Recently we have been struggling with what looks like a JVM bug on Linux. The symptom is that the node freezes up - CPU usage goes to near zero, often all connections are backed off (usually all with the same error), or it may go completely catatonic. When you do a stack trace, the PacketSender thread (usually) is waiting to acquire a lock, but the object in question is not locked by any thread. If you repeat the stack dump seconds or minutes later, it's exactly the same.
This appears to be due to some sort of interaction between the Sun JVM and NPTL. In 0.5 we implemented a hack to turn NPTL off by setting LD_ASSUME_KERNEL=2.4.1 or 2.2.5 (depending on distro). Unfortunately, many modern distros ship without the pthreads libraries by default, and some architectures (e.g. amd64) don't seem to support non-NPTL mode *at all*. We had had many users turn it off in 0.5 for this reason, without bad reports, so we assumed it was fixed. It isn't. At least not up to 1.5.0_06. There is nothing in the 1.5.0_07 changelog about it, so it is probably still present in that version too. We have had some good reports from people using the 1.6 beta JVM. I suggest that you try this, if you are running a node on linux and experiencing backoff on all connections with low cpu usage, or other strange symptoms. And if it helps, or if it doesn't, please tell us. Thank you. It is possible that this will go away by itself with random code tweaking; it didn't affect 0.7 much until fairly recently. At present, Freenet 0.7 does not run under Kaffe, although it may under sableVM. It does run under GCJ, but at present this produces a 12MB binary, with minor issues. Nextgens is one of our 4 successful Google Summer of Code students, and he will investigate this in more detail later in the summer. He has recently written some update-over-freenet code which will be rolled out soon. Finally, the latest versions of Freenet have various improvements: - Basic container support is implemented, and debugged. (*Very* large freesites will not be fully containerized, but they will succeed, and not produce unfetchable freesites). - Basic inter-node messaging support. - There is a new fproxy theme, "sky". - Lots of bug fixes. -- Matthew J Toseland - toad at amphibian.dyndns.org Freenet Project Official Codemonkey - http://freenetproject.org/ ICTHUS - Nothing is impossible. Our Boss says so. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: Digital signature URL: <https://emu.freenetproject.org/pipermail/tech/attachments/20060527/d721f8f3/attachment.pgp>
