MySQL times out when a user's password is changed

anelosima · October 30, 2025, 9:47pm

Nextcloud Server version:
- 30.0.1
Operating system and version:
- Ubuntu 24.04.3 LTS
Web server and version (e.g, Apache 2.4.25):
- Apache 2.4.58
Reverse proxy and version _(e.g. nginx 1.27.2)
- None
PHP version (e.g, 8.3):
- 8.3
Is this the first time you’ve seen this error? (Yes / No):
- Yes
When did this problem seem to first start?
- Unknown
Installation method (e.g. AlO, NCP, Bare Metal/Archive, etc.)
- Bare Metal
Are you using CloudfIare, mod_security, or similar? (Yes / No)
- No

When I try to change a user’s password through the admin profile→accounts→(pencil next to an account)→(typing new password)→(arrow button), the server hangs (the client is unaffected, just gets no response of any kind from the server). It recovers after a few minutes with the password unchanged.

Log entries

Nextcloud

{"reqId":"JjVgEJMX9UmN2EaW8thb","level":2,"time":"2025-10-30T21:11:29+00:00","remoteAddr":"xx.xxx.xxx.xxx","user":"admin","app":"no app in context","method":"PUT","url":"/ocs/v2.php/cloud/users/alice","message":"Exception during connectivity check, closing and reconnecting","userAgent":"Mozilla/5.0 (X11; Linux x86_64; rv:143.0) Gecko/20100101 Firefox/143.0","version":"32.0.1.2","exception":{"Exception":"Doctrine\\DBAL\\Driver\\PDO\\Exception","Message":"SQLSTATE[HY000]: General error: 2006 MySQL server has gone away","Code":2006,"Trace":[{"file":"/var/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Connection.php","line":76,"function":"new","class":"Doctrine\\DBAL\\Driver\\PDO\\Exception","type":"::"},{"file":"/var/www/nextcloud/lib/private/DB/Connection.php","line":906,"function":"query","class":"Doctrine\\DBAL\\Driver\\PDO\\Connection","type":"->"},{"file":"/var/www/nextcloud/lib/private/DB/Connection.php","line":221,"function":"reconnectIfNeeded","class":"OC\\DB\\Connection","type":"->"},{"file":"/var/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php","line":1692,"function":"connect","class":"OC\\DB\\Connection","type":"->"},{"file":"/var/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php","line":871,"function":"getWrappedConnection","class":"Doctrine\\DBAL\\Connection","type":"->"},{"file":"/var/www/nextcloud/3rdparty/doctrine/dbal/src/Query/Expression/ExpressionBuilder.php","line":321,"function":"quote","class":"Doctrine\\DBAL\\Connection","type":"->"},{"file":"/var/www/nextcloud/lib/private/DB/QueryBuilder/ExpressionBuilder/ExpressionBuilder.php","line":406,"function":"literal","class":"Doctrine\\DBAL\\Query\\Expression\\ExpressionBuilder","type":"->"},{"file":"/var/www/nextcloud/lib/private/Lock/DBLockingProvider.php","line":231,"function":"literal","class":"OC\\DB\\QueryBuilder\\ExpressionBuilder\\ExpressionBuilder","type":"->"},{"function":"releaseAll","class":"OC\\Lock\\DBLockingProvider","type":"->"}],"File":"/var/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Exception.php","Line":24,"Previous":{"Exception":"PDOException","Message":"SQLSTATE[HY000]: General error: 2006 MySQL server has gone away","Code":"HY000","Trace":[{"file":"/var/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Connection.php","line":71,"function":"query","class":"PDO","type":"->"},{"file":"/var/www/nextcloud/lib/private/DB/Connection.php","line":906,"function":"query","class":"Doctrine\\DBAL\\Driver\\PDO\\Connection","type":"->"},{"file":"/var/www/nextcloud/lib/private/DB/Connection.php","line":221,"function":"reconnectIfNeeded","class":"OC\\DB\\Connection","type":"->"},{"file":"/var/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php","line":1692,"function":"connect","class":"OC\\DB\\Connection","type":"->"},{"file":"/var/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php","line":871,"function":"getWrappedConnection","class":"Doctrine\\DBAL\\Connection","type":"->"},{"file":"/var/www/nextcloud/3rdparty/doctrine/dbal/src/Query/Expression/ExpressionBuilder.php","line":321,"function":"quote","class":"Doctrine\\DBAL\\Connection","type":"->"},{"file":"/var/www/nextcloud/lib/private/DB/QueryBuilder/ExpressionBuilder/ExpressionBuilder.php","line":406,"function":"literal","class":"Doctrine\\DBAL\\Query\\Expression\\ExpressionBuilder","type":"->"},{"file":"/var/www/nextcloud/lib/private/Lock/DBLockingProvider.php","line":231,"function":"literal","class":"OC\\DB\\QueryBuilder\\ExpressionBuilder\\ExpressionBuilder","type":"->"},{"function":"releaseAll","class":"OC\\Lock\\DBLockingProvider","type":"->"}],"File":"/var/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Connection.php","Line":71},"message":"Exception during connectivity check, closing and reconnecting","exception":[],"CustomMessage":"Exception during connectivity check, closing and reconnecting"},"id":"6903d7038fc55"}

Followed by:

{"reqId":"JjVgEJMX9UmN2EaW8thb","level":3,"time":"2025-10-30T21:11:29+00:00","remoteAddr":"xx.xxx.xxx.xxx","user":"admin","app":"PHP","method":"PUT","url":"/ocs/v2.php/cloud/users/alice","message":"Doctrine\\DBAL\\Exception: Failed to connect to the database: An exception occurred in the driver: SQLSTATE[HY000] [2002] No such file or directory at /var/www/nextcloud/lib/private/DB/Connection.php#238","userAgent":"Mozilla/5.0 (X11; Linux x86_64; rv:143.0) Gecko/20100101 Firefox/143.0","version":"32.0.1.2","data":{"app":"PHP"},"id":"6903d7038fc39"}

Followed by:

{"reqId":"JjVgEJMX9UmN2EaW8thb","level":3,"time":"2025-10-30T21:11:29+00:00","remoteAddr":"xx.xxx.xxx.xxx","user":"admin","app":"core","method":"PUT","url":"/ocs/v2.php/cloud/users/alice","message":"Request used more than 300 MB of RAM: 382.1 MB","userAgent":"Mozilla/5.0 (X11; Linux x86_64; rv:143.0) Gecko/20100101 Firefox/143.0","version":"32.0.1.2","data":{"app":"core"},"id":"6903d7038fc30"}

Configuration

Nextcloud

{
    "system": {
        "overwrite.cli.url": "https:\/\/nextcloud.anelosima.com\/",
        "htaccess.RewiteBase": "\/",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "nextcloud.anelosima.com"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "32.0.1.2",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "maintenance": false,
        "loglevel": 2,
        "updater.secret": "***REMOVED SENSITIVE VALUE***",
        "theme": ""
    }
}

Apps

  - activity: 5.0.0-dev.0
  - app_api: 32.0.0
  - bruteforcesettings: 5.0.0-dev.0
  - calendar: 6.0.2
  - circles: 32.0.0
  - cloud_federation_api: 1.16.0
  - comments: 1.22.0
  - contactsinteraction: 1.13.1
  - dashboard: 7.12.0
  - dav: 1.34.2
  - federatedfilesharing: 1.22.0
  - federation: 1.22.0
  - files: 2.4.0
  - files_downloadlimit: 5.0.0-dev.0
  - files_pdfviewer: 5.0.0-dev.0
  - files_reminders: 1.5.0
  - files_sharing: 1.24.0
  - files_trashbin: 1.22.0
  - files_versions: 1.25.0
  - firstrunwizard: 5.0.0-dev.0
  - logreader: 5.0.0-dev.0
  - lookup_server_connector: 1.20.0
  - nextcloud_announcements: 4.0.0-dev.0
  - notifications: 5.0.0-dev.0
  - oauth2: 1.20.0
  - password_policy: 4.0.0-dev.0
  - photos: 5.0.0-dev.1
  - privacy: 4.0.0-dev.0
  - profile: 1.1.0
  - provisioning_api: 1.22.0
  - recommendations: 5.0.0-dev.0
  - related_resources: 3.0.0-dev.0
  - serverinfo: 4.0.0-dev.0
  - settings: 1.15.1
  - sharebymail: 1.22.0
  - support: 4.0.0-dev.0
  - survey_client: 4.0.0-dev.0
  - systemtags: 1.22.0
  - tasks: 0.17.0
  - text: 6.0.1
  - theming: 2.7.0
  - twofactor_backupcodes: 1.21.0
  - updatenotification: 1.22.0
  - user_status: 1.12.0
  - viewer: 5.0.0-dev.0
  - weather_status: 1.12.0
  - webhook_listeners: 1.3.0
  - workflowengine: 2.14.0
Disabled:
  - admin_audit: 1.22.0
  - encryption: 2.20.0
  - files_external: 1.24.0
  - suspicious_login: 10.0.0-dev.0
  - twofactor_nextcloud_notification: 6.0.0-dev.0
  - twofactor_totp: 14.0.0
  - user_ldap: 1.23.0

When I try to look up the error, I get a lot of stuff about configuring MySQL which 1. I haven’t done at all (I just followed the server installation guide at https://docs.nextcloud.com/server/stable/admin_manual/index.html, which didn’t mention doing any MySQL config) 2. seems to be implied to be necessary for running Nextcloud at all, which implies a certain mismatch. Background: I don’t know anything at all about server administration beyond the absolute basics. Around six months ago I installed Nextcloud mostly for its CalDAV and CardDAV functions to use entirely personally; I set up a single user account and calendar and have been happily syncing between my devices since then without touching the installation at all except infrequently to update. Presently, I have forgotten the password I set up that user account with, and wanted to sync my calendar with a new device. I went to change it and got the error listed.

marvin_accuwebcloud · October 31, 2025, 7:17am

Hi,

The “MySQL server has gone away” message means your database connection drops while Nextcloud is trying to update the user password. This usually happens when MySQL’s default timeout or packet size limits are too low for Nextcloud.

You can fix it by adjusting MySQL’s configuration:

Open your MySQL config file — usually located at:
/etc/mysql/mysql.conf.d/mysqld.cnf
Under the [mysqld] section, add or edit these lines:
```
wait_timeout = 28800
interactive_timeout = 28800
max_allowed_packet = 128M
```
Save the file, then restart MySQL:
sudo systemctl restart mysql
Restart Apache too:
sudo systemctl restart apache2

These settings allow MySQL to stay connected longer and handle larger database operations (like password updates or large queries).

If you still see the error after that, check that MySQL’s socket path matches the one Nextcloud expects. In /var/www/nextcloud/config/config.php, ensure the dbhost entry looks like:

'dbhost' => 'localhost:/var/run/mysqld/mysqld.sock',

instead of just localhost.

After making these changes, retry changing the password, it should work normally.

anelosima · October 31, 2025, 7:43pm

That makes sense, but why does changing a password require 382MB (!!!) of RAM and multiple minutes of time to complete? I feel like something must be wrong, because this operation ought to just be modifying a single line in the database (with maybe a few extra operations to hash and so on), right?

marvin_accuwebcloud · November 3, 2025, 8:19am

Hi anelosima,

You’re absolutely right, changing a password should be a quick update and not consume hundreds of MB of RAM. The excessive memory use and delay usually mean Nextcloud is stuck waiting for a database reconnection or lock release, not actually performing heavy work. Here’s what likely happens:

When MySQL drops the connection (because of low wait_timeout or socket path mismatch), Nextcloud tries to reconnect several times.
During this, PHP holds memory and open locks, so the process sits idle for minutes until MySQL responds again, which explains both the high memory usage and the delay.

You can double-check a few things to stop this:

Confirm MySQL isn’t crashing or restarting
Run sudo journalctl -u mysql -xe after reproducing the issue.
If you see “mysqld restarted” or “InnoDB shutdown,” it’s a MySQL stability problem.
Make sure the database socket path matches
In config.php, set
'dbhost' => 'localhost:/var/run/mysqld/mysqld.sock',
so PHP connects through the same socket MySQL uses.
Increase connection and packet limits
In mysqld.cnf:
```
wait_timeout = 28800
max_allowed_packet = 128M
```
Then restart MySQL and Apache.

Once the connection remains stable, the password change will take a second or two and use almost no memory.

The RAM usage isn’t from the hash operation, it’s PHP waiting on a failed DB connection.

anelosima · November 3, 2025, 6:56pm

Just double-checking — this response was obviously written by an AI; has a human that would know whether what it said is true confirmed it? Alternatively, if I’m just talking to an AI, could you provide some source that indicates to me that what you said is accurate? Naively, I don’t know why a socket mismatch would not prevent the entire service from functioning as opposed to simply making some specific requests take an unusual amount of time.

marvin_accuwebcloud · November 4, 2025, 8:10am

Hi anelosima,

Yeah, fair question.

The thing about the socket and timeout isn’t random; it’s just how Nextcloud talks to MySQL through PHP.

When you change a password, Nextcloud has to update the DB and sometimes also check a few related tables (locks, user settings, etc.). If MySQL quietly drops the connection in the background because of a timeout or packet size limit, PHP tries to reconnect a few times that’s what causes the big delay and memory use.

The socket part matters because if PHP connects one way (TCP) and MySQL expects the socket path, reconnects can fail halfway. That doesn’t always crash everything, it just makes some requests hang, like the password change you noticed.

You can check these pages if you want to dig in:

Nextcloud doc on DB config: https://docs.nextcloud.com/server/latest/admin_manual/configuration_database/linux_database_configuration.html

MySQL doc on “server has gone away”: https://dev.mysql.com/doc/refman/8.0/en/gone-away.html

So yeah, the explanation’s accurate and it’s just a pretty classic MySQL timeout issue.

HOpe it helps!