Administering Platform LSF - SAS

Adding and Removing Hosts Dynamically
WARNING
Chapter 4
Working with Hosts
By default, all configuration changes made to LSF are static. You must manually
change the configuration and restart the cluster (or at least all master
candidates). Dynamic host configuration allows you to add hosts to the cluster
or remove them without manually changing the configuration.
When the dynamic host configuration is enabled, any host will be able to
join the cluster. You can limit which hosts can be LSF hosts with the
parameter LSF_HOST_ADDR_RANGE in lsf.cluster.cluster_name.
How dynamic host configuration works
Master LIM
For dynamic host configuration, the master LIM:
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Master candidate LIMs (LSF_MASTER_LIST)
Receives request to add hosts
Informs other master candidates to refresh themselves when a host is
added or removed
Detects host unavailability and, if LSF_DYNAMIC_HOST_TIMEOUT is
defined, removes unavailable hosts that are not master candidates
To enable dynamic host configuration, you must define LSF_MASTER_LIST in
lsf.conf. Specify a list of hosts that are candidates to become the master
host for the cluster.
This set of hosts reads the LSF configuration files when a new host is added to
the cluster; other hosts (slave hosts) only receive the host configuration from
master LIM. LSF_MASTER_LIST also identifies the hosts that need to be
reconfigured after configuration change.
Master candidate hosts are informed when a new host is added. When a master
candidate becomes master host, its LIM receives requests from dynamic hosts
to add them to the cluster.
Master candidate hosts should share LSF configuration and binaries.
Slave LIMs
Dynamically added LSF hosts that will not be master candidates are slave
hosts. Each dynamic slave host has its own LSF binaries and local lsf.conf
and shell environment scripts (cshrc.lsf and profile.lsf). You must
install LSF on each slave host.
If LSF_STRICT_CHECKING is defined in lsf.conf to protect your cluster in
untrusted environments, and your cluster has slave hosts that are
dynamically added, LSF_STRICT_CHECKING must be configured in the local
lsf.conf on all slave hosts.
Slave LIMs report their availability to the master LIM when they start. When
each slave host starts, it first contacts the master LIM to add itself to the cluster.
The master host adds the host if it is not in its host table, or returns ok if the
host has already been added.
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