Deprecation: #85687 - Deprecate RuntimeCacheWriter

See forge#85687


The RuntimeCacheWriter was introduced in TYPO3 9.3 and misused the TYPO3 Caching Framework to provide InMemoryLogging for the AdminPanel. Instead of having a generic LogWriter in the LoggingFramework this belongs to the admin panel scope wise and implementation wise separated from the CachingFramework.

The RuntimeCacheWriter has therefore been deprecated and the AdminPanel will use custom log writers on demand when they will become necessary.


Calling RuntimeCacheWriter will trigger a PHP E_USER_DEPRECATED error.

Affected Installations

Any installation using the RuntimeCacheWriter.


Write your own CacheWriter (see \TYPO3\CMS\Core\Log\Writer\WriterInterface) or - if you need the exact same functionality - copy the old RuntimeCacheWriter to your own extension scope and use it.