Informix News
18 Nov 13 - ZDNet - Top 20 mobile skills in demand... Read
09 Sep 13 - telecompaper - Shaspa and Tatung have shown a new smart home platform at Ifa in Berlin. Powered by the IBM Informix software... Read
06 Sep 13 - IBM data magazine - Mission Accomplished - Miami, Florida will be the backdrop for the 2014 IIUG Informix Conference... Read
01 Feb 13 - IBM Data Magazine - Are your database backups safe? Lester Knutsen (IBM Champion) writes about database back up safety using "archecker"... Read
14 Nov 12 - IBM - IBM's Big Data For Smart Grid Goes Live In Texas... Read
3 Oct 12 - The Financial - IBM and TransWorks Collaborate to Help Louisiana-Pacific Corporation Achieve Supply Chain Efficiency... Read
28 Aug 12 - techCLOUD9 - Splunk kicks up a SaaS Storm... Read
10 Aug 12 - businessCLOUD9 - Is this the other half of Cloud monitoring?... Read
3 Aug 12 - IBM data management - Supercharging the data warehouse while keeping costs down IBM Informix Warehouse Accelerator (IWA) delivers superior performance for in-memory analytics processing... Read
2 Aug 12 - channelbiz - Oninit Group launches Pay Per Pulse cloud-based service... Read
28 May 12 - Bloor - David Norfolk on the recent Informix benchmark "pretty impressive results"... Read
23 May 12 - DBTA - Informix Genero: A Way to Modernize Informix 4GL Applications... Read
9 Apr 12 - Mastering Data Management - Upping the Informix Ante: Advanced Data Tools... Read
22 Mar 12 - developerWorks - Optimizing Informix database access... Read
14 Mar 12 - - International Informix User Group set to meet in San Diego... Read
1 Mar 12 - IBM Data Management - IIUG Heads West for 2012 - Get ready for sun and sand in San Diego... Read
1 Mar 12 - IBM Data Management - Running Informix on Solid-State Drives.Speed Up Database Access... Read
26 Feb 12 - - Better results, lower cost for a broad set of new IBM clients and partners... Read
24 Feb 12 - developerWorks - Informix Warehouse Accelerator: Continuous Acceleration during Data Refresh... Read
6 Feb 12 - PRLOG - Informix port delivers unlimited database scalability for popular SaaS application ... Read
2 Feb 12 - developerWorks - Loading data with the IBM Informix TimeSeries Plug-in for Data Studio... Read
1 Feb 12 - developerWorks - 100 Tech Tips, #47: Log-in to Fix Central... Read
13 Jan 12 - MC Press online - Informix Dynamic Server Entices New Users with Free Production Edition ... Read
11 Jan 12 - Computerworld - Ecologic Analytics and Landis+Gyr -- Suitors Decide to Tie the Knot... Read
9 Jan 12 - - DNS impact on Informix / Impacto do DNS no Informix... Read
8 Sep 11 - - IBM Offers Database Solution to Enable Smart Meter Data Capture... Read
1 Aug 11 - IBM Data Management Magazine - IIUG user view: Happy 10th anniversary to IBM and Informix... Read
8 Jul 11 - Database Trends and Applications - Managing Time Series Data with Informix... Read
31 May 11 - Smart Grid - The meter data management pitfall utilities are overlooking... Read
27 May 11 - IBM Data Management Magazine - IIUG user view: Big data, big time ( Series data, warehouse acceleration, and 4GLs )... Read
16 May 11 - Business Wire - HiT Software Announces DBMoto for Enterprise Integration, Adds Informix. Log-based Change Data Capture... Read
21 Mar 11 - Yahoo! Finance - IBM and Cable&Wireless Worldwide Announce UK Smart Energy Cloud... Read
14 Mar 11 - MarketWatch - Fuzzy Logix and IBM Unveil In-Database Analytics for IBM Informix... Read
11 Mar 11 - InvestorPlace - It's Time to Give IBM Props: How many tech stocks are up 53% since the dot-com boom?... Read
9 Mar 11 - DBTA - Database Administration and the Goal of Diminishing Downtime... Read
2 Feb 11 - DBTAs - Informix 11.7 Flexible Grid Provides a Different Way of Looking at Database Servers... Read
27 Jan 11 - exactsolutions - Exact to Add Informix Support to Database Replay, SQL Monitoring Solutions... Read
25 Jan 11 - PR Newswire - Bank of China in the UK Works With IBM to Become a Smarter, Greener Bank... Read
12 Oct 10 - Database Trends and Applications - Informix 11.7: The Beginning of the Next Decade of IBM Informix... Read
20 Sep 10 - - ITG analyst paper: Cost/Benefit case for IBM Informix as compared to Microsoft SQL Server... Read
20 Jul 10 - IBM Announcements - IBM Informix Choice Edition V11.50 helps deploy low-cost scalable and reliable solutions for Apple Macintosh and Microsoft Windows... Read
20 Jul 10 - IBM Announcements - Software withdrawal: Elite Support for Informix Ultimate-C Edition... Read
24 May 10 - eWeek Europe - IBM Supplies Database Tech For EU Smart Grid... Read
23 May 10 - SiliconIndia - IBM's smart metering system allows wise use of energy... Read
21 May 10 - CNET - IBM to help people monitor energy use... Read
20 May 10 - ebiz - IBM Teams With Hildebrand To Bring Smart Metering To Homes Across Britain... Read
19 May 10 - The New Blog Times - Misurare il consumo energetico: DEHEMS è pronto... Read
19 May 10 - ZDNet - IBM software in your home? Pact enables five-city smart meter pilot in Europe... Read
17 March 10 - ZDNet (blog) David Morgenstern - TCO: New research finds Macs in the enterprise easier, cheaper to manage than... Read
17 March 2010 - Virtualization Review - ...key components of Big Blue's platform to the commercial cloud such as its WebSphere suite of application ser vers and its DB2 and Informix databases... Read
10 February 2010 - The Wall Street Journal - International Business Machines is expanding an initiative to win over students and professors on its products. How do they lure the college crowd?... Read

End of Support Dates

IIUG on Facebook IIUG on Twitter

[ View Thread ] [ Post Response ] [ Return to Index ] [ Read Prev Msg ] [ Read Next Msg ]

IDS Forum

Re: Performance issue

Posted By: Madison Pruet
Date: Monday, 8 June 2015, at 12:35 p.m.

In Response To: Performance issue (Marcus Haarmann)

While your IO complex may be fast, you still need to be careful not to
overload it. Also you might want to check to make sure that your log
chunks are not on units that are having to do a lot of read activity.

From: "Marcus Haarmann" <>
Date: 06/08/2015 10:43 AM
Subject: Performance issue [35233]
Sent by:

Hi experts,

we are encountering a performance problem on one of our database systems,
which happens periodically,
not limited to a specific high load.
The effect is that all our application servers are blocked with some
transactions (which are committing
at this time), until 20-30 seconds later all the threads are unblocked all
a sudden.
(in the same millisecond, spread over all client machines).
The common thing is that all these threads have a connection to a specific
database instance and
have all done mostly read-only work (within a XA transaction, which is
necessary to support multiple
Since this effect is not really happening really regularly, but between 4-8

times spread over the day,
it is not easy to find out what is the main blocker here.

We have now done some measurements in the application to get the correct
when the situation occurs
and executed a script each 10 seconds to get some status information from
common DB instance.
The script put a timestamp in a log and executed onstat -g sql, followed by

onstat -g stk

What seems to be interesting:
1) online.log does not show anything when the effect occurs (no checkpoint,
full log, no entry at all)
2) What we found as common output ist the following thread during the

Stack for thread: 1101943 sqlexec
base: 0x00000003aff07000
len: 135168
pc: 0x00000000012ce881
tos: 0x00000003aff25190
state: sleeping
vp: 1

0x00000000012ce881 (/opt/informix/bin/oninit) yield=5Fprocessor=5Fmvp
0x00000000012d76df (/opt/informix/bin/oninit) mt=5Fyield
0x0000000000e975a7 (/opt/informix/bin/oninit) logm=5Fflush
0x0000000000d526ef (/opt/informix/bin/oninit) logflush
0x0000000000d21e55 (/opt/informix/bin/oninit) bfphysflush
0x0000000000d22a37 (/opt/informix/bin/oninit) bfphyslogx
0x0000000000cfe082 (/opt/informix/bin/oninit) btadditem
0x0000000000d00382 (/opt/informix/bin/oninit) rsbtadditem
0x00000000013be6b0 (/opt/informix/bin/oninit) fm=5Fidxinsert
0x000000000139bdea (/opt/informix/bin/oninit) fmwrite
0x0000000000688d82 (/opt/informix/bin/oninit) aud=5Fsqiswrite
0x000000000082a233 (/opt/informix/bin/oninit) chkrowcons
0x00000000007da790 (/opt/informix/bin/oninit) addone
0x00000000007de57a (/opt/informix/bin/oninit) insone=5Fnext
0x00000000008399b7 (/opt/informix/bin/oninit) doinsert
0x00000000005af784 (/opt/informix/bin/oninit) excommand
0x00000000009abfd0 (/opt/informix/bin/oninit) sq=5Fexecute
0x0000000000a6a3fb (/opt/informix/bin/oninit) sqmain
0x00000000013dbe3b (/opt/informix/bin/oninit) spawn=5Fthread
0x00000000013151c0 (/opt/informix/bin/oninit) th=5Finit=5Finitgls
0x00000000012e1a38 (/opt/informix/bin/oninit) startup

This seems to be an insert, which triggers an index (btree) write, which
triggers a physical log flush.
(there have been many inserts between the blocking times, which did not
trigger such a flush.
This only occurs sometimes.)

3) also a very high number of threads does the following:

Stack for thread: 905431 sqlexec
base: 0x00000003a7b48000
len: 135168
pc: 0x00000000012ce881
tos: 0x00000003a7b67250
state: cond wait
vp: 8

0x00000000012ce881 (/opt/informix/bin/oninit) yield=5Fprocessor=5Fmvp
0x00000000012e1216 (/opt/informix/bin/oninit) mt=5Ffast=5Fwait
0x0000000000d52e82 (/opt/informix/bin/oninit) logwrite
0x0000000000e99b9e (/opt/informix/bin/oninit) logm=5Fwrite
0x0000000000d504bb (/opt/informix/bin/oninit) logputx
0x0000000000ccd40f (/opt/informix/bin/oninit) rscommit
0x0000000000de2a6b (/opt/informix/bin/oninit) xa=5Fcommit
0x00000000009dd04b (/opt/informix/bin/oninit) ifx=5Fcommon=5Fxcommit
0x00000000009dd39d (/opt/informix/bin/oninit) sq=5Fxcommit
0x0000000000a6a3fb (/opt/informix/bin/oninit) sqmain
0x00000000013dbe3b (/opt/informix/bin/oninit) spawn=5Fthread
0x00000000013151c0 (/opt/informix/bin/oninit) th=5Finit=5Finitgls
0x00000000012e1a38 (/opt/informix/bin/oninit) startup

This seems to be one of the threads blocking in commit. The reason is
obviously a logwrite call,
which it is waiting for. We have 95 threads a this time which have a
stack member !

Now my question: How can we prevent this flushing ? Or make it happen
faster ?
Or are we on the wrong way when looking at the source of the problem ?
What is really happening during logwrite ? Since the hardware is relatively

and the disk array is very fast, I/O should not be the problem.

We have here: IDS 11.70FC8XB8GE running on Linux x64, using huge memory

Machine has 24GB Ram, Database uses ~15GB.
Checkpoints are done on 3-4 seconds, flush time 1.5-2.4 seconds (this
trigger 20 seconds of
blocking from my point of view).
onstat -F shows only chunk writes. onstat -p shows 99,8% read cached and
86,47% write cached.
Physical log is 5GB, rarely used > 5%
Checkpoints occur each 300sec, no other triggers than interval.

The machine is paired with a secondary instance via HDR. HDR pair was up
running without any trace of
"real" activity (checkpoints 1 second).

Any idea will be appreciated, we cannot file a bug, since we are not able
reproduce the behaviour
or even present an onstat -a output.
Yes, the instance is loaded very high, but we have other instances with
or higher load, which
are not behaving like this.

Marcus Haarmann


Forum Note: Use "Reply" to post a response in the discussion forum.

Messages In This Thread

[ View Thread ] [ Post Response ] [ Return to Index ] [ Read Prev Msg ] [ Read Next Msg ]

IDS Forum is maintained by Administrator with WebBBS 5.12.