Although Prometheus continues to be a solid option for a self-managed observability stack, many teams managing modern cloud-native distributed systems bump into its single-node limitations as their metrics grow in cardinality and sheer volume, and when they start needing high-availability setup. Thanos extends Prometheus by adding features that make it suitable for large-scale, long-term and highly available monitoring. It does this, for example, by introducing components that will read data from Prometheus instances and store it in object stores, manage retention and compaction in the object stores and federate querying across multiple Prometheus instances. Our teams have found the migration from Prometheus seamless, as Thanos maintains compatibility with the Prometheus query API. This means they can continue to use their existing dashboards, alerting tools and other tools that integrate with the Prometheus API. Although our teams have been successful with Thanos, we also recommend keeping an eye on Cortex, as another way to extend Prometheus.
