The Making of Kloudfuse 3.5: Engineering Stream-Specific Rate Control to Prevent Runaway Costs
Control costs at ingestion with stream-level throttling and filter-based prioritization.
Published on
Dec 2, 2025
Table of Contents
When we talk to platform teams, one complaint comes up repeatedly: observability costs are unpredictable. A global digital pharmacy saw their bill jump 40% despite stable traffic. A fintech company experienced 100x data growth with no way to distinguish valuable telemetry from noise.
These aren't edge cases. They reflect a fundamental problem with how observability platforms handle cost control. Account-level ingestion limits sound protective until you realize they create a single point of failure: throttle everything or throttle nothing.
We built stream-specific rate control in Kloudfuse 3.5 because observability infrastructure deserves the same operational controls as any production system.
Why Account-Level Limits Don't Work
Traditional observability platforms offer a blunt instrument: set an account-level ingestion limit, and when you hit it, ingestion stops. A development team deploys a new service with overly verbose logging. Within minutes, you hit your account-wide log ingestion limit. Now production logs stop flowing too. Your on-call engineer loses visibility into customer-facing services because someone in development misconfigured a logger.
The "protection" mechanism becomes a reliability risk. We saw customers working around this with duct tape solutions: separate observability accounts for production and non-production, manual coordination to avoid hitting limits, constant threshold adjustments. The tooling was fighting against them instead of helping them operate.
Thinking in Streams
Kloudfuse organizes observability data into five distinct streams: metrics, logs, traces, events, and RUM. Each stream has different characteristics, different volumes, and different operational requirements.
Metrics flow at consistent rates and require predictable capacity. Logs spike during incidents and need burst tolerance. Traces scale with traffic patterns. Events mark deployments and configuration changes. RUM depends on active user sessions.
These streams already flow through separate ingestion pipelines with independent storage backends. Our OLAP data lake processes them differently. Query patterns differ. Retention policies vary. The architectural separation was already there.
Stream-specific rate control became a natural extension of this architecture. Set independent ingestion limits for each stream. A log flood doesn't affect metrics capacity. A traces spike doesn't throttle events. Each stream operates with appropriate guardrails.
The architectural foundation for stream-specific rate control is Pinot Stream Isolation, implemented at the data lake level. Each stream: metrics, logs, traces, events, and RUM—flows through dedicated ingestion pipelines with independent resource allocation. This isolation ensures that resource exhaustion in one stream cannot cascade to others, maintaining platform stability even under extreme load conditions.
For the fintech company managing 100x data growth, this meant setting aggressive log limits while keeping metrics and traces flowing freely. For the healthcare platform, it meant guaranteeing production metrics capacity regardless of what development teams were doing with logs and traces.
Filter-Based Prioritization
Stream separation solved the blast radius problem, but we wanted more precision. Not all metrics are equally valuable. Production metrics from checkout services matter more than experimental metrics from feature flags. Customer-facing service logs need different treatment than internal admin tool logs.
We implemented filter-based prioritization using label and tag matching. The same Kubernetes labels, service tags, and custom attributes you already use for organization become prioritization rules.
Define filters that specify: prioritize environment=production metrics, prioritize logs from tier=critical services, prioritize traces matching namespace=checkout. When ingestion approaches your configured limit, Kloudfuse applies these filters automatically. High-priority data continues flowing. Lower-priority data gets throttled.
This isn't just about preventing problems. It's about expressing operational priorities through configuration rather than hoping usage patterns stay predictable.
Real-Time Consumption Tracking
Rate control without visibility is guessing. We built consumption tracking dashboards that show exactly what's being ingested, from where, and by whom.
Break down ingestion by stream, by service, by team, by any custom tracking label you've configured. View real-time rates and historical trends. When consumption spikes, identify the responsible service immediately.
The consumption dashboard provides granular breakdown by tracking labels and authentication scopes. Platform teams can monitor chargeback at the stream level, attribute costs to specific organizational units, and track ingestion patterns in real-time. This visibility extends beyond simple volume metrics—real-time cardinality analysis detects high-volume data during ingestion, helping teams identify cost optimization opportunities before they impact storage and processing budgets.
This visibility enabled something customers had been requesting: chargeback models. The digital pharmacy attributes observability costs to engineering teams. Consumption tracking shows which teams generate which volumes. This created accountability that changed behavior. Teams added sampling where appropriate. They reduced retention for non-critical data. They instrumented with intention rather than instrumenting everything.
Ingestion-Time Throttling
Here's the fundamental architectural difference: Kloudfuse throttles at ingestion time, not billing time.
With usage-based SaaS vendors, you discover problems retrospectively. A misconfigured service emits excessive metrics for a week. You receive an invoice for unwanted data. No refund. No warning system that caught it before it became expensive.
With Kloudfuse, rate control acts immediately. When a canary deployment started emitting high-cardinality metrics, rate control kicked in within seconds. The deployment's metrics were throttled. Production monitoring continued unaffected. Teams fixed the instrumentation bug and lifted the throttle. No cost impact. No surprise bill.
This matters because observability should protect operations, not create financial risk.
Platform Engineering Integration
Rate control integrates with broader platform engineering workflows. We added service accounts with bearer token authentication for programmatic management. Platform teams can adjust limits dynamically through Kloudfuse's API, enabling integration with CI/CD pipelines, infrastructure-as-code workflows using Terraform, and automated responses to consumption anomalies. Authentication follows standard security models with RBAC policies applied to programmatic access, ensuring automated rate limit adjustments maintain the same security boundaries as manual configuration.
Stream-specific rate control maintains effectiveness even during infrastructure failures. Kloudfuse's multi-zone high availability architecture ensures rate limiting policies remain enforced across availability zones. When one zone experiences issues, rate control continues operating in healthy zones, maintaining both cost protection and observability continuity.
Combined with consumption tracking, multi-zone high availability, and stream-specific RBAC, rate control becomes part of comprehensive operational management. You operate observability infrastructure with the same discipline applied to databases and message queues.
Several customers have described this as the difference between observability as a cost center they minimize and observability as infrastructure they operate confidently.
Self-SaaS Deployment Advantage
Rate control is particularly valuable in Kloudfuse's Self-SaaS deployment model. Kloudfuse deploys entirely within your VPC, giving you direct control over ingestion infrastructure. Rate limits protect your infrastructure capacity, not a vendor's multi-tenant cluster.
You can be aggressive with rate limits because you're protecting your own capacity. You can adjust them as your infrastructure scales. You can experiment with different configurations without worrying about vendor billing implications.
This deployment model, combined with fixed pricing that doesn't penalize increased usage, fundamentally changes the economics of observability cost management. Several customers have told us this is the difference between observability as a cost center they try to minimize and observability as infrastructure they operate with confidence.
What We Built
Stream-specific rate control in Kloudfuse 3.5 delivers:
Independent rate limits for metrics, logs, traces, events, and RUM
Filter-based prioritization within each stream using labels and tags
Real-time consumption tracking with granular attribution
Ingestion-time throttling that prevents surprise bills
Programmatic management through service accounts
Integration with platform engineering workflows
The healthcare platform managing 300+ teams now operates observability infrastructure with clear cost boundaries and team accountability. The fintech company scaling 100x controls exactly which telemetry consumes capacity. The digital pharmacy eliminated bill surprises while maintaining complete production visibility.
Observability infrastructure deserves operational controls that match its importance. Stream-specific rate control makes that possible.
Learn more about platform engineering controls in Kloudfuse 3.5 in our launch announcement.

