Accessing the web interface of my nextcloud creates runaway apache processes consuming 100% cpu

Nextcloud version (eg, 12.0.2): 13.0.2
Operating system and version (eg, Ubuntu 17.04): openSUSE Leap 42.3
Apache or nginx version (eg, Apache 2.4.25): apache 2.4.23
PHP version (eg, 7.1): php 7.0.7

The issue you are facing:

As soon as someone accesses the web frontend of my owncloud I see runaway httpd processes on my server consuming all available cpu power. The user does not even have to be logged in, just the login screen is enough.

Is this the first time you’ve seen this error? (Y/N): N

Steps to replicate it:

  1. open the login page of my cloud
  2. look at the process list

The output of your Nextcloud log in Admin > Logging:

nothing in the logs...

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

<?php
$CONFIG = array (
  'instanceid' => '---',
  'passwordsalt' => '---',
  'secret' => '---',
  'trusted_domains' => 
  array (
    0 => 'nextcloud.eregion.de',
  ),
  'datadirectory' => '/srv/www/htdocs/nextcloud/data',
  'overwrite.cli.url' => 'https://nextcloud.eregion.de',
  'htaccess.RewriteBase' => '/',
  'dbtype' => 'mysql',
  'version' => '13.0.2.1',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'nextcloud',
  'dbpassword' => '---',
  'installed' => true,
  'mail_smtpmode' => 'sendmail',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_from_address' => 'admin',
  'mail_domain' => 'eregion.de',
  'loglevel' => 1,
  'filelocking.enabled' => true,
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'redis' => 
  array (
    'host' => 'localhost',
    'port' => 6379,
  ),
  'maintenance' => false,
);

The output of your Apache/nginx/system log in /var/log/____:

nothing suspicious in there either:

nextcloud:/var/log/apache2 # tail error_log 
[Sun May 20 23:29:27.303742 2018] [core:notice] [pid 13757] AH00052: child pid 28320 exit signal Quit (3)
[Sun May 20 23:29:27.303758 2018] [core:notice] [pid 13757] AH00052: child pid 28321 exit signal Quit (3)
[Sun May 20 23:29:27.303776 2018] [core:notice] [pid 13757] AH00052: child pid 31686 exit signal Quit (3)
[Sun May 20 23:29:27.303797 2018] [core:notice] [pid 13757] AH00052: child pid 31807 exit signal Quit (3)
[Sun May 20 23:29:27.303814 2018] [core:notice] [pid 13757] AH00052: child pid 31808 exit signal Quit (3)
[Sun May 20 23:29:27.303829 2018] [core:notice] [pid 13757] AH00052: child pid 32431 exit signal Quit (3)
[Sun May 20 23:29:27.303846 2018] [core:notice] [pid 13757] AH00052: child pid 637 exit signal Quit (3)
[Sun May 20 23:29:27.303864 2018] [core:notice] [pid 13757] AH00052: child pid 745 exit signal Quit (3)
[Sun May 20 23:29:27.303879 2018] [core:notice] [pid 13757] AH00052: child pid 835 exit signal Quit (3)
[Sun May 20 23:29:27.303914 2018] [core:notice] [pid 13757] AH00052: child pid 4735 exit signal Quit (3)
nextcloud:/var/log/apache2 # tail nextcloud.eregion.de-error_log 
[Sun May 20 23:22:40.962778 2018] [authz_core:error] [pid 15588] [client 79.211.110.208:35676] AH01630: client denied by server configuration: /srv/www/htdocs/nextcloud/data/.ocdata
[Sun May 20 23:22:44.444093 2018] [authz_core:error] [pid 15571] [client 79.211.110.208:35680] AH01630: client denied by server configuration: /srv/www/htdocs/nextcloud/data/.ocdata
[Sun May 20 23:23:54.686146 2018] [authz_core:error] [pid 15571] [client 79.211.110.208:35698] AH01630: client denied by server configuration: /srv/www/htdocs/nextcloud/data/.ocdata
[Sun May 20 23:26:18.215977 2018] [authz_core:error] [pid 15631] [client 79.211.110.208:35786] AH01630: client denied by server configuration: /srv/www/htdocs/nextcloud/data/.ocdata
[Sun May 20 23:26:19.483707 2018] [authz_core:error] [pid 27962] [client 79.211.110.208:35802] AH01630: client denied by server configuration: /srv/www/htdocs/nextcloud/data/.ocdata
[Sun May 20 23:27:18.453101 2018] [authz_core:error] [pid 31808] [client 79.211.110.208:35870] AH01630: client denied by server configuration: /srv/www/htdocs/nextcloud/data/.ocdata
[Sun May 20 23:27:20.777444 2018] [authz_core:error] [pid 745] [client 79.211.110.208:35878] AH01630: client denied by server configuration: /srv/www/htdocs/nextcloud/data/.ocdata
[Sun May 20 23:27:23.872001 2018] [authz_core:error] [pid 835] [client 79.211.110.208:35896] AH01630: client denied by server configuration: /srv/www/htdocs/nextcloud/data/.ocdata
[Sun May 20 23:30:51.856044 2018] [authz_core:error] [pid 18589] [client 79.211.110.208:36070] AH01630: client denied by server configuration: /srv/www/htdocs/nextcloud/data/.ocdata
[Sun May 20 23:30:53.976779 2018] [authz_core:error] [pid 18588] [client 79.211.110.208:36084] AH01630: client denied by server configuration: /srv/www/htdocs/nextcloud/data/.ocdata
nextcloud:/var/log/apache2 # tail nextcloud.eregion.de-access_log 
79.211.110.208 - - [20/May/2018:23:32:55 +0200] "GET /ocs/v2.php/apps/notifications/api/v2/notifications HTTP/1.1" 200 74 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0"
79.211.110.208 - - [20/May/2018:23:32:52 +0200] "GET /apps/logreader/poll?lastReqId=bNlnGQPLHGL0XrM8wbM9 HTTP/1.1" 200 2 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0"
79.211.110.208 - mathias [20/May/2018:23:33:15 +0200] "PROPFIND /remote.php/dav/files/mathias/ HTTP/1.1" 207 515 "-" "Mozilla/5.0 (Linux) mirall/2.3.3 (Nextcloud)"
79.211.110.208 - - [20/May/2018:23:33:25 +0200] "GET /ocs/v2.php/apps/notifications/api/v2/notifications HTTP/1.1" 200 74 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0"
79.211.110.208 - - [20/May/2018:23:33:12 +0200] "GET /apps/logreader/poll?lastReqId=bNlnGQPLHGL0XrM8wbM9 HTTP/1.1" 200 2 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0"
79.211.110.208 - mathias [20/May/2018:23:33:47 +0200] "PROPFIND /remote.php/dav/files/mathias/ HTTP/1.1" 207 515 "-" "Mozilla/5.0 (Linux) mirall/2.3.3 (Nextcloud)"
79.211.110.208 - - [20/May/2018:23:33:32 +0200] "GET /apps/logreader/poll?lastReqId=bNlnGQPLHGL0XrM8wbM9 HTTP/1.1" 200 2 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0"
79.211.110.208 - - [20/May/2018:23:33:55 +0200] "GET /ocs/v2.php/apps/notifications/api/v2/notifications HTTP/1.1" 200 74 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0"
79.211.110.208 - - [20/May/2018:23:33:53 +0200] "GET /apps/logreader/poll?lastReqId=bNlnGQPLHGL0XrM8wbM9 HTTP/1.1" 200 2 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0"
79.211.110.208 - mathias [20/May/2018:23:34:19 +0200] "PROPFIND /remote.php/dav/files/mathias/ HTTP/1.1" 207 515 "-" "Mozilla/5.0 (Linux) mirall/2.3.3 (Nextcloud)"

solved (?).

disabled the theming app, now the server behaves as expected.

Did you just change the color and the logo via webinterface or did you use your own theme?

changed the color, texts and the link, replaced the background image, but not the logo.

Ok, this should obviously not happen. I see from your logs, that the logreader app creates a few requests over time. Perhaps it doesn’t work well with theming?? Or perhaps use the developer tools of your browser to see which resource takes so long to be loaded.

Did this error appear with an update? Or just related to theming? Perhaps you can try to apply similar theming stuff to the demo setups and see if you can reproduce it:

my nextcloud is a fresh installation using the opensuse rpm packages avaiiable from the opensuse build service.