Next Major Memcached release / roadmap?

Brad Fitzpatrick brad at danga.com
Sat Jun 16 20:09:24 UTC 2007


On Sun, 17 Jun 2007, Iain Wade wrote:

> With tugela/BDB, when you ask to fetch a key it
> single-threaded/synchronously fetches the data from it's store (fast
> if in cache, slower if disk) into a freshly malloc'd buffer where it
> is handed off to the same event based flushing code as in memcached.

So basically you block.  Gross.

> In my view, the blocking nature of the item access could be directly
> compared to accesing a memory page on a non-mlock'd or over-committed
> memcache instance that would need to be paged in from swap.

Running a memcached instance on a machine without enough memory and
swapping is terribly broken too, just like Tugela.

Unless Tugela can do BDB API calls in other thread, it's not suitable for
mainline inclusion.

I would, however, be interested in a set of patches to make the
storage system pluggable.  An updated (threaded) Tugela could then later
implement that interface.

- Brad



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