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[TIGGE #EEC-237791]: Memory problem with LDM Server at CMA

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  • Subject: [TIGGE #EEC-237791]: Memory problem with LDM Server at CMA
  • Date: Mon, 14 Jan 2008 10:58:45 -0700
Dear Ma Qiang,

We will help you as much as we can.

First, is there truly a problem?  Does the LDM system crash?
Does the LDM system stop receiving data?  I ask this because 
Linux system attempt to use all available memory -- even if
it's not necessary.  I've attached the output of "top" from
one of our LDM systems.  Note that its output is similar
to yours (no free memory, no swap space used, mostly idle).

If you still believe that there is a problem, then...

No other LDM site has reported this problem, so it is probably 
caused by something unique to the CMA.  For example, the LDM
configuration might be a little off or the CMA network might
somehow cause LDM processes to not terminate.

How much physical memory do the other TIGGE systems have for
the same amount of data?  How much swap space?

The number of LDM processes (50 to 60) seems large.  How many
REQUEST entries are in your LDM configuration-file?  What is
the output from the command "netstat -pat | grep ldm"?

Is the hostname of the LDM system "tigge-ldm.cma.gov.cn"?

May I log into the LDM system as the LDM user?  We have done
this before from our host "zero.unidata.ucar.edu".

Regards,
Steve Emmerson
LDM Developer

> Dear Sir,
> 
> I am MA Qiang, and I am working for TIGGE project at CMA.
> 
> Recently, I found that the memory usage increased rapidly on LDM Server at 
> CMA.
> 
> I added the physical memory to 8GB. But the memory run out in 3 - 4 days.
> 
> Please refer to the forward email as follows.
> 
> Could you please tell us how to deal with this problem and give us some 
> advice.
> (
> The version of LDM running at CMA is ldm-6.6.5, OS is RHEL 4.4.
> $ uname -a
> Linux tgn01 2.6.9-42.ELsmp #1 SMP Wed Jul 12 23:32:02 EDT 2006 x86_64 x86_64 
> x86_64 GNU/Linux
> There is no other user application running on the LDM Server.
> The attachment is the output of top command which is sorted by Resident size 
> (kb).
> )
> 
> Thank you!
> 
> Best regards,
> MA Qiang
> 
> National Meteorological Information Center
> 2008-01-14
Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: EEC-237791
Department: Support IDD TIGGE
Priority: Normal
Status: On Hold