OpenTelemetry Profiles Public Alpha — How the eBPF Fourth Signal, Collector v0.151.0, and OpAMP Fleet Management Redefine Unified Observability in 2026 On March 26, 2026 the CNCF announced the Public Alpha of the OpenTelemetry Profiles signal . After metrics, traces, and logs, continuous profiling joins as the fourth signal , and OpenTelemetry becomes the first open standard to put all four observability pillars under a single SDK, a single OTLP wire protocol, and a single semantic-convention layer. In the same release cycle, OpenTelemetry Collector v0.151.0 shipped on April 29, 2026 with winget distribution, Run/Shutdown lifecycle synchronization, and richer send_failed metrics that smoothed out the operational surface. And IBM Instana's GA of OpAMP-powered Collector Fleet Management makes it clear that the 2026 default for OTel operations is moving from SSH and rolling restarts to supervisor-driven OpAMP.…