[Bug]: Used memory grew by more than 10 MB when executing job OCA\\Files_Trashbin\\BackgroundJob\\ExpireTrash

[SystemKeeper]

⚠️ 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 OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Every few cron runs I see the warning Used memory grew by more than 10 MB when executing job OCA\\Files_Trashbin\\BackgroundJob\\ExpireTrash in the log. Running with loglevel 0 does not reveal any more details:

{
    "reqId": "ai9MUjylJUXj6YXlKtXv",
    "level": 0,
    "time": "2024-05-05T19:41:34+02:00",
    "remoteAddr": "",
    "user": "--",
    "app": "cron",
    "method": "",
    "url": "--",
    "message": "CLI cron call has selected job OCA\\Files_Trashbin\\BackgroundJob\\ExpireTrash (id: 5, arguments: null)",
    "userAgent": "--",
    "version": "29.0.0.19",
    "data": {
        "app": "cron"
    }
}
 {
    "reqId": "ai9MUjylJUXj6YXlKtXv",
    "level": 0,
    "time": "2024-05-05T19:41:34+02:00",
    "remoteAddr": "",
    "user": "--",
    "app": "cron",
    "method": "",
    "url": "--",
    "message": "Starting job OCA\\Files_Trashbin\\BackgroundJob\\ExpireTrash (id: 5, arguments: null)",
    "userAgent": "--",
    "version": "29.0.0.19",
    "data": {
        "app": "cron"
    }
}
 {
    "reqId": "ai9MUjylJUXj6YXlKtXv",
    "level": 0,
    "time": "2024-05-05T19:41:36+02:00",
    "remoteAddr": "",
    "user": "--",
    "app": "cron",
    "method": "",
    "url": "--",
    "message": "Finished job OCA\\Files_Trashbin\\BackgroundJob\\ExpireTrash (id: 5, arguments: null) in 2 seconds",
    "userAgent": "--",
    "version": "29.0.0.19",
    "data": {
        "app": "cron"
    }
}
 {
    "reqId": "ai9MUjylJUXj6YXlKtXv",
    "level": 2,
    "time": "2024-05-05T19:41:36+02:00",
    "remoteAddr": "",
    "user": "--",
    "app": "cron",
    "method": "",
    "url": "--",
    "message": "Used memory grew by more than 10 MB when executing job OCA\\Files_Trashbin\\BackgroundJob\\ExpireTrash (id: 5, arguments: null): 48.7 MB (before: 33 MB)",
    "userAgent": "--",
    "version": "29.0.0.19",
    "data": {
        "app": "cron"
    }
}

Steps to reproduce

Wait for cron to run

Expected behavior

No error.

Installation method

Community Manual installation with Archive

Nextcloud Server version

29

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.2

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?

None

What user-backends are you using?

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

Configuration report

{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "...",
            "..."
        ],
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "overwrite.cli.url": "...",
        "htaccess.RewriteBase": "\/",
        "dbtype": "mysql",
        "version": "29.0.0.19",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "mail_smtpmode": "sendmail",
        "mail_smtpauthtype": "LOGIN",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "25",
        "log_type": "syslog",
        "logtimezone": "Europe\/Berlin",
        "logfile": "",
        "loglevel": 2,
        "enabledPreviewProviders": [
            "OC\\Preview\\PNG",
            "OC\\Preview\\JPEG",
            "OC\\Preview\\GIF",
            "OC\\Preview\\BMP",
            "OC\\Preview\\XBitmap",
            "OC\\Preview\\MP3",
            "OC\\Preview\\TXT",
            "OC\\Preview\\MarkDown",
            "OC\\Preview\\TIFF"
        ],
        "maintenance": false,
        "theme": "",
        "memcache.local": "\\OC\\Memcache\\APCu",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 0,
            "timeout": 0
        },
        "preview_max_x": 1024,
        "preview_max_y": 1024,
        "preview_max_scale_factor": 1,
        "skeletondirectory": "",
        "updater.release.channel": "stable",
        "default_language": "de",
        "app_install_overwrite": [
            "tasks",
            "polls",
            "previewgenerator",
            "forms",
            "spreed",
            "groupfolders"
        ],
        "trashbin_retention_obligation": "auto, 30",
        "default_phone_region": "DE",
        "allow_local_remote_servers": true,
        "debug": false,
        "defaultapp": "files,dashboard"
    }
}

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

[Markoise]

I also get this when subscribed Google Calendars are queried.

I read in the Nextcloud forum that you can increase the following value in cron.php.

if ($memoryAfter - $memoryBefore > 10_000_000) {

But I'm not sure if this is a good idea.

[solracsf]

This is more a "hint" for developpers to (potentially, if possible) optimize code paths than something users should be worried about (unless we're talking about a great amount of RAM increase, like hundreds of MiB).

In the example above, this represents 5MiB more than the treshold of 10MiB that triggers the warning:

48.7 MB (before: 33 MB)

You can almost always safely ignore this.