[리눅스] 레디스 설치 후 경고 메시지 처리(redis warning)

레디스 설치 후 경고 메시지 처리(redis warning)

redis 로그

$ tail -f /var/log/redis/redis.log
...
30912:M 06 Aug 2021 11:33:33.677 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
30912:M 06 Aug 2021 11:33:33.677 # Server initialized
30912:M 06 Aug 2021 11:33:33.677 # 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.

TCP backlog 경고

현재 설정 값 확인

$ sysctl -a | grep net.core.somaxconn
net.core.somaxconn = 128

WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.

설정 값 변경

$ sysctl -w net.core.somaxconn=1024

$ echo "net.core.somaxconn = 1024" >> /etc/sysctl.conf

현재 설정 값 확인

$ sysctl -a | grep net.core.somaxconn
net.core.somaxconn = 1024

overcommit_memory 경고

현재 설정 값 확인

$ sysctl -a | grep vm.overcommit_memory
vm.overcommit_memory = 0

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.

설정 값 변경

$ sysctl -w vm.overcommit_memory=1

$ echo "vm.overcommit_memory = 1" >> /etc/sysctl.conf

현재 설정 값 확인

$ sysctl -a | grep vm.overcommit_memory
vm.overcommit_memory = 1

THP 경고

현재 설정 값 확인

$ cat /sys/kernel/mm/transparent_hugepage/enabled
always [madvise] never

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.

설정 값 변경

$ echo never > /sys/kernel/mm/transparent_hugepage/enabled

$ echo "echo never > /sys/kernel/mm/transparent_hugepage/enabled" >> /etc/rc.local

$ cat /etc/rc.local | grep transparent_hugepage
echo never > /sys/kernel/mm/transparent_hugepage/enabled

현재 설정 값 확인

$ cat /sys/kernel/mm/transparent_hugepage/enabled
always madvise [never]

AnonHugePages가 0이면 정상

$ cat /proc/meminfo | grep AnonHugePages
AnonHugePages:         0 kB

 

참고URL

- https://www.kernel.org/doc/Documentation/vm/overcommit-accounting

- https://access.redhat.com/site/documentation/ko-KR/Red_Hat_Enterprise_Linux/6/html/Performance_Tuning_Guide/s-memory-transhuge.html