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newbieOnLinux 12-07-2007 02:36 AM

How can I solve out Of Memory Error on RedHat 4 Update 5 Server
I'm new on linux server. One of our clients (which is a bank) use RedHat linux version 4 update 5 server. Our client got out of memory error while try to get excell reports which size bigger that 60000. There would be two reason for this error. Excell part and linux part. In excell part I solved programatically.
I changed the program like that : if the size of data bigger that 60000 than there would be more that one excell sheet. So every sheet has data which are lesser than 60000. (Because of excell not supported a data more that 65536 I divided the data into separate sheets)

But it doesn't solve the linux part. Because till the report finishing, all the datas are stored on server the cashe.

I'm just want to learn, whether there is any way to improve cashing mechanism of linux or preventing not to take out of Memory error in the operation of bigger.
I'm now reading linux vm management, But if any of you give me better idea to solve the problem I'd be very happy.
Thank you very much

syg00 12-07-2007 06:15 AM

unless the application is doing something whacky in allocation,adding Swap space should alleviate the problem.
There are workloads that don't like the changes 2.6 introduced, but more memory (best) or more swap (affordable, if somewhat slow) should resolve all those.

Look at your SAR data to see what is actually happening with the memory/swap.

salasi 12-08-2007 06:45 AM

If I've understood correctly, the bank has RH Linux (Not RHEL!) as a server, and this is some way serves (Samba? Nfs?) to some clients which probably aren't Linux boxes (Windows?).

RH 4 must be from some time in the late 1990s (this is where it is important whether it is RH or RHEL...RHEL 4 would be only a couple of years old and would probably still be supported).

I'm assuming, though you don't say this, that you are not trying to open these 'excell' files on the server. (If you are, what with? Excel doesn't run on Linux. Wine??? On the server? OO?)

The out of memory error occurs on the server and not the client.

You comment on reducing the size of the data. I think that you mean the number of data elements and not the size of an individual data element, but I'm not sure.

If I've guessed any of this right, then:

-You need to say how you are serving these files. I'm guessing samba, but you should confirm this and say what version, just in case its relevant and whether there are any error messages from the file server program.

-I see no real evidence that caching is in any way involved. It may be an 'out of virtual memory' problem. It may be useful to say:
-how much physical memory you have
-ditto, swap space
and post the output from "vmstat 10 10" to give an idea of what you are seeing going on.

Also, please try to post the actual error message.

newbieOnLinux 12-10-2007 02:20 AM

Hello Salasi,
I searched the reason of the error. This error is thrown from the program as java error. This program is written PL/SQL. For creating the excell file hssfworkbook object is used . When I searched for this object I saw that for preventing out of memory error, I have to increase JVM heap size.
So I will try this.
Because as I said before on linux part there isn't error message in the logs. (As they said to me . Actually I don't have error logs on linux part) So the problem most probably doesn't related with linux.

Thank you all for your help.
And sorry for taking your time

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