Lustre 1.6 Operations Manual

31.2.2 SOCKLND Kernel TCP/IP LND
The SOCKLND kernel TCP/IP LND (socklnd) is connection-based and uses the
acceptor to establish communications via sockets with its peers.
It supports multiple instances and load balances dynamically over multiple
interfaces. If no interfaces are specified by the ip2nets or networks module
parameter, all non-loopback IP interfaces are used. The address-within-network is
determined by the address of the first IP interface an instance of the socklnd
encounters.
Consider a node on the “edge” of an InfiniBand network, with a low-bandwidth
management Ethernet (eth0), IP over IB configured (ipoib0), and a pair of GigE NICs
(eth1,eth2) providing off-cluster connectivity. This node should be configured with
"networks=vib,tcp(eth1,eth2)” to ensure that the socklnd ignores the management
Ethernet and IPoIB.
Variable
timeout
(50,W)
nconnds
(4)
min_reconnectms
(1000,W)
max_reconnectms
(6000,W)
eager_ack
(0 on linux,
1 on darwin,W)
typed_conns
(1,Wc)
min_bulk
(1024,W)
tx_buffer_size,
rx_buffer_size
(8388608,Wc)
nagle
(0,Wc)
Description
Time (in seconds) that communications may be stalled before the
LND completes them with failure.
Sets the number of connection daemons.
Minimum connection retry interval (in milliseconds). After a failed
connection attempt, this is the time that must elapse before the first
retry. As connections attempts fail, this time is doubled on each
successive retry up to a maximum of 'max_reconnectms'.
Maximum connection retry interval (in milliseconds).
Boolean that determines whether the socklnd should attempt to
flush sends on message boundaries.
Boolean that determines whether the socklnd should use different
sockets for different types of messages. When clear, all
communication with a particular peer takes place on the same
socket. Otherwise, separate sockets are used for bulk sends, bulk
receives and everything else.
Determines when a message is considered "bulk".
Socket buffer sizes. Setting this option to zero (0), allows the
system to auto-tune buffer sizes. WARNING: Be very careful
changing this value as improper sizing can harm performance.
Boolean that determines if nagle should be enabled. It should never
be set in production systems.
31-8 Lustre 1.6 Operations Manual • September 2008