keys/scan redis commands shouldn't be used

[stefanoparkopedia]

I've upgraded to Laravel 8 and the performance was poor; digging into it I found out that $registry->getMetricFamilySamples(), when using the Redis adapter, uses the keys Redis command that's a performance killer (redis is single-threaded).

prometheus_client_php/src/Prometheus/Storage/Redis.php

Line 488 in 1088114

$keys = $this->redis->keys($summaryKey . ':*:meta');

[ikhabitoff]

We also met with a similar problem. Radis recommends using scan instead of keys when looking for keys. I tried to replace the method without breaking the library tests and created pull request. You can try to use my solution temporarily. #91

[LKaemmerling]

Hey,

thanks to @ikhabitoff who fixed it :) The release with the fix was just tagged (2.6.1).