drbd: New net configuration option socket-check-timeout

In setups involving a DRBD-proxy and connections that experience a lot of
buffer-bloat it might be necessary to set ping-timeout to an
unusual high value. By default DRBD uses the same value to wait if a newly
established TCP-connection is stable. Since the DRBD-proxy is usually located
in the same data center such a long wait time may hinder DRBD's connect process.

In such setups socket-check-timeout should be set to
at least to the round trip time between DRBD and DRBD-proxy. I.e. in most
cases to 1.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This commit is contained in:
Philipp Reisner 2014-03-18 14:24:35 +01:00
parent 4920e37a9e
commit 5d0b17f1a2
3 changed files with 36 additions and 16 deletions

View File

@ -819,7 +819,7 @@ static int receive_first_packet(struct drbd_connection *connection, struct socke
* drbd_socket_okay() - Free the socket if its connection is not okay
* @sock: pointer to the pointer to the socket.
*/
static int drbd_socket_okay(struct socket **sock)
static bool drbd_socket_okay(struct socket **sock)
{
int rr;
char tb[4];
@ -837,6 +837,30 @@ static int drbd_socket_okay(struct socket **sock)
return false;
}
}
static bool connection_established(struct drbd_connection *connection,
struct socket **sock1,
struct socket **sock2)
{
struct net_conf *nc;
int timeout;
bool ok;
if (!*sock1 || !*sock2)
return false;
rcu_read_lock();
nc = rcu_dereference(connection->net_conf);
timeout = (nc->sock_check_timeo ?: nc->ping_timeo) * HZ / 10;
rcu_read_unlock();
schedule_timeout_interruptible(timeout);
ok = drbd_socket_okay(sock1);
ok = drbd_socket_okay(sock2) && ok;
return ok;
}
/* Gets called if a connection is established, or if a new minor gets created
in a connection */
int drbd_connected(struct drbd_peer_device *peer_device)
@ -878,8 +902,8 @@ static int conn_connect(struct drbd_connection *connection)
struct drbd_socket sock, msock;
struct drbd_peer_device *peer_device;
struct net_conf *nc;
int vnr, timeout, h, ok;
bool discard_my_data;
int vnr, timeout, h;
bool discard_my_data, ok;
enum drbd_state_rv rv;
struct accept_wait_data ad = {
.connection = connection,
@ -923,17 +947,8 @@ static int conn_connect(struct drbd_connection *connection)
}
}
if (sock.socket && msock.socket) {
rcu_read_lock();
nc = rcu_dereference(connection->net_conf);
timeout = nc->ping_timeo * HZ / 10;
rcu_read_unlock();
schedule_timeout_interruptible(timeout);
ok = drbd_socket_okay(&sock.socket);
ok = drbd_socket_okay(&msock.socket) && ok;
if (ok)
break;
}
if (connection_established(connection, &sock.socket, &msock.socket))
break;
retry:
s = drbd_wait_for_connect(connection, &ad);
@ -979,8 +994,7 @@ static int conn_connect(struct drbd_connection *connection)
goto out_release_sockets;
}
ok = drbd_socket_okay(&sock.socket);
ok = drbd_socket_okay(&msock.socket) && ok;
ok = connection_established(connection, &sock.socket, &msock.socket);
} while (!ok);
if (ad.s_listen)

View File

@ -174,6 +174,7 @@ GENL_struct(DRBD_NLA_NET_CONF, 5, net_conf,
/* 9: __str_field_def(31, DRBD_GENLA_F_MANDATORY, name, SHARED_SECRET_MAX) */
/* 9: __u32_field(32, DRBD_F_REQUIRED | DRBD_F_INVARIANT, peer_node_id) */
__flg_field_def(33, 0 /* OPTIONAL */, csums_after_crash_only, DRBD_CSUMS_AFTER_CRASH_ONLY_DEF)
__u32_field_def(34, 0 /* OPTIONAL */, sock_check_timeo, DRBD_SOCKET_CHECK_TIMEO_DEF)
)
GENL_struct(DRBD_NLA_SET_ROLE_PARMS, 6, set_role_parms,

View File

@ -225,4 +225,9 @@
#define DRBD_AL_STRIPE_SIZE_MAX 16777216
#define DRBD_AL_STRIPE_SIZE_DEF 32
#define DRBD_AL_STRIPE_SIZE_SCALE 'k' /* kilobytes */
#define DRBD_SOCKET_CHECK_TIMEO_MIN 0
#define DRBD_SOCKET_CHECK_TIMEO_MAX DRBD_PING_TIMEO_MAX
#define DRBD_SOCKET_CHECK_TIMEO_DEF 0
#define DRBD_SOCKET_CHECK_TIMEO_SCALE '1'
#endif