1.5.what? also yes, chunk_size_growth_factor. don't set it to 1.02. set it to something so your slab classes are more evenly distributed. the max is 63.
On Thu, 12 Nov 2020, Tony Wu wrote: > Hi Dormando, > > Thanks for the reply, I believe the engine version is 1.5. By multiplier > I assumed you meant “chunk_size_growth_factor”, which is currently set > at 1.02. > > Best, > > Tony Wu > > > On Nov 12, 2020, at 2:26 PM, dormando <dorma...@rydia.net> wrote: > > > > What version are they running now? That stat output looks pretty sparse. > > > > Unfortunately when it comes to elasticache the answer is probably to just > > beg them to upgrade to a newer version. they tend to run really old and > > newer verisons do a lot better at balancing memory. > > > > This is also suspect: > >> STAT 62:chunk_size 712 > >> STAT 62:total_chunks 4416 > >> STAT 62:free_chunks 631 > >> STAT 62:free_chunks_end 0 > >> STAT 63:chunk_size 524288 > > > > anything you store that's larger than 712 bytes will use half a megabyte > > of memory. If you're setting the slab multiplier (-f) to something really > > aggressive, you should stop that :) > > > > On Thu, 12 Nov 2020, Tony Wu wrote: > > > >> We are currently using memcached provided by AWS ElastiCache service in > >> modern mode to store web session keys > >> among other things. We are observing session keys being evicted before TTL > >> even though the cluster seems to have > >> ample free memory, which hints at slab imbalance. I've included a print > >> out of slab stats below in terms of > >> sizing and total / free pages. > >> What would be the best way to smooth out this imbalance? We already > >> enabled slab reassign / auto-move under > >> modern mode. > >> > >> Thanks. > >> > >> STAT 1:chunk_size 96 > >> STAT 1:total_chunks 131064 > >> STAT 1:free_chunks 1664 > >> STAT 1:free_chunks_end 0 > >> STAT 2:chunk_size 104 > >> STAT 2:total_chunks 60492 > >> STAT 2:free_chunks 5327 > >> STAT 2:free_chunks_end 0 > >> STAT 3:chunk_size 112 > >> STAT 3:total_chunks 46810 > >> STAT 3:free_chunks 79 > >> STAT 3:free_chunks_end 0 > >> STAT 4:chunk_size 120 > >> STAT 4:total_chunks 26214 > >> STAT 4:free_chunks 48 > >> STAT 4:free_chunks_end 0 > >> STAT 5:chunk_size 128 > >> STAT 5:total_chunks 32768 > >> STAT 5:free_chunks 6193 > >> STAT 5:free_chunks_end 0 > >> STAT 6:chunk_size 136 > >> STAT 6:total_chunks 23130 > >> STAT 6:free_chunks 4594 > >> STAT 6:free_chunks_end 0 > >> STAT 7:chunk_size 144 > >> STAT 7:total_chunks 7281 > >> STAT 7:free_chunks 5894 > >> STAT 7:free_chunks_end 0 > >> STAT 8:chunk_size 152 > >> STAT 8:total_chunks 13796 > >> STAT 8:free_chunks 12008 > >> STAT 8:free_chunks_end 0 > >> STAT 9:chunk_size 160 > >> STAT 9:total_chunks 6553 > >> STAT 9:free_chunks 6316 > >> STAT 9:free_chunks_end 0 > >> STAT 10:chunk_size 168 > >> STAT 10:total_chunks 6241 > >> STAT 10:free_chunks 6186 > >> STAT 10:free_chunks_end 0 > >> STAT 11:chunk_size 176 > >> STAT 11:total_chunks 5957 > >> STAT 11:free_chunks 5946 > >> STAT 11:free_chunks_end 0 > >> STAT 12:chunk_size 184 > >> STAT 12:total_chunks 5698 > >> STAT 12:free_chunks 5664 > >> STAT 12:free_chunks_end 0 > >> STAT 13:chunk_size 192 > >> STAT 13:total_chunks 5461 > >> STAT 13:free_chunks 5380 > >> STAT 13:free_chunks_end 0 > >> STAT 14:chunk_size 200 > >> STAT 14:total_chunks 5242 > >> STAT 14:free_chunks 5135 > >> STAT 14:free_chunks_end 0 > >> STAT 15:chunk_size 208 > >> STAT 15:total_chunks 5041 > >> STAT 15:free_chunks 4892 > >> STAT 15:free_chunks_end 0 > >> STAT 16:chunk_size 216 > >> STAT 16:total_chunks 4854 > >> STAT 16:free_chunks 4770 > >> STAT 16:free_chunks_end 0 > >> STAT 17:chunk_size 224 > >> STAT 17:total_chunks 4681 > >> STAT 17:free_chunks 4655 > >> STAT 17:free_chunks_end 0 > >> STAT 18:chunk_size 232 > >> STAT 18:total_chunks 4519 > >> STAT 18:free_chunks 4489 > >> STAT 18:free_chunks_end 0 > >> STAT 19:chunk_size 240 > >> STAT 19:total_chunks 4369 > >> STAT 19:free_chunks 4345 > >> STAT 19:free_chunks_end 0 > >> STAT 20:chunk_size 248 > >> STAT 20:total_chunks 4228 > >> STAT 20:free_chunks 4217 > >> STAT 20:free_chunks_end 0 > >> STAT 21:chunk_size 256 > >> STAT 21:total_chunks 4096 > >> STAT 21:free_chunks 4091 > >> STAT 21:free_chunks_end 0 > >> STAT 22:chunk_size 264 > >> STAT 22:total_chunks 3971 > >> STAT 22:free_chunks 3966 > >> STAT 22:free_chunks_end 0 > >> STAT 23:chunk_size 272 > >> STAT 23:total_chunks 3855 > >> STAT 23:free_chunks 3851 > >> STAT 23:free_chunks_end 0 > >> STAT 24:chunk_size 280 > >> STAT 24:total_chunks 3744 > >> STAT 24:free_chunks 3738 > >> STAT 24:free_chunks_end 0 > >> STAT 25:chunk_size 288 > >> STAT 25:total_chunks 3640 > >> STAT 25:free_chunks 3638 > >> STAT 25:free_chunks_end 0 > >> STAT 26:chunk_size 296 > >> STAT 26:total_chunks 3542 > >> STAT 26:free_chunks 3533 > >> STAT 26:free_chunks_end 0 > >> STAT 27:chunk_size 304 > >> STAT 27:total_chunks 3449 > >> STAT 27:free_chunks 3448 > >> STAT 27:free_chunks_end 0 > >> STAT 28:chunk_size 312 > >> STAT 28:total_chunks 3360 > >> STAT 28:free_chunks 3350 > >> STAT 28:free_chunks_end 0 > >> STAT 29:chunk_size 320 > >> STAT 29:total_chunks 3276 > >> STAT 29:free_chunks 3273 > >> STAT 29:free_chunks_end 0 > >> STAT 30:chunk_size 328 > >> STAT 30:total_chunks 3196 > >> STAT 30:free_chunks 3174 > >> STAT 30:free_chunks_end 0 > >> STAT 31:chunk_size 336 > >> STAT 31:total_chunks 3120 > >> STAT 31:free_chunks 3118 > >> STAT 31:free_chunks_end 0 > >> STAT 32:chunk_size 344 > >> STAT 32:total_chunks 3048 > >> STAT 32:free_chunks 3043 > >> STAT 32:free_chunks_end 0 > >> STAT 33:chunk_size 352 > >> STAT 33:total_chunks 2978 > >> STAT 33:free_chunks 2954 > >> STAT 33:free_chunks_end 0 > >> STAT 34:chunk_size 360 > >> STAT 34:total_chunks 2912 > >> STAT 34:free_chunks 2903 > >> STAT 34:free_chunks_end 0 > >> STAT 35:chunk_size 368 > >> STAT 35:total_chunks 2849 > >> STAT 35:free_chunks 2828 > >> STAT 35:free_chunks_end 0 > >> STAT 36:chunk_size 376 > >> STAT 36:total_chunks 2788 > >> STAT 36:free_chunks 2766 > >> STAT 36:free_chunks_end 0 > >> STAT 37:chunk_size 384 > >> STAT 37:total_chunks 2730 > >> STAT 37:free_chunks 2684 > >> STAT 37:free_chunks_end 0 > >> STAT 38:chunk_size 392 > >> STAT 38:total_chunks 2674 > >> STAT 38:free_chunks 2621 > >> STAT 38:free_chunks_end 0 > >> STAT 39:chunk_size 400 > >> STAT 39:total_chunks 2621 > >> STAT 39:free_chunks 2564 > >> STAT 39:free_chunks_end 0 > >> STAT 40:chunk_size 408 > >> STAT 40:total_chunks 2570 > >> STAT 40:free_chunks 2527 > >> STAT 40:free_chunks_end 0 > >> STAT 41:chunk_size 416 > >> STAT 41:total_chunks 2520 > >> STAT 41:free_chunks 2216 > >> STAT 41:free_chunks_end 0 > >> STAT 42:chunk_size 424 > >> STAT 42:total_chunks 2473 > >> STAT 42:free_chunks 2256 > >> STAT 42:free_chunks_end 0 > >> STAT 43:chunk_size 432 > >> STAT 43:total_chunks 2427 > >> STAT 43:free_chunks 2299 > >> STAT 43:free_chunks_end 0 > >> STAT 44:chunk_size 440 > >> STAT 44:total_chunks 2383 > >> STAT 44:free_chunks 1898 > >> STAT 44:free_chunks_end 0 > >> STAT 45:chunk_size 448 > >> STAT 45:total_chunks 2340 > >> STAT 45:free_chunks 1962 > >> STAT 45:free_chunks_end 0 > >> STAT 46:chunk_size 456 > >> STAT 46:total_chunks 2299 > >> STAT 46:free_chunks 2192 > >> STAT 46:free_chunks_end 0 > >> STAT 47:chunk_size 472 > >> STAT 47:total_chunks 2221 > >> STAT 47:free_chunks 2061 > >> STAT 47:free_chunks_end 0 > >> STAT 48:chunk_size 488 > >> STAT 48:total_chunks 2148 > >> STAT 48:free_chunks 2047 > >> STAT 48:free_chunks_end 0 > >> STAT 49:chunk_size 504 > >> STAT 49:total_chunks 2080 > >> STAT 49:free_chunks 1955 > >> STAT 49:free_chunks_end 0 > >> STAT 50:chunk_size 520 > >> STAT 50:total_chunks 2016 > >> STAT 50:free_chunks 1788 > >> STAT 50:free_chunks_end 0 > >> STAT 51:chunk_size 536 > >> STAT 51:total_chunks 1956 > >> STAT 51:free_chunks 1870 > >> STAT 51:free_chunks_end 0 > >> STAT 52:chunk_size 552 > >> STAT 52:total_chunks 1899 > >> STAT 52:free_chunks 1829 > >> STAT 52:free_chunks_end 0 > >> STAT 53:chunk_size 568 > >> STAT 53:total_chunks 1846 > >> STAT 53:free_chunks 1762 > >> STAT 53:free_chunks_end 0 > >> STAT 54:chunk_size 584 > >> STAT 54:total_chunks 1795 > >> STAT 54:free_chunks 1613 > >> STAT 54:free_chunks_end 0 > >> STAT 55:chunk_size 600 > >> STAT 55:total_chunks 1747 > >> STAT 55:free_chunks 1446 > >> STAT 55:free_chunks_end 0 > >> STAT 56:chunk_size 616 > >> STAT 56:total_chunks 1702 > >> STAT 56:free_chunks 1358 > >> STAT 56:free_chunks_end 0 > >> STAT 57:chunk_size 632 > >> STAT 57:total_chunks 1659 > >> STAT 57:free_chunks 1497 > >> STAT 57:free_chunks_end 0 > >> STAT 58:chunk_size 648 > >> STAT 58:total_chunks 1618 > >> STAT 58:free_chunks 1398 > >> STAT 58:free_chunks_end 0 > >> STAT 59:chunk_size 664 > >> STAT 59:total_chunks 3158 > >> STAT 59:free_chunks 1784 > >> STAT 59:free_chunks_end 0 > >> STAT 60:chunk_size 680 > >> STAT 60:total_chunks 1542 > >> STAT 60:free_chunks 1301 > >> STAT 60:free_chunks_end 0 > >> STAT 61:chunk_size 696 > >> STAT 61:total_chunks 3012 > >> STAT 61:free_chunks 302 > >> STAT 61:free_chunks_end 0 > >> STAT 62:chunk_size 712 > >> STAT 62:total_chunks 4416 > >> STAT 62:free_chunks 631 > >> STAT 62:free_chunks_end 0 > >> STAT 63:chunk_size 524288 > >> STAT 63:total_chunks 26108 > >> STAT 63:free_chunks 0 > >> STAT 63:free_chunks_end 0 > >> > >> -- > >> > >> --- > >> 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 > >> memcached+unsubscr...@googlegroups.com. > >> To view this discussion on the web visit > >> 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