Setup postgreSQL RDS using Ansible

Setting up PostgreSQL on RDS using ansible is a bit tricky because the main user on RDS is not a SUPERUSER and roles membership is not automatically granted for ex: “ERROR: must be member of role ..” is quite common. Here is a working solution:

increase linux file descriptors

Check Installing CentOS 6.2 on VMware and mounting partitions with noatime posts.

This is very important performance tuning for any web server more information here

#adduser www first
ulimit -n unlimited - www
#check default number of concurrently open file descriptors 
cat /proc/sys/fs/file-max
#set the number to high value depending on server config
echo '1773914' > /proc/sys/fs/file-max
echo 'fs.file-max=1773914' >> /etc/sysctl.conf
/sbin/sysctl -w fs.file-max=1773914