You are here: 17 Object Triggers > References > Trigger Components

17.17 Trigger Components

17.17.1 Required Trigger Components

17.17.1.A AType

Action type	Description
cancel	Cancels the object
changeparam	Causes Moab to give a parameter to a new value
exec	Launches an external program or script on the command line when the dependencies are fulfilled. See Using a Trigger to Execute a Script for more information.
internal	Modifies Moab without using the command line. See Using a Trigger to Perform Internal Moab Actions for more information.
jobpreempt	Indicates the preempt policy to apply to all jobs currently allocated resources assigned to the trigger's parent reservation
mail	Causes Moab to send mail. See Using a Trigger to Send Email for more information.

17.17.1.B Action

Cancel Action
Format	NONE
Description	Indicates that Moab should cancel the reservation when the event occurs. No action should be specified.
Example	Etype=threshold,Threshold=usage<10,FailOffset=1:00,AType=cancel When less than 10% of the reservation has been in use for a minute, Moab cancels it.

Changeparam Action
Format	Action="<STRING>"
Description	Specifies the parameter to change and its new value (using the same syntax and behavior as the changeparam command)
Example	Atype=changeparam,Action="JOBCPURGETIME 02:00:00" Moab maintains detailed job information for two hours after a job has completed.

Jobpreempt Action
Format	Action="cancel\|checkpoint\|requeue\|suspend"
Description	Signifies PREEMPTPOLICY to apply to jobs that are running on allocated resources
Example	RSVPROFILE[adm1] TRIGGER=EType=start,Offset=-240,AType=jobpreempt,Action="cancel" 40 minutes after the reservation adm1 starts, all jobs using the reservation's resources adopt a PREEMPTPOLICY of cancel.

Mail Action
Format	Action="<MESSAGE>"
Description	When AType=mail, the Action parameter contains the message body of the email. This can be configured to include certain variables. See Using a Trigger to Send Email for details. Mail triggers can be configured to launch for node failures, reservation creation or release, scheduler failures, and even job events. In this way, site administrators can keep track of scheduler events through email. The email comes from moabadmin, has a subject of moab update, and has a body of whatever you specified in the Action attribute. The recipient list depends on the type of object the trigger is attached to. Node - The primary user (first listed in ADMINCFG[1]), typically `root` Scheduler - The primary user Job - The user who owns the job Reservation - The primary user
Example	NODECFG[DEFAULT] TRIGGER=EType=fail,AType=mail,Action="node $OID will failed.",Offset=05:00:00 This example sends an email to the primary administrator informing him/her that the node (including the node ID) has failed.

Mail Action

Format Action="<MESSAGE>"

Description

When AType=mail, the Action parameter contains the message body of the email. This can be configured to include certain variables. See Using a Trigger to Send Email for details.

Mail triggers can be configured to launch for node failures, reservation creation or release, scheduler failures, and even job events. In this way, site administrators can keep track of scheduler events through email.

The email comes from moabadmin, has a subject of moab update, and has a body of whatever you specified in the Action attribute. The recipient list depends on the type of object the trigger is attached to.

Node - The primary user (first listed in ADMINCFG[1]), typically root
Scheduler - The primary user
Job - The user who owns the job
Reservation - The primary user

Example

NODECFG[DEFAULT] TRIGGER=EType=fail,AType=mail,Action="node $OID will failed.",Offset=05:00:00

This example sends an email to the primary administrator informing him/her that the node (including the node ID) has failed.

Exec Action
Format	Action="<script>"
Description	Exec triggers will launch an external program or script when their dependencies are fulfilled. The following example will submit job.cmd and then execute monitor.pl three minutes after the job is started. See Using a Trigger to Execute a Script for more information.
Example	> msub -l trig=EType=start\&AType=exec\&Action="/tmp/monitor.pl" job.cmd\&Offset=03:00

Internal Action
Format	Action="<objectType>:-:<cancel\|reserve>"
Description	A couple different actions are valid depending on what type of object the internal trigger is acting upon. The following list shows the available actions: Reserve a node Cancel a job Cancel a reservation See Using a Trigger to Perform Internal Moab Actions for more information.
Example	NODECFG[node01] TRIGGER=EType=start,AType=internal,Action="node:-:reserve" When node01 starts, it becomes a reservation. > msub moab.3 -l 'trig=EType=fail\&AType=internal\&Action="job:-:cancel" If moab.3 fails, Moab cancels it. > mrsvctl -c -a user==joe -h node50 -T EType=start,AType=internal,Action="reservation:-:cancel",Offset=10:00 User joe's jobs are given a ten-minute window to start, then the reservation cancels.

Internal Action

Format

Action="<objectType>:-:<cancel|reserve>"

Description

A couple different actions are valid depending on what type of object the internal trigger is acting upon. The following list shows the available actions:

Reserve a node
Cancel a job
Cancel a reservation

See Using a Trigger to Perform Internal Moab Actions for more information.

Example

NODECFG[node01] TRIGGER=EType=start,AType=internal,Action="node:-:reserve"

When node01 starts, it becomes a reservation.

> msub moab.3 -l 'trig=EType=fail\&AType=internal\&Action="job:-:cancel"

If moab.3 fails, Moab cancels it.

> mrsvctl -c -a user==joe -h node50 -T EType=start,AType=internal,Action="reservation:-:cancel",Offset=10:00

User joe's jobs are given a ten-minute window to start, then the reservation cancels.

17.17.1.C EType

Event type	Description
cancel	The event is triggered when the parent object is either canceled or deleted.
checkpoint	Triggers fire when the job is checkpointed. checkpoint triggers can only be attached to jobs.
create	Triggers fire when the parent object is created. create triggers can be attached to nodes, jobs, reservations, and the scheduler (when attached to the scheduler, triggers fire when Moab starts).
discover	Triggers fire when the node is loaded from a resource manager and Moab cannot recorgnize it nor find it in the checkpoint file.
end	Triggers fire when the parent object ends. end triggers can be attached to nodes, jobs, reservations, and the scheduler. When attached to the scheduler, triggers fire when Moab shuts down. When attached to jobs, triggers fire when jobs return successfully (completion code of 0).
fail	fail triggers can be attached to jobs, nodes, resource managers, and the scheduler. Triggers fire when the resource manager is in a corrupt or down state for longer than the configured fail time, when Moab detects a corruption in a node's reservation table, or when the job returns an unsuccessful completion code.
hold	Triggers fire when the job is put on hold. hold triggers can only be attached to jobs.
modify	Triggers fire when the parent object is modified. modify triggers can be attached to jobs and reservations
preempt	Triggers fire when the job is preempted. preempt triggers can only be attached to jobs.
standing	Triggers fire multiple times based on a certain period. They can be used with Period and Offset attributes. standing triggers can be attached to nodes and the scheduler.
start	Triggers fire when the parent object or Moab starts. start triggers can be attached to jobs, reservations, resource managers, and the scheduler (when Moab starts and at the beginning of Moab's first iteration).
threshold	Triggers fire when a threshold, such as usage or a gmetric comparison, is true. threshold triggers can be attached to nodes and reservations. Triggers with ETypes set to threshold must include the Threshold attribute.

17.17.1.D TType

Trigger type	Description
elastic	Specifies trigger for Elastic Computing. Only applicable for QoS triggers.
generic	Default trigger type. Not applicable for Elastic Computing.

Trigger type

Description

elastic

Specifies trigger for Elastic Computing. Only applicable for QoS triggers.

generic

Default trigger type. Not applicable for Elastic Computing.

17.17.2 Event-modifying Trigger Components

The following trigger attributes modify the event that causes the trigger to fire.

RearmTime
Possible Values	[[HH:]MM:]SS
Description	The amount of time that must pass before a trigger can fire again. RearmTime is enforced from the trigger event time.
Usage Notes	---

Offset
Possible Values	[-][[HH:]MM:]SS
Description	The relative time offset from event when trigger can fire
Usage Notes	Only end triggers can have a negative value for Offset. Offset cannot be used with cancel.

Period
Possible Values	Minute, Hour, Day, Week, Month, Infinity
Description	The period at which the trigger will regularly fire
Usage Notes	---

Threshold
Possible Values	Threshold={<metric>[<metricName>]}{> >= < <= ==}<FLOAT> Where <metric> is one of: gmetric usage
Description	When the object meets, drops below, or increases past the configured Threshold, the trigger will fire.
Usage Notes	Threshold triggers allow sites to configure triggers to launch based on internal scheduler statistics, such as the usage of a reservation.

FailOffset
Possible Values	[[HH:]MM:]SS
Description	The time that the threshold condition must exist before the trigger fires
Usage Notes	Use with fail triggers to avoid transient triggers.

17.17.3 Action-modifying Trigger Components

Flags
Possible Values	Flags=<flag>[:<flag>] or Flags=[<flag>][[<flag>]] attacherror - If the trigger outputs anything to stderr, Moab attaches it as a message to the trigger object. cleanup - If the trigger is still running when the parent object completes or is canceled, Moab kills the trigger. checkpoint - Moab always checkpoints this trigger. For more information, see Checkpointing a Trigger. objectxmlstdin - Trigger passes its parent's object XML information into the trigger's stdin. This only works for exec triggers with reservation type parents. removestdfiles - When the trigger is deleted, Moab will remove the stdin, stdout, and stderr files used by the trigger. resetonmodify - The trigger resets if its object is modified, even if RearmTime is not set. user - The trigger executes under the user ID of the object's owner. If the parent object is the scheduler, you may explicitly specify the user using the format `user+<username>`. For example: `Flags=user+john`.
Description	Specifies various trigger behaviors and actions
Usage Notes	When specifying multiple flags, each flag can be delimited by colons (:) or with square brackets; for example: `Flags=[user][cleanup]` or `Flags=user:cleanup`

Flags

Possible Values

Flags=<flag>[:<flag>] or Flags=[<flag>][[<flag>]]

attacherror - If the trigger outputs anything to stderr, Moab attaches it as a message to the trigger object.

cleanup - If the trigger is still running when the parent object completes or is canceled, Moab kills the trigger.

checkpoint - Moab always checkpoints this trigger. For more information, see Checkpointing a Trigger.

objectxmlstdin - Trigger passes its parent's object XML information into the trigger's stdin. This only works for exec triggers with reservation type parents.

removestdfiles - When the trigger is deleted, Moab will remove the stdin, stdout, and stderr files used by the trigger.

resetonmodify - The trigger resets if its object is modified, even if RearmTime is not set.

user - The trigger executes under the user ID of the object's owner. If the parent object is the scheduler, you may explicitly specify the user using the format user+<username>. For example: Flags=user+john.

Description Specifies various trigger behaviors and actions

Usage Notes

When specifying multiple flags, each flag can be delimited by colons (:) or with square brackets; for example:

Flags=[user][cleanup] or Flags=user:cleanup

BlockTime
Possible Values	[[HH:]MM:]SS
Description	The amount of time Moab will suspend normal operation to wait for trigger execution to finish
Usage Notes	Use caution; Moab will completely stop normal operation until BlockTime expires.

ExpireTime
Possible Values	<INTEGER>
Description	The time at which trigger should be terminated if it has not already been activated
Usage Notes	---

Timeout
Possible Values	[+\|-][[HH:]MM:]SS
Description	The time allotted to this trigger before it is marked as unsuccessful and its process (if any) killed
Usage Notes	---

MaxRetry
Possible Values	MaxRetry=<INTEGER>
Description	The number of times Action will be attempted before the trigger is designated a failure
Usage Notes	If Action fails, the trigger will restart immediately (up to MaxRetry times). If it fails more than MaxRetry times, the trigger has failed. This restart ignores FailOffset and RearmTime.

17.17.4 Organizational Trigger Components

Name
Possible Values	Name=<STRING>
Description	Name of the trigger
Usage Notes	Because Moab uses its own internal ID to distinguish triggers, the Name need not be unique. Only the first 16 characters of Name are stored by Moab.

Description
Possible Values	Description=<STRING>
Description	Description of the trigger
Usage Notes	---