> Thanks. Any reason to move item_lock(s) back to cache_lock ?
>
> We've done preliminary performance runs using memaslap. Memory limits
> are altered from 32MB up to 2GB. The total transaction-per-second
> numbers drop as the memory limits are increased. All other parameters
> take the defaults based on memcached 1.4.11. The thing concerns (and
> puzzles) me most is the get hit counts that are flat after memory
> limit is set to 256 MB. Get and put ratio is 9:1 (using default). Data
> size is 1K, key size is 100 bytes.
>
> I suspect the flat-ness is caused by slabs_lock. Any one saw a similar
> "flat-ness" before (and knows the bottleneck) ?  Enclosed a chart that
> shows this issue.

I was never able to get good numbers out of memslap, and memaslap is even
buggier and worse.

mc-crusher should work much better for testing:
https://github.com/dormando/mc-crusher

it doesn't do short run tests, it does steady state testing while you
measure the rate via memcached's stats.

Reply via email to