Re: Redundant databases/real-time backup

On Thu, Nov 30, 2000 at 12:08:20AM -0800, hamptone wrote:
> > [ about processing the postgresql log ]
>
> Thanks for the tips Ragnar...although I wish you would explain more about
> FIFO. The only thing that rings a bell on this is First In First Out from
> the inventory chaper of my accounting textbook.....

I guess you're familiar with pipes?
like:
cat logfile | program

a FIFO is pretty much the same thing, only it has a filename. This mean
a process can write to the FIFO thinking it's writing to a regular file,
and another process can read from the FIFO thinking it's reading from a
regular file.

This makes it possible to process the file in realtime instead of in
batch, if you choose to.

If you use a FIFO, your postgresql process will block if there is
nothing actually reading from the FIFO. This means two things:
1. If the program processing the logfile dies, postgresql die too.
2. The postgresql server can't work faster than your logfile processer.

But the good news is your backupserver will always be up-to-date.

--
Ragnar Kjørstad