HTTP: Add TCP_NODELAY to accepted connections

This adds the TCP_NODELAY option to accepted connections on the HTTP
server built into Asterisk. This option disables the Nagle algorithm
which controls queueing of outbound data and in some cases can cause
delays on receipt of response by the client due to how the Nagle
algorithm interacts with TCP delayed ACK. This option is already set on
all non-HTTP AMI connections and this change would cover standard HTTP
requests, manager HTTP connections, and ARI HTTP requests and
websockets in Asterisk 12+ along with any future use of the HTTP
server.

Review: https://reviewboard.asterisk.org/r/3466/

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@412745 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/main/http.c b/main/http.c
index 1770dd30ac5b662dbd5daafbdc01a0463ebd0ec5..cc3fc9fc51f4859d05329f3c8be34576ffa5826c 100644 (file)
--- a/main/http.c
+++ b/main/http.c
@@ -883,11 +883,27 @@ static void *httpd_helper_thread(void *data)
        char *uri, *method;
        enum ast_http_method http_method = AST_HTTP_UNKNOWN;
        int remaining_headers;
+       struct protoent *p;
 
        if (ast_atomic_fetchadd_int(&session_count, +1) >= session_limit) {
                goto done;
        }
 
+       /* here we set TCP_NODELAY on the socket to disable Nagle's algorithm.
+        * This is necessary to prevent delays (caused by buffering) as we
+        * write to the socket in bits and pieces. */
+       p = getprotobyname("tcp");
+       if (p) {
+               int arg = 1;
+               if( setsockopt(ser->fd, p->p_proto, TCP_NODELAY, (char *)&arg, sizeof(arg) ) < 0 ) {
+                       ast_log(LOG_WARNING, "Failed to set TCP_NODELAY on HTTP connection: %s\n", strerror(errno));
+                       ast_log(LOG_WARNING, "Some HTTP requests may be slow to respond.\n");
+               }
+       } else {
+               ast_log(LOG_WARNING, "Failed to set TCP_NODELAY on HTTP connection, getprotobyname(\"tcp\") failed\n");
+               ast_log(LOG_WARNING, "Some HTTP requests may be slow to respond.\n");
+       }
+
        if (!fgets(buf, sizeof(buf), ser->f)) {
                goto done;
        }

diff --git a/main/manager.c b/main/manager.c
index 557353b1231ec7ed17e724e4864543ecaccc1c5e..586fef566950e984989f18dfbbea13011b07e49e 100644 (file)
--- a/main/manager.c
+++ b/main/manager.c
@@ -5089,7 +5089,7 @@ static void *session_do(void *data)
 
        /* here we set TCP_NODELAY on the socket to disable Nagle's algorithm.
         * This is necessary to prevent delays (caused by buffering) as we
-        * write to the socket in bits and peices. */
+        * write to the socket in bits and pieces. */
        p = getprotobyname("tcp");
        if (p) {
                int arg = 1;