Introduction

Dynamically modifies the broker's num.network.threads configuration to reduce the number of threads available for processing network requests. This limits the broker's ability to accept and process requests from producers and consumers. The original value is automatically restored when the attack ends.

Details

Kafka restricts large changes to its current configuration. If the requested number of network threads falls outside the permissible range, the extension applies intermediate adjustments incrementally until the target value is achieved.

Use Cases

• Reduce network threads to simulate a broker under heavy network load and test client timeout/retry behavior.
• Verify that producers and consumers handle degraded broker responsiveness without data loss.

Parameters

Parameter	Description	Default
Duration	How long the configuration change stays in effect. The original num.network.threads value is automatically restored when the duration expires.	60s
Number of Network Threads	The target number of network threads per broker. Set to a low value (e.g., 1) to severely limit the broker's network request processing capacity. The original value is restored at the end of the attack. The change may be applied incrementally if Kafka's permissible range requires it.