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 Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated.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.
>From: David YEUNG <address@hidden> >Organization: CCAR HKUST >Keywords: 200512080652.jB86qB7s009443 LDM assertion failure Hi David, re: >Our LDM suddenly stopped with following error: > >Dec 08 05:24:22 rcz006 atm[13870]: assertion "n > 0" failed: file "pq.c", line >2187 >Dec 08 05:24:28 rcz006 rpc.ldmd[13865]: child 13870 terminated by signal 6 >Dec 08 05:24:28 rcz006 rpc.ldmd[13865]: Killing (SIGINT) process group >Dec 08 05:24:28 rcz006 rpc.ldmd[13865]: SIGINT >Dec 08 05:24:28 rcz006 rtstats[13869]: Interrupt >Dec 08 05:24:28 rcz006 idd[13871]: SIGINT >Dec 08 05:24:28 rcz006 rtstats[13869]: Exiting Dec 08 05:24:28 rcz006 >rpc.ldmd[13865]: Terminating process group > >And I tried to restart it and still failed: > >Dec 08 05:40:01 rcz006 rpc.ldmd[8913]: Starting Up (version: 6.0.14; built: Oct >1 2003 09:48:41) >Dec 08 05:40:01 rcz006 atm[8918]: Starting Up(6.0.14): atm.geo.nsf.gov: >TS_ZERO TS_ENDT {{IDS|DDPLUS, ".*"}} >Dec 08 05:40:01 rcz006 atm[8918]: Desired product class: 20051208044001.982 >TS_ENDT {{IDS|DDPLUS, ".*"}} >Dec 08 05:40:01 rcz006 idd[8919]: Starting Up(6.0.14): idd.unidata.ucar.edu: >TS_ZERO TS_ENDT {{IDS|DDPLUS, ".*"}} >Dec 08 05:40:01 rcz006 idd[8919]: Desired product class: 20051208044001.983 >TS_ENDT {{IDS|DDPLUS, ".*"}} >Dec 08 05:40:02 rcz006 rtstats[8917]: Starting Up (8913) >Dec 08 05:40:02 rcz006 idd[8919]: Connected to upstream LDM-6 >Dec 08 05:40:02 rcz006 atm[8918]: Connected to upstream LDM-6 >Dec 08 05:40:02 rcz006 idd[8919]: Upstream LDM is willing to feed >Dec 08 05:40:02 rcz006 atm[8918]: Upstream LDM is willing to feed >Dec 08 05:41:09 rcz006 atm[8918]: assertion "n > 0" failed: file "pq.c", line >2187 >Dec 08 05:41:15 rcz006 rpc.ldmd[8913]: child 8918 terminated by signal 6 >Dec 08 05:41:15 rcz006 rpc.ldmd[8913]: Killing (SIGINT) process group >Dec 08 05:41:15 rcz006 rpc.ldmd[8913]: SIGINT >Dec 08 05:41:15 rcz006 rtstats[8917]: Interrupt >Dec 08 05:41:15 rcz006 rtstats[8917]: Exiting >Dec 08 05:41:15 rcz006 idd[8919]: SIGINT >Dec 08 05:41:15 rcz006 rpc.ldmd[8913]: Terminating process group > >I have even rebooted the machine and it doesn't help. >We are running LDM 6.0.14 on RedHat9. >Could you kindly help? We can't get any LDM data now. The assertion failure indicated that there was most likely something wrong with your LDM queue (what exactly, I can't say just yet). The action I would have taken at this point would be to delete and remake the queue and then restart: <as 'ldm'> ldmadmin clean ldmadmin delqueue ldmadmin mkqueue -f ldmadmin start >The problem is gone after I upgrade the LDM to the latest version (6.4.4). >Is the problem related to the old version LDM I was using? I don't think so. Upgrading to a current version of the LDM, however, was something that I was toing to recommend anyway. I will look further into the assertion error and see if I can figure out what was going on. >Regards 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.