我设置了一个专门用于MySQL的新的1GB VPS服务器实例。一切似乎都很好。但是，我注意到mysqld的内存使用量迅速增长，峰值大约在700MB（正如预期的那样），但随后它会在1-2天内缓慢“爬行”。然后当它达到大约770MB时，该过程被OOM Killer杀死并在几秒钟内重新启动。这不是一个大规模的停机时间，但我希望它是稳定的。
我使用的是MySQL 5.7.21版。以下是我在my.cnf文件中从默认值更改的变量，其他所有变量都设置为默认值。最大的变化是将innodb_buffer_pool_size的内存增加到512M：
!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mysql.conf.d/
[mysqld]
sql_mode = "NO_ENGINE_SUBSTITUTION"
innodb_buffer_pool_size = 384M
innodb_log_buffer_size = 2097152
innodb_log_file_size = 20971520
innodb_strict_mode = OFF
join_buffer_size = 1048576
key_buffer_size = 88080384
max_connect_errors = 10000
max_connections = 151
myisam_recover_options = "BACKUP,FORCE"
performance_schema = 0
read_buffer_size = 1048576
slow_query_log = ON
sort_buffer_size = 1048576
sync_binlog = 0
thread_stack = 262144
wait_timeout = 14400
我对MySQL管理有点愚蠢，所以我希望有更多经验的人可以提供一些建议，让我的MySQL实例在我的1GB实例上更加稳定，OOM杀手策略和使数据库更快/更高效在同一时间。
编辑：我添加了一些额外的文件以获取更多信息：
显示全球状态：https://pastebin.com/SSVEJrQc
显示全球变量：https://pastebin.com/gV5yGdFR
SHOW ENGINE INNODB状态：https://pastebin.com/suHwbpiP
/var/log/mysql/error.log: https://pastebin.com/cRFGrNTp（过去几天合并）
my.cnf文件显示在顶部。我对它进行了一些更改以减少一些内存使用，例如将innodb_buffer_pool_size降低到384M而不是512M。根据“top -c”，内存使用率迅速上升至550MB左右，并缓慢上升至约740M，尚未崩溃。
此外，服务器实例有1GB的RAM，所以我不确定为什么MySQL必须在770M左右崩溃。它只是Ubuntu 16.04和MySQL的全新安装，没有别的，没有apache或php。
编辑：我已经包含了更多数据，我在Dreamhost DreamCompute云服务器上运行实例：
“热门”结果：https://pastebin.com/RNBYMf0b
“df -h”结果：
Filesystem Size Used Avail Use% Mounted on
udev 488M 0 488M 0% /dev
tmpfs 100M 11M 89M 11% /run
/dev/vda1 78G 22G 56G 29% /
tmpfs 497M 0 497M 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 497M 0 497M 0% /sys/fs/cgroup
tmpfs 100M 0 100M 0% /run/user/1000
“iostat -x”：https://pastebin.com/xUNu7fEi
“mysqltuner”：https://pastebin.com/pVC3kN1C
我看到很多“tmpfs”目录（使用RAM）？这个清单上应该或不应该有什么东西吗？另外，我刚刚用Wilson Hauck提供的值更新了my.cnf，并将重新启动mysqld。
编辑：关于“ulimit”，在阅读了更多关于它之后，我编辑了/etc/security/limits.conf并添加了以下内容：“* - nofile 40000”。现在，当我使用“sudo sh -c”ulimit -n“时，它显示的是40000而不是1024。
“iostat -x”和“mysqltuner”报告是在我重新启动MySQL之后立即创建的，因为由于“内存不足”而无法安装。感谢Wilson提供的mysqltuner建议，看起来像是一个很棒的程序。
更新：2/25/2018： 设置了所有推荐的设置后，大约10小时前我的mysql再次崩溃了。以下是syslog中的详细信息：
Feb 25 09:41:52 database kernel: [739566.195215] snapd invoked oom-killer: gfp_mask=0x24201ca, order=0, oom_score_adj=-900
Feb 25 09:41:52 database kernel: [739566.195276] snapd cpuset=/ mems_allowed=0
Feb 25 09:41:52 database kernel: [739566.195310] CPU: 0 PID: 1228 Comm: snapd Not tainted 4.4.0-112-generic #135-Ubuntu
Feb 25 09:41:52 database kernel: [739566.195311] Hardware name: OpenStack Foundation OpenStack Nova, BIOS Bochs 01/01/2011
Feb 25 09:41:52 database kernel: [739566.195313] 0000000000000286 245c0a16fc0af5b0 ffff8800000839d8 ffffffff813fc233
Feb 25 09:41:52 database kernel: [739566.195317] ffff880000083b90 ffff88003ae39c00 ffff880000083a48 ffffffff8120dafe
Feb 25 09:41:52 database kernel: [739566.195319] ffffffff81cd8367 0000000000000000 ffffffff81e6b1a0 0000000000000206
Feb 25 09:41:52 database kernel: [739566.195321] Call Trace:
Feb 25 09:41:52 database kernel: [739566.195361] [<ffffffff813fc233>] dump_stack+0x63/0x90
Feb 25 09:41:52 database kernel: [739566.195375] [<ffffffff8120dafe>] dump_header+0x5a/0x1c5
Feb 25 09:41:52 database kernel: [739566.195383] [<ffffffff811946a2>] oom_kill_process+0x202/0x3c0
Feb 25 09:41:52 database kernel: [739566.195385] [<ffffffff81194ac9>] out_of_memory+0x219/0x460
Feb 25 09:41:52 database kernel: [739566.195394] [<ffffffff8119aad5>] __alloc_pages_slowpath.constprop.88+0x965/0xb00
Feb 25 09:41:52 database kernel: [739566.195396] [<ffffffff8119aef6>] __alloc_pages_nodemask+0x286/0x2a0
Feb 25 09:41:52 database kernel: [739566.195404] [<ffffffff811e483c>] alloc_pages_current+0x8c/0x110
Feb 25 09:41:52 database kernel: [739566.195406] [<ffffffff81190c6b>] __page_cache_alloc+0xab/0xc0
Feb 25 09:41:52 database kernel: [739566.195407] [<ffffffff8119317a>] filemap_fault+0x14a/0x3f0
Feb 25 09:41:52 database kernel: [739566.195418] [<ffffffff812a5d56>] ext4_filemap_fault+0x36/0x50
Feb 25 09:41:52 database kernel: [739566.195419] [<ffffffff811bfe70>] __do_fault+0x50/0xe0
Feb 25 09:41:52 database kernel: [739566.195421] [<ffffffff811c39c2>] handle_mm_fault+0xfa2/0x1820
Feb 25 09:41:52 database kernel: [739566.195433] [<ffffffff810bbc6c>] ? set_next_entity+0x9c/0xb0
Feb 25 09:41:52 database kernel: [739566.195443] [<ffffffff8106b687>] __do_page_fault+0x197/0x400
Feb 25 09:41:52 database kernel: [739566.195445] [<ffffffff8106b957>] trace_do_page_fault+0x37/0xe0
Feb 25 09:41:52 database kernel: [739566.195450] [<ffffffff81063f29>] do_async_page_fault+0x19/0x70
Feb 25 09:41:52 database kernel: [739566.195464] [<ffffffff81849af8>] async_page_fault+0x28/0x30
Feb 25 09:41:52 database kernel: [739566.195465] Mem-Info:
Feb 25 09:41:52 database kernel: [739566.195470] active_anon:220242 inactive_anon:1399 isolated_anon:0
Feb 25 09:41:52 database kernel: [739566.195470] active_file:799 inactive_file:1712 isolated_file:0
Feb 25 09:41:52 database kernel: [739566.195470] unevictable:913 dirty:1 writeback:0 unstable:0
Feb 25 09:41:52 database kernel: [739566.195470] slab_reclaimable:5664 slab_unreclaimable:3906
Feb 25 09:41:52 database kernel: [739566.195470] mapped:1931 shmem:2691 pagetables:1544 bounce:0
Feb 25 09:41:52 database kernel: [739566.195470] free:12712 free_pcp:113 free_cma:0
Feb 25 09:41:52 database kernel: [739566.195473] Node 0 DMA free:4548kB min:716kB low:892kB high:1072kB active_anon:5548kB inactive_anon:12kB active_file:1068kB inactive_file:1968kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15992kB managed:15908kB mlocked:0kB dirty:4kB writeback:0kB mapped:808kB shmem:364kB slab_reclaimable:220kB slab_unreclaimable:500kB kernel_stack:368kB pagetables:936kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:19320 all_unreclaimable? yes
Feb 25 09:41:52 database kernel: [739566.195491] lowmem_reserve[]: 0 958 958 958 958
Feb 25 09:41:52 database kernel: [739566.195495] Node 0 DMA32 free:46300kB min:44336kB low:55420kB high:66504kB active_anon:875420kB inactive_anon:5584kB active_file:2128kB inactive_file:4880kB unevictable:3652kB isolated(anon):0kB isolated(file):0kB present:1032184kB managed:1000192kB mlocked:3652kB dirty:0kB writeback:0kB mapped:6916kB shmem:10400kB slab_reclaimable:22436kB slab_unreclaimable:15124kB kernel_stack:3376kB pagetables:5240kB unstable:0kB bounce:0kB free_pcp:452kB local_pcp:452kB free_cma:0kB writeback_tmp:0kB pages_scanned:42084 all_unreclaimable? yes
Feb 25 09:41:52 database kernel: [739566.195502] lowmem_reserve[]: 0 0 0 0 0
Feb 25 09:41:52 database kernel: [739566.195504] Node 0 DMA: 1*4kB (U) 6*8kB (UME) 81*16kB (UME) 32*32kB (UM) 8*64kB (ME) 7*128kB (ME) 3*256kB (UM) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 4548kB
Feb 25 09:41:52 database kernel: [739566.195514] Node 0 DMA32: 107*4kB (MEH) 240*8kB (ME) 249*16kB (UMEH) 141*32kB (UMEH) 108*64kB (UMEH) 59*128kB (UMEH) 20*256kB (UMEH) 13*512kB (UME) 9*1024kB (UMH) 0*2048kB 0*4096kB = 46300kB
Feb 25 09:41:52 database kernel: [739566.195526] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
Feb 25 09:41:52 database kernel: [739566.195560] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
Feb 25 09:41:52 database kernel: [739566.195561] 5817 total pagecache pages
Feb 25 09:41:52 database kernel: [739566.195576] 0 pages in swap cache
Feb 25 09:41:52 database kernel: [739566.195581] Swap cache stats: add 0, delete 0, find 0/0
Feb 25 09:41:52 database kernel: [739566.195582] Free swap = 0kB
Feb 25 09:41:52 database kernel: [739566.195583] Total swap = 0kB
Feb 25 09:41:52 database kernel: [739566.195584] 262044 pages RAM
Feb 25 09:41:52 database kernel: [739566.195585] 0 pages HighMem/MovableOnly
Feb 25 09:41:52 database kernel: [739566.195585] 8019 pages reserved
Feb 25 09:41:52 database kernel: [739566.195586] 0 pages cma reserved
Feb 25 09:41:52 database kernel: [739566.195587] 0 pages hwpoisoned
Feb 25 09:41:52 database kernel: [739566.195588] [ pid ] uid tgid total_vm rss nr_ptes nr_pmds swapents oom_score_adj name
Feb 25 09:41:52 database kernel: [739566.195593] [ 348] 0 348 9237 1199 21 3 0 0 systemd-journal
Feb 25 09:41:52 database kernel: [739566.195595] [ 451] 0 451 25742 46 17 3 0 0 lvmetad
Feb 25 09:41:52 database kernel: [739566.195597] [ 452] 0 452 10744 376 24 3 0 -1000 systemd-udevd
Feb 25 09:41:52 database kernel: [739566.195599] [ 550] 100 550 25081 61 19 3 0 0 systemd-timesyn
Feb 25 09:41:52 database kernel: [739566.195601] [ 940] 0 940 4030 222 11 3 0 0 dhclient
Feb 25 09:41:52 database kernel: [739566.195603] [ 1054] 0 1054 1305 29 8 3 0 0 iscsid
Feb 25 09:41:52 database kernel: [739566.195604] [ 1055] 0 1055 1430 877 8 3 0 -17 iscsid
Feb 25 09:41:52 database kernel: [739566.195606] [ 1063] 0 1063 68647 1056 37 3 0 0 accounts-daemon
Feb 25 09:41:52 database kernel: [739566.195608] [ 1072] 0 1072 6932 491 19 3 0 0 cron
Feb 25 09:41:52 database kernel: [739566.195609] [ 1078] 0 1078 6511 337 18 3 0 0 atd
Feb 25 09:41:52 database kernel: [739566.195611] [ 1091] 0 1091 1099 300 8 3 0 0 acpid
Feb 25 09:41:52 database kernel: [739566.195613] [ 1094] 0 1094 7136 99 19 3 0 0 systemd-logind
Feb 25 09:41:52 database kernel: [739566.195614] [ 1099] 0 1099 16377 273 35 3 0 -1000 sshd
Feb 25 09:41:52 database kernel: [739566.195616] [ 1101] 104 1101 64098 348 27 3 0 0 rsyslogd
Feb 25 09:41:52 database kernel: [739566.195618] [ 1105] 107 1105 10722 380 27 3 0 -900 dbus-daemon
Feb 25 09:41:52 database kernel: [739566.195619] [ 1113] 0 1113 70365 2590 31 6 0 -900 snapd
Feb 25 09:41:52 database kernel: [739566.195621] [ 1114] 0 1114 158952 1017 31 4 0 0 lxcfs
Feb 25 09:41:52 database kernel: [739566.195623] [ 1150] 0 1150 3343 36 11 3 0 0 mdadm
Feb 25 09:41:52 database kernel: [739566.195624] [ 1159] 0 1159 69294 181 38 3 0 0 polkitd
Feb 25 09:41:52 database kernel: [739566.195626] [ 1203] 0 1203 3618 374 12 3 0 0 agetty
Feb 25 09:41:52 database kernel: [739566.195627] [13137] 0 13137 3664 356 11 3 0 0 agetty
Feb 25 09:41:52 database kernel: [739566.195629] [13141] 0 13141 3664 329 12 3 0 0 agetty
Feb 25 09:41:52 database kernel: [739566.195631] [ 4475] 112 4475 345228 190282 441 4 0 0 mysqld
Feb 25 09:41:52 database kernel: [739566.195635] [28991] 0 28991 1126 141 8 3 0 0 apt.systemd.dai
Feb 25 09:41:52 database kernel: [739566.195638] [28998] 0 28998 1126 383 8 3 0 0 apt.systemd.dai
Feb 25 09:41:52 database kernel: [739566.195640] [29036] 0 29036 11324 1282 27 3 0 0 apt-get
Feb 25 09:41:52 database kernel: [739566.195641] [29217] 0 29217 11324 867 23 3 0 0 apt-get
Feb 25 09:41:52 database kernel: [739566.195643] [29220] 0 29220 1126 157 8 3 0 0 sh
Feb 25 09:41:52 database kernel: [739566.195645] [29221] 0 29221 1126 367 9 3 0 0 update-motd-upd
Feb 25 09:41:52 database kernel: [739566.195646] [29235] 0 29235 40967 16609 84 3 0 0 apt-check
Feb 25 09:41:52 database kernel: [739566.195648] [29570] 0 29570 12235 358 28 3 0 0 cron
Feb 25 09:41:52 database kernel: [739566.195649] [29571] 0 29571 1126 144 8 3 0 0 sh
Feb 25 09:41:52 database kernel: [739566.195651] [29572] 0 29572 2809 278 10 3 0 0 bash
Feb 25 09:41:52 database kernel: [739566.195653] [29579] 0 29579 12235 290 28 3 0 0 cron
Feb 25 09:41:52 database kernel: [739566.195654] [29580] 0 29580 1126 163 7 3 0 0 sh
Feb 25 09:41:52 database kernel: [739566.195656] [29581] 0 29581 2809 91 9 3 0 0 bash
Feb 25 09:41:52 database kernel: [739566.195658] [29582] 0 29582 14775 135 30 3 0 0 sshd
Feb 25 09:41:52 database kernel: [739566.195659] [29584] 0 29584 12235 358 28 3 0 0 cron
Feb 25 09:41:52 database kernel: [739566.195661] [29589] 0 29589 14775 134 32 3 0 0 sshd
Feb 25 09:41:52 database kernel: [739566.195662] [29592] 0 29592 12855 431 30 3 0 0 sudo
Feb 25 09:41:52 database kernel: [739566.195664] [29597] 0 29597 1126 70 8 3 0 0 sh
Feb 25 09:41:52 database kernel: [739566.195665] [29598] 0 29598 2809 124 9 3 0 0 bash
Feb 25 09:41:52 database kernel: [739566.195667] [29602] 0 29602 12235 357 28 3 0 0 cron
Feb 25 09:41:52 database kernel: [739566.195668] [29603] 0 29603 1126 92 8 3 0 0 sh
Feb 25 09:41:52 database kernel: [739566.195670] [29604] 0 29604 2809 321 10 3 0 0 bash
Feb 25 09:41:52 database kernel: [739566.195672] [29615] 0 29615 5787 36 13 3 0 0 systemctl
Feb 25 09:41:52 database kernel: [739566.195673] [29620] 0 29620 12235 276 28 3 0 0 cron
Feb 25 09:41:52 database kernel: [739566.195675] [29621] 0 29621 11236 413 26 3 0 0 sudo
Feb 25 09:41:52 database kernel: [739566.195677] [29623] 0 29623 1126 139 8 3 0 0 sh
Feb 25 09:41:52 database kernel: [739566.195678] [29624] 0 29624 2807 234 10 3 0 0 bash
Feb 25 09:41:52 database kernel: [739566.195680] [29628] 0 29628 14775 75 30 3 0 0 sshd
Feb 25 09:41:52 database kernel: [739566.195681] [29629] 0 29629 12235 476 28 3 0 0 cron
Feb 25 09:41:52 database kernel: [739566.195683] [29641] 0 29641 6945 111 18 3 0 0 sudo
Feb 25 09:41:52 database kernel: [739566.195684] [29642] 0 29642 6945 87 18 3 0 0 sudo
Feb 25 09:41:52 database kernel: [739566.195686] [29643] 0 29643 1126 152 8 3 0 0 sh
Feb 25 09:41:52 database kernel: [739566.195687] [29644] 0 29644 345 1 5 3 0 0 bash
Feb 25 09:41:52 database kernel: [739566.195689] Out of memory: Kill process 4475 (mysqld) score 750 or sacrifice child
Feb 25 09:41:52 database kernel: [739566.197374] Killed process 4475 (mysqld) total-vm:1380912kB, anon-rss:761128kB, file-rss:0kB
Feb 25 09:41:53 database kernel: [739566.658202] [UFW BLOCK] IN=ens3 OUT= MAC=fa:16:3e:bc:28:e3:44:f4:77:a7:c0:20:08:00 SRC=***.***.***.*** DST=***.***.***.*** LEN=40 TOS=0x00 PREC=0x00 TTL=61 ID=20807 DF PROTO=TCP SPT=54168 DPT=3306 WINDOW=0 RES=0x00 RST URGP=0
Feb 25 09:41:53 database kernel: [739566.658214] [UFW BLOCK] IN=ens3 OUT= MAC=fa:16:3e:bc:28:e3:44:f4:77:a7:c0:20:08:00 SRC=***.***.***.*** DST=***.***.***.*** LEN=40 TOS=0x00 PREC=0x00 TTL=61 ID=20808 DF PROTO=TCP SPT=49412 DPT=3306 WINDOW=0 RES=0x00 RST URGP=0
Feb 25 09:41:53 database kernel: [739566.658291] [UFW BLOCK] IN=ens3 OUT= MAC=fa:16:3e:bc:28:e3:44:f4:77:a7:c0:20:08:00 SRC=***.***.***.*** DST=***.***.***.*** LEN=40 TOS=0x00 PREC=0x00 TTL=61 ID=20809 DF PROTO=TCP SPT=54293 DPT=3306 WINDOW=0 RES=0x00 RST URGP=0
Feb 25 09:41:53 database kernel: [739566.666146] [UFW BLOCK] IN=ens3 OUT= MAC=fa:16:3e:bc:28:e3:44:f4:77:a7:c0:20:08:00 SRC=***.***.***.*** DST=***.***.***.*** LEN=40 TOS=0x00 PREC=0x00 TTL=61 ID=20810 DF PROTO=TCP SPT=53588 DPT=3306 WINDOW=0 RES=0x00 RST URGP=0
Feb 25 09:41:53 database kernel: [739566.666160] [UFW BLOCK] IN=ens3 OUT= MAC=fa:16:3e:bc:28:e3:44:f4:77:a7:c0:20:08:00 SRC=***.***.***.*** DST=***.***.***.*** LEN=40 TOS=0x00 PREC=0x00 TTL=61 ID=20811 DF PROTO=TCP SPT=53612 DPT=3306 WINDOW=0 RES=0x00 RST URGP=0
Feb 25 09:41:53 database systemd[1]: Started MySQL Community Server.
Feb 25 09:41:53 database CRON[29570]: (CRON) info (No MTA installed, discarding output)
Feb 25 09:41:53 database systemd[1]: mysql.service: Main process exited, code=killed, status=9/KILL
Feb 25 09:41:53 database systemd[1]: mysql.service: Unit entered failed state.
Feb 25 09:41:53 database systemd[1]: mysql.service: Failed with result 'signal'.
Feb 25 09:41:53 database systemd[1]: mysql.service: Service hold-off time over, scheduling restart.
Feb 25 09:41:53 database systemd[1]: Stopped MySQL Community Server.
Feb 25 09:41:53 database systemd[1]: Starting MySQL Community Server...
Feb 25 09:41:53 database kernel: [739567.046536] [UFW BLOCK] IN=ens3 OUT= MAC=fa:16:3e:bc:28:e3:44:f4:77:a7:c0:20:08:00 SRC=***.***.***.*** DST=***.***.***.*** LEN=40 TOS=0x00 PREC=0x00 TTL=42 ID=21475 DF PROTO=TCP SPT=37118 DPT=22 WINDOW=0 RES=0x00 RST URGP=0
Feb 25 09:41:53 database kernel: [739567.066187] [UFW BLOCK] IN=ens3 OUT= MAC=fa:16:3e:bc:28:e3:44:f4:77:a7:c0:20:08:00 SRC=***.***.***.*** DST=***.***.***.*** LEN=40 TOS=0x00 PREC=0x00 TTL=61 ID=20869 DF PROTO=TCP SPT=54293 DPT=3306 WINDOW=0 RES=0x00 RST URGP=0
Feb 25 09:41:53 database kernel: [739567.066313] [UFW BLOCK] IN=ens3 OUT= MAC=fa:16:3e:bc:28:e3:44:f4:77:a7:c0:20:08:00 SRC=***.***.***.*** DST=***.***.***.*** LEN=40 TOS=0x00 PREC=0x00 TTL=61 ID=20870 DF PROTO=TCP SPT=49412 DPT=3306 WINDOW=0 RES=0x00 RST URGP=0
Feb 25 09:41:53 database kernel: [739567.066324] [UFW BLOCK] IN=ens3 OUT= MAC=fa:16:3e:bc:28:e3:44:f4:77:a7:c0:20:08:00 SRC=***.***.***.*** DST=***.***.***.*** LEN=40 TOS=0x00 PREC=0x00 TTL=61 ID=20871 DF PROTO=TCP SPT=54168 DPT=3306 WINDOW=0 RES=0x00 RST URGP=0
Feb 25 09:41:53 database kernel: [739567.082221] [UFW BLOCK] IN=ens3 OUT= MAC=fa:16:3e:bc:28:e3:44:f4:77:a7:c0:20:08:00 SRC=***.***.***.***DST=***.***.***.*** LEN=40 TOS=0x00 PREC=0x00 TTL=61 ID=20873 DF PROTO=TCP SPT=53612 DPT=3306 WINDOW=0 RES=0x00 RST URGP=0
Feb 25 09:41:54 database kernel: [739567.524532] audit: type=1400 audit(1519551714.232:296): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/29710/status" pid=29710 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=112 ouid=112
Feb 25 09:41:54 database kernel: [739567.524603] audit: type=1400 audit(1519551714.232:297): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=29710 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=112 ouid=0
Feb 25 09:41:54 database kernel: [739567.524670] audit: type=1400 audit(1519551714.232:298): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/29710/status" pid=29710 comm="mysqld" requested_mask="r" denied_mask="r" fsuid=112 ouid=112
Feb 25 09:41:56 database systemd[1]: Started MySQL Community Server.
根据MySQLtuner的说法，它说：“最大可能内存使用量：664.8M（已安装RAM的66.99％）”，因此它必须以某种方式超出此值。
答案 0 :(得分：1)
为my.cnf / ini [mysqld]部分考虑的建议，
ulimit -n 40000 # at your Linux command prompt to raise n open files limit
table_open_cache=10000 # from 2000 to support 1M+ opened in 2 days
table_definition_cache=2500 # from default to support 2000+ opened in 2 days
open_files_limit=30000 # from 5000 to support 900,000 + opened in 2 days
max_connections=50 # from 151 to support 17 max_used_connections
read_rnd_buffer_size=128K # from 256k default to reduce RD RPS
innodb_change_buffer_max_size=15 # from 25% of innodb_buffer_pool_size 1% used
innodb_log_buffer_size=12M # from 2M to cover 30 minutes of log
innodb_log_file_size=120M # from ~ 20M to cover a few days
#max_allowed_packet=16M # lead with # for default of 1M m_a_p
如果您需要超过1M，请在SESSION中 SET @ max_allowed_packet = nnnnnnnn;高达1G和1G是LIMIT。
query_cache_size=0 # from 16M - it is already OFF, do not waste RAM on it
query_cache_limit=1K # from 1M to conserve more RAM
query_cache_min_res_unit=512 # from 4096 to store more small results, if ever used
innodb_buffer_pool_instances=8 # from 1 to minimize mutex contention
对你来说没问题
innodb_lru_scan_depth=128 # from 1024 which is causing page_cleaner warnings
innodb_page_cleaners=64 # from 1 to auto follow = innodb_buffer_pool_instances
thread_cache_size=50 # from 8 default to support 17 max_used with room for growth.
从我的角度来看，备份你当前的my.cnf / ini并实现所有。另一天有更多的机会。 我们下周可以使用Stack Overflow的聊天吗？
答案 1 :(得分：0)
那已经是~650M，这让MySQL在其他东西上大约有50M。
如果您调整其中一些设置，可能会保持在700M以下。除非您的MySQL版本确实存在内存泄漏。
尝试将这些数字中的一部分再减少50M。
加成：
刚刚找到这个计算器：http://www.mysqlcalculator.com/。可能会帮助您更准确地解决这个问题。但不能说这个工具有多准确
答案 2 :(得分：0)
回答部分问题：
此外，服务器实例有1GB的RAM，所以我不确定为什么MySQL必须在770M左右崩溃。它只是Ubuntu 16.04和MySQL的全新安装，没有别的，没有apache或php。
服务器没有＆＃34;根本没有其他东西＆＃34;即使你自己没有安装任何其他东西，也总会有背景资料，无论你的VPS图像包括什么。您可以使用top（或者如果可用我的首选工具htop）查看正在运行的内容以及使用内存的内容。
例如，在OOM终止日志中，apt-check的{{1}}大小为rss，这意味着它自己再占用70 GB的RAM（参见{{3} - 数字表示4kB块）。此外，许多系统＆＃34;目录＆＃34;例如16848实际上存储在RAM而不是磁盘上。您可以通过运行/tmp来查看计算机上是否存在这些问题 - 由df -h列出的任何内容都存储在RAM中，如果它有空间，则使用RAM作为好。
将各种各样的东西放在一起，即使没有专门安装任何其他进程，各种系统进程也可以占用大量的RAM开销，这是合理的。