How Modern IT Monitoring Systems Keep Your Services Running Smoothly

In today's era of rapid economic growth and information explosion, services and software systems become increasingly complex, making monitoring and maintenance a critical challenge for IT professionals.

Functions of Monitoring Systems

Monitoring systems provide real‑time status tracking, data collection, fault risk prediction, alerting, fault localization, solution assistance, continuous stable operation, and data visualization for analysis and reporting.

Classification of Monitoring Systems

Monitoring solutions are divided into three categories:

Log‑based : Instruments applications to emit logs, which are collected and analyzed using stacks such as ELK (Elasticsearch, Logstash, Kibana) together with Kafka, Redis or RabbitMQ.

Trace‑based : Captures the full request path across microservices, using tools like Zipkin and Spring Cloud Sleuth to generate Trace IDs and Span IDs for end‑to‑end visibility.

Metric‑based : Stores time‑series data in databases (TSDB) and uses LSM‑tree storage (e.g., LevelDB) to handle high‑volume writes, modeling data as Metrics, Points, Timestamps, Tags, and Fields.

Log‑based Monitoring

Logs are recorded at the system and business level, then aggregated via ELK pipelines; Kafka/Redis/RabbitMQ transport log files to Logstash, which indexes them into Elasticsearch for visualization in Kibana.

Trace‑based Monitoring

Each request receives a Trace ID that remains constant across services, while each service interaction generates a unique Span ID. Sleuth records four states—Server Received, Client Sent, Server Sent, Client Received—to reconstruct the call chain.

Metric‑based Monitoring

Time‑series databases capture measurements over time; data are written to a Write‑Ahead Log, then to an in‑memory memtable, flushed to immutable memtables, and finally persisted as SSTable files using an LSM‑tree structure.

Layered Architecture of Monitoring

Client Layer : Captures user behavior, response codes, client performance, OS, version, etc.

Business Layer : Monitors core business actions such as login, registration, order placement, payment.

Application Layer : Tracks technical metrics like URL request counts, service calls, SQL results, cache usage, QPS.

System Layer : Observes host‑level resources—CPU, memory, disk.

Network Layer : Measures gateway traffic, packet loss, error rates, connection counts.

Popular Monitoring Systems

Zabbix

Zabbix is an enterprise‑grade open‑source distributed monitoring solution composed of Server, Agent, and optional Proxy. It supports active checks (Server pulls data) and passive checks (Agent pushes data), offers a rich API, and provides web‑based dashboards, reporting, and alerting.

Prometheus

Prometheus is a cloud‑native monitoring system built around a time‑series database. It pulls metrics from targets, stores them locally, and provides a powerful query language (PromQL). Its ecosystem includes Exporters, a Pushgateway, Alertmanager, and a built‑in Web UI.

Comparison

Zabbix offers higher maturity and quicker onboarding but relies on relational databases, which can limit scalability. Prometheus has a steeper learning curve, greater flexibility, and native time‑series storage, making it better suited for cloud‑native environments.

Conclusion

Effective IT monitoring spans five layers—from client to network—and can be implemented via log‑based, trace‑based, or metric‑based solutions. Selecting the right tool depends on the environment: Zabbix excels in stable, on‑premises settings, while Prometheus shines in dynamic, cloud‑native deployments.