Simple & Reliable Monitoring That Scales

This article walks through how data flows from collection to storage, explaining how vmstorage processes incoming metrics, assigns unique IDs to time series, and organizes everything into different types of storage parts. The whole system is pretty clever - it uses in-memory buffers for speed, smart compression to save space, and has various watchdogs keeping an eye on things like disk space and data retention.

Through the weak package, you can create these special pointers that automatically become nil when their target memory gets collected. While they’re a bit trickier to use than regular pointers, they’re super useful for things like canonicalization maps and memory-efficient caching. The implementation is pretty clever too, using an 8-byte indirection object to make garbage collection more efficient.

VictoriaMetrics agent, or vmagent, is a lightweight tool designed to gather metrics from a number of different sources. Once it pulls in all those metrics, vmagent lets you ‘design’ them (through ‘relabeling’) or filter them down (doing things like reducing cardinality, stream aggregation, deduplication, and so on) before shipping them off to wherever you want to store them.