session-31.txt

expense-dev-db
project-name-envrionment-sg-name
backend ip - 10.0.11.83
db ip - 10.0.21.225

DB SG Rule
-------------------------
MySQL 3306 expense-dev-backend
MySQL 3306 10.0.0.0/16

allow traffic on 3306 from the instances which are attached to expense-dev-backend SG

Stateful vs Stateless
-----------------------

State == Storage

MySQL = data is stored == Stateful application

Backend = no storage for backend == Stateless application

Frontend = no storage for frontend == Stateless application

very difficult to retreive data from Stateful applications

easy to restore backend application, because of no state

DB Admin teams
----------------------
every day backup, every 3hr/6hr backup
test the backup/restore
high availability(atleast 2 servers) and data replication(duplicate into another server for safety)
load balancing
major upgrade --> 5.3 --> 5.4
minor upgrade --> 5.3.1 --> 5.3.2


Database services
--------------------
RDS --> upgrades are cloud responsibility, HA is cloud responsibility, load balancing, snapshot/backup is easy to configure