When you have a powerful machine with many CPU cores, you might run into an error like
ERR DB index is out of range (Redis::CommandError)
This is because Redis defaults to at most 16 databases (0 to 15) and running tests in parallel might exceed that (your tests might run on databases 1..n
or 2..(n+1)
).
You can increase that limit:
Get number of CPUs of your machine.
nproc --all
Open up Redis configuration file.
sudo vim /etc/redis/redis.conf
Find databases
row and increase it, e.g. set to CPU count + 2:
databases 18
Save and close config file, then restart Redis:
sudo service redis-server restart
Confirm your configuration has been updated. The following command should return "OK
".
redis-cli select `nproc --all`