Closed-Loop Remediation Patterns
The Four-Phase Remediation Loop π
A closed-loop remediation system has exactly four phases, and every robust implementation maps to them. If any phase is missing, you no longer have a loop - you have a script that fires once and hopes for the best.
Detect - A signal indicates that something is wrong. This might be a Prometheus alert threshold crossing, a Kubernetes event of type Warning, a MeshSync state change that Meshery surfaces, or an SLO burn rate triggering.
Decide - Given the signal, the system (or agent) reasons about what action to take. This is the phase where raw alert data becomes a proposed remediation: restart the pod, scale the deployment, roll back the release, or escalate to a human.
Act - The proposed action is executed against the cluster. For agent-driven workflows, this is typically a kubectl command, a Meshery API call, or a design deployment via mesheryctl.
Verify - After acting, the system checks whether the condition that triggered detection has resolved. If it has not resolved within a timeout window, the loop either retries a different action or escalates.
This loop is not novel - it mirrors the Kubernetes controller model. What changes with agent-driven remediation is the sophistication of the decide phase and the scope of actions in the act phase.
What Kubernetes Already Handles π
Before reaching for an agent, understand what your cluster already does for free.
| Failure Mode | Kubernetes Mechanism | How It Works |
|---|---|---|
| Container crash | Restart policy + kubelet | kubelet restarts crashed containers up to the backoff limit |
| Node failure | Pod eviction + scheduler | Pods are evicted and rescheduled on healthy nodes |
| Replica count drift | ReplicaSet controller | Controller adds or removes pods to match desired count |
| Rollout failure | Deployment rollout strategy | maxUnavailable and maxSurge limit blast radius during rollouts |
| Resource pressure | Vertical Pod Autoscaler | Adjusts resource requests and limits based on usage history |
| Traffic load | Horizontal Pod Autoscaler | Scales replica count based on CPU or custom metrics |
These mechanisms are fast, low-overhead, and do not require human involvement. They are the right answer for the failure modes they cover.
Where Agent-Driven Remediation Begins π
Kubernetes’ controllers are intentionally narrow. They operate on well-defined state transitions within a single resource type. They cannot:
- Correlate signals across multiple services to identify a dependency failure
- Consult a runbook and decide which of several possible fixes to apply
- Distinguish between a transient spike and a sustained degradation that requires intervention
- Propose a rollback and ask a human to approve it before executing
This is where a coding agent adds value. An agent operating in the decide phase can take a raw alert payload, query Meshery for current component state, pull recent events from MeshSync, and reason over that combined context to produce a specific, actionable recommendation.
Import the policy guardrails design to give your agent a structured set of constraints to reason within:
mesheryctl design import -f designs/policy-guardrails.yaml -s "Kubernetes Manifest"
This design defines the boundaries within which automated actions are permitted - the agent checks proposed actions against these policies before executing.
Matching the Pattern to the Failure π
A practical heuristic for choosing between Kubernetes self-healing and agent-driven remediation:
If the fix can be expressed as a single-resource state transition
-> Use a Kubernetes controller
If the fix requires correlating signals across multiple resources or services
-> Use an agent in the decide phase
If the fix changes cluster topology, involves data, or exceeds a defined blast radius
-> Require human approval before acting
The last rule is the most important. Agents are reasoning systems, not infallible authorities. A closed loop without a human gate is a liability when the action space includes writes that cannot be safely undone. The next lesson covers how to design those gates.
Verifying the Loop End-to-End π
Before building anything more complex, verify that your Meshery environment can observe the signals that feed the detect phase:
# Check that Meshery Operator and MeshSync are active
mesheryctl system check
# Verify designs are being tracked - signals require reconciled state
mesheryctl design list
If mesheryctl system check reports MeshSync is not running, your detect phase has no reliable data source. Resolve this before proceeding to the decide and act phases - an agent reasoning over stale state will produce incorrect remediations with high confidence.