LSF Version 7.3 - Administering Platform LSF

Administering Platform LSF 75
Working with Hosts
Adding Hosts Dynamically
By default, all configuration changes made to LSF are static. To add or remove hosts
within the cluster, you must manually change the configuration and restart all
master candidates.
Dynamic host configuration allows you to add and remove hosts without manual
reconfiguration. To enable dynamic host configuration, all of the parameters
described in the following table must be defined.
IMPORTANT: If you choose to enable dynamic hosts when you install LSF, the installer adds the
parameter LSF_HOST_ADDR_RANGE to lsf.cluster.cluster_name using a default value
that allows any host to join the cluster. To enable security, configure LSF_HOST_ADDR_RANGE in
lsf.cluster.cluster_name after installation to restrict the hosts that can join your cluster.
How dynamic host configuration works
Master LIM The master LIM runs on the master host for the cluster. The master LIM receives
requests to add hosts, and tells the master host candidates defined by the parameter
LSF_MASTER_LIST to update their configuration information when a host is
dynamically added or removed.
Upon startup, both static and dynamic hosts wait to receive an acknowledgement
from the master LIM. This acknowledgement indicates that the master LIM has
added the host to the cluster. Static hosts normally receive an acknowledgement
because the master LIM has access to static host information in the LSF
configuration files. Dynamic hosts do not receive an acknowledgement, however,
until they announce themselves to the master LIM. The parameter
LSF_DYNAMIC_HOST_WAIT_TIME in
lsf.conf determines how long a
dynamic host waits before sending a request to the master LIM to add the host to
the cluster.
Master candidate LIMs The parameter LSF_MASTER_LIST defines the list of master host candidates.
These hosts receive updated host information from the master LIM so that any
master host candidate can take over as master host for the cluster.
IMPORTANT: Master candidate hosts should share LSF configuration and binaries.
Parameter Defined in … Description
LSF_MASTER_LIST lsf.conf Defines a list of master host candidates.
These hosts receive information when a
dynamic host is added to or removed
from the cluster. Do not add dynamic
hosts to this list, because dynamic hosts
cannot be master hosts.
LSF_DYNAMIC_HOST_WAIT_TIME
lsf.conf Defines the length of time a dynamic
host waits before sending a request to
the master LIM to add the host to the
cluster.
LSF_HOST_ADDR_RANGE
lsf.cluster.cluster_name Identifies the range of IP addresses for
hosts that can dynamically join or leave
the cluster.