Caching is often enough (2003)

mnot.net

19 points·Tomte··6 comments

If you’re doing web application development the absolute first stop on performance tuning is caching static content, pre-rendering every view possible, and handling everything else with thoughtful db indexing.

That’s always going to be the biggest performance jumps, but I think a lot of people end up doing a lot of other marginal improvements prior to nailing those basics.

Something I’ve noticed is that web developers generally have no idea about the performance of different operations even to the nearest three orders of magnitude. Errors of six to ten orders of magnitude are common.

Similarly, obtaining useful metrics is absurdly difficult. Artificial load tests for example tend to be too repetitive and hence are too easily cached compared to real user workloads.

I just watched a developer tuning a query over a 100 GB database but he had the query tool open in an IDE on his laptop… which meant he was benchmarking his home internet and the corporate VPN more than the query!

Yes, and everything is super context dependent. The optimizations one would apply to say, a search engine, versus a web mail interface, are quite distinct.

We surely have some spare computation time nowadays to put towards better algorithms than least recently used or least frequently used.

"There are two hard problems in computer science: cache invalidation and naming things".

...and off by one errors.

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