server: set http2 max frame size

else we get the default of 16k, which is quite low for our use case.
this improves the TLS upload benchmark speed by about 30-40% for me.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

Cargo.toml

@@ -26,7 +26,7 @@ futures = "0.3"
 h2 = { version = "0.2", features = ["stream"] }
 handlebars = "3.0"
 http = "0.2"
-hyper = "0.13"
+hyper = "0.13.6"
 lazy_static = "1.4"
 libc = "0.2"
 log = "0.4"

src/api2/backup.rs

@@ -159,6 +159,7 @@ async move {
                 let window_size = 32*1024*1024; // max = (1 << 31) - 2
                 http.http2_initial_stream_window_size(window_size);
                 http.http2_initial_connection_window_size(window_size);
+                http.http2_max_frame_size(4*1024*1024);
 
                 http.serve_connection(conn, service)
                     .map_err(Error::from)

src/api2/reader.rs

@@ -121,6 +121,7 @@ fn upgrade_to_backup_reader_protocol(
                         let window_size = 32*1024*1024; // max = (1 << 31) - 2
                         http.http2_initial_stream_window_size(window_size);
                         http.http2_initial_connection_window_size(window_size);
+                        http.http2_max_frame_size(4*1024*1024);
 
                         http.serve_connection(conn, service)
                             .map_err(Error::from)