# RDP Preread When using the RDP protocol, this module allows extracting cookies, which are used for session identification and management, before making a load balancing decision. When [building from the source code](https://en.angie.software//angie/docs/installation/sourcebuild.md#sourcebuild), the module must be enabled with the `‑‑with‑stream_rdp_preread_module` [build option](https://en.angie.software//angie/docs/installation/sourcebuild.md#configure). In packages and images from [our repos](https://en.angie.software//angie/docs/installation/index.md#install-packages), the module is included in the build. ## Configuration Example ### Binding to the Cookie-Issuing Server This configuration uses the `learn` mode of the [sticky](https://en.angie.software//angie/docs/configuration/modules/stream/stream_upstream.md#s-u-sticky) directive: ```nginx stream { rdp_preread on; upstream rdp { server 127.0.0.1:3390 sid=a; server 127.0.0.1:3391 sid=b; sticky learn lookup=$rdp_cookie create=$rdp_cookie zone=sessions:1m; } } ``` ## Directives ### rdp_preread | [Syntax](https://en.angie.software//angie/docs/configuration/configfile.md#configfile) | `rdp_preread` `on` | `off`; | |------------------------------------------------------------------------------------------|-------------------------------| | Default | `rdp_preread off;` | | [Context](https://en.angie.software//angie/docs/configuration/configfile.md#configfile) | stream, server | Controls extracting information from RDP protocol cookies during the [preread stage](https://en.angie.software//angie/docs/configuration/processing.md#stream-sessions). If the setting is `on`, the variables listed below will be populated in the context where it is specified. ## Built-in Variables The semantics of cookie values depend on the RDP protocol version. ### `$rdp_cookie` The entire cookie value. ### `$rdp_cookie_` The value of the cookie field with the specified name.