installing redis

sean

No need to install Redis yourself!

We've installed Redis v5 on all of our servers, so you can create your Redis config in your home directory and just launch Redis like:

scl enable rh-redis5 'redis-server $HOME/redis.conf'

Redis v6 will be available on new servers later in 2021 when we start rolling out machines on CentOS 8.

charles_h

sean Hi Sean, I am just wondering if all the servers are installed Redis including the shared server?

davidh

I get some warnings when running redis-server -- are they safe to ignore?

30656:M 13 Nov 2020 19:20:37.012 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
30656:M 13 Nov 2020 19:20:37.012 # Server initialized
30656:M 13 Nov 2020 19:20:37.012 # 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.
30656:M 13 Nov 2020 19:20:37.012 # 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.

sean

davidh most likely yes, but do let us know if you notice any problems that you think might be related.

debiprasad

I got the following message:

Could not create server TCP listening socket 127.0.0.1:6379: bind: Address already in use

Is this okay or should I do something?

I did not make any changes to the default redis.conf file. Is this fine?

How can I make sure that Redis always runs and restart automatically if it stops?

sean

debiprasad I did not make any changes to the default redis.conf file. Is this fine?

Please do not use the default port 6379 unless it's been specifically assigned to you, ie by creating a proxy port application in the dashboard.

Better yet, do not use a port at all - configure your Redis to listen only on a filesystem socket and make your connections through that. It's more secure and you'll have better performance.

debiprasad How can I make sure that Redis always runs and restart automatically if it stops?

Use a process manager like supervisord. I'll try to get a HOWTO up here in the forum soon.

debiprasad

sean Better yet, do not use a port at all - configure your Redis to listen only on a filesystem socket and make your connections through that. It's more secure and you'll have better performance.

Thanks. I set it up.

How can I know that Redis is running (in the background)? It looks like redis-cli is not installed.

debiprasad

sean Use a process manager like supervisord. I'll try to get a HOWTO up here in the forum soon.

I need to install supervisord. Please tell me how to do it.

sean

debiprasad All of the Redis binaries are available under /opt/rh/rh-redis5/root/bin:

[root@opal1 ~]# ls -l /opt/rh/rh-redis5/root/bin/
total 3008
-rwxr-xr-x 1 root root  588856 Aug  7  2019 redis-benchmark
lrwxrwxrwx 1 root root      12 Nov 11 02:04 redis-check-aof -> redis-server
lrwxrwxrwx 1 root root      12 Nov 11 02:04 redis-check-rdb -> redis-server
-rwxr-xr-x 1 root root  756512 Aug  7  2019 redis-cli
lrwxrwxrwx 1 root root      12 Nov 11 02:04 redis-sentinel -> redis-server
-rwxr-xr-x 1 root root 1729520 Aug  7  2019 redis-server

sean

debiprasad I need to install supervisord. Please tell me how to do it.

Install supervisor: pip install --user supervisor
Make a config file for supervisor: example
Start supervisor: supervisord -c $HOME/supervisor.conf

debiprasad

sean Which application should I create for unix_http_server?

debiprasad

sean

How can I apply the changes to the configuration? What do I need to do after making changes in supervisor.conf file?

sean

debiprasad You can set that path to the directory for whichever app you're controlling with supervisor.

Or, you can make a directory like ~/supervisor or whatever and put the config, socket, and pid in there.

debiprasad

sean I want to create a website where I can see Supervisor status. I had done it on Webfaction by creating a custom app (listening on port). Do you have any advice to achieve this? I would prefer to do this without a port if that is faster and secure.

sean

debiprasad If you want to serve supervisor's web UI as a site on our platform then you'll need to use a proxy port app to get a port assignment and then configure the inet_http_server settings the same way you did at WF. Once that's done, add the proxy port app to a site route.

loupgarou

sean hi!
Any chance we may get a complete tutorial in the future? 🙂
I'm using an online instance from redislabs to handle a website made in php, but as you can imagine it's not exactly ideal compared to a local instance.

thanks !

sean

loupgarou on the TODO list 🙂

loupgarou

sean sweet!

ehsanquddusi

sean What is the update?

sean

ehsanquddusi none at this time.

sean

charles_h Redis v5 is available on all of our servers including shared.

charles_h

sean That's really awesome. thanks Sean.