fix: Fix message truncation in disagg flow

[tanmayv25]

Overview:

For some longer prompts, the differing cache_transceiver configs can lead to this error:

[TensorRT-LLM][ERROR] Exception in DataRequester request(): Message truncated

Removing cache_transceiver_config can assist in selecting the correct defaults by TRTLLM library.

Summary by CodeRabbit

• Chores
  • Updated configuration files to increase available GPU memory allocation for cache from 40% to 75%.
  • Removed cache transceiver settings related to maximum token count from server configurations.

[coderabbitai]

Walkthrough

The configuration files for both disaggregated and router-based single-node setups were updated. The free_gpu_memory_fraction parameter in the kv_cache_config sections for context_servers and generation_servers was increased from 0.40 to 0.75, and the cache_transceiver_config subsection was removed from both server configurations.

Changes

File(s)	Change Summary
examples/tensorrt_llm/configs/llmapi_disagg_configs/single_node_config.yaml examples/tensorrt_llm/configs/llmapi_disagg_router_configs/single_node_config.yaml	Increased free_gpu_memory_fraction in kv_cache_config from 0.40 to 0.75 and removed cache_transceiver_config section from context_servers and generation_servers.

Poem

A tweak to the configs, a hop in my stride,
More GPU for caching, no tokens to hide.
Old transceivers removed, the settings are neat,
With memory more free, our servers compete!
🐇✨

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📥 Commits

Reviewing files that changed from the base of the PR and between 4abab20 and 774ac94.

📒 Files selected for processing (2)

• examples/tensorrt_llm/configs/llmapi_disagg_configs/single_node_config.yaml (2 hunks)
• examples/tensorrt_llm/configs/llmapi_disagg_router_configs/single_node_config.yaml (2 hunks)

⏰ Context from checks skipped due to timeout of 90000ms (2)

• GitHub Check: Mirror Repository to GitLab
• GitHub Check: Build and Test - vllm

🔇 Additional comments (2)

examples/tensorrt_llm/configs/llmapi_disagg_configs/single_node_config.yaml (1)

33-33: Validate memory config & default token limits after removal
kv_cache_config.free_gpu_memory_fraction was increased to 0.75 and the cache_transceiver_config block (with custom max_num_tokens) was removed. Confirm that TRTLLM’s defaults (≥10240 tokens for context, ≥256 for generation) cover your longest prompts without triggering truncation, and benchmark GPU memory usage under peak load to avoid OOMs or contention.

examples/tensorrt_llm/configs/llmapi_disagg_router_configs/single_node_config.yaml (1)

33-33: Validate memory config & default token limits in router flow
The free_gpu_memory_fraction is now 0.75 for both context and generation servers, and cache_transceiver_config has been removed. Verify that TRTLLM’s built-in token limits handle your longest prompts without “Message truncated” errors and test memory headroom under full router load to prevent OOMs.

Also applies to: 51-51

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