socket: use TCP_USER_TIMEOUT to detect client failures quicker

Use the network.ping-timeout to set the TCP_USER_TIMEOUT socket option
(see 'man 7 tcp'). The option sets the transport.tcp-user-timeout option
that is handled in the rpc/socket layer on the protocol/server side.
This socket option makes detecting unclean disconnected clients more
reliable.

When the socket gets closed, any locks that the client held are been
released. This makes it possible to reduce the fail-over time for
applications that run on systems that became unreachable due to
a network partition or general system error client-side (kernel panic,
hang, ...).

It is not trivial to create a test-case for this at the moment. We need
a client that unclean disconnects and an other client that tries to take
over the lock from the disconnected client.

URL: http://supercolony.gluster.org/pipermail/gluster-devel/2014-May/040755.html
Change-Id: I5e5f540a49abfb5f398291f1818583a63a5f4bb4
BUG: 1129787
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/8065
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: soumya k <skoduri@redhat.com>
Reviewed-by: Santosh Pradhan <santosh.pradhan@gmail.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/rpc/rpc-lib/src/rpc-transport.c b/rpc/rpc-lib/src/rpc-transport.c
index f6774b72353..23fbf37360d 100644
--- a/rpc/rpc-lib/src/rpc-transport.c
+++ b/rpc/rpc-lib/src/rpc-transport.c
@@ -572,7 +572,7 @@ out:
 //why call it if you dont set it.
 int
 rpc_transport_keepalive_options_set (dict_t *options, int32_t interval,
-                                     int32_t time)
+                                     int32_t time, int32_t timeout)
 {
         int                     ret = -1;
 
@@ -588,6 +588,11 @@ rpc_transport_keepalive_options_set (dict_t *options, int32_t interval,
                 "transport.socket.keepalive-time", time);
         if (ret)
                 goto out;
+
+        ret = dict_set_int32 (options,
+                "transport.tcp-user-timeout", timeout);
+        if (ret)
+                goto out;
 out:
         return ret;
 }