Re: out of virtual shared memory

>In article <530p0d$o12@cssun.mathcs.emory.edu>, >Ralph.Halter@pac.panmail.com writes >>Hi all! >> >>We're running OnLine 7.10.UD1 on AIX 4.1.2 on an RS6000-J30 with 256MB memory >>and 480MB paging space. There are 15 uniface developers/users filling about >>50MB of logical logs per day with a peak of 30 concurrent users. >> >>My question: Why can't OnLine free some memory instead of just adding >>more and more virtual segments? [sniped] >>When I saw this message today I checked with onstat -g seg and saw that >>we have the following segments >>id key addr size ovhd class blkused blkfree >>98305 1381451777 30000000 70541312 1880 R 8607 4 > Resident segment size is segment 70MB, this is for fixed size tables > and mainly dependent on the number of BUFFERS configured. > >>98306 1381451778 40000000 30720000 1064 V 2529 1221 > > One vritual segment. >>77827 1381451779 50000000 557056 604 M 65 3 > > One message segment used to send messages to/from client, size not > configurable. ... Not completely true... Message segment size is determined by onconfig NETTYPE parameter. When you configure your Online instance for accepting connections via Shared Memory (ipcshm), the amount of memory allocated for this purpose is about 10-12 Kb multiplied by the number of poll threads multiplied by the number of threads. For example, consider following (I have this configuration on my Sequent machine): NETTYPE ipcshm,3,600,NET Three segments (equal to poll threads!) of 6,373,376 bytes of shared memory are allocated. The surprising fact to me was that (apparently... My thoughts...) each poll thread allocate its own message buffer (I couldn't find in the manuals...). I'd like to hear comments on this ... > [sniped] > > Limiting the amount of shared memory using SHMTOTAL is rarely a good >idea. THings will start to fail once SHMTOTAL is reached. Why have >things fail when the swap space is available to let them succeed. OK >they will run slowly but surely that is better than them failing. Why things fail when SHMTOTAL is reached? ... Limiting Informix shared memory may be a good idea when you share memory between Informix and an application. Informix tech support told me SHMTOTAL must be defined in 8 Kb increments... Anyone else can confirm that? HTH. Roberto Trevisol Banco Bamerindus