Platform LSF Administration Guide Version 6.2

Chapter 37
Achieving Performance and Scalability
Administering Platform LSF
545
Limiting the number of batch queries
In large clusters, job querying can grow very quickly. If your site sees a lot of high traffic
job querying, you can tune LSF to limit the number of job queries that
mbatchd can
handle. This helps decrease the load on the master host.
If a job information query is sent after the limit has been reached, an error message is
displayed and
mbatchd keeps retrying, in one second intervals. If the number of job
queries later drops below the limit,
mbatchd handles the query.
You define the maximum number of concurrent jobs queries to be handled by
mbatchd
in the parameter
MAX_CONCURRENT_JOB_QUERY in lsb.params:
◆ If mbatchd is using multithreading, a dedicated query port is defined by the
parameter
LSB_QUERY_PORT in lsf.conf. When mbatchd has a dedicated
query port, the value of
MAX_CONCURRENT_JOB_QUERY sets the maximum
number of queries that can be handled by each child
mbatchd that is forked by
mbatchd. This means that the total number of job queries handled can be more
than the number specified by
MAX_CONCURRENT_JOB_QUERY
(MAX_CONCURRENT_JOB_QUERY
multiplied by the number of child daemons
forked by
mbatchd.)
◆ If mbatchd is not using multithreading, the value of
MAX_CONCURRENT_JOB_QUERY sets the maximum total number of job queries
that can be handled by
mbatchd
Syntax
MAX_CONCURRENT_JOB_QUERY= max_query
Where:
max_query
Specifies the maximum number of job queries that can be handled by mbatchd. Valid
values are positive integers between
1 and 100. The default value is unlimited.
Examples MAX_CONCURRENT_JOB_QUERY=20
Specifies that no more than 20 queries can be handled by mbatchd.
MAX_CONCURRENT_JOB_QUERY=101
Incorrect value. The default value will be used. An unlimited number of job queries will
be handled by
mbatchd.
Managing your user’s ability to move jobs in a queue
JOB_POSITION_CONTROL_BY_ADMIN=Y allows an LSF administrator to control
whether users can use
btop and bbot to move jobs to the top and bottom of queues.
When set, only the LSF administrator (including any queue administrators) can use
bbot and btop to move jobs within a queue. A user attempting to user bbot or btop
receives the error “User permission denied.”
Syntax JOB_POSITION_CONTROL_BY_ADMIN=Y
You must be an LSF administrator to set this parameter.