In this session, we will start with the importance of monitoring of services and infrastructure. We will discuss about Prometheus an opensource monitoring tool. We will discuss the architecture of Prometheus. We will also discuss some visualization tools which can be used over Prometheus. Then we will have a quick demo for Prometheus and Grafana.

1. Monitoring with
Prometheus
Himanshu Rajput
Software Consultant
Knoldus Inc.

2. Agenda
● Monitoring and its importance
● Logs vs Metrics
● Types of Metrics
● Prometheus
● Architecture of Prometheus
● Exporters
● Visualization
● Alerting
● Demo

3. Monitoring and Its importance
● Faults that cause critical situations may appear at any time.
● It will be necessary to control the operation so that a possible
error does not end up affecting the service given to users.
● To detect and prevent failures.
● Analyse the operation and performance, and to detect and
alert about possible errors of devices, infrastructures,
applications, services.
● Analysis in real time, alerts, visualization etc

4. Logs vs Metrics
Logs
● Generally plain text or Json
● Source - Application, databases, Kafka etc.
● Little hard to process and query
● Parse logs to obtain metrics
Metrics
● A key-value pair that give information about a particular
process or activity.
● Measured over intervals of time— time series.
● Can be compressed, stored, processed and retrieved far more
efficiently than logs.

5. Type of Metrics
● Counter
● Gauge
● Histogram

6. Prometheus
● An open-source systems monitoring and alerting toolkit.
● Multi-dimensional data model with time series data identified
by metric name and key/value pairs.
● A flexible query language (PromQL)
● Targets are discovered via service discovery or static
configuration
● Time series collection happens via a pull model over HTTP
● Pushing time series is supported via an intermediary gateway
● Graphing and dashboarding support.

7. Architecture

8. Exporters
● Libraries and servers which help in exporting existing metrics
from third-party systems as Prometheus metrics.
● Some exporters are maintained as part of the official
Prometheus GitHub organization
● Easy to setup and integrate
● Predefined metrics in Prometheus format.
Complete list of exporters can be found here

9. Visualization
● Prometheus has expression browser available at /graph.
● This is primarily useful for ad-hoc queries and debugging.
● For better visualization use Grafana
● Grafana.com maintains a collection of shared dashboards.

10. Alerting
● Alerting with Prometheus is separated into two parts.
● Alerting rules in Prometheus servers send alerts to an
Alertmanager
● Alertmanager then manages those alerts, including silencing,
inhibition, aggregation
● Alertmanager sends out notifications via methods such as
email, PagerDuty and HipChat.

11. Organizations using Prometheus

12. Alternatives to Prometheus
● Nagios
● InfluxDB
● Graphite
● OpenTSDB
● Sensu

13. References
● Prometheus docs

14. THANK YOU!