It's definitely non-deterministic, unfortunately. I do have a reliable reproduction for Bionic and Focal I can trigger on my laptop, but it's a huge pile of proprietary Ruby code that just happens to hit all the right timings on my machine. I can validate a -proposed package if you need though.
The reproduction instructions basically boil down to "Have IPv6, call getaddrinfo(), and if you're unlucky, it will take > 5 seconds and make 4 DNS queries instead of two". There is also a test case provided in the upstream glibc patch that could also be applied. https://sourceware.org/git/?p=glibc.git;a=blob;f=resolv/tst-resolv- txnid- collision.c;h=611d37362f3e5e89b92766f0790459340cc071b3;hb=2dfa659a66f20facc4082207884c20e986ddecee -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1961697 Title: Transaction ID collisions cause slow DNS lookups in getaddrinfo To manage notifications about this bug go to: https://bugs.launchpad.net/glibc/+bug/1961697/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
