Web interface very slow after upgrade from 20.0.1 to 20.0.2 RC1

Nextcloud version: 20.0.2 RC1
Operating system and version: Ubuntu 20.04
Apache or nginx version: Apache 2.4.41
PHP version: 7.4.12

The issue I am facing: After upgrading Ubuntu 18.04 to 20.04 the web interface was extremely snappy/fast/responsive compared to what I had before. Page loading times before were around 6s. After the update from 20.0.1 to 20.0.2 RC1 the Web interface always needs exactly 45-46 seconds to load some elements (listed below).

The Update to 20.0.2 was successful and did not solve my problem.

Every help is welcome! :blush:

Elements taking 45 seconds to load:

Files page
.../index.php/apps/files/
.../remote.php/dav/files/USER/ 
.../index.php/apps/recommendations/api/recommendations 
.../index.php/core/preview?fileId=NUMBER&c=CODE&x=250&y=250&forceIcon=0
Contacts page
/index.php/apps/contacts/

Nextcloud logging just listed Problems with the App deck. I disabled it.

PHP	Error: Undefined offset: 1 at /var/www/html/nextcloud/apps/deck/lib/Service/ConfigService.php#68

The output of my config.php file

<?php
$CONFIG = array (
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'filelocking.enabled' => true,
  'instanceid' => 'ID',
  'passwordsalt' => 'PWSALT',
  'secret' => 'SECRET',
  'trusted_domains' =>
  array (
    0 => 'LOCALIP',
    1 => 'localhost',
    2 => 'DOMAIN',
  ),
  'datadirectory' => '/mnt/storage/nextcloud',
  'dbtype' => 'mysql',
  'version' => '20.0.2.1',
  'overwrite.cli.url' => 'LOCALIP',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'USER',
  'dbpassword' => 'PW',
  'installed' => true,
  'maintenance' => false,
  'skeletondirectory' => '',
  'mail_smtpmode' => 'smtp',
  'mail_smtpsecure' => 'tls',
  'mail_from_address' => 'XX',
  'mail_domain' => 'DOMAIN',
  'mail_smtphost' => 'smtp.XXXX',
  'mail_smtpport' => '587',
  'mail_smtpauth' => 1,
  'mail_smtpname' => 'EMAIL',
  'mail_smtppassword' => 'PASSW',
  'mail_smtpauthtype' => 'LOGIN',
  'updater.secret' => 'SECRET',
  'theme' => '',
  'loglevel' => 2,
  'updater.release.channel' => 'beta',
  'log_rotate_size' => 104857600,
  'app_install_overwrite' =>
  array (
    0 => 'carnet',
    1 => 'bookmarks_fulltextsearch',
  ),
  'mysql.utf8mb4' => true,
  'has_rebuilt_cache' => true,
);

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

Which log is needed here?

Example network analysis for Settings page:
Screenshot

You can try to apply the fix, mentioned in this issue ticket to get rid of the error message:

Thanks a lot for your answer!

Today there was an Error in the nextcloud error log. That’s what helped me to find the cause.
The main problem was caused by the Collabora Online - Built-in CODE Server
6.4.14 app. Disabling this made everything fast again. Maybe the error log helps to find a bug.

Error	richdocuments	GuzzleHttp\Exception\ConnectException: cURL error 28: Connection timed out after 45001 milliseconds (see https://curl.haxx.se/libcurl/c/libcurl-errors.html)

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/Handler/CurlFactory.php - line 155:

    GuzzleHttp\Handler\CurlFactory::createRejection()

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/Handler/CurlFactory.php - line 105:

    GuzzleHttp\Handler\CurlFactory::finishError()

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/Handler/CurlHandler.php - line 43:

    GuzzleHttp\Handler\CurlFactory::finish()

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/Handler/Proxy.php - line 28:

    GuzzleHttp\Handler\CurlHandler->__invoke()

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/Handler/Proxy.php - line 51:

    GuzzleHttp\Handler\Proxy::GuzzleHttp\Handler\{closure}("*** sensiti ... *")

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/PrepareBodyMiddleware.php - line 37:

    GuzzleHttp\Handler\Proxy::GuzzleHttp\Handler\{closure}("*** sensiti ... *")

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/Middleware.php - line 29:

    GuzzleHttp\PrepareBodyMiddleware->__invoke()

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/RedirectMiddleware.php - line 70:

    GuzzleHttp\Middleware::GuzzleHttp\{closure}("*** sensiti ... *")

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/Middleware.php - line 59:

    GuzzleHttp\RedirectMiddleware->__invoke()

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/HandlerStack.php - line 71:

    GuzzleHttp\Middleware::GuzzleHttp\{closure}("*** sensiti ... *")

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/Client.php - line 361:

    GuzzleHttp\HandlerStack->__invoke()

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/Client.php - line 163:

    GuzzleHttp\Client->transfer()

    /var/www/html/nextcloud/3rdparty/guzzlehttp/guzzle/src/Client.php - line 183:

    GuzzleHttp\Client->requestAsync()

    /var/www/html/nextcloud/lib/private/Http/Client/Client.php - line 233:

    GuzzleHttp\Client->request()

    /var/www/html/nextcloud/apps/richdocuments/lib/WOPI/DiscoveryManager.php - line 81:

    OC\Http\Client\Client->get()

    /var/www/html/nextcloud/apps/richdocuments/lib/WOPI/DiscoveryManager.php - line 56:

    OCA\Richdocuments\WOPI\DiscoveryManager->fetchFromRemote()

    /var/www/html/nextcloud/apps/richdocuments/lib/WOPI/Parser.php - line 41:

    OCA\Richdocuments\WOPI\DiscoveryManager->get()

    /var/www/html/nextcloud/apps/richdocuments/lib/TokenManager.php - line 210:

    OCA\Richdocuments\WOPI\Parser->getUrlSrc()

    /var/www/html/nextcloud/apps/richdocuments/lib/Controller/DocumentController.php - line 256:

    OCA\Richdocuments\TokenManager->getToken("*** sensiti ... *")

    /var/www/html/nextcloud/lib/private/AppFramework/Http/Dispatcher.php - line 169:

    OCA\Richdocuments\Controller\DocumentController->index()

    /var/www/html/nextcloud/lib/private/AppFramework/Http/Dispatcher.php - line 100:

    OC\AppFramework\Http\Dispatcher->executeController()

    /var/www/html/nextcloud/lib/private/AppFramework/App.php - line 152:

    OC\AppFramework\Http\Dispatcher->dispatch()

    /var/www/html/nextcloud/lib/private/Route/Router.php - line 308:

    OC\AppFramework\App::main()

    /var/www/html/nextcloud/lib/base.php - line 1008:

    OC\Route\Router->match()

    /var/www/html/nextcloud/index.php - line 37:

    OC::handleRequest()