SkyRL

Operational guide for choosing and combining parallelism strategies (TP/PP/DP/CP/SP/EP) for the SkyRL Megatron backend. Use when sizing parallelism for a new model, debugging OOM/throughput on a given cluster topology, or extending an existing recipe to a new GPU count. Includes model-size sizing rules, hardware topology mapping, sequence-length thresholds, MoE-specific patterns, and pitfalls.