20030606: problems viewing the NIMAGE images from NOAAPORT

>From:  "Kevin Polston" <address@hidden>
>Organization:  NOAA
>Keywords:  200306061559.h56FxDLd001670 LDM ldmd.conf

Kevin,

>I am having some problems here and I am not sure what to do.  First of
>all......for some reason 2 days ago the satellite data 
>started coming in "blank".  By that I mean no image was showing on any
>of the satellite data I have coming in even though in 
>the data directory it appears that I am receiving a regular file.

Please send a listing of your ~ldm/etc/ldmd.conf and NIMAGE entries in
your ~ldm/etc/pqact.conf files.  It could be that your system is
attempting to process the Zlib compressed images that are coming in the
NOAAPORT datasetream that becomes NIMAGE.  These files are not yet
supported by the PNG uncompression routines that have been working for
folks using the NIMAGE feed.

I can tell you that there is no systematic problem with the images
as we are receiving them here and are able to display all of them
with no problems (I know this to be the case since I worked my way
through all of the images in the feed a couple of days ago when
I setup a new test machine here in the office).

>I am
>not sure if I did something or not but it is getting frsutrating 
>to try and figure this out.  All other LDM data coming in is working
>fine and if you were to look at the data directory it would 
>suggest that the satellite data is there since there are files and they
>are the proper size and so forth.

The proper size comment would tend to indicate that the problem lies
somewhere other than your ingest and decoding setup, but I will need
to take a look at your files to make sure.

>The only thing I can think 
>of (and I may be off on the wrong track here) is somehow the "readpng"
>is not being read. When I looked at the png.log file it 
>says
>
>" wrote 1639680 bytes from 691489 compressed bytes [1281 1280]   Jun 06
>15:39:43 readpng[21847]: Starting Up"

This tells that:

- you have not updated your NIMAGE decoding setup in a long time.
  readpng was replaced by the ldm-mcidas routine pngg2gini in
  the v2002b release of ldm-mcidas

While on the same subject, I have not seen you upgrade your LDM
to a current release, or, if you have, you have not configured
it to report real time statistics back to us.  If you have
upgraded your LDM, then you need to add the following 'exec' line
to ~ldm/etc/ldmd.conf:

exec    "rtstats -h rtstats.unidata.ucar.edu"

This should be the last 'exec' line in ldmd.conf.  After making the
change, you will need to stop and restart your LDM for the change to
take effect.

>This makes me think everything is running properly since it apparently
>wrote the file and that  suggests to me that the readpng 
>file is being seen.
>
>
>But the reason I think I am having a problem here is because when I have
>edited my pqact.conf file I run these three steps in 
>this order --  ldmadmin pqactcheck       (/home/ldm/etc/pqact.conf is
>syntactically correct)
>           --  ldmadmin pqactHUP         (Check pqact HUP with command 
>ldmadmin tail    Hangup)
>           --  ldmadmin tail                      (ReReading
>configuration file /usr/local/ldm/etc/pqact.conf)

Without seeing the pqact.conf entries for NIMAGE, I can't really
comment on the above other than to say that these are the correct
steps to take when modifying pqact.conf.

>I have never seen before the "Hangup" line after running ldmadmin
>pqactHUP and I am wondering if this is causing the 
>"readpng" not to be read.

No, the 'hangup' comment is telling you that a HUP signal has been
sent to the process 'pqact'.  This signal tells 'pqact' to reread
its configuration file.

>Also, if this is causing a problem with my
>pqact.conf file from being read, then what do I need to do 
>to fix it?

This is not the problem.

>I recently upgraded to Redhat 9.0 and it went smoothly and I
>was having no problems before a couple of days ago.

And you made no other changes in the interim?

>I 
>have tried loading satellite data into NSAT and also GARP but I am still
>just getting the "black" image there as well.  So if you 
>have any suggestions I would be most grateful as I am stumped as to what
>to do next.

Let's start with an examination of your ldmd.conf and pqact.conf files.
Please send these to address@hidden.

Tom
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* Tom Yoksas                                             UCAR Unidata Program *
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