raiderx/lock-demo

Demo application for PostgreSQL advisory locks

Lock Demo

Demo of usage PostgreSQL advisory locks.

1. Run Postgres server

   $ docker run -d --name my-postgres -p 55432:5432 \
           -e POSTGRES_PASSWORD=mysecretpassword postgres:12.5-alpine

2. Connect to Postgres server via command line interface:

   $ docker exec -it my-postgres psql -U postgres

   And run the following sql:

   CREATE ROLE testuser WITH 
       LOGIN
       PASSWORD 'P@ssw0rd1+';
       
   CREATE DATABASE testdb
       WITH OWNER testuser;

3. Connect to Postgres server again:

   $ docker exec -it my-postgres psql -d testdb -U testuser 

   And run the following sql:

   CREATE TABLE messages (
       id uuid NOT NULL,
       message text NOT NULL,
       status text NOT NULL,
       version int NOT NULL,
       CONSTRAINT messages_pk PRIMARY KEY (id)
   );

4. Build application using Maven:

   $ mvn package
   

5. Run multiple instances of Consumer:

   $ ./run-consumer.sh

6. Run Producer:

   $ ./run-producer.sh