protocol/server: make listen backlog value as configurable

problem:

When we call listen from protocol/server, we are giving a
hard coded valie of 10 if it is not manually given.
With multiplexing, especially when glusterd restarts all
clients may try to connect to the server at a time.
Which will result in overflowing the queue, and kernel
will complain about the errors.

Solution:

This patch will introduce a volume set command to make backlog
value as a configurable. This patch also changes the default
values for backlog from 10 to 128. This changes is only applicable
for sockets listening from protocol.

Example:

gluster volume set <volname> transport.listen-backlog 1024

Note: 1 Brick has to be restarted to get this value in effect
      2 This changes won't be reflected in glusterd, or other
        xlators which calls listen. If you need, you have to
        add this option to the volfile.

Change-Id: I0c5a2bbf28b5db612f9979e7560e05dd82b41477
BUG: 1456405
Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>
Reviewed-on: https://review.gluster.org/17411
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-by: Raghavendra Talur <rtalur@redhat.com>
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Reviewed-by: Jeff Darcy <jeff@pl.atyp.us>

1 files changed, 3 insertions, 5 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd.c b/xlators/mgmt/glusterd/src/glusterd.c
index 789bc6e9ed1..14c1c6ae942 100644
--- a/xlators/mgmt/glusterd/src/glusterd.c
+++ b/xlators/mgmt/glusterd/src/glusterd.c
@@ -462,14 +462,12 @@ glusterd_rpcsvc_options_build (dict_t *options)
         int             ret = 0;
         uint32_t        backlog = 0;
 
-        ret = dict_get_uint32 (options, "transport.socket.listen-backlog",
-                               &backlog);
+        ret = dict_get_uint32 (options, "transport.listen-backlog", &backlog);
 
         if (ret) {
-                backlog = GLUSTERD_SOCKET_LISTEN_BACKLOG;
+                backlog = GLUSTERFS_SOCKET_LISTEN_BACKLOG;
                 ret = dict_set_uint32 (options,
-                                      "transport.socket.listen-backlog",
-                                      backlog);
+                                      "transport.listen-backlog", backlog);
                 if (ret)
                         goto out;
         }