Submodular Max-Delay Batch Timer
Implementation & benchmark of arXiv:2608.06796 — Online Multi-Level Aggregation with Per-Batch Maximum Delay
Source paper: Online Multi-Level Aggregation with Per-Batch Maximum Delay arXiv:2608.06796 ⓘ · analyzed Aug 31, 2026
AI-generated research hypothesis, automatically tested. Not peer-reviewed.
Idea description
Replace a fixed maximum-wait timeout in dynamic neural inference batching with a service-aware timer. The timer estimates the marginal reduction in computation or communication cost from adding another request and delays service only while that saving justifies the additional oldest-request delay.
Formulas
Mathematical statement
The paper charges a service batch B cleared at time t by C(S,B,t)=w(S)+max_{r\in B}(t-a(r)), where S is the selected rooted service subtree, w(S) is its service cost, a(r) is request arrival time, and the maximum is the oldest-request delay. Its parameterized potential is h^L_ heta(i,j)=D_L(i,j)-(1- heta)M(i,j), where D_L(i,j) is the optimized cost of serving interval [i,j], M(i,j) is the service-only cost, and heta\in[0,1]. The key structural inequality is M(i,p-1)+M(k,j)\ge M(i,j)+M(k,p-1) for i\le k\le p\le j, expressing diminishing marginal service cost. The adaptation uses the same principle: keep a batch open when the estimated service-cost saving from merging the next request exceeds (1- heta) times its added maximum delay.
Implementation notes
Integrate this at the dynamic batching queue immediately before a Transformer forward pass or a batched MoE dispatch. Each queued request r has arrival time a(r), token count, sequence length, and routing or device metadata. For a candidate batch B, estimate M(B) as the predicted service cost: for inference this can be measured FLOPs plus padding overhead, while for MoE it can be the number of expert-token transfers and active expert kernels. Maintain the current batch B and periodically inspect the oldest not-yet-served request r_next. Pseudocode: initialize B empty; on arrival append r; at every scheduler tick compute M(B), M(B union {r_next}), and the merging saving DeltaM=M(B)+M({r_next})-M(B union {r_next}); compute the current oldest-request delay DeltaD=t-a(r_oldest); if DeltaM < (1-theta)*DeltaD, flush B, otherwise keep waiting until the next tick or a hard deadline. Use a short-horizon dynamic program over the last K arrivals when several possible boundaries are available: F[j]=min_{i<j}(F[i-1]+w(S_{i:j})+max_delay(i:j)), and choose the minimizing interval as the proposed flush boundary. The paper supplies the submodular inequality and h_theta potential; M, delay predictions, and hardware service times are estimated online. First test on a 1B-parameter decoder with Poisson and bursty request arrivals, comparing fixed 10, 20, and 50 ms timeouts and token-count batching. Measure tokens per second, p95 and p99 latency, average oldest-request delay, and GPU utilization. Success means at least 10% higher throughput at equal p99 latency, or lower p99 latency at equal throughput, without unstable oscillation between tiny and oversized batches.
Verification
This idea has not been verified yet.
Verification happens in two stages: Stage 1 — a mechanism check on a toy system confirms the claimed mathematical phenomenon reproduces; Stage 2 — a benchmark implements the idea on a real (small) neural network task and compares it against a tuned baseline over 8 paired seeds with a permutation test.
Artifacts
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