Redis6.2 SYSTEMd startup prompt redis service: Failed with result ‘protocol‘.

Problem description

Today we installed redis Latest version 6.2.6（ As of the latest version before the release of the article ）, Install and enable tls All functions are normal , The configuration file is OK ,systemctl Startup time There's a hint redis.service: Failed with result 'protocol'.

Online system version

[email protected]:/etc/redis/conf# cat /etc/issue
Ubuntu 18.04.5 LTS \n \l

Be puzzled when something happens , Search online

I was quite ignorant , Leng Leng's copy error Go to google , I ordered Several articles on similar issues ,Daemonization of Redis 6.0 #7217、Redis service is not starting, After reading their discussion , I tried one of the methods that felt a little useful .

1. Cancel background operation , The foreground runs to check the error output
daemonize yes --> daemonize no
I modified it and ran it again systemctl start redis, Found that it did not report any errors , It runs directly . This makes me even more confused .

2. direct redis-server redis.conf
After running , I can only call good guys directly , I'm even more confused .
you 're right , I run again , No error message , My heart is longing for error tips , But it didn't work as I wished .

solve the problem

I've tried the above method , Also restart, I don't know how many times redis service , It still suggests redis.service: Failed with result 'protocol'. I admit that my mentality is a little broken , But it's not empty , also systemd Of redsi.service file Didn't check , In fact, I don't believe it in my heart redis.service Erroneous , Because my local real machine This is how the configuration runs , No problem .

Local real machine

[Unit]
Description=redis
After=network.target remote-fs.target nss-lookup.target

[Service]
Type=notify
ExecStart=/usr/local/bin/redis-server /etc/redis/conf/redis.conf --supervised systemd
ExecReload=/bin/kill -s HUP $MAINPID
ExecStop=/usr/local/bin/redis-cli -p 6379 shutdown
PrivateTmp=true

[Install]
WantedBy=multi-user.target

Explain this --supervised systemd , Because in systemd Run under redis, You need to set supervised systemd. It also needs to go through Type=notify stay [Service]section To tell systemd redis Will run in this mode .
This is still my local systemd start-up redis when Always Exit time , To search for articles .Redis not starting with systemctl

Online servers

But it is this that leads to my online server redis It won't start , Now after modification , Has been able to work normally systemd Control start

[Unit]
Description=redis
After=network.target remote-fs.target nss-lookup.target

[Service]
Type=forking
ExecStart=/usr/bin/redis-server /etc/redis/conf/redis.conf
ExecReload=/bin/kill -s HUP $MAINPID
#  This is filled in according to the configuration 
ExecStop=/usr/bin/redis-cli -p 6379 -a 123456 shutdown
PrivateTmp=true

[Install]
WantedBy=multi-user.target

Although the problem has been solved , But I still don't know why add --supervised systemd It doesn't start successfully .