RFC: New log_destination 'fifo'

On Wed, Nov 7, 2012 at 9:55 PM, Joshua D. Drake <jd@commandprompt.com> wrote:

Hello,

So it is possible to do this in other ways but I thought it might be
interesting to allow people to define fifo or pipe as a log_desination. This
would allow a person to tail the fifo to receive the outputs of the log as
it happens but would not take up precious IO or space from the disk. I
personally have found this valuable when diagnosing immediate unexpected
problems. It would also work on Windows.

This is something that has been discussed before a couple of times.
I've even gotten started on an implementation at one point, though in
fairness I didn't get much past "git branch".

I definitely think it would be a useful thing.

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On Wed, Nov 07, 2012 at 12:55:03PM -0800, Joshua D. Drake wrote:

Hello,

So it is possible to do this in other ways but I thought it might be
interesting to allow people to define fifo or pipe as a
log_desination. This would allow a person to tail the fifo to
receive the outputs of the log as it happens but would not take up
precious IO or space from the disk. I personally have found this
valuable when diagnosing immediate unexpected problems. It would
also work on Windows.

I've often wanted this feature, and it's a pleasant surprise (at least
to me) that Windows has the underlying capability.

Cheers,
David.
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On Wed, 2012-11-07 at 12:55 -0800, Joshua D. Drake wrote:

So it is possible to do this in other ways but I thought it might be
interesting to allow people to define fifo or pipe as a
log_desination.

You could do this with a logging hook as a plugin, so you don't have to
make the effort to get this integrated into the main line (yet).

One problem to consider with fifos and pipes is what happens when the
receiving side is down or not keeping up. You don't want the logging to
become a potential source of failures.

On 11/07/2012 02:46 PM, David Fetter wrote:

On Wed, Nov 07, 2012 at 12:55:03PM -0800, Joshua D. Drake wrote:

Hello,

So it is possible to do this in other ways but I thought it might be
interesting to allow people to define fifo or pipe as a
log_desination. This would allow a person to tail the fifo to
receive the outputs of the log as it happens but would not take up
precious IO or space from the disk. I personally have found this
valuable when diagnosing immediate unexpected problems. It would
also work on Windows.

I've often wanted this feature, and it's a pleasant surprise (at least
to me) that Windows has the underlying capability.

Alright, we will see what we can do to put this together.

JD

Cheers,
David.

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On 11/07/2012 10:22 PM, Peter Eisentraut wrote:

On Wed, 2012-11-07 at 12:55 -0800, Joshua D. Drake wrote:

So it is possible to do this in other ways but I thought it might be
interesting to allow people to define fifo or pipe as a
log_desination.

You could do this with a logging hook as a plugin, so you don't have to
make the effort to get this integrated into the main line (yet).

One problem to consider with fifos and pipes is what happens when the
receiving side is down or not keeping up. You don't want the logging to
become a potential source of failures.

Good point.

JD

--
Command Prompt, Inc. - http://www.commandprompt.com/
PostgreSQL Support, Training, Professional Services and Development
High Availability, Oracle Conversion, Postgres-XC
@cmdpromptinc - 509-416-6579