I second the idea of making the value a little more clear/useful. My only reservation is to not convert it to a lossy calculated value... It's useful to be able to write a monitor to watch the more exact ratios, or graph exact sizes. Which you lose if you calculate down the information too far.
That said ... I don't have any great alternative ideas offhand. -Dormando On Wed, 8 Apr 2009, Eric Lambert wrote: > > Looks fine to me. Although perhaps we could use a better description. The text > 'mem_requested' is a little unclear to me. May be we call it > "bytes_used_in_slab" .... but that's a bit wordy .... > > Also I wonder if we should represent this value a little differently. So the > point of this is to expose wasted space in the slab, right? If we just > represent this as a raw number of bytes, its not immediately clear that there > is an issue ... I have to compare this value against the chunks size and > number of chunks used. Couldnt we instead represent this as a ratio of bytes > used to bytes available (bytes_used/used_chunks * chunk_size) , thereby making > it a bit clearer, at least to me :-), what the significance of this number is. > > For example, in your case, you have one entry that uses 51 bytes of an 80 byte > chunk. If we represent this value as a ratio, the stats would show that this > slab config results in wasting ~38% of the available slab space. > > my $.02 > > Eric > > Trond Norbye wrote: > > > > Issue: http://code.google.com/p/memcached/issues/detail?id=42 > > > > It should be possible to detect the number of bytes actually allocated in a > > given slab class to make it easier to detect if one is using the wrong > > growth factor. > > > > > > Patch: http://github.com/trondn/memcached/tree/issue_42 > > > > The stats slabs output looks like: > > > > set a 1 0 1 > > a > > STORED > > stats slabs > > STAT 1:chunk_size 80 > > STAT 1:chunks_per_page 13107 > > STAT 1:total_pages 1 > > STAT 1:total_chunks 13107 > > STAT 1:used_chunks 1 > > STAT 1:free_chunks 0 > > STAT 1:free_chunks_end 13106 > > STAT 1:mem_requested 51 > > STAT 1:get_hits 0 > > STAT 1:cmd_set 1 > > STAT 1:delete_hits 0 > > STAT 1:incr_hits 0 > > STAT 1:decr_hits 0 > > STAT 1:cas_hits 0 > > STAT 1:cas_badval 0 > > STAT active_slabs 1 > > STAT total_malloced 1048560 > > END > > quit > > > > Cheers, > > > > Trond > > > >
