Starting on October 19, 2021, we will enable single-sign-on for our Plesk Support Center to provide a seamless login/account experience. This implies that you’ll be able to use a single account across any of our web-facing properties.
To be prepared for this change and to avoid the need to register during your next ticket submission after the change, we encourage you to create an account here before October 19 using the same email address as your current Zendesk login (support account). It’s essential that you use the same email address on our support center to ensure that your tickets stay attached to the same account. You will continue to use ZenDesk authentication until we switch over to single-sign-on on October 19th.

 Warnings in /var/log/maillog on Plesk server: client_limit is lower than required under max. load

Follow

Comments

11 comments

  • Avatar
    Unknown User

    Just as info, the posted resolution will only end in another error if used with the latest Plesk Onyx 17.8.11 on a CentOS 7.5 as you can read here.

    Aug 27 20:17:45 cebede dovecot: doveconf: Warning: service auth { client_limit=1000 } is lower than required under max. load (2248) 

    Aug 27 20:17:45 cebede dovecot: doveconf: Warning: service anvil { client_limit=1000 } is lower than required under max. load (2251)

    As you see, it's the same error just with a higher max. load in my maillog and I found this site by searching for a fix.  So after following the steps of this resolution, I got  this error:

    Aug 27 20:47:26 cebede dovecot: Warning: fd limit (ulimit -n) is lower than required under max. load (1024 < 2500), because of default_client_limit

    It looks like dovecot doesn't accept a default_client_limit, anyway if it is set in /etc/dovecot/conf.d/10-master.conf or in the dovecot.conf as client_limit like this, which was posted as resolution on another forum:

    service auth {
     client_limit = 10300
          unix_listener auth-userdb {
            mode = 0666
            user = vmail
            group = vmail
          }
     }
    
     service anvil {
     client_limit = 10300
     }

    If you will try the second, it will end with that error:

    Aug 27 21:04:00 cebede dovecot: doveconf: Fatal: Error in configuration file /etc/dovecot/dovecot.conf line 40: Unknown setting: service { {client_limit 

    Aug 27 21:04:00 cebede dovecot: doveconf: Error: managesieve-login: dump-capability process returned 89

    But the solution to get no errors is quite easy and really simple, there's no need to get a higher client_limit, in fact it's better to reduce the number of clients, which should be able to use the services of IMAP, POP3, IMAP over SSL/TLS or POP3 over SSL/TLS at the same time. If your client_limit is set to 1000 (Plesk's default), reduce it around 2/3 to 350, may depend on your server, but in my case this will work and you get rid of the errors.

    0
    Comment actions Permalink
  • Avatar
    Pavel Rozental

    Hi Michael Mahlke

    I checked that solution from this article helped several our clients. For this reason I will not change it.

    Probably in your case also resolution from https://support.plesk.com/hc/en-us/articles/115000155573 could help.

    Thank you for provided solution. 

    0
    Comment actions Permalink
  • Avatar
    b_p

    Hi @Pavel Rozental,

    I just tried the solution provided in this article (in my case the requested limits were a bit bigger than 2200). Thus, I set the default_client_limit to 2300. However, now I get the error message as stated by Michael:

    Warning: fd limit (ulimit -n) is lower than required under max. load (1024 < 2300), because of default_client_limit

    So it seems that your article does not help yet - at least for Plesk 17.8.11.

     

    0
    Comment actions Permalink
  • Avatar
    Pavel Rozental

    Hi b_p,

    > However, now I get the error message as stated by Michael:

    Did you try solution from https://support.plesk.com/hc/en-us/articles/115000155573 ?

    -1
    Comment actions Permalink
  • Avatar
    b_p

    Well, the article is not available?!

    0
    Comment actions Permalink
  • Avatar
    Pavel Rozental

    Hello,

    I did not notice that it's internal article
    For "d limit (ulimit -n)" could you check this solution.

    1. Increase limit for file descriptors: 

      For RHEL/CentOS :

      Add the following line in the end of /etc/sysconfig/dovecot: 

      ulimit -n 1200

      For Debian/Ubuntu :

      Add the following line in /lib/systemd/system/dovecot.service in [Service] section: 

      LimitNOFILE=1400

      Note: the ulimit -n and LimitNOFILE values should be equal or more than default_client_limit one.

    2. Reload the daemon and restart the dovecot service: 

      # systemctl daemon-reload 
      # service dovecot start

    0
    Comment actions Permalink
  • Avatar
    Peter Kielbasiewicz

    My ubuntu server has LimitNOFILE=65535 and I still get the client_error from time to time.
    I think increasing any limit just tackles the symptoms, not the cause.

    So I'd rather like to reduce the number of allowed simultaneous connections to my mail services.

    I do not know how I can do this though.

    0
    Comment actions Permalink
  • Avatar
    Daria Gavrilova

    Hello @Peter,

    To reduce the number of allowed simultaneous connections, please navigate to Plesk > Tools & Settings > Mail Server Settings and set required value for Maximum number of connections (IMAP, POP3, IMAP over SSL/TLS, or POP3 over SSL/TLS).

    More information about this option you can also find here: Configuring Server-Wide Mail Settings

    0
    Comment actions Permalink
  • Avatar
    Kathy Sechrist

    I have many years experience with other web servers, and I have to say moving to Plesk recently has been extremely frustrating. Some days I'm nearly in tears because my other tasks are piling up while I'm tracking down bugs like this one. I'm not a sys admin, I'm a web developer who always manages the server (and it's NEVER been this hard!)  Usually when I have an issue, I can do a web search, read a little bit, and fix it, no problem. And the issues weren't frequent.

    For the past month it has been a daily task to check to make sure everything is working and track down issues. I'm so frustrated! 

    Ok - rant over -

    There are different methods of handling this issue listed above, and I'm not sure which way to go. Can someone please help? CentOS and Obsidian 18.0.28.  Here's a snippet of my maillog from today:

    Jul 28 15:43:54 1112381-server postfix/postfix-script[16787]: refreshing the Postfix mail system
    Jul 28 15:43:54 1112381-server postfix/master[14912]: reload -- version 3.4.8, configuration /etc/postfix
    Jul 28 15:43:54 1112381-server postfix/anvil[16516]: statistics: max connection rate 1/60s for (smtp:(redacted)) at Jul 28 15:42:16
    Jul 28 15:43:54 1112381-server postfix/anvil[16516]: statistics: max connection count 1 for (smtp:(redacted)) at Jul 28 15:42:16
    Jul 28 15:43:54 1112381-server postfix/anvil[16516]: statistics: max cache size 5 at Jul 28 15:42:56
    Jul 28 15:43:54 1112381-server dovecot: master: Warning: Killed with signal 15 (by pid=16826 uid=0 code=kill)
    Jul 28 15:43:54 1112381-server dovecot: service=imap, user=(redacted), ip=[(redacted)]. Server shutting down. rcvd=124, sent=1238
    Jul 28 15:43:54 1112381-server dovecot: service=imap, user=(redacted), ip=[(redacted)]. Server shutting down. rcvd=124, sent=1081
    Jul 28 15:43:56 1112381-server dovecot: master: Warning: service auth { client_limit=1500 } is lower than required under max. load (2248)
    Jul 28 15:43:56 1112381-server dovecot: master: Warning: service anvil { client_limit=1500 } is lower than required under max. load (2251)
    Jul 28 15:43:56 1112381-server dovecot: master: Dovecot v2.3.10.1 (a3d0e1171) starting up for imap, pop3, sieve (core dumps disabled)
    Jul 28 15:43:56 1112381-server dovecot: config: Warning: service auth { client_limit=1500 } is lower than required under max. load (2248)
    Jul 28 15:43:56 1112381-server dovecot: config: Warning: service anvil { client_limit=1500 } is lower than required under max. load (2251)
    Jul 28 15:43:56 1112381-server dovecot: master: Warning: Killed with signal 15 (by pid=16885 uid=0 code=kill)
    Jul 28 15:43:57 1112381-server dovecot: master: Warning: service auth { client_limit=1500 } is lower than required under max. load (2248)
    Jul 28 15:43:57 1112381-server dovecot: master: Warning: service anvil { client_limit=1500 } is lower than required under max. load (2251)
    Jul 28 15:43:57 1112381-server dovecot: master: Dovecot v2.3.10.1 (a3d0e1171) starting up for imap, pop3, sieve (core dumps disabled)
    Jul 28 15:43:57 1112381-server dovecot: config: Warning: service auth { client_limit=1500 } is lower than required under max. load (2248)
    Jul 28 15:43:57 1112381-server dovecot: config: Warning: service anvil { client_limit=1500 } is lower than required under max. load (2251)
    Jul 28 15:43:58 1112381-server dovecot: master: Warning: Killed with signal 15 (by pid=17019 uid=0 code=kill)
    Jul 28 15:43:59 1112381-server dovecot: master: Warning: service auth { client_limit=1500 } is lower than required under max. load (2248)
    Jul 28 15:43:59 1112381-server dovecot: master: Warning: service anvil { client_limit=1500 } is lower than required under max. load (2251)
    Jul 28 15:43:59 1112381-server dovecot: master: Dovecot v2.3.10.1 (a3d0e1171) starting up for imap, pop3, sieve (core dumps disabled)
    Jul 28 15:43:59 1112381-server dovecot: config: Warning: service auth { client_limit=1500 } is lower than required under max. load (2248)
    Jul 28 15:43:59 1112381-server dovecot: config: Warning: service anvil { client_limit=1500 } is lower than required under max. load (2251)
    Jul 28 15:43:59 1112381-server dovecot: master: Warning: Killed with signal 15 (by pid=17065 uid=0 code=kill)

    0
    Comment actions Permalink
  • Avatar
    julian bonpland mignaquy

    Hi Kathy Sechrist please open a support ticket with us here https://support.plesk.com/hc/en-us/articles/213608509-How-to-submit-a-request-to-Plesk-support- so we can troubleshoot the issue. If this did not help there is clearly something else.

    0
    Comment actions Permalink
  • Avatar
    Kathy Sechrist

    Thanks Julian. I am not sure how, but these errors went away. Sorry I didn't see your reply sooner - I'm chasing down new issues almost every day!

    0
    Comment actions Permalink

Please sign in to leave a comment.

Have more questions? Submit a request