github.com/NVIDIA/aistore@v1.3.23-0.20240517131212-7df6609be51d/docs/_posts/2022-03-15-whats-new-in-v3.9.md (about) 1 --- 2 layout: post 3 title: "What's new in AIS v3.9" 4 date: Mar 15, 2022 5 author: Alex Aizman 6 categories: aistore 7 --- 8 9 AIS **v3.9** is substantial [productization and performance-improving release](https://github.com/NVIDIA/aistore/releases/tag/3.9). Much of the codebase has been refactored for consistency, with micro-optimization and stabilization fixes across the board. 10 11 ## Highlights 12 13 * [promote](/docs/overview.md#promote-local-or-shared-files): redefine to handle remote file shares; collaborate when promoting via entire cluster; add usability options; productize; 14 * [xmeta](https://github.com/NVIDIA/aistore/blob/main/cmd/xmeta/README.md): extend to also dump in a human-readable format: a) erasure-coded metadata and b) object metadata; 15 * memory usage and fragmentation: consistently use mem-pooling (via `sync.Pool`) for all control structures in the datapath; 16 * optimistic concurrency when running batch `prefetch` jobs; refactor and productize; 17 * optimize PUT datapath; 18 * core logic to deconflict running concurrent `xactions` (asynchronous jobs): bucket rename vs bucket copy, put a node into maintenance mode vs offline ETL, and similar; 19 * extend and reinforce resilvering logic to withstand simultaneous disk losses/attachments - at runtime and with no downtime; 20 * stabilize global rebalance to successfully pass multiple hours of random node "kills" and restarts - *node-left* and *node-joined* events - in presence of stressful data traffic; 21 * self-healing: object metadata cache to support recovery upon `mountpath` events (e.g., drive failures); 22 * error handling: phase out generic `fmt.Errorf` and consistently use assorted error types instead; 23 * additional options to speedup listing of very large buckets ([list-objects](/docs/bucket.md#list-objects)); 24 * numerous micro-optimizing improvements: fast datapath query (`DPQ`) and many more.