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SambaStack supports extended token generation via the ignore_eos API parameter. By default, a model stops generating as soon as it produces an EOS (End of Sequence) token – a signal that it has finished its response. With ignore_eos enabled, the model ignores that signal and continues producing tokens until it reaches max_tokens. This is useful for benchmarking tools like AIPerf that require a fixed output length regardless of when the model would naturally stop.
ignore_eos is disabled by default. A SambaStack administrator must enable it explicitly per deployment before users can pass the parameter in API requests. If you pass ignore_eos: true on a deployment where ENABLE_IGNORE_EOS is not set, no error is returned – the parameter is silently ignored and the model behaves as if ignore_eos: false.

Enable ignore_eos for a deployment

To allow users to pass ignore_eos on a deployment, add ENABLE_IGNORE_EOS: "true" under engineConfig.env_vars in your ModelDeployment yaml.
The example above deploys a bundle through spec.bundle. The same engineConfig.env_vars block applies to a single-model deployment that uses an inline spec.models instead. Apply the updated ModelDeployment yaml:
SambaWiz users only need to add the engineConfig.env_vars block to the generated YAML on the Model Deployment page – the rest of the spec is generated automatically.

Use ignore_eos in API requests

Once a deployment has ENABLE_IGNORE_EOS set, users can pass ignore_eos: true in their chat completions request body.
ignore_eos is a vLLM extension and is not part of the standard OpenAI API. Both the SambaNova and OpenAI Python clients accept it via extra_body.

Behavior

ignore_eos is intended for benchmarking and testing workloads, not production user traffic. Known concurrency limits in SambaStack 1.2 (expected to be addressed in SambaStack 2.0):
  • Concurrency 1: Stable.
  • Concurrency 3: Failures at output lengths of 64K tokens or more.
  • Concurrency 10+: 100% failure rate at all output sizes.