1. Persistent connections in php redis just not work. Don't waste your time on it. Its not worth. Today we met another bug related with persistent connections to Redis - so we have to turn it off. No matter how expensive it is.
2. Gmail is awesome. Once amount of emails in your inbox brought limit of several hundreds per day - you have to learn "shortcut kung-fu". Its saves a lot of time.
3. Once we start use Redis at production, I realise how fast was memcache. Before this I just know - "yes, memcache is fast".... now I can compare memcache with other in memory storage systems, and yes - memcache is fastest engine I've even seen. Yes, Redis performance can be close to memcache one - just few times slowly then memcache. But Redis consume much more CPU. If you run Redis on the same server with PHP-FPM, you should use CPU affinity and renice(8). It help us stabilise Redis latency.
4. If you use Percona server - you must set innodb_adaptive_hash_index_partitions=64, it greatly improve our performance.
5. I've tried new version of cloud.percona.com and I would like to say - its really nice. Of course some features still missed, some amount of bugs exists - but this tool help me a lot during last few weeks. I can recommend you to give it a try.
