Comment #6 on issue 202 by [email protected]: TOP_KEYS feature fixes
http://code.google.com/p/memcached/issues/detail?id=202
Having sflow support would be nice (probably pretty great, even), but as an
option to folks who want sflow. I think it's orthogonal to this thing.
topkeys has the usability right, but the math wrong.
sflow has the math (closer), but the usability wrong (for this particular
need we have).
I imagined a similar feature a few years ago after talking with a former
NDB guy and looking at varnish, which would somewhat intrinsically allow
sflow and avoid tcpdump... It's stupid to describe it here, but in short
it's that pattern where you write logs into a ringbuffer and allow
listeners to stream the logs (+ a runtime tunable sampling ratio).
So "topkeys" ends up being closer to what varnishlog/varnishhist/varnishtop
are. I love those utilities so much I wanted them for memcached, but not
enough to actually write the feature myself... yet...
So all I can do is grandstand at someone who's already written a feature
that's partway there? Please understand that I do feel pretty stupid
pushing back on this already working thing. However, it smells like a
customer feature and we *know* there are better ways of doing this. Is the
only reason to keep it exactly the way it is because it's already done and
you have customers who rely on it?
Remember it's very very hard to change something like this after the fact.
I'd rather be in varnish's position at the end of the day.
