Administering Platform LSF - SAS

Tuning mbatchd on UNIX
Operating system
support
Chapter 37
Tuning the Cluster
On UNIX platforms that support thread programming, you can change default
mbatchd behavior to use multithreading and increase performance of query
requests when you use the bjobs command.
Multithreading is beneficial for busy clusters with many jobs and frequent
query requests. This may indirectly increase overall mbatchd performance.
See the Online Support area of the Platform Computing Web site at
www.platform.com for the latest information about operating systems that support
multithreaded mbatchd.
In this section ◆ “How mbatchd works without multithreading” on page 491
◆ “How mbatchd works with multithreading” on page 491
◆ “Setting a query-dedicated port for mbatchd” on page 492
◆ “Specifying an expiry time for child mbatchds” on page 492
How mbatchd works without multithreading
Ports
Servicing
Requests
By default, mbatchd uses the port defined by the parameter LSB_MBD_PORT
in lsf.conf or looks into the system services database for port numbers to
communicate with LIM and job request commands.
It uses this port number to receive query requests from clients.
For every query request received, mbatchd forks a child mbatchd to service
the request. Each child mbatchd processes the request and then exits.
How mbatchd works with multithreading
To change mbatchd behavior to use multithreading, complete the following
procedures:
1 Mandatory.
Specify a query-dedicated port for the mbatchd. You do this by setting the
parameter LSB_QUERY_PORT in lsf.conf.
See “Setting a query-dedicated port for mbatchd” on page 492.
2 Optional.
Set an interval of time to indicate when a new child mbatchd is to be
forked. You do this by setting the parameter MBD_REFRESH_TIME in
lsb.params. The default value of MBD_REFRESH_TIME is 5 seconds, and
valid values are 5-300 seconds.
See “Specifying an expiry time for child mbatchds” on page 492.
When mbatchd has a dedicated port specified by the parameter
LSB_QUERY_PORT in lsf.conf, it forks a child mbatchd which in turn
creates threads to process query requests.
As soon as mbatchd has forked a child mbatchd, the child mbatchd takes over
and listens on the port to process more query requests. For each query request,
the child mbatchd creates a thread to process it.
Administering Platform LSF 491