Add http-server.max-request-header-size to properties.rst

Author: steveburnett

presto-docs/src/main/sphinx/admin/properties.rst

@@ -96,7 +96,7 @@ session properties are included.
 .. _tuning-memory:
 
 ``per-query-retry-limit``
-^^^^^^^^^^^^^^^^^^^^
+^^^^^^^^^^^^^^^^^^^^^^^^^
 
 * **Type:** ``integer``
 * **Minimum value:** ``0``
@@ -105,6 +105,17 @@ session properties are included.
 The number of times that a query is automatically retried in the case of a transient query or communications failure. 
 The default value ``0`` means that retries are disabled. 
 
+``http-server.max-request-header-size``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* **Type:** ``data size``
+* **Default value:** ``8 kB``
+
+The maximum size of the request header from the HTTP server. Because Presto 
+sessions are encoded in the headers of all requests to Presto servers, 
+the default value can cause errors when large session properties or other 
+large session information is involved. If this happens, increase the value.
+
 Memory Management Properties
 ----------------------------