What it does
Mackerel is a SaaS monitoring service that registers physical and virtual servers through its mackerel-agent, container workloads through a sidecar agent, and supported cloud services through integrations. Teams can group hosts by service or role, define Warning and Critical thresholds, and route alerts to collaboration tools or webhooks. The hosted console combines infrastructure status, metric graphs, and custom dashboards, while usage-based fees depend on hosts, metrics, and trace volume.
To monitor a physical or virtual server, install mackerel-agent, place the organization's API key in its configuration, and start the agent. The documentation says a working agent registers the host as a Standard host in Mackerel. For Kubernetes, the container agent runs as a sidecar; AWS and Azure managed services can be registered through cloud integrations. These are documented setup paths, not installations performed for this entry.
Once a host appears, create a monitor with Warning and Critical thresholds for a metric that reflects the service's health. Mackerel groups alerts, can send notifications through services such as Slack or webhooks, and offers custom dashboards for viewing host or role status. It is most useful when the team defines what healthy means and routes the resulting alerts to people who can investigate; Mackerel detects and presents signals but does not fix the underlying fault.
Check the limits before connecting more hosts
Mackerel offers a two-week trial and a Free plan. The pricing page lists up to five standard or micro hosts and 500 metrics on Free, with one-day retention. Standard pricing is in Japanese yen: ¥2,180 per standard-host month, ¥660 per micro-host month, and ¥11 per metric, tax included. If billable Standard features are used, the minimum usage fee is ¥2,180 for the month; trace spans are separately charged after the included free allowance. The host count is based on a monthly average, so adding agents can affect the bill even if the fleet changes during the month.
Strengths
- Supports server agents, container sidecars, and cloud integrations in one hosted monitoring service.
- Warning and Critical thresholds, alert grouping, notification routes, and custom dashboards support team operations.
- A limited Free plan and two-week trial allow teams to evaluate host and metric workflows before paying.
Watch out for
- The Free plan has host, metric, and retention limits, and the Standard plan has a minimum monthly usage fee when billable features are used.
- The public price list is in Japanese yen, and the agent or cloud integration still needs to be configured for each monitoring target.
Best for
- Teams monitoring servers and cloud infrastructure through agents and integrations
- Operators who want host groups, threshold alerts, and role-oriented dashboards
- Organizations comfortable with host- and metric-based pricing in Japanese yen
Sources
- Mackerel: A Revolutionary Server Management and Monitoring Service (Oct 25, 2026)
- What is a host? - Mackerel Docs (Oct 25, 2026)
- Installing mackerel-agent - Mackerel Docs (Oct 25, 2026)
- Full-fledged Monitoring - Mackerel (Oct 25, 2026)
- Pricing - Mackerel (Oct 25, 2026)