[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: 19990601: Linux LDM memory problem (fwd)

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: Re: 19990601: Linux LDM memory problem (fwd)
  • Date: Wed, 2 Jun 1999 12:44:58 -0500 (CDT)
On Tue, 1 Jun 1999, Robb Kambic wrote:

> David,
> 
> How about trying not to use a memmapped queue file. Set the environment
> variable NO_MMMAP = 1 .  One would have to do a make distclean and rerun
> configure.  It might be better or worst, It would be interested to find
> out.  Keep me informed.
> 
> Robb...


OK...

 It fixes the caching problem.  LDM stops immediately when
you run ldmadmin stop.   However, it very seriously impacts
performance.... I tried it on the machine ingesting the NMC2
feed and was getting latencies over an hour and missing
many products (presumably they were going out of the queue
on the source end before they could be transmitted).   Switching
back to the mmap version quickly returned latencies
to only seconds.  So, that doesn't look to be an answer.

--david