Monitoring and maintaining your IS

IT monitoring involves continuously monitoring the status and performance of an information system (servers, networks, workstations, applications, and cloud services) in order to detect anomalies before they become incidents.

Its goal: to ensure availability, anticipate outages, and maintain the long-term security of the information system.

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Supervision, Monitoring, and Observability

These three concepts are related but distinct. Monitoring refers to the collection of real-time technical metrics (CPU, memory, service availability).

Monitoring encompasses monitoring, alert analysis, and human intervention to resolve incidents. Observability goes a step further by cross-referencing metrics, logs, and traces to understand the root cause of abnormal behavior.

Types of IT Oversight

• Network monitoring: availability and performance of links, routers, firewalls, and Wi-Fi (latency, packet loss, congestion).
• Server and system monitoring: CPU, memory, disks, services, operating systems, virtual machines, and hypervisors.
• Application Monitoring: Availability and response times of business applications, databases, and APIs.
• Security monitoring: monitoring logs, access, and weak signals to detect intrusions or configuration deviations.
• Cloud monitoring: resources, performance, and costs for Azure, AWS, or Google Cloud environments and SaaS services.

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The Objectives of Information System Oversight

• Ensure the availability of business-critical services.
• Detect failures and vulnerabilities before an incident occurs, rather than having to deal with them after the fact.
• Anticipate performance issues and resource saturation.
• Provide reliable metrics (availability, incidents, SLAs) to manage and ensure the long-term sustainability of the information system.

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Monitoring Tools

There are many tools available on the market, and the choice depends on the size of the infrastructure and the environments to be monitored: Nagios, Zabbix, Centreon, or PRTG for infrastructure monitoring; Grafana and Prometheus for visualization and metrics; or cloud-native services such as Azure Monitor.

The tool itself is less important than the configuration of thresholds, the correlation of alerts, and human oversight—which transform a measurement into action.

Proactive or Reactive Monitoring

Reactive monitoring simply reports a failure after it has occurred. Proactive monitoring analyzes trends (disk space usage, increasing load, expiring certificates) to take action before service is interrupted. It is this preventive approach that safeguards business continuity and the long-term viability of the information system.

Specifically, effective supervision includes:

• the availability of servers, the network, and critical applications;
• health metrics (CPU, memory, disks, latency, certificates, backups);
• Security: monitoring logs and weak signals;
• real-time alerting, prioritized by severity;
• reporting to manage the performance and sustainability of the information system.