Framing the Problem
DAGs describe flows of jobs, assets, and dependencies. In practice, errors, retries, and external failures distort the DAG, introducing apparent cycles. Monitoring today is event-driven but not predictive — lacking a formal basis for quantifying disorder and anticipating collapse.
Entropy as a Field on DAGs
- Each edge or stage has associated metrics: throughput, backlog, error rate.
- We define entropy as a measure of unpredictability in those distributions.
- More important is the rate of change of entropy (dS/dt): fast rises signal systemic instability.
This makes entropy a field defined across the DAG, like a potential that can be differentiated to predict flow failures.
Markov Chains for Flow Dynamics
Flows can be modeled as Markov chains:
- States = stages of the DAG, plus failure/retry states.
- Transitions = probabilities of job movement between states.
- Transition matrices adapt over time from empirical metrics.
- Entropy then characterizes uncertainty in the transition matrix.
This enables simulation of “most likely future paths” and early-warning signals for rare but costly transitions (e.g., cascading retries).
Bayesian Belief Updates
Bayesian inference layers on top of Markov dynamics:
- Prior = baseline flow performance distribution.
- Evidence = observed metrics (backlog, latency, errors).
- Posterior = updated belief about DAG health, SLA compliance, and risk.
This allows continuous learning: flows become self-aware of their reliability, with confidence intervals for risk prediction.
Analogy to Ampère–Maxwell Law
The Ampère–Maxwell law describes how currents and changing electric fields generate magnetic fields:
∇ × B = μ₀ ( J + ε₀ dE/dt )
By analogy:
- Flow current (J) = throughput of jobs across the DAG.
- Electric field (E) = accumulated backlog or pressure in the system.
- Magnetic field (B) = governance or operational response field (alerts, tickets, interventions).
- Displacement current (dE/dt) = rate of change of backlog/entropy, which drives governance activity even without immediate throughput.
This reframes governance as a field response proportional not only to actual flow but also to changes in systemic stress. Just as in physics, ignoring displacement terms underestimates risk.
Implementation Sketch
- Data Plane: Ingest job transitions, metrics, logs.
- Markov Substrate: Build adaptive transition matrices from observed data.
- Entropy Fields: Compute entropy and its derivative per stage/edge.
- Bayesian Inference: Continuously update DAG health beliefs.
- Governance Field: Encode SLO/SLA response as the Maxwell-like closure law.
Research Implications
- Unifies stochastic models (Markov), inferential models (Bayesian), and field-theory analogies (Maxwell) into one framework.
- Provides a scientific foundation for predictive observability, going beyond dashboards into principled AI-driven governance.
- Offers a bridge between SRE practice and theoretical physics-inspired research.
Next Steps
- Formalize the entropy field equations for DAG substrates.
- Test predictive accuracy of dS/dt against incident data.
- Extend the Ampère–Maxwell analogy into full Maxwell-like equations for observability, potentially linking with information-theoretic conservation laws.
This technical note is designed to guide deeper research collaboration and experimental validation of entropy-augmented DAG observability.