Docker starts the general solution of three warnings of redis official image

Preface

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Warning message

As shown below ：

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

terms of settlement

About TCP backlog Set up

• Prompt information

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

tcp The number of connections is set to 128 Too small

• Treatment measures ( The host performs the operation )

]# cat >> /etc/sysctl.conf <<-EOF
net.core.somaxconn=551   #  The data here is adjusted according to the needs of production and the performance of the computer , Must be greater than or equal to  551
EOF
]# sysctl -p

About overcommit_memory Set up

• Prompt information

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.

overcommit_memory Is set to 0 when Under low memory conditions , Background save may fail

• Treatment measures ( The host performs the operation )

]# cat >> /etc/sysctl.conf <<-EOF
vm.overcommit_memory=1
EOF
]# sysctl -p

About THP Supported settings

• Prompt information

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.

Transparent large pages are enabled in the kernel （THP） Support . This will lead to Redis The latency and memory usage problems of

• Treatment measures ( The host performs the operation )

]# cat >> /etc/rc.local <<-EOF
echo never > /sys/kernel/mm/transparent_hugepage/enabled
EOF
]# chmod +x /etc/rc.local
]# source /etc/rc.local

restart redis service

]# /data/deploy/redis
]# docker-compose down
]# docker-compose up -d
]# docker exec redis cat /proc/sys/net/core/somaxconn
128

• If I found somaxconn The value of the or 128, Not into 551 when , The description does not take effect in the container , You need to execute the command in the container , New deployment redis Of docker-compose.yml The file is shown below

version: "3.5"
services:
  redis:
    image: redis:5.0.0
    container_name: redis
    hostname: redis
    privileged: true
    user: root
    ports:
      - 6379:6379
    command:          #  Multiple commands are executed at the same time 
      - /bin/bash 
      - -c 
      - |                 
        echo 551 > /proc/sys/net/core/somaxconn	#  Key orders 
        redis-server --requirepass na1234
    volumes:
      - /etc/timezone:/etc/timezone:ro
      - /etc/localtime:/etc/localtime:ro
      - /data/volume/redis:/data
    restart: always
    tty: true

Update deployment

]# docker-compose up -d
]# docker exec redis cat /proc/sys/net/core/somaxconn
551

Conclusion

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