redis使用問題彙總

1 發現redis掛掉了，查看狀態雖然爲「active」

可是ps和netstat不查看不到，從日誌中能夠確認,報錯信息

# WARNING overcommit_memory is set to 0! Background save may fail under low memory condition.
To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run
the command 'sysctl vm.overcommit_memory=1' for this to take effect.
# WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will
create latency and memory usage issues with Redis. To fix this issue run the command 'echo 
never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your/etc/rc.local in order to retain the setting after a reboot. 
Redis must be restarted after THP is disabled.

vm.overcommit_memory 內存分配策略
transparent_hugepage 透明大頁 對mysql的影響

這兩個參數的修改直接按照報錯信息修改便可。