OPcache interned_strings_buffer
Currently opcache total memory size can be tuned via the UI, but not the interned strings buffer, which is another performance knob that normally people suggest to raise alongside total cache size.
It would be nice to also allow tweaking of opcache.internedstringsbuffer via the UI (perhaps in power-of-two increments - 8M (default), 16MB, 32MB, ...) which can become performance-critical when hosting many or bigger sites. Currently the 8M option is limiting when the cache size is >=128M and hit rate is still at 50%.
Fabio Scaccabarozzi
shared this idea
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Khuzaima Aftab commented
Currently, the UI allows tuning only opcache.memory_consumption, but not opcache.interned_strings_buffer, which is critical for performance on large or high-traffic insurance websites (https://insurancecoverage.site). The default 8 MB buffer can quickly become a bottleneck, causing lower hit rates even when total OPcache memory is high. Allowing this setting in the UI (e.g., 8 MB, 16 MB, 32 MB) would align with best practices and prevent interned string exhaustion. This would significantly improve cache efficiency and overall performance.
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willisthiel074en
commented
That’s a great point; it’s definitely a missed opportunity since a cramped interned strings buffer can bottleneck performance even if you have plenty of total https://happyrewards.io/ RAM. Adding a UI toggle for those power-of-two increments would make fine-tuning much more accessible for high-traffic environments.