Large insert into Redis Server cause many RDB: Background Save to Disk
You maybe get Error in your redis log like:
# Can't save in background: fork: Cannot allocate memory
SOLUTION
Edit File: /etc/sysctl.conf
Put this at the end of line (Put in the bottom of file):
vm.overcommit_memory=1
Restart Sysctl to Get new CONFIG
sudo sysctl -p /etc/sysctl.conf
Optional, restart your redis server
/etc/init.d/redis-server restart
or
systemctl restart redis-server
SOURCE
https://stackoverflow.com/questions/11752544/redis-bgsave-failed-because-fork-cannot-allocate-memory