I tried to do some benchmarking on postgres master head commit 72a98a639574d2e25ed94652848555900c81a799 Author: Andres Freund <and...@anarazel.de> Date: Tue Apr 26 20:32:51 2016 -0700
CASE : Read-Write Tests when data exceeds shared buffers. Non Default settings and test ./postgres -c shared_buffers=8GB -N 200 -c min_wal_size=15GB -c max_wal_size=20GB -c checkpoint_timeout=900 -c maintenance_work_mem=1GB -c checkpoint_completion_target=0.9 & ./pgbench -i -s 1000 postgres ./pgbench -c $threads -j $threads -T 1800 -M prepared postgres Machine : "cthulhu" 8 node numa machine with 128 hyper threads. >numactl --hardware available: 8 nodes (0-7) node 0 cpus: 0 65 66 67 68 69 70 71 96 97 98 99 100 101 102 103 node 0 size: 65498 MB node 0 free: 37885 MB node 1 cpus: 72 73 74 75 76 77 78 79 104 105 106 107 108 109 110 111 node 1 size: 65536 MB node 1 free: 31215 MB node 2 cpus: 80 81 82 83 84 85 86 87 112 113 114 115 116 117 118 119 node 2 size: 65536 MB node 2 free: 15331 MB node 3 cpus: 88 89 90 91 92 93 94 95 120 121 122 123 124 125 126 127 node 3 size: 65536 MB node 3 free: 36774 MB node 4 cpus: 1 2 3 4 5 6 7 8 33 34 35 36 37 38 39 40 node 4 size: 65536 MB node 4 free: 62 MB node 5 cpus: 9 10 11 12 13 14 15 16 41 42 43 44 45 46 47 48 node 5 size: 65536 MB node 5 free: 9653 MB node 6 cpus: 17 18 19 20 21 22 23 24 49 50 51 52 53 54 55 56 node 6 size: 65536 MB node 6 free: 50209 MB node 7 cpus: 25 26 27 28 29 30 31 32 57 58 59 60 61 62 63 64 node 7 size: 65536 MB node 7 free: 43966 MB node distances: node 0 1 2 3 4 5 6 7 0: 10 21 21 21 21 21 21 21 1: 21 10 21 21 21 21 21 21 2: 21 21 10 21 21 21 21 21 3: 21 21 21 10 21 21 21 21 4: 21 21 21 21 10 21 21 21 5: 21 21 21 21 21 10 21 21 6: 21 21 21 21 21 21 10 21 7: 21 21 21 21 21 21 21 10 I see some regression when compared to 9.5 *Sessions* *PostgreSQL-9.5 scale 1000* *PostgreSQL-9.6 scale 1000* %diff *1* 747.367249 892.149891 19.3723557185 *8* 5281.282799 4941.905008 -6.4260484416 *16* 9000.915419 8695.396233 -3.3943123758 *24* 11852.839627 10843.328776 -8.5170379653 *32* 14323.048334 11977.505153 -16.3760054864 *40* 16098.926583 12195.447024 -24.2468312336 *48* 16959.646965 12639.951087 -25.4704351271 *56* 17157.737762 12543.212929 -26.894715941 *64* 17201.914922 12628.002422 -26.5895542487 *72* 16956.994835 11280.870599 -33.4736448954 *80* 16775.954896 11348.830603 -32.3506132834 *88* 16609.137558 10823.465121 -34.834273705 *96* 16510.099404 11091.757753 -32.8183466278 *104* 16275.724927 10665.743275 -34.4683980416 *112* 16141.815128 10977.84664 -31.9912503461 *120* 15904.086614 10716.17755 -32.6199749153 *128* 15738.391503 10962.333439 -30.3465450271 When I run git bisect on master (And this is for 128 clients). 2 commitIds which affected the performance 1. # first bad commit: [ac1d7945f866b1928c2554c0f80fd52d7f977772] Make idle backends exit if the postmaster dies. this made performance to drop from 15947.21546 (15K +) to 13409.758510 (arround 13K+). 2. # first bad commit: [428b1d6b29ca599c5700d4bc4f4ce4c5880369bf] Allow to trigger kernel writeback after a configurable number of writes. this made performance to drop further to 10962.333439 (10K +) I think It did not recover afterwards. -- Thanks and Regards Mithun C Y EnterpriseDB: http://www.enterprisedb.com
