[syslog-ng]performance test questions

Achim Gsell syslog-ng@lists.balabit.hu
Wed, 26 Feb 2003 00:04:28 +0100

On Tuesday 25 February 2003 23:36, Balazs Scheidler wrote:
> On Tue, Feb 25, 2003 at 11:24:38PM +0100, Achim Gsell wrote:
> > On Monday 24 February 2003 13:03, Roberto Nibali wrote:
> > You can also test & try the attached "macro.c" which uses a hash function
> > generated with gperf. In my tests the binary search made the macro
> > expansion (4 macros in the template) about 2.5 times faster and the hash
> > function (and some other minor changes) about 3 times.
> The real solution for further improvements would be to preprocess the
> template description and cache the results. A template is  a sequence of:
> constant_string macro constant_string macro ...
> e.g. a single pass would be enough to convert the string to an internal
> format representing the sequence above, then a much faster algorithm could
> be used to format the results as no lookups would be needed. (macros could
> be stored as looked up macro ids)

Yes, of course ...

> I plan something like this in syslog-ng 2, as the basic infrastructure is
> there, it would however be a bit more difficult for 1.5.x.

I had the same idea and this was the reason I didn't implemented it yet! But 
may be we should use one of the faster algorithms as a fist shot.