Join IIUG
 for   
 

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 - BernieSpang.com - 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 - BernieSpan.com - 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 - planetIDS.com - DNS impact on Informix / Impacto do DNS no Informix... Read
8 Sep 11 - TMCnet.com - 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 - planetIDS.com - 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: 11.5 UC7E crashes

Posted By: Martin Fuerderer
Date: Thursday, 22 December 2011, at 5:17 a.m.

In Response To: Re: 11.5 UC7E crashes (KLAUS GLAHN)

Hallo Klaus,

you got already some (new) answers, so here
I'll only write down some of my thoughts that may
not have been covered by those previous answers ...

> ... tried onclean, but this doesn't help. ...
I didn't check out the source code of this utility,
but there can't be too much magic for what it is
doing (or trying to do). Does the onclean show
any error or warning message?

> /proc/<pid>/maps is empty for all my oninit-processes
What exactly do you mean by "empty" ?
After the server crashed, when the oninit processes have
died, there should not even be a /proc/<pid> directory
anymore for those processes, as they don't exist anymore.
If a process (still) exists, its maps file in /proc/<pid> should
never be empty (i.,e. contain nothing at all), as any process
will at least occupy some memory, if it is only the TEXT
portion (i.e. the program code itself, that is loaded into memory).

These two statements from you ... somehow do not fit the
picture, that is expected of a Linux system ... hmm.

My guess is, that when there is the situation of
"shmget: [EEXIST][17]: key 52574802: shared memory
already exists", there is still some (old) process "hanging
around" and still attached to that shared memory segment.
In this case, the onclean utility will not be able to remove
the SHM segment, because Linux doesn't allow it. Also
as user "root" using the ipcrm system utility you will not
be able to remove an SHM segment to which some process
is still attached.

Using "ipcs -m" as user root, you should be able to
identify that SHM segment (using the key). The output of
"ipcs -m" usually has a column named "nattch" which means
"number of processes attached". It is likely non-zero (otherwise
onclean would have removed it already). Possibly the column
"status" says something like "destroyed", which means that
the Linux OS will automatically remove it once the last process
has detached from it. Unfortunately, "ipcs" doesn't tell, which
process (pid) is still attached. :-(
So the task is to find and kill that process (or those processes).

There are two possibilities:

a) There is an (old) oninit process left over, that is still attached
to the SHM segment. If this Informix Server instance is the
only one running on this machine, then simply do a command
like "ps -efw | grep oninit" to see, if there is an oninit process
still (half) alive. If you identify some oninit processes that
should not be there anymore: kill them as user "root":
"kill -9 <pid> [ <pid> ... ]"
In case you have other Informix Server instances running on
this machine, set the respective environment for each instance
and do "onstat -g sch". The output will include a listing of all the
associated oninit processes with their PID. These PIDs should
not be killed with above "kill -9 ..." command ... :)

b) Some client process (i.e. not an oninit process) is still running
and attached to the SHM segment. This could e.g. be an onbar
process (try "ps -efw | grep onbar"). In case you have configured
SHM communication between clients and Informix Server, it could
be any local client process that has connected to the server using
SHM for communication. Check in the sqlhosts file, whether there
is an entry with "onipcshm" as the second parameter. Check for
any client process (you have to know or figure out, what could be
their name ... usually "dbaccess" is one candidate for running ad
hoc test queries), using the same "ps -efw | grep ..." method.
If you find something ... kill it as well, using "kill -9 <pid>".

Once all process are gone (have been killed), the SHM segments
should have been removed. In a rare case where a segment could
still be left over, again running onclean should do the job.

Regards, Martin
--
Martin Fuerderer
IBM Informix Development Munich, Germany
Information Management

Read about the Informix Warehouse Accelerator:
http://tinyurl.com/the-iwa-blog

IBM Deutschland Research & Development GmbH
Chairman of the Supervisory Board: Martina Koederitz
Board of Management: Dirk Wittkopp
Corporate Seat: Boeblingen, Germany
Reg.-Gericht: Amtsgericht Stuttgart, HRB 243294

ids-bounces@iiug.org wrote on 12/21/2011 08:40:45 PM:
> Hello,
>
> thank you for your answers. I already assumed that itīs a memory
problem. But
> with my limited knowledge (and I have the Eric-Herber-book ;-) itīs
already
> difficult to ask the right questions.
>
> We have a test instance and I tried
>
> SHMVIRTSIZE 800000
> SHMADD 150000
>
> but when I do oninit I get an error message
>
> 20:20:33 IBM Informix Dynamic Server gestartet.
> 20:20:33 shmget: [EEXIST][17]: key 52574802: shared memory already
exists
> 20:20:33 mt_shm_init: Segment resident kann nicht angelegt werden
>
> After that the instance couldnīt start until I changed the
SERVERNUM-Parameter
> to another number (thanks to Google :-) I donīt know how to clean this
up, I
> tried onclean - but this doesnīt help. Is reboot the only solution?
>
> As far as I know (I didnīt install the machine, there is little
documentation)
> itīs a 32-Bit-Informix running on Debian with Bigmem-Extension. The
crashes
> seem real random - but we have approx. 100 users working with the
database
> with different applications - and some of them using MS-Access and can
do
> large transactions.
>
> /proc/<pid>/maps is empty for all my oninit-processes
>
> Should I try lower values for SHMVIRTSIZE? I donīt want to experiment,
because
> I donīt want to change the SERVERNUM after each failed test.
>
> Sorry, I am really a newbie to the Informix internals. The last years
> everything was fine - until we wanted logging ... Thanks again for your
help.
>
> All the best
> Klaus
>
>
>
*******************************************************************************

> 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.