Number of slots per host
IBM® Spectrum Symphony offers you the ability to specify a number of slots for each host in a resource group that is tailored to the individual host’s attributes. You can take advantage of this flexibility when you want to configure a different number of slots for each host in a group that has heterogeneous hosts. Heterogeneous hosts are defined as hosts having a non-uniform number of processors, cores, etc within a resource group or cluster. You can define the number of slots based on resource attributes (for example, the number of processors per host or the amount of maximum memory per host), which might differ among hosts. Without this ability, a user must list all of the hosts one by one in the resource group in order to set the number of slots per host in a heterogeneous cluster, which could reduce the cluster’s expandability and increase the burden of managing the cluster.
- Number of CPUs. By default, the number of CPUs is the number of cores (per processor) multiplied by the number of processors. However, depending on the configuration of parameter EGO_DEFINE_NCPUS in the ego.conf file, the number of CPUs can equate to other CPU resources such as the number of processors or threads.
- Number of processors
- Number of cores
- Maximum memory
IBM Spectrum Symphony allows you to configure the host attribute as a factor in a simple expression to derive a new value for host slots. For example, the number of host slots is equal to the number of cores multiplied by two.
For enhanced flexibility, IBM Spectrum Symphony also supports the use of advanced expressions to define the number of slots per host. For example, you can define the number of slots based on the type of host operating system. For a description of expression guidelines, refer to Understanding resource groups
Defining the number of slots per host can be achieved by configuration using the cluster management console.