HOST_CONF(5)

NAME
host_conf - Grid Engine Enterprise Edition execution host configuration file format

DESCRIPTION
Host_conf reflects the format of the template file for the execution host configuration. Via the -ae and -me options of the command, you can add execution hosts and modify the configuration of any execution host in the cluster. Default execution host entries are added automatically as soon as a registers to for the very first time from a certain host. The -sel switch can be used to display a list of execution host being currently configured in your Grid Engine Enterprise Edition system. Via the -se option you can print the execution host configuration of a specified host.

The special hostname "global" can be used to define cluster global characteristics.

FORMAT
The format of a host_conf file is defined as follows:

hostname
    The name of the execution host.

load_scaling
    A comma separated list of scaling values to be applied to each or part of the load values being reported by the on the host and being defined in the cluster global "host" complex (see The load scaling factors are intended to level hardware or operating system specific differences between execution hosts. If, for example, the load average value (load_avg in the "host" complex; see also of a multiprocessor machine is to be compared with a single processor machine the load as reported by the single CPU host needs to be weighted up against the multiprocessor load (given the same CPU hardware) to be comparable. The load scaling factors are integers being multiplied with the reported load quantities to constitute weighted load values. Thus, following the example given above, the load value of the single processor machine needs to be multiplied by the number of processors of the single processor machine to become comparable.

    The syntax of a load factor specification is as follows: First the name of the load value (as defined in the "host" complex) is given and, separated by an equal sign, the load scaling value is provided. No blanks are allowed in between the load_scaling value string.

    The parameter load_scaling is not meaningful for the definition of the "global" host.

complex_list
    The comma separated list of administrator defined complexes (see for details) to be associated with the host. Only complex attributes contained in the enlisted complexes and those from the "global" and "host" complex, which are implicitly attached to each host, can be used in the complex_values list below. In case of the "global" host, the "host" complex is not attached and only "global" complex attributes are allowed per default in the complex_values list of the "global" host.

    The default value for this parameter is NONE, i.e. no administrator defined complexes are associated with the host.

complex_values
    complex_values defines quotas for resource attributes managed via this host. Each complex attribute is followed by an "=" sign and the value specification compliant with the complex attribute type (see Quota specifications are separated by commas. Only attributes as defined in complex_list (see above) may be used.

    The quotas are related to the resource consumption of all jobs on a host in the case of consumable resources (see for details on consumable resources) or they are interpreted on a per job slot basis in the case of non-consumable resources. Consumable resource attributes are commonly used to manage free memory, free disk space or available floating software licenses while non-consumable attributes usually define distinctive characteristics like type of hardware installed.

    For consumable resource attributes an available resource amount is determined by subtracting the current resource consumption of all running jobs on the host from the quota in the complex_values list. Jobs can only be dispatched to a host if no resource requests exceed any corresponding resource availability obtained by this scheme. The quota definition in the complex_values list is automatically replaced by the current load value reported for this attribute, if load is monitored for this resource and if the reported load value is more stringent than the quota. This effectively avoids oversubscription of resources.

    Note: Load values replacing the quota specifications may have become more stringent because they have been scaled (see load_scaling above) and/or load adjusted (see The -F option of and the load display in the queue control dialog (activated by clicking on a queue icon while the "Shift" key is pressed) provide detailed information on the actual availability of consumable resources and on the origin of the values taken into account currently.

    Note also: The resource consumption of running jobs (used for the availability calculation) as well as the resource requests of the jobs waiting to be dispatched either may be derived from explicit user requests during job submission (see the -l option to or from a "default" value configured for an attribute by the administrator (see The -r option to can be used for retrieving full detail on the actual resource requests of all jobs in the system.

    For non-consumable resources Grid Engine Enterprise Edition simply compares the job's attribute requests with the corresponding specification in complex_values taking the relation operator of the complex attribute definition into account (see If the result of the comparison is "true", the host is suitable for the job with respect to the particular attribute. For parallel jobs each job slot to be occupied by a parallel task is meant to provide the same resource attribute value.

    Note: Only numeric complex attributes can be defined as consumable resources and hence non-numeric attributes are always handled on a per job slot basis.

    The default value for this parameter is NONE, i.e. no administrator defined resource attribute quotas are associated with the host.

load_values
    This entry cannot be configured but is only displayed in case of a -se command. All load values are displayed as reported by the on the host. The load values are enlisted in a comma separated list. Each load value start with its name, followed by an equal sign and the reported value.

processors
    This entry cannot be configured but is only displayed in case of a -se command. Its value is the number of processors which has been detected by on the corresponding host.

usage_scaling
    This entry is only present in a Grid Engine Enterprise Edition system. It is not available in Grid Engine.

    The format is equivalent to load_scaling (see above), the only valid attributes to be scaled however are cpu for CPU time consumption, mem for Memory consumption aggregated over the life-time of jobs and io for data transferred via any I/O devices. The default NONE means "no scaling", i.e. all scaling factors are 1.

resource_capability_factor
    This entry is only present in a Grid Engine Enterprise Edition system. It is not available in Grid Engine.

    The resource capability factor is used by Grid Engine Enterprise Edition when assigning jobs to execution hosts. The resource capability factor tells Grid Engine Enterprise Edition how the resources (CPU, memory, I/O, etc.) of one execution host compare to the resources of other execution hosts. This helps to ensure that a job requiring a large percentage of resources (i.e. lots of tickets) gets placed on an execution host containing a large percentage of the available resources. The load situation on the execution hosts is taken into account in addition, to guarantee that the selected host is both powerful enough and lightly loaded.

    For example, you might consider setting your resource capability factors for each execution host based on the number of CPUs, the speed of the CPUs and the installed main memory:

    	#_of_CPUs * (MHz/200) + GB_of_memory

    This would give an execution host with 32 200 MHz CPUs and 10 gigabytes of memory a resource capability factor of 42, while an execution host with 24 200 MHz CPUs and 40 gigabytes of memory would get a resource capability factor of 64, i.e. memory has a significant impact in this example.

    Other factors that you might want to consider in setting the resource capability factor are:

    	job mix	- CPU or memory bound jobs
    	CPU benchmarks	- comparison by CPU vendor
    	megaflops (MFLOPS)	- for number crunching
    	I/O capabilities	- disk/network speed
    	available disk space	- at the execution host

    The resource capability factor is stored as a floating point double value. The range of values used is not important. Grid Engine Enterprise Edition only looks at the relation between values of different hosts.

user_lists
    The user_lists parameter contains a comma separated list of so called user access lists as described in Each user contained in at least one of the enlisted access lists has access to the host. If the user_lists parameter is set to NONE (the default) any user has access being not explicitly excluded via the xuser_lists parameter described below. If a user is contained both in an access list enlisted in xuser_lists and user_lists the user is denied access to the host.

xuser_lists
    The xuser_lists parameter contains a comma separated list of so called user access lists as described in Each user contained in at least one of the enlisted access lists is not allowed to access the host. If the xuser_lists parameter is set to NONE (the default) any user has access. If a user is contained both in an access list enlisted in xuser_lists and user_lists the user is denied access to the host.

projects
    The projects parameter contains a comma separated list of projects that have access to the host. Any projects not in this list are denied access to the host. If set to NONE (the default), any project has access that is not specifically excluded via the xprojects parameter described below. If a project is in both the projects and xprojects parameters, the project is denied access to the host. This parameter is only available in a Grid Engine Enterprise Edition system.

xprojects
    The xprojects parameter contains a comma separated list of projects that are denied access to the host. If set to NONE (the default), no projects are denied access other than those denied access based on the projects parameter described above. If a project is in both the projects and xprojects parameters, the project is denied access to the host. This parameter is only available in a Grid Engine Enterprise Edition system.

SEE ALSO

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