We're running a Magento 2.1.10 staging environment on a server. The session, FPC & config cache are written to REDIS. But we can't help but notice that our environment runs very slow when requesting pages. Even if they are stored as FPC. And FPC hit of the Magento product list page takes up to 350 ms, which is quite frankly way to slow to server a page from REDIS.
The speeds we're looking for are more in the regions of 100ms to 125m (or faster). But if we disable REDIS in env.php and write everything to disk, we can't help but notice that our website runs a lot faster. 150ms and lower.
REIDS should easily be faster than disk, which makes perfect sense, but not in our case.
'session' => [ 'save' => 'redis', 'redis' => [ 'host' => '127.0.0.1', 'port' => '6379', 'password' => '', 'timeout' => '2.5', 'persistent_identifier' => '', 'database' => '5', 'compression_threshold' => '2048', 'compression_library' => 'gzip', 'log_level' => '1', 'max_concurrency' => '6', 'break_after_frontend' => '5', 'break_after_adminhtml' => '30', 'first_lifetime' => '600', 'bot_first_lifetime' => '60', 'bot_lifetime' => '7200', 'disable_locking' => '0', 'min_lifetime' => '60', 'max_lifetime' => '2592000' ] ], 'cache' => [ 'frontend' => [ 'default' => [ 'backend' => 'Cm_Cache_Backend_Redis', 'backend_options' => [ 'server' => '127.0.0.1', 'port' => '6379', 'database' => '1', 'persistent' => '', 'password' => '', 'force_standalone' => 0, 'connect_retries' => 1, 'use_lua' => 1 ] ], 'page_cache' => [ 'backend' => 'Cm_Cache_Backend_Redis', 'backend_options' => [ 'server' => '127.0.0.1', 'port' => '6379', 'database' => '2', 'persistent' => '', 'password' => '', 'force_standalone' => 0, 'connect_retries' => 1, 'use_lua' => 1 ] ] ] ],
Any thoughts on what the problem might be? In New Relic, all we can do it see the fact that "REDIS HGET" take a lot of time.
Currently, we're converting the TCP traffic for REDIS over a UNIX SOCKET. Do note that we've implemented REDIS for more than 1 project and never have we experienced this kind of "lag" on REDIS. And REDIS is configured the same way on every server. Which leads me to think the Magento version and CM_Redis plugin has something to do with it.