Storage used for maintaining messages for inactive users: Cassandra
Apache Cassandra 3.11 require python and jdk8 installed in your computer.
Ran the following commands to install Cassandra:
pip install --upgrade pip setuptools
brew update
brew install cassandra
To start Cassandra: brew services start cassandra
On success, the following text is displayed "Successfully started cassandra (label: homebrew.mxcl.cassandra)"
To be able to connect to Cassandra from the js application: installed Cassandra driver using the command: npm install cassandra-driver
reference: https://medium.com/@manishyadavv/how-to-install-cassandra-on-mac-os-d9338fcfcba4
Getting started with Cassandra schema design:
schema design guide: https://medium.com/code-zen/cassandra-schemas-for-beginners-like-me-9714cee9236a
How to use UDT (User Defined Type) for creating schema: https://cassandra.apache.org/doc/latest/cassandra/data_modeling/data_modeling_schema.html
For learning purpose, the schema used for this application is quite simple:
keyspace: chatapp
User UDT: create type user(id UUID, username text);
Message UDT: create type message(id UUID, txt text, time timestamp);
Messages schema: create table messages(receiver frozen , sender frozen, messages list<frozen>, PRIMARY KEY (receiver, sender));