On 22.01.2017 20:24, trueriver wrote: > I believe I am seeing hash collisions in cpid on installing the client in > Debian and Mint. I also believe the Mint package is the unchanged Debian > one, inherited via Ubuntu.
Hi, there was a similar issue on the BOINC dev forums recently. https://boinc.berkeley.edu/dev/forum_thread.php?id=11397 It turned out that the user had a software installed that created a virtual network device using the same MAC on two different computers. This virtual device was listed first when doing an "ipconfig" (Windows) and thus was used to create the Host-CPID. I guess something along these lines is also happening to you. To recapitulate: the Client takes the first MAC it finds and creates the md5 of it. This is send to the server and is used there to find out if there is an old host entry that this host belongs to. What could help on the PG server side is this commit: https://github.com/BOINC/boinc/commit/9daab7acb1a8d0137fb9d52f87a8845d126b5bff it makes sure that the hosts may only differ by GPU. This would create a new host entry if the old host and the new are different. The reason of the MAC hashing is so that in a Cluster environment where a node gets reinstalled on a regular basis (at least it gets a fresh BOINC Client directory) the server doesn't create thousands of host entries but reuses old ones. This assumes that within a Cluster each node has a unique MAC. The idea about overriding host-CPID hashing and make it random may in fact solve your problem. For reference, here is the 7.6.33 implementation of how the host-CPID is determined: https://github.com/BOINC/boinc/blob/client_release/7/7.6/client/hostinfo_network.cpp#L127 If you are familiar with how debian packages work you could write a patch that you apply locally and always create a random string or read the cpid from an external file (if it exists). I'm not sure if that should go upstream. I don't see this use-case to be widespread but I don't see any danger from it right now. The occasional problems you see might stem from the fact that the network may not be working at the time when the BOINC Client tries to get the MAC address and uses a random host-CPID instead. Regards Christian _______________________________________________ boinc_dev mailing list [email protected] http://lists.ssl.berkeley.edu/mailman/listinfo/boinc_dev To unsubscribe, visit the above URL and (near bottom of page) enter your email address.
