Hello, In memcached, pages are allocated progressively when needed and allocated to the slab that need space for new items. Once a page is allocated to a slab, it cannot be deallocated nor moved to another slab, even if it gets empty.
Slab calcification is the fact that with time, all pages get allocated to some slabs and if the repartition of items size changes, some slabs will miss space whereas others are full of empty pages. Regards, Colin 2013/3/14 Chang Chen <[email protected]> > Hi All > > I am interested in how slab calcification issue is introduced. I checked > revision history that slab allocation is added almost 10 years ago! but > twitter said > > The v1.4.4 implementation of Memcached, which Twemcache is based on, >> suffers from a problem we call *slab calcification*. > > > Is slab calcification caused by certain new feature, or an intrinsic issue > from its born? > > Thanks > Chang > > -- > > --- > You received this message because you are subscribed to the Google Groups > "memcached" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- --- You received this message because you are subscribed to the Google Groups "memcached" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
