> On August 29, a routine load balancing change unintentionally increased the number of short-context requests routed to the 1M context servers. At the worst impacted hour on August 31, 16% of Sonnet 4 requests were affected.

Interesting, this implies that the 1M context servers performs worst at low context. Perhaps this is due to some KV cache compression, eviction or sparse attention scheme being applied on these 1M context servers?

This is due to RoPE scaling.

> All the notable open-source frameworks implement static YaRN, which means the scaling factor remains constant regardless of input length, potentially impacting performance on shorter texts. We advise adding the rope_scaling configuration only when processing long contexts is required. It is also recommended to modify the factor as needed. For example, if the typical context length for your application is 524,288 tokens, it would be better to set factor as 2.0.

https://huggingface.co/Qwen/Qwen3-Next-80B-A3B-Thinking

The key issue is that their post-mortem never explained what went wrong on two out of three issues.

All I know is that my requests can now travel along three completely different code paths, each on its own stack and tuned differently. Those optimizations can flip overnight, independent of any model-version bump—so whatever worked yesterday may already be broken today.

I really don't get the praise that they are getting for this postmortem, it only made me more annoyed.

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