Arjen, Thank you very much for your reply. I have looked at the logs of the recent changes submitted through SVN and found this one:
++++ Begin SVN log entry Handle all communications with the server through upscli_sendline/readline and use of select() to prevent blocking on I/O calls when the server is not responding (while still allowing it a couple of seconds to reply). The above fixes a bug with upsmon ignoring DEADTIME when the connection to the server is lost. Since we're using blocking I/O here, a read() from the server would stall upsmon. Since we can't change to non-blocking I/O (after writing a command to the server, the client immediately reads a reply), the only option left is to use select(). We do that now for all communication with the server. ++++ End SVN log entry This describes our problem and an implemented solution (the solution that I would have suggested as well!). My thanks go to all those who continue to improve the NUT software. Regards, Jon Arjen de Korte wrote: > [...] > > >> A brief examination of the NUT source code indicates that a system >> "write" statement is being used to communicate across the network with >> the upsd process of the master. We think that this system function >> blocks by default. Maybe the default blocking settings are in use. We >> don't know, this is probably very wide of the mark, but it is the best >> we have come up with! >> > > If this is indeed the cause of the problem, you may wish to upgrade to the > latest version from the SVN trunk. Just two days ago, a change to the > upsclient library was made so that it no longer blocks on read/write > actions. > > Best regards, Arjen > -- ---------------------------- Jon Clark Scientific Officer Dept. of Applied Mathematics University of Sheffield Sheffield, S3 7RH, UK ---------------------------- _______________________________________________ Nut-upsuser mailing list [email protected] http://lists.alioth.debian.org/mailman/listinfo/nut-upsuser
