High level architecture and functionality

• What is the difference between the InformixHQ server and agent?
• Is it necessary to start the agent to use InformixHQ?
• I have multiple Informix database instances running on the same host machine. Do I need one agent per host or one agent per database server?

What is the difference between the InformixHQ server and agent?

The InformixHQ server is a Java 8 based Jetty web server that hosts both the web user interface (UI) portion of the tool and the REST web services. The InformixHQ server also connects directly to the Informix database server instances to gather live data and run administration commands, manages connections to all agents, and evaluates and dispatches alerts when new monitored data comes in, among other things. You only need to run a single instance of the InformixHQ server to manage and monitor all of your Informix database server instances.

The InformixHQ agent is a lightweight Java program that runs alongside each of your Informix database server instances and gathers monitoring data. The agent is intended to be installed on the same host machine as the Informix database server that you want monitored by InformixHQ, which allows it to also gather operating system statistics about the host machine. Unlike the InformixHQ server, you will have one instance of the InformixHQ agent running for each Informix database server that you want the tool to monitor.

For information, see InformixHQ Architecture.

Is it necessary to start the agent to use InformixHQ?

The agent is not required to use InformixHQ. However, it is important to note that the agent process is the one responsible for gathering all of the monitoring data. Therefore, if you choose not to connect the agent, the tool will not be monitoring your Informix database servers when you close your web browser. You will not be able to see graphs in the UI of how various performance metrics are trending over time and you will not be able to configure alerting conditions if you are not using the agent.

I have multiple Informix database instances running on the same host machine. Do I need one agent per host or one agent per database server?

There is a one-to-one relationship between the InformixHQ agent and the Informix database server. Each agent monitors just one Informix database server instance. If you have multiple Informix database server instances on the same host and you want to monitor each of them, then you will need to have multiple agents on that same host machine, one for each database server instance.