Compatibility and support
Use this page to choose an engine, model and deployment profile. Implemented means code exists; qualified means independent review accepted the stated frozen workload. Acceptance does not extend to other models, topologies or faults. The completion plan owns remaining delivery work.
Official engine releases
| Engine | Pinned release | External-cache entry point | Qualified starting profile |
|---|---|---|---|
| vLLM | 0.31.0 | OrbitKVConnector through the official KV Connector API | V1 runner, one attention cache group, dense TP=1/PP=1 |
| SGLang | 0.5.21 | OrbitKVLinker through UnifiedRadixCache’s external linker | Dense TP=1/PP=1 with ordinary contiguous GPU pools |
Set VLLM_USE_V2_MODEL_RUNNER=0 before starting vLLM. V2, multiple cache groups
and recurrent external-cache profiles are rejected until released lifecycle
contracts can protect their pages. SGLang’s public lifecycle migration remains
open: the current adapter still consumes bounded private graph-initialization
and pending-query admission hooks. See adapter contracts and the
interface audit.
These are OrbitKV’s selected release pins, not a promise that upstream has no newer release. Historical results retain their original engine versions.
Deployment profiles
| Profile | Current evidence and limit |
|---|---|
| Single engine, DRAM or io_uring SSD | Official-engine dense recovery and engine-restart reuse independently accepted on H20; Manager stays alive |
| Two engines sharing one Manager | H20 900-second dense eager direct/kernel io_uring pressure profile accepted for correctness, progress and bounded resources; fairness and tail isolation remain open |
| CUDA Graph recovery | Explicit serial batch-1 FULL decode Graph recovery accepted for the fixed H20 direct/kernel io_uring profile; arbitrary graph shapes and hybrid replay remain open |
| Two hosts, peer cache | Both official engines have scoped two-H20 RDMA dense TP=1/PP=1 DRAM/io_uring restore, consumer restart and controlled empty-source restart acceptance; this is not cache HA qualification |
| Metadata scaling | Same-host correctness accepted; support remains four owners. Sixteen-owner ordinary visibility passes, but DRAM/SSD isolation fails and sixteen owners remain unqualified |
| TP/PP/EP | Registered loopback query control and a TP=1 worker handshake have scoped acceptance; physical multi-rank and cross-host serving remain unqualified |
| Native P/D plus cache | Official vLLM NIXL/MultiConnector and SGLang native disaggregation are composition candidates; cancellation, peer loss, delayed ACK and page reuse need separate fault gates |
| Separate containers | Shared socket, IPC resources, credentials and process visibility are required; separate-container deployment remains unqualified |
| Native GDS/cuFile | Backend implemented; working io_uring or compatibility-mode cuFile is not evidence of native GDS qualification |
Use deployment recipes, shared-cache evidence and P/D boundaries for each profile’s exact configuration. Manager shared-cache traffic uses TENT; real-time P/D uses the engine’s native backend.
Model and identity limits
Dense Qwen3-8B and Qwen3-32B have official-engine external-recovery evidence. Qwen3.8-27B BF16/FP8 have accepted native output controls only; complete external hybrid recovery and matched performance remain unqualified. DeepSeek-V4.1-Flash is a separate readiness/recovery target. See model qualification for immutable revisions and the distinction between input, output and recovery gates.
Immutable local static LoRA identity has a scoped dense eager acceptance. Dynamic adapter mutation and live weight replacement require stopping and restarting the deployment; an idle vLLM external reset does not qualify live mutation. Different engines do not automatically share interchangeable KV bytes.
Package and runtime
| Runtime | Distribution | Import |
|---|---|---|
| CUDA 12 | orbitkv-llm | orbitkv |
| CUDA 13 | orbitkv-llm-cu13 | orbitkv |
Install only one distribution per environment. Version 0.1.0 is being prepared for release; build the complete wheel using the quickstart. Upgrade native clients and Manager together. The wheel supplies native binaries; the host supplies compatible Python, CUDA and selected RDMA libraries, and the Manager also requires compatible PyTorch. See release artifact requirements.
The SSD file is recreated on Manager startup. Engine-restart reuse is supported within qualified profiles; Manager restart does not preserve this disk cache.