Arweave 2.9.7-alpha1-dev-sync-performance-20260909 Release Notes
This is a development prerelease containing changes under active
development. It may not work correctly, and some changes may not be included
in a regular release.
Based on Arweave 2.9.7-alpha1, this release introduces adaptive per-peer sync
concurrency, better balancing across storage modules, localized backpressure
for slow peers and disks, and lower sync-record snapshot memory use.
Configuration changes
sync_jobsand[sync, jobs]are removed. To limit your sync rate, use
[sync, max_download_rate]orsync_max_download_ratein bytes per second,
orinfinity(the default). A value of0
disables syncing.[sync, max_concurrent_peer_scans]and the legacy
data_discovery_max_concurrent_peer_scansoption have been removed without
replacement. Discovery concurrency is automatic.[sync, cache_size_limit]is now[sync, cache_size], measured in MiB.[network, client, http, connections_per_peer]is new and defaults to8.
Most operators should leave it unchanged.
Other option changes are below. Legacy flat names remain supported and unchanged.
| Old option | New option |
|---|---|
[disk_pool, jobs]
| [disk_pool, workers]
|
[gossip, header_sync_jobs]
| [gossip, header, workers]
|
[gossip, header_cache_size]
| [gossip, header, cache_size]
|
[network, server, tcp, ...] socket settings
| [network, server, socket, ...]
|
[network, client, tcp, ...]
| [network, client, socket, ...]
|
| Server listener, connection, and idle settings | [network, server, http, ...]
|
| Server shutdown and socket-backend settings | Nested shutdown and socket paths
|
Replica 2.9 guidance
Preparing entropy first remains recommended: start with
[sync, max_download_rate] set to 0, wait for preparation, then restart with
a positive rate or infinity.
Metrics and compatibility
Custom dashboards may need updating. Key replacements are
chunk_write_rate_bytes_per_second → store_drain_rate_bytes_per_second,
peer_interval_cache_* → chunk_interval_cache_*, and data_discovery →
sync_discovery_peers. New sync_peer_*, sync_tasks_by_*, sync_claimed_*,
and sync_sweep_offset metrics describe scheduler behavior.
If downgrading to 2.9.7-alpha1 after running this
release, stop the node and remove the peers file from data_dir; the older
release cannot read the new peer-performance cache format, and the cache will
be rebuilt automatically.