Solving Spot GPU Eviction Context Loss with Kernel-Level eBPF Socket Hijacking

Running LLM inference (vLLM/TGI) or model training on spot GPU instances offers huge cost savings, but a single provider reclamation signal can drop active TCP streams and wipe un-checkpointed sequence state.

To eliminate this data loss, we built ApexSovereign—a bare-metal GPU orchestration mesh engineered in Rust and Axum that handles spot failovers at the Linux kernel level.

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Architecture Breakdown

1. eBPF Socket Hijacking (BPF_MAP_TYPE_SOCKHASH)

When a spot node receives an eviction signal from the data center provider, user-space proxies and DNS updates are too slow.

By utilizing eBPF maps (BPF_MAP_TYPE_SOCKHASH) and attaching sk_skb stream parsers:

• Active socket descriptors are updated directly in kernel space upon receiving an eviction signal.
• Reroute latency drops to 1.67ms – 2.31ms.
• TCP connections remain open with zero client-side socket resets.