我遇到一个问题，邮件服务器总是崩溃。经过调查，我发现这是一个系统内存问题。服务器有 8GB 的 Ram，我将其增加到 16GB。现在情况好多了，但仍然消耗太多内存。
以下是我的服务器中的顶级进程：
top
top - 15:36:40 up 7:58, 1 user, load average: 91.59, 92.19, 91.31
Tasks: 455 total, 92 running, 306 sleeping, 0 stopped, 0 zombie
%Cpu(s): 96.4 us, 1.0 sy, 0.0 ni, 0.0 id, 0.0 wa, 0.0 hi, 0.0 si, 2.6 st
KiB Mem : 16424716 total, 2802776 free, 12251708 used, 1370232 buff/cache
KiB Swap: 924356 total, 924356 free, 0 used. 3784484 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
964 clamav 20 0 1645784 1.273g 32748 S 0.0 8.1 4:18.12 clamd
1553 gdm 20 0 4443620 208048 95508 S 0.0 1.3 2:05.02 gnome-shell
3413 amavis 20 0 356716 154252 9072 S 0.0 0.9 0:07.12 /usr/sbin/amavi
3040 amavis 20 0 347712 149016 11156 S 0.0 0.9 0:08.39 /usr/sbin/amavi
5892 root 20 0 370164 136068 25584 S 0.0 0.8 2:13.00 python
4493 root 20 0 370336 135972 25132 S 0.0 0.8 2:13.02 python
8301 root 20 0 368636 134792 25836 S 0.0 0.8 2:00.70 python
7144 root 20 0 368792 134440 25144 S 0.0 0.8 2:07.06 python
9649 root 20 0 368120 134328 25884 S 0.0 0.8 1:56.14 python
10783 root 20 0 367268 133152 25420 S 0.0 0.8 1:53.38 python
13154 root 20 0 367348 132748 25648 S 0.0 0.8 1:36.12 python
11919 root 20 0 366560 132388 25444 S 0.0 0.8 1:43.54 python
14346 root 20 0 367096 131868 25016 S 2.6 0.8 1:31.55 python
19062 root 20 0 366328 131736 25652 S 0.3 0.8 1:19.97 python
16717 root 20 0 365796 131604 25420 S 0.0 0.8 1:24.49 python
17853 root 20 0 365536 131392 25472 S 0.0 0.8 1:21.33 python
15498 root 20 0 365796 131320 25140 S 0.0 0.8 1:29.81 python
20243 root 20 0 365284 131140 25460 S 0.0 0.8 1:19.88 python
279 root 19 -1 242048 130968 126460 S 0.3 0.8 1:15.33 systemd-journal
26318 root 20 0 364768 130960 25788 S 0.0 0.8 1:09.60 python
32401 root 20 0 365308 130912 25832 S 0.0 0.8 0:59.69 python
22580 root 20 0 366072 130868 25036 S 0.3 0.8 1:08.76 python
21384 root 20 0 365020 130852 25444 S 0.0 0.8 1:17.45 python
27530 root 20 0 364512 130736 25824 S 0.0 0.8 1:07.66 python
28671 root 20 0 364508 130684 25772 S 0.0 0.8 1:04.15 python
29843 root 20 0 364512 130672 25756 S 0.0 0.8 0:59.03 python
25090 root 20 0 364768 130492 25320 S 0.0 0.8 1:05.57 python
23942 root 20 0 364768 130296 25132 S 0.0 0.8 1:12.47 python
7924 root 20 0 365060 130240 25404 S 0.3 0.8 0:50.47 python
9111 root 20 0 364788 130236 25668 S 0.0 0.8 0:48.10 python
22928 root 20 0 364536 130160 25836 S 0.0 0.8 0:43.47 python
31206 root 20 0 364256 130100 25460 S 0.3 0.8 0:59.90 python
12915 root 20 0 364796 130000 25420 S 0.0 0.8 0:47.30 python
21741 root 20 0 364536 129984 25656 S 0.0 0.8 0:43.85 python
6738 root 20 0 364004 129976 25852 S 0.0 0.8 0:51.10 python
30436 root 20 0 364284 129956 25876 S 0.0 0.8 0:39.76 python
4116 root 20 0 363588 129940 25824 S 0.0 0.8 0:58.51 python
26669 root 20 0 364280 129936 25856 S 0.0 0.8 0:39.85 python
25399 root 20 0 364280 129884 25808 S 0.0 0.8 0:42.84 python
2866 root 20 0 364000 129864 25744 S 0.0 0.8 0:58.40 python
1283 root 20 0 364256 129836 25460 S 0.0 0.8 0:57.17 python
29214 root 20 0 364276 129736 25656 S 0.0 0.8 0:39.39 python
12123 root 20 0 364024 129712 25844 S 0.0 0.8 0:17.65 python
32542 root 20 0 364032 129708 25840 S 0.0 0.8 0:22.26 python
16486 root 20 0 364536 129640 25316 S 0.0 0.8 0:48.89 python
29915 root 20 0 364024 129516 25656 S 0.3 0.8 0:22.66 python
5311 root 20 0 364000 129508 25388 S 0.0 0.8 0:54.04 python
9457 root 20 0 364020 129484 25620 S 0.0 0.8 0:17.12 python
22049 root 20 0 364024 129480 25604 S 0.0 0.8 0:11.85 python
20229 root 20 0 363488 129400 25776 S 0.0 0.8 0:42.52 python
27892 root 20 0 363228 129324 25840 S 0.0 0.8 0:39.54 python
11732 root 20 0 363744 129308 25428 S 0.0 0.8 0:46.03 python
15344 root 20 0 363748 129284 25400 S 0.0 0.8 0:45.86 python
14216 root 20 0 363740 129184 25320 S 0.0 0.8 0:46.72 python
此外，postgredSql 达到 max_connections 然后由于来自 postfix 的请求过多而关闭。
以下是邮件的日志文件：
Feb 18 14:17:19 mail postfix/smtp[29560]: D3D5E2466DA: to=<[email protected]>, relay=none, delay=0.11, delays=0.1/0.01/0/0, dsn=5.4.6, status=bounced (mail for mail.MyDomain.de loops back to myself)
Feb 18 14:17:19 mail postfix/qmgr[3350]: D3D5E2466DA: removed
Feb 18 14:18:14 mail dovecot: imap-login: Login: user=<[email protected]>, method=PLAIN, rip=80.144.15.182, lip=173.212.211.113, mpid=7829, TLS, session=<OAIlQ/n05+pQkA+2>
Feb 18 14:18:18 mail dovecot: imap-login: Login: user=<[email protected]>, method=PLAIN, rip=80.144.15.182, lip=173.212.211.113, mpid=7849, TLS, session=<bwdWQ/n06OpQkA+2>
Feb 18 14:18:20 mail dovecot: imap-login: Login: user=<[email protected]>, method=PLAIN, rip=80.144.15.182, lip=173.212.211.113, mpid=7870, TLS, session=<3kR5Q/n06+pQkA+2>
Feb 18 14:18:20 mail postfix/pickup[6431]: 4D4DD246690: uid=132 from=<opendkim>
Feb 18 14:18:20 mail postfix/cleanup[2707]: 4D4DD246690: message-id=<[email protected]>
Feb 18 14:18:20 mail opendkim[1289]: 4D4DD246690: no signing table match for '[email protected]'
Feb 18 14:18:20 mail opendkim[1289]: 4D4DD246690: no signature data
Feb 18 14:18:20 mail postfix/qmgr[3350]: 4D4DD246690: from=<[email protected]>, size=1286, nrcpt=1 (queue active)
Feb 18 14:18:21 mail postfix/pickup[6431]: 67DEC246691: uid=0 from=<root>
Feb 18 14:18:21 mail postfix/cleanup[5432]: 67DEC246691: message-id=<[email protected]>
Feb 18 14:18:21 mail opendkim[1289]: 67DEC246691: no signing table match for '[email protected]'
Feb 18 14:18:21 mail opendkim[1289]: 67DEC246691: no signature data
Feb 18 14:18:21 mail postfix/pickup[6431]: B5152246696: uid=1005 from=<vmail>
Feb 18 14:18:21 mail postfix/cleanup[32236]: B5152246696: message-id=<[email protected]>
Feb 18 14:18:23 mail opendkim[1289]: B5152246696: no signing table match for '[email protected]'
Feb 18 14:18:23 mail opendkim[1289]: B5152246696: no signature data
Feb 18 14:18:25 mail postfix/qmgr[3350]: B5152246696: from=<[email protected]>, size=1261, nrcpt=1 (queue active)
Feb 18 14:18:26 mail postfix/qmgr[3350]: 67DEC246691: from=<[email protected]>, size=1241, nrcpt=1 (queue active)
Feb 18 14:18:27 mail postfix/smtp[27388]: 4D4DD246690: to=<[email protected]>, orig_to=<opendkim>, relay=none, delay=6.7, delays=0.3/6.4/0.08/0, dsn=5.4.6, status=bounced (mail for mail.MyDomain.de loops back to myself)
Feb 18 14:18:27 mail postfix/smtp[29560]: B5152246696: to=<[email protected]>, orig_to=<vmail>, relay=none, delay=5.3, delays=3.4/1.9/0/0, dsn=5.4.6, status=bounced (mail for mail.MyDomain.de loops back to myself)
Feb 18 14:18:27 mail postfix/smtp[27388]: 67DEC246691: to=<[email protected]>, orig_to=<root>, relay=none, delay=5.7, delays=5.6/0.08/0/0, dsn=5.4.6, status=bounced (mail for mail.MyDomain.de loops back to myself)
Feb 18 14:18:27 mail postfix/cleanup[2707]: 23AE42466F3: message-id=<[email protected]>
Feb 18 14:18:27 mail postfix/cleanup[32236]: 397BB24670C: message-id=<[email protected]>
Feb 18 14:18:27 mail postfix/bounce[7904]: 67DEC246691: sender non-delivery notification: 397BB24670C
Feb 18 14:18:27 mail postfix/qmgr[3350]: 397BB24670C: from=<>, size=3318, nrcpt=1 (queue active)
Feb 18 14:18:27 mail postfix/bounce[7903]: B5152246696: sender non-delivery notification: 23AE42466F3
Feb 18 14:18:27 mail postfix/qmgr[3350]: 67DEC246691: removed
Feb 18 14:18:27 mail postfix/qmgr[3350]: B5152246696: removed
Feb 18 14:18:27 mail postfix/qmgr[3350]: 23AE42466F3: from=<>, size=3345, nrcpt=1 (queue active)
Feb 18 14:18:27 mail postfix/smtp[29560]: 397BB24670C: to=<[email protected]>, relay=none, delay=0.81, delays=0.1/0.7/0/0, dsn=5.4.6, status=bounced (mail for mail.MyDomain.de loops back to myself)
Feb 18 14:18:27 mail postfix/smtp[27388]: 23AE42466F3: to=<[email protected]>, relay=none, delay=0.81, delays=0.8/0.01/0/0, dsn=5.4.6, status=bounced (mail for mail.MyDomain.de loops back to myself)
Feb 18 14:18:27 mail postfix/qmgr[3350]: 397BB24670C: removed
Feb 18 14:18:27 mail postfix/qmgr[3350]: 23AE42466F3: removed
Feb 18 14:18:28 mail postfix/cleanup[5432]: 0C3EC2466A0: message-id=<[email protected]>
Feb 18 14:18:28 mail postfix/bounce[3449]: 4D4DD246690: sender non-delivery notification: 0C3EC2466A0
Feb 18 14:18:28 mail postfix/qmgr[3350]: 0C3EC2466A0: from=<>, size=3391, nrcpt=1 (queue active)
Feb 18 14:18:28 mail postfix/qmgr[3350]: 4D4DD246690: removed
Feb 18 14:18:28 mail postfix/smtp[7902]: 0C3EC2466A0: to=<[email protected]>, relay=none, delay=1.4, delays=1.3/0.09/0.01/0, dsn=5.4.6, status=bounced (mail for mail.MyDomain.de loops back to myself)
Feb 18 14:18:28 mail postfix/qmgr[3350]: 0C3EC2466A0: removed
Feb 18 14:19:14 mail postfix/pickup[6431]: AFA9B246690: uid=132 from=<opendkim>
Feb 18 14:19:14 mail postfix/cleanup[2707]: AFA9B246690: message-id=<[email protected]>
Feb 18 14:19:14 mail opendkim[1289]: AFA9B246690: no signing table match for '[email protected]'
Feb 18 14:19:14 mail opendkim[1289]: AFA9B246690: no signature data
Feb 18 14:19:14 mail postfix/qmgr[3350]: AFA9B246690: from=<[email protected]>, size=6085, nrcpt=1 (queue active)
Feb 18 14:19:14 mail postfix/pickup[6431]: C90C5246691: uid=1005 from=<vmail>
Feb 18 14:19:14 mail postfix/cleanup[32236]: C90C5246691: message-id=<[email protected]>
Feb 18 14:19:14 mail opendkim[1289]: C90C5246691: no signing table match for '[email protected]'
Feb 18 14:19:14 mail opendkim[1289]: C90C5246691: no signature data
Feb 18 14:19:14 mail postfix/proxymap[7906]: warning: connect to pgsql server 127.0.0.1: FATAL: remaining connection slots are reserved for non-replication superuser connections?
Feb 18 14:19:14 mail postfix/trivial-rewrite[5409]: warning: virtual_alias_domains: proxy:pgsql:/etc/postfix/sql-domain-aliases.cf: table lookup problem
Feb 18 14:19:14 mail postfix/trivial-rewrite[5409]: warning: virtual_alias_domains lookup failure
如您所见，邮件至[电子邮件保护]以及来自[电子邮件保护]并[电子邮件保护]即使在我们什么都没做的时候，我们也在继续奔跑。
我想这就是原因。这正常吗？我该如何阻止它们？如您所见，postgredSql 因它们而停止，现在邮件服务器不再可访问。
我不知道如何处理这个问题，或者这只是正常现象。我会很高兴得到任何帮助！