Defrag Daemon Configuration Options

These configuration variables affect the condor_defrag daemon. A general discussion of condor_defrag may be found in Defragmenting Dynamic Slots.

DEFRAG_NAME

Used to give a prefix value to the Name attribute in the condor_defrag daemon’s ClassAd. Defaults to the name given in the DAEMON_LIST. This esoteric configuration macro might be used in the situation where there are two condor_defrag daemons running on one machine, and each reports to the same condor_collector. Different names will distinguish the two daemons. See the description of MASTER_NAME in Master Daemon Configuration Options for defaults and composition of valid HTCondor daemon names.

DEFRAG_DRAINING_MACHINES_PER_HOUR

A floating point number that specifies how many machines should be drained per hour. The default is 0, so no draining will happen unless this setting is changed. Each condor_startd is considered to be one machine. The actual number of machines drained per hour may be less than this if draining is halted by one of the other defragmentation policy controls. The granularity in timing of draining initiation is controlled by DEFRAG_INTERVAL. The lowest rate of draining that is supported is one machine per day or one machine per DEFRAG_INTERVAL, whichever is lower. A fractional number of machines contributing to the value of DEFRAG_DRAINING_MACHINES_PER_HOUR is rounded to the nearest whole number of machines on a per day basis.

DEFRAG_DRAINING_START_EXPR

A ClassAd expression that replaces the machine’s START expression while it’s draining. Slots which accepted a job after the machine began draining set the machine ad attribute AcceptedWhileDraining to true. When the last job which was not accepted while draining exits, all other jobs are immediately evicted with a MaxJobRetirementTime of 0; job vacate times are still respected. While the jobs which were accepted while draining are vacating, the START expression is false. Using $(START) in this expression is usually a mistake: it will be replaced by the defrag daemon’s START expression, not the value of the target machine’s START expression (and especially not the value of its START expression at the time draining begins).

DEFRAG_REQUIREMENTS

An expression that narrows the selection of which machines to drain. By default condor_defrag will drain all machines that are drainable. A machine, meaning a condor_startd, is matched if any of its partitionable slots match this expression. Machines are automatically excluded if they cannot be drained, are already draining, or if they match DEFRAG_WHOLE_MACHINE_EXPR.

The condor_defrag daemon will always add the following requirements to DEFRAG_REQUIREMENTS

PartitionableSlot && Offline =!= true && Draining =!= true

DEFRAG_CANCEL_REQUIREMENTS

An expression that is periodically evaluated against machines that are draining. When this expression evaluates to True, draining will be cancelled. This defaults to $(DEFRAG_WHOLE_MACHINE_EXPR) . This could be used to drain partial rather than whole machines. Beginning with version 8.9.11, only machines that have no DrainReason or a value of "Defrag" for DrainReason will be checked to see if draining should be cancelled. Beginning with 10.7.0 The Defrag daemon will also check for its own name in the DrainReason.

DEFRAG_RANK

An expression that specifies which machines are more desirable to drain. The expression should evaluate to a number for each candidate machine to be drained. If the number of machines to be drained is less than the number of candidates, the machines with higher rank will be chosen. The rank of a machine, meaning a condor_startd, is the rank of its highest ranked slot. The default rank is -ExpectedMachineGracefulDrainingBadput.

DEFRAG_WHOLE_MACHINE_EXPR

An expression that specifies which machines are already operating as whole machines. The default is

Cpus == TotalSlotCpus

A machine is matched if any Partitionable slot on the machine matches this expression and the machine is not draining or was drained by condor_defrag. Each condor_startd is considered to be one machine. Whole machines are excluded when selecting machines to drain. They are also counted against DEFRAG_MAX_WHOLE_MACHINES.

DEFRAG_MAX_WHOLE_MACHINES

An integer that specifies the maximum number of whole machines. When the number of whole machines is greater than or equal to this, no new machines will be selected for draining. Each condor_startd is counted as one machine. The special value -1 indicates that there is no limit. The default is -1.

DEFRAG_MAX_CONCURRENT_DRAINING

An integer that specifies the maximum number of draining machines. When the number of machines that are draining is greater than or equal to this, no new machines will be selected for draining. Each draining condor_startd is counted as one machine. The special value -1 indicates that there is no limit. The default is -1.

DEFRAG_INTERVAL

An integer that specifies the number of seconds between evaluations of the defragmentation policy. In each cycle, the state of the pool is observed and machines are drained, if specified by the policy. The default is 600 seconds. Very small intervals could create excessive load on the condor_collector.

DEFRAG_UPDATE_INTERVAL

An integer that specifies the number of seconds between times that the condor_defrag daemon sends updates to the collector. (See Defrag ClassAd Attributes for information about the attributes in these updates.) The default is 300 seconds.

DEFRAG_SCHEDULE

A setting that specifies the draining schedule to use when draining machines. Possible values are graceful, quick, and fast. The default is graceful.

graceful

Initiate a graceful eviction of the job. This means all promises that have been made to the job are honored, including MaxJobRetirementTime. The eviction of jobs is coordinated to reduce idle time. This means that if one slot has a job with a long retirement time and the other slots have jobs with shorter retirement times, the effective retirement time for all of the jobs is the longer one.

quick

MaxJobRetirementTime is not honored. Eviction of jobs is immediately initiated. Jobs are given time to shut down according to the usual policy, as given by MachineMaxVacateTime.

fast

Jobs are immediately hard-killed, with no chance to gracefully shut down.

DEFRAG_LOG

The path to the condor_defrag daemon’s log file. The default log location is $(LOG)/DefragLog.