LSB_MAX_JOB_DISPATCH_PER_SESSION in lsf.conf and MAX_SBD_CONNS in lsb.params are set automatically during mbatchd startup to enable the fastest possible job dispatch.
LSB_MAX_JOB_DISPATCH_PER_SESSION is the maximum number of job decisions that mbschd can make during one job scheduling session. The default value is LSB_MAX_JOB_DISPATCH_PER_SESSION = Min (MAX(300, Total CPUs), 3000).
MAX_SBD_CONNS is the maximum number of open file connections between mbatchd and sbatchd. The default value is MAX_SBD_CONNS = numOfHosts + (2 * LSB_MAX_JOB_DISPATCH_PER_SESSION)+200. This formula does not provide the exact number of SBD connections because it also calculates the lost and found hosts. Therefore, the calculated number of connections might be a few more than this theoretical number.
LSB_MAX_JOB_DISPATCH_PER_SESSION and MAX_SBD_CONNS affect the number of file descriptors. Although the system sets the default values for both parameters automatically during mbatchd startup, you can adjust them manually.
To decrease the load on the master LIM, you should not to configure the master host as the first host for the LSF_SERVER_HOSTS parameter.
The values of LSB_MAX_JOB_DISPATCH_PER_SESSION and MAX_SBD_CONNS are not changed dynamically. If hosts are added dynamically, mbatchd does not increase their values. Once all the hosts are added, you must run badmin mbdrestart to set the correct values. If you know in advance that the number of hosts in your cluster will dynamically grow or shrink, then you should configure these parameters beforehand.