Software Update: Syncthing 1.4.0

Version 1.4.0 of Syncthing has been released. Syncthing is an open source program that allows files to be synchronized between two computers. This happens just like with BitTorrent Sync without a central server in between, as is the case with storage services such as Dropbox, Google Drive, OneDrive and iCloud. The software is available for Windows, Linux, macOS and Android, among others. There are also packages for Synology and Qnap. The following changes and improvements have been made in this release:

Important changes:

• A new config option maxConcurrentIncomingRequestKiB has been added to limit the maximum amount of request data being concurrently processed
  due to incoming requests. This limits Syncthing’s peak RAM usage when
  there are many connected devices all requesting file data. The default
  is 256MB.
• The config option maxConcurrentScans has been removed and replaced a
  new config option maxFolderConcurrency. In addition to just limiting
  concurrent scans it now also limits concurrent sync operations. the
  default is the number of available CPU threads (“GOMAXPROCS”).
• Syncthing now always runs the monitor process, which previously was
  disabled with -no-restart. This facilitates crash reporting and makes
  logging behaves more consistently. The observed behavior with
  -no-restart should be the same as before but the internals differ.
• The database schema has been improved and will result in a migration
  plus compaction at first startup after the upgrade.

Bug fixes:

• #4774: Doesn’t react to Ctrl-C when run in a subshell with -no-restart (Linux)
• #5952: panic: Should never get a deleted file as needed when we don’t have it
• #6281: Progress emitter uses 100% CPU
• #6300: lib/ignore: panic: runtime error: index out of range [0] with length 0
• #6304: Syncing issues, database missing sequence entries
• #6335: Crash or hard shutdown can case database inconsistency, out of sync

Enhancements:

• #5786: Consider always running the monitor process
• #5898: Database performance: reduce duplication
• #5914: Limit folder concurrency to improve performance
• #6302: Avoid thundering herd issue by global request limiter