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 256 MiB.
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 behave 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.
Bugfixes:
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
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