Over the weekend I have become obsessed with two things: the Allman Brothers Band and Jeremy Schneider's diagnosis of the listener/ONS bug found in Oracle The former due to "Jessica" being in the playlist for Guitar Hero II, the latter because not only did it provide me a rhyme and reason (and workaround) for my Oracle listener hanging, but it is one of the most well-written and presented diagnoses that I've seen, even busting out tcpdump to sniff the wire.

I somehow missed Jeremy's post when he originally wrote it a month ago, and stumbled across it today via Doug Burns. Doug mentions that he first noticed a problem when he saw multiple listener processes. A-HEM:

$ ps -aef | grep lsnr
oracle 32573 1 0 May13 ? 00:16:15 /u00/app/oracle/product/10.2.0/db_1/bin/tnslsnr LISTENER -inherit
oracle 32574 32573 0 May13 ? 00:00:16 /u00/app/oracle/product/10.2.0/db_1/bin/tnslsnr LISTENER -inherit
oracle 32575 32574 0 May13 ? 00:00:10 /u00/app/oracle/product/10.2.0/db_1/bin/tnslsnr LISTENER -inherit
oracle 32576 32574 0 May13 ? 00:00:00 /u00/app/oracle/product/10.2.0/db_1/bin/tnslsnr LISTENER -inherit

At the risk of gushing like a fanboi, I'll just direct you to Jeremy's post while I remain here and aspire to pull it together like he does when faced with such things. Plus I can watch this: