960 512
Scans: Total Free Quantum
1048576 1048576 1
Load Control: (Memory) (Scans) (Priority) (Max Queries) (Reinit)
Gate 1 Gate 2 Gate 3 Gate 4 Gate 5
(Queue Length) 0 0 0 0 0
Active Queries: None
Ready Queries: None
Free Resource Average # Minimum #
-------------- --------------- ---------
Memory 0.0 +- 0.0 25620
Scans 0.0 +- 0.0 1048576
Queries Average # Maximum # Total #
-------------- --------------- --------- -------
Active 0.0 +- 0.0 0 0
Ready 0.0 +- 0.0 0 0
Resource/Lock Cycle Prevention count: 0
Emiliano Romero
Art Kagel escribió:
> There are several problems with this query and your configuration. The
> ONCONFIG first. There are a couple of parameters that I would configure
> differently, however, the only one that is affecting this query severely is:
>
> DS_NONPDQ_QUERY_MEM 128
>
> This controls how much memory is available for sorting in memory when
> PDQPRIORITY is zero or unset. In earlier engines (before 11.xx) the
> environment variable DBUPSPACE controlled this and the default was 15MB. In
> the onconfig.std the default setting for this new parameter, which overrides
> DBUPSPACE BTW, is 128KB and that is the setting which you have retained.
> That means that you have about 1/120th the space in memory for sorting data
> for ORDER BY and other requirements. This query required between 700KB and
> 1MB of memory to sort the results. That means that this query must do its
> sorting to the tempdbspaces and disk is MUCH slower than memory. That may
> be the main cause of the IO waits. Increase DS_NONPDQ_QUERY_MEM to 15360
> (15MB) to get back to the default for the IDS version you came from or,
> better, increase it to 51240 (50MB) to allow even larger sorts to happen in
> memory.
>
> Next, the table posicion had to be index scanned to determine which rows
> satisfied the secondary filter criteria on the eventoid and fechaposicion
> columns. You would do better with an index on those two columns along with
> the join column holderid in this order: (holderid, eventoid,
> fechaposicion). Without this index to filter, the engine had to scan over
> 800,000 rows in order to return just 50,000 rows. Another major source or
> excess IO processing. If that index exists already and wasn't used, that
> may be due to the next problem I see:
>
> Looking at the SET EXPLAIN output, I notice in the statistics section that
> while the engine had to scan almost 50000 rows it estimated that it would
> only have to scan just over 9000 rows. This indicates that the data
> distributions for the index key and filter columns are not sufficient to
> give the optimizer the data it needs to formulate a good query plan.
>
> If you relied on the IDS 11.50's ability to build minimal data distributions
> on key columns during the index build process to gather the statistics, you
> should know that only the first column of each index key is used to build
> those statistical distributions which is not sufficient for more complex
> queries like this one. Look in the Performance Guide manual for details of
> the recommended suite of commands that you need to run to gather a useful
> level of statistics with minimal effort and time. You can also use my
> dostats utility which implements those recommendations automatically for
> you. Dostats is free and is contained in the package utils2_ak which you
> can download from either the Oninit web site (www.oninit.com/utils) or the
> IIUG Software Repository (www.iiug.org/software)
>
> Art
>
> Art S. Kagel
> Oninit (www.oninit.com)
> IIUG Board of Directors (art@iiug.org)
>
> Disclaimer: Please keep in mind that my own opinions are my own opinions and
> do not reflect on my employer, Oninit, the IIUG, nor any other organization
> with which I am associated either explicitly or implicitly. Neither do
> those opinions reflect those of other individuals affiliated with any entity
> with which I am affiliated nor those of the entities themselves.
>
> On Tue, Sep 15, 2009 at 10:56 AM, Emiliano Romero <eromero@sitrack.com>wrote:
>
>
>> Hi list,
>>
>> First sorry about my english,
>>
>> I have migrate my informix server from 10.0 to 11.5FC5 and also migrate
>> hardware. I move to a new 2xQuad Xeon+4x150 Gb Disk 10000RPM+8Gb of Ram.
>> In tests it seems to be a much faster, but when i go to my production
>> enviroment I see some Queries taking too much to be resolved.
>>
>> My plataform is Linux.
>>
>> Syntoms when I execute theses queries:
>> 1) Like 35% of CPU in Waiting (I/O)
>> 2) Status of session changing between "IO WAIT" and "yield bufwait-"
>>
>> Example of query:
>> Explain out:
>> QUERY: (OPTIMIZATION TIMESTAMP: 09-14-2009 15:27:32)
>> ------
>> SELECT posicion.fechaposicion as fechaposicion , posicion.holderid as^M
>>
>> holderid , posicion.eventoid as eventoid , holder.dominio as
>> dominio ^M
>>
>> FROM posicion INNER JOIN holder ON
>> (holder.holderid=posicion.holderid) ^M
>>
>> WHERE ( posicion.holderid in^M
>>
>>
>>
>>
>>
> (14273,14440,14448,14274,14442,15171,14275,14271,14443,14253,13045,14278,14292,14279,14250,13044,13011,13002,14306,14305,14291)
>
>> ) AND (^M
>>
>> posicion.eventoid in (7, 6, 4) ) AND ( posicion.fechaposicion >=^M
>>
>> '2009-09-08 04:00:00' ) AND ( posicion.fechaposicion <= '2009-09-14
>> 03:59:00' ) ORDER BY fechaposicion
>>
>> Estimated Cost: 87861
>> Estimated # of Rows Returned: 9117
>> Temporary Files Required For: Order By
>>
>> 1) informix.holder: INDEX PATH
>>
>> (1) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14273
>>
>> (2) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14440
>>
>> (3) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14448
>>
>> (4) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14274
>>
>> (5) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14442
>>
>> (6) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 15171
>>
>> (7) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14275
>>
>> (8) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> (9) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14443
>>
>> (10) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14253
>>
>> (11) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 13045
>>
>> (12) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14278
>>
>> (13) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14292
>>
>> (14) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14279
>>
>> (15) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14250
>>
>> (16) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 13044
>>
>> (17) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 13011
>>
>> (18) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 13002
>>
>> (19) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14306
>>
>> (20) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14305
>>
>> (21) Index Name: root. 216_289
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid = 14291
>>
>> 2) informix.posicion: INDEX PATH
>>
>> Filters: ((informix.posicion.fechaposicion >=
>> datetime(2009-09-08 04:00:00) year to second AND
>> informix.posicion.eventoid IN (7 , 6 , 4 )) AND
>> informix.posicion.fechaposicion <= datetime(2009-09-14 03:59:00) year to
>> second )
>>
>> (1) Index Name: root. 100_909
>>
>> Index Keys: holderid (Serial, fragments: ALL)
>>
>> Lower Index Filter: informix.holder.holderid =
>> informix.posicion.holderid
>> NESTED LOOP JOIN
>>
>> Query statistics:
>> -----------------
>>
>> Table map :
>> ----------------------------
>> Internal name Table name
>> ----------------------------
>> t1 holder
>> t2 posicion
>>
>> type table rows_prod est_rows rows_scan time est_cost
>> -------------------------------------------------------------------
>> scan t1 21 21 21 00:00.00 5
>>
>> type table rows_prod est_rows rows_scan time est_cost
>> -------------------------------------------------------------------
>> scan t2 49511 9117 844729 06:31.26 4006
>>
>> type rows_prod est_rows time est_cost
>> -------------------------------------------------
>> nljoin 49511 9118 06:31.27 87861
>>
>> type rows_sort est_rows rows_cons time
>> -------------------------------------------------
>> sort 49511 9118 49511 06:32.55
>>
>> # onstat -g ses 5382
>>
>> IBM Informix Dynamic Server Version 11.50.FC5 -- On-Line -- Up
>> 01:39:11 -- 6651320 Kbytes
>>
>> session effective #RSAM
>> total used dynamic
>> id user user tty pid hostname threads
>> memory memory explain
>> 5382 informix - reflex 8 Emiliano 1
>> 253952 225008 off
>>
>> tid name rstcb flags curstk status
>> 5532 sqlexec 19ee4ebd8 ---PR-- 13488 *IO Wait-*
>>
>> Memory pools count 3
>> name class addr totalsize freesize #allocfrag
>> #freefrag
>> 5382 V 1a027b040 167936 17168 240
>> 16
>> 5382*O0 V 1a1131040 4096 808 1
>> 1
>> 5382_SORT_0 V 1a23e8040 81920 10968 19
>> 3
>>
>> name free used name free
>> used
>> overhead 0 9864 scb 0
>> 144
>> opentable 0 8096 filetable 0
>> 2240
>> ru 0 600 log 0
>> 16536
>> temprec 0 2320 keys 0
>> 216
>> ralloc 0 74160 gentcb 0
>> 1584
>> ostcb 0 2920 sort 0
>> 67488
>> sqscb 0 21736 sql 0
>> 72
>> srtmembuf 0 200 rdahead 0
>> 1120
>> hashfiletab 0 552 osenv 0
>> 2072
>> sqtcb 0 8528 fragman 0
>> 3640
>> shmblklist 0 776 sapi 0
>> 64
>>
>> sqscb info
>> scb sqscb optofc pdqpriority sqlstats
>> optcompind directives
>> 1a15dd028 19f728028 0 0 0
>> 2 1
>>
>> Sess SQL Current Iso Lock SQL ISAM F.E.
>> Id Stmt type Database Lvl Mode ERR ERR
>> Vers Explain
>> 5382 SELECT db3g CR Not Wait 0 0
>> 9.29 On
>>
>> Current statement name : _ixceb
>>
>> #onstat -g ses 5382
>> IBM Informix Dynamic Server Version 11.50.FC5 -- On-Line -- Up
>> 01:39:20 -- 6651320 Kbytes
>>
>> session effective #RSAM
>> total used dynamic
>> id user user tty pid hostname threads
>> memory memory explain
>> 5382 informix - reflex 8 Emiliano 1
>> 253952 225008 off
>>
>> tid name rstcb flags curstk status
>> 5532 sqlexec 19ee4ebd8 B--PR-- 12432 *yield bufwait-*
>>
>> Memory pools count 3
>> name class addr totalsize freesize #allocfrag
>> #freefrag
>> 5382 V 1a027b040 167936 17168 240
>> 16
>> 5382*O0 V 1a1131040 4096 808 1
>> 1
>> 5382_SORT_0 V 1a23e8040 81920 10968 19
>> 3
>>
>> name free used name free
>> used
>> overhead 0 9864 scb 0
>> 144
>> opentable 0 8096 filetable 0
>> 2240
>> ru 0 600 log 0
>> 16536
>> temprec 0 2320 keys 0
>> 216
>> ralloc 0 74160 gentcb 0
>> 1584
>> ostcb 0 2920 sort 0
>> 67488
>> sqscb 0 21736 sql 0
>> 72
>> srtmembuf 0 200 rdahead 0
>> 1120
>> hashfiletab 0 552 osenv 0
>> 2072
>> sqtcb 0 8528 fragman 0
>> 3640
>> shmblklist 0 776 sapi 0
>> 64
>>
>> sqscb info
>> scb sqscb optofc pdqpriority sqlstats
>> optcompind directives
>> 1a15dd028 19f728028 0 0 0
>> 2 1
>>
>> Sess SQL Current Iso Lock SQL ISAM F.E.
>> Id Stmt type Database Lvl Mode ERR ERR
>> Vers Explain
>> 5382 SELECT db3g CR Not Wait 0 0
>> 9.29 On
>>
>> Current statement name : _ixceb
>>
>> # onstat -g iof
>> gfd pathname bytes read page reads bytes write page
>> writes io/s
>> 3 rootdbs 1521664 743 751740928
>> 367061 79.1
>>
>> op type count avg. time
>>
>> seeks 0 N/A
>>
>> reads 0 N/A
>>
>> writes 0 N/A
>>
>> kaio_reads 464 0.0106
>>
>> kaio_writes 238035 0.0126
>>
>> 4 tempdbs1 510468096 249252 541411328
>> 264361 108.7
>>
>> op type count avg. time
>>
>> seeks 0 N/A
>>
>> reads 0 N/A
>>
>> writes 0 N/A
>>
>> kaio_reads 10944 0.0091
>>
>> kaio_writes 15505 0.0093
>>
>> 5 tempdbs2 510189568 249116 534435840
>> 260955 73.7
>>
>> op type count avg. time
>>
>> seeks 0 N/A
>>
>> reads 0 N/A
>>
>> writes 0 N/A
>>
>> kaio_reads 11252 0.0143
>>
>> kaio_writes 15417 0.0130
>>
>> 6 datadbs 5195923456 2537072 291811328
>> 142486 71.0
>>
>> op type count avg. time
>>
>> seeks 0 N/A
>>
>> reads 0 N/A
>>
>> writes 0 N/A
>>
>> kaio_reads 2006322 0.0136
>>
>> kaio_writes 103883 0.0227
>>
>> online.log:
>> 13:48:38 IBM Informix Dynamic Server Started.
>>
>> Mon Sep 14 13:48:39 2009
>>
>> 13:48:39 pid 31174: can't get real path of
>> 13:48:40 Event alarms enabled. ALARMPROG =
>> '/opt/informix/etc/alarmprogram.sh'
>> 13:48:40 Booting Language <c> from module <>
>> 13:48:40 Loading Module <CNULL>
>> 13:48:40 Booting Language <builtin> from module <>
>> 13:48:40 Loading Module <BUILTINNULL>
>> 13:48:40 Affinitied VP 1 to phys proc 1
>> 13:48:40 Affinitied VP 3 to phys proc 2
>> 13:48:40 Affinitied VP 4 to phys proc 3
>> 13:48:45 DR: DRAUTO is 0 (Off)
>> 13:48:45 DR: ENCRYPT_HDR is 0 (HDR encryption Disabled)
>> 13:48:45 Event notification facility epoll enabled.
>> 13:48:47 IBM Informix Dynamic Server Version 11.50.FC5 Software
>> Serial Number AAA#B000000
>> 13:48:49 IBM Informix Dynamic Server Initialized -- Shared Memory
>> Initialized.
>>
>> 13:48:49 Started 1 B-tree scanners.
>> 13:48:49 B-tree scanner threshold set at 5000.
>> 13:48:49 B-tree scanner range scan size set to -1.
>> 13:48:49 B-tree scanner ALICE mode set to 6.
>> 13:48:49 B-tree scanner index compression level set to med.
>> 13:48:49 Physical Recovery Started at Page (1:1207439).
>> 13:48:49 Physical Recovery Complete: 0 Pages Examined, 0 Pages Restored.
>> 13:48:49 Logical Recovery Started.
>> 13:48:49 10 recovery worker threads will be started.
>> 13:48:50 Logical Recovery has reached the transaction cleanup phase.
>> 13:48:50 Logical Recovery Complete.
>>
>> 0 Committed, 0 Rolled Back, 0 Open, 0 Bad Locks
>> 13:48:51 Onconfig parameter PHYSFILE modified from 2500000 to 20000.
>> 13:48:51 Onconfig parameter LOGFILES modified from 58 to 12.
>> 13:48:51 Dataskip is now OFF for all dbspaces
>> 13:48:52 Checkpoint Completed: duration was 1 seconds.
>> 13:48:52 Mon Sep 14 - loguniq 45, logpos 0x5507018, timestamp:
>> 0x89c892e1 Interval: 1321
>>
>> 13:48:52 Maximum server connections 0
>> 13:48:52 Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns
>> blocked 0, Plog used 2, Llog used 1
>>
>> 13:48:52 On-Line Mode
>> 13:48:53 SCHAPI: Started dbScheduler thread.
>> 13:48:53 Booting Language <spl> from module <>
>> 13:48:53 Loading Module <SPLNULL>
>> 13:48:53 SCHAPI: Started 2 dbWorker threads.
>> 13:49:26 Loading Module </opt/informix/lib/libcubi.so>
>> 13:49:26 pid 31177: can't get real path of
>> 13:49:26 The C Language Module </opt/informix/lib/libcubi.so> loaded
>> 13:49:58 Loading Module </opt/informix/lib/libcheckzona.so>
>> 13:49:58 pid 31174: can't get real path of
>> 13:49:58 The C Language Module </opt/informix/lib/libcheckzona.so> loaded
>> 13:53:55 Explain file for session 5382 : /home/informix/sqexplain.out
>> 13:54:00 Checkpoint Completed: duration was 9 seconds.
>> 13:54:00 Mon Sep 14 - loguniq 45, logpos 0x8489018, timestamp:
>> 0x89cd46e1 Interval: 1322
>>
>> 13:54:00 Maximum server connections 65
>> 13:54:00 Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns
>> blocked 1, Plog used 6439, Llog used 12265
>>
>> 13:59:15 Checkpoint Completed: duration was 13 seconds.
>> 13:59:15 Mon Sep 14 - loguniq 45, logpos 0xae6d018, timestamp:
>> 0x89d3045e Interval: 1323
>>
>> 13:59:15 Maximum server connections 65
>> 13:59:15 Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns
>> blocked 2, Plog used 5533, Llog used 11095
>>
>> 14:01:13 Logical Log 45 Complete, timestamp: 0x89d4ddc9.
>> 14:01:14 Process exited with return code 126: /bin/sh /bin/sh -c
>> /opt/informix/etc/alarmprogram.sh 2 23 "" "Logical Log 45 Complete,
>> timestamp: 0x89d4ddc9." ""
>> 14:04:30 Checkpoint Completed: duration was 14 seconds.
>> 14:04:30 Mon Sep 14 - loguniq 46, logpos 0x1ed3018, timestamp:
>> 0x89d7be90 Interval: 1324
>>
>> 14:04:30 Maximum server connections 65
>> 14:04:30 Checkpoint Statistics - Avg. Txn Block Time 0.065, # Txns
>> blocked 5, Plog used 6429, Llog used 13539
>>
>> I upload my onconfig file to: http://pastebin.com/f1295b23d
>>
>> Any idea of how could I tune that times? In my another instance of
>> Informix 10.0 with older hardware that queries works much better.
>>
>> Regards and thanks for any help.
>>
>> Emiliano Romero
>>
>> This email and any attachments thereof may contain confidential,
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>>
>>
>>
>>
>>
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>
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>>
>
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