Hi, The engine version we have running right now is 1.5.16. I just saw an announcement that 1.6.6 is available, so we’ll probably plan to migrate.
Adjusting growth factor makes sense. I did a quick google and don’t see any definitive formula to calculate an appropriate number. I’ll probably start with 2 or 3 and adjust it from there. Thanks, Tony Wu > On Nov 12, 2020, at 3:50 PM, dormando <dorma...@rydia.net> wrote: > > 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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