(Illustration by Gaich Muramatsu)
Hi, I'm from a company in germany that produces a controling system for a lot of different processes eg. a powerplant or a central controling of Coce mashines. I thought about running a database (with ODBC and JDBC drivers) on a coda filesystem to get a redundant data holding. I think the problem will be that there will be one or two large files (the database and the logfile) and tese files are written to. So if always the whole file is copied to all servers if the database does a fsync() it will be nearly impossible to insert any data to the database without a timeout. But on the other hand if the database does an fsync() I have to be sure, that all changes to the file are copied to the other servers. Else I do not have the redundant data holding I need to keep the date consistend even if some hardware crashes. I see the only possible solution in adressing and copying the file in blocks of eg 4k. Even if I look at my private mailfolder I see this problem. I acualy delete my old mail about once a month. So there is also the point that closing my mailbox will take several minutes if it has to be copied completely over the net to all servers. Well I don't have problems in giving the servers for our controling system gigabit networking cards, but I don't thing this is the right way to solve this problem. Yours sincerly Wolfram TomallaReceived on 1999-01-21 06:06:37