Guard against unsigned integer underflow in cgroup CPU calculation.
When processes exit and new ones start, totalTicks can be less than
the previous value, causing the subtraction to wrap around to a huge
positive number.
Now checks totalTicks >= prev before calculating delta, treating
process churn as 0 CPU usage for that sample.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add cgroup-based process grouping to the resource collector. Processes are
grouped by their cgroup path, with container names resolved via configurable
process-to-container mapping.
New features:
- Read cgroup info from /proc/[pid]/cgroup (supports v1 and v2)
- Parse K8s resource notation (500m, 1Gi, etc.) for CPU/memory limits
- Group metrics by container using CGROUP_PROCESS_MAP env var
- Calculate usage percentages against limits from CGROUP_LIMITS env var
- Output cgroup metrics with CPU cores used, memory RSS, and percentages
Environment variables:
- CGROUP_PROCESS_MAP: Map process names to container names for discovery
- CGROUP_LIMITS: Define CPU/memory limits per container in K8s notation
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Add Go application that collects CPU and RAM metrics from /proc filesystem:
- Parse /proc/[pid]/stat for CPU usage (user/system time)
- Parse /proc/[pid]/status for memory usage (RSS, VmSize, etc.)
- Aggregate metrics across all processes
- Output via structured logging (JSON/text)
- Continuous collection with configurable interval
Designed for monitoring pipeline runner resource utilization to enable
dynamic runner sizing.
