[Bug]: Mysql Deadlock (Serialization failure) on occ preview:genherate-all command with large SMB share

[mate1213]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• Nextcloud Server is running on 64bit capable CPU, PHP and OS.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Start to improve performance of nextcloud, therefore I ran php occ previrew:generate-all

Steps to reproduce

1. Install nextcloud server
2. Add SMB share (in my case contains over 100K images mixed jpg and RAW)
3. Run occ command sudo -u www-data php occ preview:generate-all
4. Wait 10-15 mins

Expected behavior

It will generate all preview.

Installation method

Community Manual installation with Archive

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.1

Web server

Apache (supported)

Database engine version

MariaDB

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "system": {
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "cloud.zsolyahome.com",
            "172.16.1.89"
        ],
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "default_phone_region": "HU",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "25.0.3.2",
        "overwrite.cli.url": "***REMOVED SENSITIVE VALUE***",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "filelocking.enabled": true,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "maintenance": false,
        "log_type": "syslog",
        "syslog_tag": "Nextcloud",
        "loglevel": 1,
        "logfile": "",
        "log.condition": {
            "apps": [
                "admin_audit"
            ]
        },
        "log_type_audit": "syslog",
        "syslog_tag_audit": "NextcloudAudit",
        "logfile_audit": "",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpmode": "smtp",
        "mail_sendmailmode": "smtp",
        "mail_smtpsecure": "ssl",
        "mail_smtpauthtype": "LOGIN",
        "mail_smtpauth": 1,
        "mail_smtpport": "465",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "theme": "",
        "app_install_overwrite": [
            "activitylog",
            "files_bpm",
            "spreed",
            "files_texteditor",
            "talk_simple_poll",
            "files_markdown",
            "breezedark"
        ],
        "enable_previews": true,
        "enabledPreviewProviders": [
            "OC\\Preview\\Imaginary"
        ],
        "preview_imaginary_url": "http:\/\/172.16.1.94:5648",
        "updater.release.channel": "stable",
        "data-fingerprint": "f73dc831633a092bcdaa54861dd227fd"
    }
}

List of activated Apps

Enabled:
  - activity: 2.17.0
  - admin_audit: 1.15.0
  - approval: 1.0.12
  - audioplayer: 3.3.1
  - breezedark: 25.0.0
  - bruteforcesettings: 2.5.0
  - calendar: 4.2.3
  - camerarawpreviews: 0.8.1
  - circles: 25.0.0
  - cloud_federation_api: 1.8.0
  - comments: 1.15.0
  - contacts: 5.1.0
  - contactsinteraction: 1.6.0
  - dashboard: 7.5.0
  - dav: 1.24.0
  - deck: 1.8.3
  - encryption: 2.13.0
  - event_update_notification: 2.0.0
  - federatedfilesharing: 1.15.0
  - federation: 1.15.0
  - files: 1.20.1
  - files_external: 1.17.0
  - files_fulltextsearch: 25.0.0
  - files_fulltextsearch_tesseract: 25.0.0
  - files_markdown: 2.3.6
  - files_pdfviewer: 2.6.0
  - files_rightclick: 1.4.0
  - files_sharing: 1.17.0
  - files_texteditor: 2.15.0
  - files_trashbin: 1.15.0
  - files_versions: 1.18.0
  - firstrunwizard: 2.14.0
  - fulltextsearch: 25.0.0
  - fulltextsearch_elasticsearch: 25.0.0
  - groupfolders: 13.1.1
  - integration_github: 1.0.15
  - integration_gitlab: 1.0.12
  - integration_google: 1.0.9
  - integration_reddit: 1.0.5
  - logreader: 2.10.0
  - lookup_server_connector: 1.13.0
  - nextcloud_announcements: 1.14.0
  - notifications: 2.13.1
  - oauth2: 1.13.0
  - password_policy: 1.15.0
  - phonetrack: 0.7.4
  - photos: 2.0.1
  - previewgenerator: 5.2.0
  - privacy: 1.9.0
  - provisioning_api: 1.15.0
  - quota_warning: 1.15.0
  - recommendations: 1.4.0
  - serverinfo: 1.15.0
  - settings: 1.7.0
  - sharebymail: 1.15.0
  - spreed: 15.0.3
  - support: 1.8.0
  - suspicious_login: 4.3.0
  - systemtags: 1.15.0
  - talk_simple_poll: 1.3.1
  - tasks: 0.14.5
  - theming: 2.0.1
  - twofactor_backupcodes: 1.14.0
  - twofactor_totp: 7.0.0
  - updatenotification: 1.15.0
  - user_status: 1.5.0
  - user_usage_report: 1.9.0
  - viewer: 1.9.0
  - weather_status: 1.5.0
  - welcome: 1.0.8
  - workflowengine: 2.7.0
Disabled:
  - end_to_end_encryption: 1.11.1
  - related_resources: 1.0.3
  - socialsharing_diaspora: 2.5.0
  - socialsharing_email: 2.5.0
  - socialsharing_facebook: 2.5.0
  - socialsharing_twitter: 2.5.0
  - survey_client: 1.13.0
  - text: 3.3.0
  - user_ldap: 1.12.0

Nextcloud Signing status

No response

Nextcloud Logs

2023-02-12T16:01:22+00:00 
2023-02-12T16:01:22+00:00 In DbalException.php line 71:
2023-02-12T16:01:22+00:00                                                                                                                                                                   
2023-02-12T16:01:22+00:00   [OC\DB\Exceptions\DbalException (1213)]                                                                                                                         
2023-02-12T16:01:22+00:00   An exception occurred while executing a query: SQLSTATE[40001]: Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction  
2023-02-12T16:01:22+00:00                                                                                                                                                                   
2023-02-12T16:01:22+00:00 
2023-02-12T16:01:22+00:00 Exception trace:
2023-02-12T16:01:22+00:00   at /var/www/nextcloud/lib/private/DB/Exceptions/DbalException.php:71
2023-02-12T16:01:22+00:00  OC\DB\Exceptions\DbalException::wrap() at /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php:329
2023-02-12T16:01:22+00:00  OC\DB\QueryBuilder\QueryBuilder->executeStatement() at /var/www/nextcloud/lib/private/Lock/DBLockingProvider.php:144
2023-02-12T16:01:22+00:00  OC\Lock\DBLockingProvider->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Common.php:762
2023-02-12T16:01:22+00:00  OC\Files\Storage\Common->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/View.php:1964
2023-02-12T16:01:22+00:00  OC\Files\View->lockPath() at /var/www/nextcloud/lib/private/Files/View.php:2083
2023-02-12T16:01:22+00:00  OC\Files\View->lockFile() at /var/www/nextcloud/lib/private/Files/View.php:1161
2023-02-12T16:01:22+00:00  OC\Files\View->basicOperation() at /var/www/nextcloud/lib/private/Files/View.php:1004
2023-02-12T16:01:22+00:00  OC\Files\View->fopen() at /var/www/nextcloud/lib/private/Files/Node/File.php:114
2023-02-12T16:01:22+00:00  OC\Files\Node\File->fopen() at /var/www/nextcloud/lib/private/Preview/Imaginary.php:80
2023-02-12T16:01:22+00:00  OC\Preview\Imaginary->getCroppedThumbnail() at /var/www/nextcloud/lib/private/Preview/GeneratorHelper.php:63
2023-02-12T16:01:22+00:00  OC\Preview\GeneratorHelper->getThumbnail() at /var/www/nextcloud/lib/private/Preview/Generator.php:343
2023-02-12T16:01:22+00:00  OC\Preview\Generator->getMaxPreview() at /var/www/nextcloud/lib/private/Preview/Generator.php:162
2023-02-12T16:01:22+00:00  OC\Preview\Generator->generatePreviews() at /var/www/nextcloud/lib/private/PreviewManager.php:200
2023-02-12T16:01:22+00:00  OC\PreviewManager->generatePreviews() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:230
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFile() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:212
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:190
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->generateUserPreviews() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:142
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->execute() at /var/www/nextcloud/3rdparty/symfony/console/Command/Command.php:255
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Command\Command->run() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:1009
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->doRunCommand() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:273
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->doRun() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:149
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->run() at /var/www/nextcloud/lib/private/Console/Application.php:213
2023-02-12T16:01:22+00:00  OC\Console\Application->run() at /var/www/nextcloud/console.php:100
2023-02-12T16:01:22+00:00  require_once() at /var/www/nextcloud/occ:11
2023-02-12T16:01:22+00:00 
2023-02-12T16:01:22+00:00 In ExceptionConverter.php line 37:
2023-02-12T16:01:22+00:00                                                                                                                                                                   
2023-02-12T16:01:22+00:00   [Doctrine\DBAL\Exception\DeadlockException (1213)]                                                                                                              
2023-02-12T16:01:22+00:00   An exception occurred while executing a query: SQLSTATE[40001]: Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction  
2023-02-12T16:01:22+00:00                                                                                                                                                                   
2023-02-12T16:01:22+00:00 
2023-02-12T16:01:22+00:00 Exception trace:
2023-02-12T16:01:22+00:00   at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/API/MySQL/ExceptionConverter.php:37
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Driver\API\MySQL\ExceptionConverter->convert() at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php:1780
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Connection->handleDriverException() at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php:1719
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Connection->convertExceptionDuringQuery() at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php:1173
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Connection->executeStatement() at /var/www/nextcloud/lib/private/DB/Connection.php:294
2023-02-12T16:01:22+00:00  OC\DB\Connection->executeStatement() at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Query/QueryBuilder.php:354
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Query\QueryBuilder->execute() at /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php:281
2023-02-12T16:01:22+00:00  OC\DB\QueryBuilder\QueryBuilder->execute() at /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php:327
2023-02-12T16:01:22+00:00  OC\DB\QueryBuilder\QueryBuilder->executeStatement() at /var/www/nextcloud/lib/private/Lock/DBLockingProvider.php:144
2023-02-12T16:01:22+00:00  OC\Lock\DBLockingProvider->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Common.php:762
2023-02-12T16:01:22+00:00  OC\Files\Storage\Common->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/View.php:1964
2023-02-12T16:01:22+00:00  OC\Files\View->lockPath() at /var/www/nextcloud/lib/private/Files/View.php:2083
2023-02-12T16:01:22+00:00  OC\Files\View->lockFile() at /var/www/nextcloud/lib/private/Files/View.php:1161
2023-02-12T16:01:22+00:00  OC\Files\View->basicOperation() at /var/www/nextcloud/lib/private/Files/View.php:1004
2023-02-12T16:01:22+00:00  OC\Files\View->fopen() at /var/www/nextcloud/lib/private/Files/Node/File.php:114
2023-02-12T16:01:22+00:00  OC\Files\Node\File->fopen() at /var/www/nextcloud/lib/private/Preview/Imaginary.php:80
2023-02-12T16:01:22+00:00  OC\Preview\Imaginary->getCroppedThumbnail() at /var/www/nextcloud/lib/private/Preview/GeneratorHelper.php:63
2023-02-12T16:01:22+00:00  OC\Preview\GeneratorHelper->getThumbnail() at /var/www/nextcloud/lib/private/Preview/Generator.php:343
2023-02-12T16:01:22+00:00  OC\Preview\Generator->getMaxPreview() at /var/www/nextcloud/lib/private/Preview/Generator.php:162
2023-02-12T16:01:22+00:00  OC\Preview\Generator->generatePreviews() at /var/www/nextcloud/lib/private/PreviewManager.php:200
2023-02-12T16:01:22+00:00  OC\PreviewManager->generatePreviews() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:230
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFile() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:212
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:190
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->generateUserPreviews() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:142
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->execute() at /var/www/nextcloud/3rdparty/symfony/console/Command/Command.php:255
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Command\Command->run() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:1009
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->doRunCommand() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:273
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->doRun() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:149
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->run() at /var/www/nextcloud/lib/private/Console/Application.php:213
2023-02-12T16:01:22+00:00  OC\Console\Application->run() at /var/www/nextcloud/console.php:100
2023-02-12T16:01:22+00:00  require_once() at /var/www/nextcloud/occ:11
2023-02-12T16:01:22+00:00 
2023-02-12T16:01:22+00:00 In Exception.php line 26:
2023-02-12T16:01:22+00:00                                                                                                                    
2023-02-12T16:01:22+00:00   [Doctrine\DBAL\Driver\PDO\Exception (1213)]                                                                      
2023-02-12T16:01:22+00:00   SQLSTATE[40001]: Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction  
2023-02-12T16:01:22+00:00                                                                                                                    
2023-02-12T16:01:22+00:00 
2023-02-12T16:01:22+00:00 Exception trace:
2023-02-12T16:01:22+00:00   at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Exception.php:26
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Driver\PDO\Exception::new() at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Statement.php:94
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Driver\PDO\Statement->execute() at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php:1163
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Connection->executeStatement() at /var/www/nextcloud/lib/private/DB/Connection.php:294
2023-02-12T16:01:22+00:00  OC\DB\Connection->executeStatement() at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Query/QueryBuilder.php:354
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Query\QueryBuilder->execute() at /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php:281
2023-02-12T16:01:22+00:00  OC\DB\QueryBuilder\QueryBuilder->execute() at /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php:327
2023-02-12T16:01:22+00:00  OC\DB\QueryBuilder\QueryBuilder->executeStatement() at /var/www/nextcloud/lib/private/Lock/DBLockingProvider.php:144
2023-02-12T16:01:22+00:00  OC\Lock\DBLockingProvider->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Common.php:762
2023-02-12T16:01:22+00:00  OC\Files\Storage\Common->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/View.php:1964
2023-02-12T16:01:22+00:00  OC\Files\View->lockPath() at /var/www/nextcloud/lib/private/Files/View.php:2083
2023-02-12T16:01:22+00:00  OC\Files\View->lockFile() at /var/www/nextcloud/lib/private/Files/View.php:1161
2023-02-12T16:01:22+00:00  OC\Files\View->basicOperation() at /var/www/nextcloud/lib/private/Files/View.php:1004
2023-02-12T16:01:22+00:00  OC\Files\View->fopen() at /var/www/nextcloud/lib/private/Files/Node/File.php:114
2023-02-12T16:01:22+00:00  OC\Files\Node\File->fopen() at /var/www/nextcloud/lib/private/Preview/Imaginary.php:80
2023-02-12T16:01:22+00:00  OC\Preview\Imaginary->getCroppedThumbnail() at /var/www/nextcloud/lib/private/Preview/GeneratorHelper.php:63
2023-02-12T16:01:22+00:00  OC\Preview\GeneratorHelper->getThumbnail() at /var/www/nextcloud/lib/private/Preview/Generator.php:343
2023-02-12T16:01:22+00:00  OC\Preview\Generator->getMaxPreview() at /var/www/nextcloud/lib/private/Preview/Generator.php:162
2023-02-12T16:01:22+00:00  OC\Preview\Generator->generatePreviews() at /var/www/nextcloud/lib/private/PreviewManager.php:200
2023-02-12T16:01:22+00:00  OC\PreviewManager->generatePreviews() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:230
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFile() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:212
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:190
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->generateUserPreviews() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:142
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->execute() at /var/www/nextcloud/3rdparty/symfony/console/Command/Command.php:255
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Command\Command->run() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:1009
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->doRunCommand() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:273
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->doRun() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:149
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->run() at /var/www/nextcloud/lib/private/Console/Application.php:213
2023-02-12T16:01:22+00:00  OC\Console\Application->run() at /var/www/nextcloud/console.php:100
2023-02-12T16:01:22+00:00  require_once() at /var/www/nextcloud/occ:11
2023-02-12T16:01:22+00:00 
2023-02-12T16:01:22+00:00 In Statement.php line 92:
2023-02-12T16:01:22+00:00                                                                                                                    
2023-02-12T16:01:22+00:00   [PDOException (40001)]                                                                                           
2023-02-12T16:01:22+00:00   SQLSTATE[40001]: Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction  
2023-02-12T16:01:22+00:00                                                                                                                    
2023-02-12T16:01:22+00:00 
2023-02-12T16:01:22+00:00 Exception trace:
2023-02-12T16:01:22+00:00   at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Statement.php:92
2023-02-12T16:01:22+00:00  PDOStatement->execute() at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Driver/PDO/Statement.php:92
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Driver\PDO\Statement->execute() at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Connection.php:1163
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Connection->executeStatement() at /var/www/nextcloud/lib/private/DB/Connection.php:294
2023-02-12T16:01:22+00:00  OC\DB\Connection->executeStatement() at /var/www/nextcloud/3rdparty/doctrine/dbal/src/Query/QueryBuilder.php:354
2023-02-12T16:01:22+00:00  Doctrine\DBAL\Query\QueryBuilder->execute() at /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php:281
2023-02-12T16:01:22+00:00  OC\DB\QueryBuilder\QueryBuilder->execute() at /var/www/nextcloud/lib/private/DB/QueryBuilder/QueryBuilder.php:327
2023-02-12T16:01:22+00:00  OC\DB\QueryBuilder\QueryBuilder->executeStatement() at /var/www/nextcloud/lib/private/Lock/DBLockingProvider.php:144
2023-02-12T16:01:22+00:00  OC\Lock\DBLockingProvider->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Common.php:762
2023-02-12T16:01:22+00:00  OC\Files\Storage\Common->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php:610
2023-02-12T16:01:22+00:00  OC\Files\Storage\Wrapper\Wrapper->acquireLock() at /var/www/nextcloud/lib/private/Files/View.php:1964
2023-02-12T16:01:22+00:00  OC\Files\View->lockPath() at /var/www/nextcloud/lib/private/Files/View.php:2083
2023-02-12T16:01:22+00:00  OC\Files\View->lockFile() at /var/www/nextcloud/lib/private/Files/View.php:1161
2023-02-12T16:01:22+00:00  OC\Files\View->basicOperation() at /var/www/nextcloud/lib/private/Files/View.php:1004
2023-02-12T16:01:22+00:00  OC\Files\View->fopen() at /var/www/nextcloud/lib/private/Files/Node/File.php:114
2023-02-12T16:01:22+00:00  OC\Files\Node\File->fopen() at /var/www/nextcloud/lib/private/Preview/Imaginary.php:80
2023-02-12T16:01:22+00:00  OC\Preview\Imaginary->getCroppedThumbnail() at /var/www/nextcloud/lib/private/Preview/GeneratorHelper.php:63
2023-02-12T16:01:22+00:00  OC\Preview\GeneratorHelper->getThumbnail() at /var/www/nextcloud/lib/private/Preview/Generator.php:343
2023-02-12T16:01:22+00:00  OC\Preview\Generator->getMaxPreview() at /var/www/nextcloud/lib/private/Preview/Generator.php:162
2023-02-12T16:01:22+00:00  OC\Preview\Generator->generatePreviews() at /var/www/nextcloud/lib/private/PreviewManager.php:200
2023-02-12T16:01:22+00:00  OC\PreviewManager->generatePreviews() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:230
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFile() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:212
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:210
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->parseFolder() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:190
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->generateUserPreviews() at /var/www/nextcloud/apps/previewgenerator/lib/Command/Generate.php:142
2023-02-12T16:01:22+00:00  OCA\PreviewGenerator\Command\Generate->execute() at /var/www/nextcloud/3rdparty/symfony/console/Command/Command.php:255
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Command\Command->run() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:1009
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->doRunCommand() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:273
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->doRun() at /var/www/nextcloud/3rdparty/symfony/console/Application.php:149
2023-02-12T16:01:22+00:00  Symfony\Component\Console\Application->run() at /var/www/nextcloud/lib/private/Console/Application.php:213
2023-02-12T16:01:22+00:00  OC\Console\Application->run() at /var/www/nextcloud/console.php:100
2023-02-12T16:01:22+00:00  require_once() at /var/www/nextcloud/occ:11

Additional info

I looked in mysql log, and found no error.

[st3iny]

Thanks for the report.

This is probably related to nextcloud/server#6899.

You could fix it by using another lock provider. The DB lock provider is kind of unreliable sometimes and I highly recommend using Redis. Redis is super simple to set up and has a minimal impact on server resource usage.

Ref https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/caching_configuration.html#id2

'memcache.locking' => '\OC\Memcache\Redis',