Burn test: 5 assets errored during proxy with 'aborted'/'socket hang up'
during the master DOWNLOAD. The masters all exist in S3 (262-269MB) — it's
the connection-limited RustFS backend dropping streams when 8 jobs hammer it
at once. Two fixes:
1. downloadFromS3/uploadToS3 now retry transient failures (aborted, socket
hang up, ECONNRESET, timeout, 5xx, throttle) up to 5x with exponential
backoff, cleaning the partial file between download attempts. A single
mid-stream abort no longer errors the whole asset.
2. Reuse ONE shared S3 client instead of createS3Client()+client.destroy()
per call. The per-call destroy tore down the keep-alive agent's sockets
every time, so connection pooling never happened and each transfer opened
fresh connections — exactly what overwhelmed RustFS. A long-lived client
lets the keep-alive pool actually be reused.
ZGaetano
3c7cc1a77f