Middleware

This page relates to the middleware components deployed to application servers.

Click here fto learn more about middleware.

Database

Central to the application is the database server; acumen utilises a database server called MariaDB - the database server runs within its own Docker Container

Checking the container status

• Start an ssh session to the relevant application server;
• At the prompt, type the following commands:

1. <user>@acumen-app-server:~$ cd ~/dockerise/
2. <user>@acumen-app-server:~$ docker ps | grep "STATUS\|mysql"

The program will output information about the status of the container, for example:

In the above example, we can observer that the STATUS of the container was created 12 days ago and has been 'Up' for 12 days, which indicates that there is no issue with the container.

Container logging

Where an issue with the database container has been observed then the Adminsitrator should check the logs:

• Start an ssh session to the relevant application server;
• At the prompt, type the following commands:

1. <user>@acumen-app-server:~$ cd ~/dockerise/
2. <user>@acumen-app-server:~$ docker-compose logs -f mysql"

This action will stream the logs to the terminal; observing this output for a short time should provide some indications to any potential issues.

Press [CTRL+C] to stop the logging output and return to the prompt.

Note: It is usual to see [Warning] entries within the container logs - if any entries are classified [Error] or [Critical], then please copy any errors and add to the issue ticket.

Redis

The application server uses an in-memory key/value store called Redis