>From: "Edwin Pryor" <address@hidden> >Organization: DOC/NOAA/NWS - National Weather Service >Keywords: 200412121835.iBCIZalI029494 LDM queue check Hi Ned, >I originally tried to reach Jeff Weber but learned he is on travel. >Any assistance you may provide on my LDM question would be appreciated. Please send all inquiries directly to Unidata User Support <address@hidden>. Since multiple folks here at the UPC read the support inbox, you are less likely to have to wait for a reply than when sending questions directly to a UPC staff member who, like Jeff, may be on travel. >My name is Ned Pryor and I work for the NWS Middle Atlantic River >Forecast Center in State College, PA. > >I spoke to you recently as we installed LDM version 5.2.2 on a Linux >machine that is part of our AWIPS network. Hopefully, Jeff strongly advised you to upgrade your LDM 5.x installation to the latest LDM-6 offering. The primary reasons for this are: - we no longer support LDM-5 - LDM-6 is much more efficient at relaying data than LDM-5 - LDM-6 fixed several bugs that existed in LDM 5.x >We have used various >versions of LDM over the years and I was never quite sure about storing >incoming products in the event LDM stopped running. We have had times >when LDM has died for one reason or another but we continue to queue >products using "pqinsert" from a separate data handling script. The issues you note about unexpected LDM-5 stops are a good reason to upgrade to the latest LDM-6 distribution. Our experience with LDM-6 is that it runs for months without any interruption. In fact, the LDMs running on our NOAAPORT ingest machines only get restarted when we do something like upgrade the OS or software that processes the NOAAPORT offerings into the various IDD datastreams or there is an power outage. >Ideally >we would like LDM (once restarted) to work its way through any queue >that has built up over time rather than blasting the queue or paring the >queue. Do you have any ideas or info on this topic? Depending on why your LDM stops, there may or may not be a need to delete and remake the queue. The automatic startup script that we recommend folks run to start the LDM at machine bootup checks the ingegrity of the queue so as to not lose anything in it if it is not damaged. If the queue is damaged, there is no option but to delete and remake the queue and then start the LDM. You could/should adopt the same approach of checking your queue integrity before deleting and remaking it. There are two ways of doing this: LDM-6.1.x: - use 'pqcheck -q <LDM_product_queue>' to check the product count in the queue. If the count is not zero, the queue may be damaged LDM-5.2.x, LDM-6.X: - use 'pqcat -s' to check the queue If you are running LDM-6.1.x and the 'pqcheck' test passes, you should be able to safely start your LDM. If the 'pqcheck' check fails, you should run the 'pqcat' check to see if the queue is, in fact, in an inconsistent state. If it is not, you should be able to start the LDM safely. If the 'pqcat' check fails or hangs, you will need to delete and remake your queue before restarting. PLEASE upgrade to use of the latest LDM-6 distribution. The NWS adopted this distribution for use in the NEXRAD Level II gathering and redistribution project, so it is not like it is not being used in an operational setting. Cheers, Tom Yoksas -- NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.
NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.