Overview

The unilateral communication library provides simple, reliable, and efficient point-to-point data transfer for cluster scenarios through simple APIs, bridging multiple AI applications and transmission links. It can be used in various scenarios such as large language model (LLM) prefill-decode (PD) disaggregation, reinforcement learning (RL) post-training parameter switching, and model parameter caching.

This document is a development guide for the unilateral communication library, showing developers how to use its APIs for inter-cluster data transmission and to build a disaggregated LLM inference framework.

Table 1 Use cases

Manual

Description

Unilateral Communication Library (C++)

Describes Huawei Xfer Library (HIXL) APIs for C++, including link management, memory management, and data transmission. In distributed memory pool scenarios, HIXL provides a pure transmission capability based on local and remote addresses.

D2D, D2H, and H2D transmissions are supported.

Describes how to perform link management and key-value (KV) cache management via the C++-based LLM-DataDist APIs. This scenario supports unilateral link establishment. Decode and Prompt can bidirectionally pull and push the KV cache.

Unilateral Communication Library (Python)

Describes how to perform link management and KV cache management via the Python-based LLM-DataDist APIs in CacheManager mode. Both unilateral and bilateral link establishments are supported. That is, all LLM-DataDist instances can initiate link establishments simultaneously. Decode and Prompt can bidirectionally pull and push the KV cache.

D2D, D2H, and H2D transmissions are supported.