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Resilience Analyzers

Resilience Analyzers​

Resilience analyzers provide build-time detection of incomplete error handling configuration. While runtime validation throws clear InvalidOperationException exceptions when prerequisites are missing, these analyzers catch issues earlier during development.

NP9001: Incomplete Resilient Configuration​

ID: NP9001 Severity: Warning
Category: Resilience

This analyzer detects when an error handler can return PipelineErrorDecision.RestartNode but is missing one or more of three mandatory prerequisites for node restart functionality.

The Problem​

Without using this analyzer, developers may miss one of the three mandatory prerequisites for node restart. The system validates these requirements at runtime and throws InvalidOperationException with clear messages when prerequisites are missing, but build-time detection helps catch issues earlier.

With Analyzer​

CSC : warning NP9001: Error handler can return PipelineErrorDecision.RestartNode
but node may not have all three mandatory prerequisites configured...

This gets flagged immediately at build time, during development, before runtime execution.

Solution: Complete Configuration​

For detailed step-by-step configuration instructions, see Getting Started with Resilience guide.

The three mandatory prerequisites are:

  1. ResilientExecutionStrategy wrapping node
  2. MaxNodeRestartAttempts > 0 in PipelineRetryOptions
  3. MaxMaterializedItems != null in PipelineRetryOptions (bounded materialization)

If any prerequisite is missing when RestartNode is returned, the system throws InvalidOperationException at runtime with a clear message indicating which requirement failed.

Best Practices​

  1. Always configure all three prerequisites together - They work as a unit
  2. Use ResilientExecutionStrategy consistently - Apply it to all nodes that need restart capability
  3. Set realistic MaxNodeRestartAttempts - Usually 2-3 attempts is sufficient
  4. Configure MaxMaterializedItems appropriately - Balance memory usage with retry capability

Configuration Guidance: Always set MaxMaterializedItems to a positive bounded value. Setting it to null (unbounded) will cause InvalidOperationException at runtime when RestartNode is attempted. See the Getting Started with Resilience guide for detailed explanation of why bounded buffers are required for resilience guarantees.

See Also​