Re: Cannot connect to Online

Dirk Scheer wrote: > > Hello out there, > > since 4 weeks, there's a very strange behaviour with INFORMIX Online 7.13.UC3 > on HP-UX 10.01. From time to time it happens, that no new user can establish a > connection to Online (the process hangs, until online shutdown). Users > currently logged in can continue their work without any problems. But when a > currently logged in user closes the connection and tries to reestablish it, > this user also hangs. All I can do is a "onmode -ky; oninit" to reboot online. > After this everything is working fine again for a while. > We are currently using 7.13.UC1 on HPUX 10.01 and have seen similiar problems once in a while. > I've configured 2 connection methods: > NETTYPE ipcshm,1,200,CPU > NETTYPE soctcp,1,30,NET> > I've discovered that the above described problem only occurs on > ipcshm-connection. If I change INFORMIXSERVER to the tcp/ip-connection, I can > connect to Online. So I think there must be a problem with the shared memory. > The "onstat -g seg" gives the following: > We use shmem connections exclusively. > INFORMIX-OnLine Version 7.13.UC3 -- On-Line -- Up 09:18:59 -- 526000 Kbytes > > Segment Summary: > (resident segments are locked) > id key addr size ovhd class blkused blkfree > 520 1381517313 c0cb0000 473088000 8072 R 57746 4 > 265 1381517314 dcfdc000 65536000 1604 V 1842 6158 > 29 1381517315 ebf00000 2154496 640 M 260 3 > > There are no error messages in the INFORMIX or system log file! > Same here. > I don't have any ideas where to search for an error. The system is running > now for more than 2 years. There was no INFORMIX update! The problem occurs > the first time 4 weeks ago. > > On the machine runs a third party product which uses Online. Is it possible, > that this application crashes the shared memory area of Online? Until now I > believed, that this is not possible, but in the last 4 weeks there were > several updates of this software. Ofcourse the vendor denies, that our > problems could be caused by his software. > > Can anybody give me a hint, what's going on here? > Any hints are welcome. Thanks in advance... > When the problem shows up again, do a onstat -g ntu | grep unknown These unknown threads are owned by root. In a normal onstat -g ses, you will find two sessions near the top of the list, owned by root. These session numbers will eventually become 'owned' by a user session wishing to connect to OnLine. Every now and then, it appears that somehow the session information is not updated correctly when the user attempts the connection to OnLine. OnLine gets confused and what should become an 'sqlexec' thread instead becomes 'unknown'. This is a known bug with 7.13 that have been fixed in 7.14. I just wish I could remember the bug number. Hope this helps John Carlson Informix DBA WH Smith, Inc.