[dba-Tech] Any ideas

Gustav Brock gustav at cactus.dk
Tue Oct 21 09:47:02 CDT 2003


Hi Martin

You could let the single PC read the line it has written. If it is not
found, write it again. Limit this to, say, ten times.

I would let each PC write a file, then on the minute concatenate these
files into a single file.

/gustav


> Date: 2003-10-21 16:32

> Anyone have any ideas re the following?

> I have a system whereby each PC in the SCCs sends in one short line per
> minute to a central server. Each line is of the form IP address, time,
> date[, user id]. The central server is only a P450 with 256Mb memory but
> I have used a P733 with the same results.

> When a user logs in to a PC, it writes a line to the same file on the
> central server as all the other used PCs. Each PC writes at the same
> second each minute, but the PCs determine their second to write by
> chance, basically. Thus the incoming data for the file is reasonably
> well spread across 60 seconds.

> On the minute, the software on the central server renames the input
> file, thereby causing a new one to be created with the next record sent
> to it. The central file is held on a share to which each PC has to
> authenticate.

> When enough PCs are active, and I have not been able to deduce if there
> is a threshold figure for that number, some or most of a record may be
> lost. That can be seen from the input files.

> During stress tests, when my PC was the only system communicating with
> the server, My PC could send in about 630 lines per minute and none
> would be lost. And this over a period of say an hour. However, when
> multiple PCs send in lines, the data loss may arise with 50 PCs active.
> The difference is the number of active network connections.

> As I don't believe the data is being lost on the network (I have
> monitored this and have not seen losses so far), it is most likely being
> lost through the networking code/file system combination, and probably
> the former.

> I was wondering if anyone had a better method for collecting this
> asynchronous auditing information, one which did not lose data.
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