#25173 [Bug] core:archive incorrectly counts cron/flock wrapper processes as concurrent archivers

What happened?

When core:archive is executed by a cron job wrapped with flock and shell processes, Matomo incorrectly counts the wrapper processes as separate concurrent archivers.

The cron job creates a process tree similar to:

/bin/sh
  -> /usr/bin/flock
     -> /bin/bash
        -> php83 .../matomo/console core:archive

Only the final PHP process is an actual Matomo archiver.

However, in core/CronArchive.php, hasReachedMaxConcurrentArchivers() counts every process whose command line contains both:

strpos($process, ' core:archive') !== false &&
strpos($process, 'console ') !== false

Since the parent shell and flock processes contain the complete child command in their arguments, all four processes match.

Matomo therefore reports:

Archiving will stop now because 4 archivers are already running and max 3 are supposed to run at once.
Reached maximum concurrent archivers allowed (3), aborting run.

The same core:archive command executed directly from the shell works normally and reports:

1 out of 3 archivers running currently

This occurs on Hetzner hosting, where frequent cron jobs are wrapped/protected with flock to prevent overlapping executions.

Related discussion about Hetzner's cron/flock requirement: https://github.com/contao/contao/issues/9404

What should happen?

A single core:archive invocation should be counted as one concurrent archiver, regardless of whether it is started through cron, flock, or shell wrapper processes.

Matomo should distinguish the actual PHP core:archive process from parent processes whose command-line arguments merely contain the text console core:archive.

The current behavior prevents scheduled report archiving from running, even though only one real Matomo archiver exists.

As a workaround, moving the actual core:archive command into a separate executable shell script and having flock execute only that script prevents the wrapper processes from containing console core:archive.

How can this be reproduced?

Configure a cron job where core:archive is executed through flock and a shell, for example:

05 * * * * '/usr/bin/flock' -n -E 0 '/path/to/archive.lck' '/bin/bash' -c '/usr/bin/php /path/to/matomo/console core:archive --url="https://stats.example.com/" >> /path/to/matomo-archive.log'

When the cron job runs, inspect matching processes:

ps -eo pid,ppid,args | grep 'core:archive' | grep 'console '

In our case one cron execution produced:

80572 80569 /bin/sh -c '/usr/bin/flock' ... '/bin/bash' -c '/usr/bin/php .../matomo/console core:archive ...'
80575 80572 /usr/bin/flock ... /bin/bash -c /usr/bin/php .../matomo/console core:archive ...
80577 80575 /bin/bash -c /usr/bin/php .../matomo/console core:archive ...
80580 80577 php83 ... /matomo/console core:archive ...

There is only one actual PHP archiver, but all four command lines contain console core:archive.

Matomo then reports:

Archiving will stop now because 4 archivers are already running and max 3 are supposed to run at once.
Reached maximum concurrent archivers allowed (3), aborting run.

For comparison, running the underlying command directly:

/usr/bin/php /path/to/matomo/console core:archive --url="https://stats.example.com/"

results in:

1 out of 3 archivers running currently

and archiving completes successfully.

Matomo version

5.13.0

PHP version

8.3

Server operating system

Debian GNU/Linux 12 (bookworm)

What browsers are you seeing the problem on?

No response

Computer operating system

No response

Relevant log output

INFO      [2026-08-28 10:05:02] 80580  Running Matomo 5.13.0 as Super User
INFO      [2026-08-28 10:05:02] 80580  Async process archiving supported, using CliMulti.
INFO      [2026-08-28 10:05:02] 80580  Starting Matomo reports archiving...
INFO      [2026-08-28 10:05:02] 80580  Archiving will stop now because 4 archivers are already running and max 3 are supposed to run at once.
INFO      [2026-08-28 10:05:02] 80580  Reached maximum concurrent archivers allowed (3), aborting run.

Process list captured during the same cron invocation:

80572 80569 /bin/sh -c '/usr/bin/flock' ... '/bin/bash' -c '/usr/bin/php .../matomo/console core:archive ...'
80575 80572 /usr/bin/flock ... /bin/bash -c /usr/bin/php .../matomo/console core:archive ...
80577 80575 /bin/bash -c /usr/bin/php .../matomo/console core:archive ...
80580 80577 php83 ... /matomo/console core:archive ...

Validations

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