added note to v4 migration guide about worker thread update
@@ -9,6 +9,7 @@ Headings marked with :warning: are **breaking behavioral changes** and will prob
## Table of Contents:
- [MSRV](#msrv)
+- [Server Settings](#server-settings)
- [Module Structure](#module-structure)
- [`NormalizePath` Middleware :warning:](#normalizepath-middleware-warning)
- [`FromRequest` Trait](#fromrequest-trait)
@@ -20,6 +21,11 @@ Headings marked with :warning: are **breaking behavioral changes** and will prob
The MSRV of Actix Web has been raised from 1.42 to 1.54.
+## Server Settings
+
+Until actix-web v4, actix-server used the total number of available logical cores as the default number of worker threads. The new default number of worker threads for actix-server is the number of [physical CPU cores available](https://github.com/actix/actix-net/commit/3a3d654cea5e55b169f6fd05693b765799733b1b#diff-96893e8cb2125e6eefc96105a8462c4fd834943ef5129ffbead1a114133ebb78). For more information about this change, refer to [this analysis](https://github.com/actix/actix-web/issues/957).
+
+
## Module Structure
Lots of modules has been organized in this release. If a compile error refers to "item XYZ not found in module..." or "module XYZ not found", refer to the [documentation on docs.rs](https://docs.rs/actix-web) to to search for items' new locations.
