Changeset 715 for draft-ietf-httpbis/latest/p1-messaging.xml

Timestamp:

Oct 21, 2009, 8:52:21 AM (10 years ago)

Author:

julian.reschke@…

Message:

Remove hard limit of two connections per server (see #131)

File:

• draft-ietf-httpbis/latest/p1-messaging.xml (modified) (3 diffs)

draft-ietf-httpbis/latest/p1-messaging.xml

@@ -2260 +2260 @@
 </t>
 <t>
-   Clients that use persistent connections &SHOULD; limit the number of
-   simultaneous connections that they maintain to a given server. A
-   single-user client &SHOULD-NOT; maintain more than 2 connections with
-   any server or proxy. A proxy &SHOULD; use up to 2*N connections to
-   another server or proxy, where N is the number of simultaneously
-   active users. These guidelines are intended to improve HTTP response
-   times and avoid congestion.
+   Clients (including proxies) &SHOULD; limit the number of simultaneous
+   connections that they maintain to a given server (including proxies).
+</t>
+<t>
+   Previous revisions of HTTP gave a specific number of connections as a
+   ceiling, but this was found to be impractical for many applications. As a
+   result, this specification does not mandate a particular maximum number of
+   connections, but instead encourages clients to be conservative when opening
+   multiple connections.
+</t>
+<t>
+   In particular, while using multiple connections avoids the "head-of-line
+   blocking" problem (whereby a request that takes significant server-side
+   processing and/or has a large payload can block subsequent requests on the
+   same connection), each connection used consumes server resources (sometimes
+   significantly), and furthermore using multiple connections can cause
+   undesirable side effects in congested networks. 
+</t>
+<t>
+   Note that servers might reject traffic that they deem abusive, including an
+   excessive number of connections from a client.
 </t>
 </section>
@@ -4635 +4649 @@
 </t>
 <t>
+  Remove hard limit of two connections per server.
+  (<xref target="persistent.practical"/>)
+</t>
+<t>
   Clarify exactly when close connection options must be sent.
   (<xref target="header.connection"/>)
@@ -5249 +5267 @@
     </t>
     <t>
+      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/131"/>:
+      "increase connection limit"
+    </t>
+    <t>
       <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/157"/>:
       "IP addresses in URLs"