<div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Hello Group,</div><div><br></div><div>We have dovecot deployed as solely a Pop3 service that is used by our applications to pass mail from one application to another internally. We have roughly 4 applications that connect to the Pop3 service every 2 seconds, to check for new messages and pop them for processing if they are present. Depending on the site, we have between 1024-2048MB of memory set for default_vsz_limit. In all systems we see the Out of memory alert several times a day. We previously did not see this at all when running on CentOS6, with less memory.<br></div><div><br></div><div> We have tried increasing the memory to the vsz_limit up to 2gb without success. <br></div><div><br></div><div>We are running on CentOS 7 servers, running dovecot 2.3.6 (7eab80676) (from the dovecot repo).</div><div><br></div><div>Can anyone advise any other settings that could be modified in order to correct these out of memory issues?</div><div><br></div><div># dovecot -n<br># 2.3.6 (7eab80676): /etc/dovecot/dovecot.conf<br># OS: Linux 3.10.0-957.5.1.el7.x86_64 x86_64 CentOS Linux release 7.6.1810 (Core) <br># Hostname: ******
#<modified for security>
<br>auth_cache_size = 10 M<br>auth_verbose = yes<br>default_vsz_limit = 1 G<br>instance_name = Pop3 Mail Service<br>listen = 10.*.*.*
#<modified for security>
<br>log_path = /var/log/dovecot.log<br>login_greeting = Pop3 Mail Service<br>login_trusted_networks = 10.*.*.* 10.*.*.* 10.*.*.* 10.*.*.* 10.*.*.* #<modified for security><br>mail_location = maildir:~/Maildir<br>namespace inbox {<br> inbox = yes<br> location = <br> mailbox Drafts {<br> special_use = \Drafts<br> }<br> mailbox Junk {<br> special_use = \Junk<br> }<br> mailbox Sent {<br> special_use = \Sent<br> }<br> mailbox "Sent Messages" {<br> special_use = \Sent<br> }<br> mailbox Trash {<br> special_use = \Trash<br> }<br> prefix = <br>}<br>passdb {<br> args = cache_key=#hidden_use-P_to_show#<br> driver = pam<br>}<br>protocols = pop3<br>ssl_cert = </etc/pki/dovecot/certs/dovecot.pem<br>ssl_key = # hidden, use -P to show it<br>userdb {<br> driver = passwd<br>}<br>verbose_ssl = yes<br></div><div><br></div><div>May 10 06:44:05 config: Fatal: pool_system_malloc(8192): Out of memory<br>May 10 06:44:05 config: Fatal: master: service(config): child 27887 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)<br>May 10 14:56:31 config: Fatal: pool_system_malloc(8192): Out of memory<br>May 10 14:56:31 config: Fatal: master: service(config): child 2495 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)<br>May 10 23:09:02 config: Fatal: pool_system_malloc(8192): Out of memory<br>May 10 23:09:02 config: Fatal: master: service(config): child 10581 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)<br>May 11 10:18:43 config: Fatal: pool_system_malloc(8192): Out of memory<br>May 11 10:18:43 config: Fatal: master: service(config): child 30511 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)<br>May 11 18:30:59 config: Fatal: pool_system_malloc(1608): Out of memory<br>May 11 18:30:59 config: Fatal: master: service(config): child 12134 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)<br>May 12 02:57:28 config: Fatal: pool_system_malloc(8192): Out of memory<br>May 12 02:57:28 config: Fatal: master: service(config): child 24940 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)<br>May 12 11:07:34 config: Fatal: pool_system_malloc(8192): Out of memory<br>May 12 11:07:35 config: Fatal: master: service(config): child 8203 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)<br>May 12 19:17:52 config: Fatal: pool_system_malloc(8192): Out of memory<br>May 12 19:17:52 config: Fatal: master: service(config): child 14623 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)<br>May 13 03:26:34 config: Fatal: pool_system_malloc(8192): Out of memory<br>May 13 03:26:35 config: Fatal: master: service(config): child 21479 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)<br>May 13 11:35:42 config: Fatal: pool_system_malloc(8192): Out of memory<br>May 13 11:35:43 config: Fatal: master: service(config): child 26900 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)<br>May 13 19:34:26 config: Fatal: pool_system_malloc(8192): Out of memory<br>May 13 19:34:26 config: Fatal: master: service(config): child 32187 returned error 83 (Out of memory (service config { vsz_limit=1024 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump).</div><div><br></div><div>Thanks,</div><div><br></div><div>Kevin<br></div></div></div></div></div></div>