{section: How to insert custom ClassAd attributes into a machine ad}

Known to work with HTCondor version: 7.0

In the following exapmles, a custom {quote: ClassAd} attribute named _MachineOwner_ is created with the value "chemistry".  You can use whatever attribute name you want, but avoid conflicting with attribute names used by HTCondor.  See the manual or run {code}condor_status -long{endcode} on a machine to see the attributes that are there.

{subsection: How to insert custom ClassAd attributes in a machine ad via the config file}

Using the config file to insert a custom machine attribute is particularly
appropriate for static attribute values that do not change often - if your attribute value is dynamic, see below.

{code}
MachineOwner = "chemistry"
STARTD_ATTRS = $(STARTD_ATTRS) MachineOwner
{endcode}

If you want different values for different slots within the same machine, do this:

{code}
SLOT1_MachineOwner = "chemistry"
SLOT2_MachineOwner = "physics"

STARTD_ATTRS = $(STARTD_ATTRS) MachineOwner
{endcode}

*Alternate*.  If you are using HTCondor 8.3.8 or later, you can set different attributes in different slot *types*. This makes configuration simpler when the number of slots (and thus the slot id's) is not fixed, but varies based on some other configuration value such as NUM_CPUS

{code}
NUM_SLOTS_TYPE_1 = 2
NUM_SLOTS_TYPE_2 = $(NUM_CPUS) - $(NUM_SLOTS_TYPE_1)

STARTD_ATTRS = MachineOwner $(STARTD_ATTRS)

SLOT_TYPE_1_MachineOwner = "chemistry"
SLOT_TYPE_2_MachineOwner = "physics"
{endcode}

{subsection: How to insert custom ClassAd attributes in a machine ad via a script}

You can insert dynamic attributes that are periodically updated from a script.  Here's an example of what you put in the HTCondor configuration file to periodically call a script:

{code}
STARTD_CRON_JOBLIST = CRON
CRON_JOBLIST =

CRON_JOBLIST = $(CRON_JOBLIST) kernel
CRON_kernel_PREFIX = kernel_
CRON_kernel_EXECUTABLE = /path/to/kernel
CRON_kernel_PERIOD = 1h
CRON_kernel_MODE = periodic
CRON_kernel_RECONFIG = false
CRON_kernel_KILL = true
CRON_kernel_ARGS =
{endcode}

The script named 'kernel' could add some attributes that give information about the system kernel.  For example, it could output something like the following:

{code}
version = "2.6.9-55.0.12.ELsmp"
bigmem = FALSE
hugemem = FALSE
{endcode}

Given the configuration above, this would result in {quote: ClassAd} attributes being added to the machine {quote: ClassAd} with the following names: kernel_version, kernel_bigmem, and kernel_hugemem.

{subsection: How to insert a custom ClassAd attribute into a machine ad from the Windows registry}

New in 7.5.6: A list of windows registry keys may be specified in the configuration file to be published in the machine {quote: ClassAd}. Example:

{code}
STARTD_PUBLISH_WINREG = \
 Perl_BinDir = HKLM\Software\Perl\BinDir; \
 Kerberos_Version = HKLM\SOFTWARE\MIT\Kerberos\Client\CurrentVersion\VersionString
{endcode}