GlideinWMS The Glidein-based Workflow Management System

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WMS Factory

Custom Condor Variables

Description

This document describes what configuration variables are used by the glideins. Most administrators never need to touch most of them, but a sophisticated Glidein Factory administrator may need to tweak some of them to implement the desired policies (for example: require encryption over the wire) or to address the needs of a particular site (for example: max allowed wallclock time).

Configuration variable location

The glideinWMS ships with a set of pre-defined configuration variables, that are stored in two files, known as condor vars files:

glideinWMS/creation/web_base/condor_vars.lst
glideinWMS/creation/web_base/condor_vars.lst.entry

The two files are equivalent, but were split for historical reasons, and the second one is meant to contain site specific configuration variables.
These files should never be modified, and represent just the default shipped by the software!

A glideinWMS administrator can change the values of the predefined variables (with some exceptions, see below), and define new ones using the Glidein Factory configuration file.

Condor vars files

The condor vars files contain the glideinWMS pre-defined configuration variables, and should never be modified.
However, a glideinWMS administrator should nevertheless be able to read them.

Each of them is an ASCII file, with one entry per row.
Lines starting with # are comments and are ignored.

Each non comment line must have 7 columns. Each column has a specific meaning:

  1. Attribute name
  2. Attribute type
    • I – integer
    • S – quoted string
    • C – unquoted string (i.e. Condor keyword or expression)
  3. Default value, use – if no default
  4. Condor name, i.e. under which name should this attributed be known in the configuration used by Condor daemons
  5. Is a value required for this attribute?
    Must be Y or N. If Y and the attribute is not defined, the glidein will fail.
  6. Will condor_startd publish this attribute to the collector?
    Must be Y or N.
  7. Will the attribute be exported to the user job environment?
    • - - Do not export (for glidein/condor internal use)
    • + - Export to the user job environment using the original attribute name
    • @ - Export to the user job environment using the Condor name

Here below, you can see a short extract; the semantics of the variables is defined below.

# VarName               Type    Default         CondorName                      Req.    Export  UserJobEnvName
#                       S=Quote - = No Default  + = VarName                             Condor  - = Do not export
#                                                                                               + = Use VarName
#                                                                                               @ = Use CondorName
#################################################################################################################
X509_USER_PROXY         C       -               GSI_DAEMON_PROXY                Y       N       -
USE_MATCH_AUTH          C       -     SEC_ENABLE_MATCH_PASSWORD_AUTHENTICATION  N       N       -
GLIDEIN_Factory         S       -               +                               Y       Y       @
GLIDEIN_Name            S       -               +                               Y       Y       @
GLIDEIN_Collector       C       -               HEAD_NODE                       Y       N       -
GLIDEIN_Expose_Grid_Env C       False     JOB_INHERITS_STARTER_ENVIRONMENT      N       Y       +
TMP_DIR                 S       -               GLIDEIN_Tmp_Dir                 Y       Y       @
CONDORG_CLUSTER         I       -               GLIDEIN_ClusterId               Y       Y       @
CONDORG_SUBCLUSTER      I       -               GLIDEIN_ProcId                  Y       Y       @
CONDORG_SCHEDD          S       -               GLIDEIN_Schedd                  Y       Y       @
SEC_DEFAULT_ENCRYPTION  C       OPTIONAL        +                               N       N       -
SEC_DEFAULT_INTEGRITY   C       REQUIRED        +                               N       N       -
MAX_MASTER_LOG          I       1000000         +                               N       N       -
MAX_STARTD_LOG          I       10000000        +                               N       N       -

Glidein Variables

This section defines all the variables that the glideins explicity use. Please be aware that, apart from the below mentioned variable many other variables will be used by the Condor daemons, since glideins are Condor based; see the Condor manual for more details.

The variables can be divided based on their source:

Factory config xml - attr tags

This section presents all the variables that can be directly changed by a Glidein Factory administrator using attr tags in the factory configuration XML using the following tags:

<attr name=“namevalue=“valtype=“type” .../>

More information on the XML format can be found in Glidein Factory configuration section.
If not specified in the XML, most of these variables have defaults set in condor vars files, which are used if the Glidein Factory administrator does not override them. These defaults are listed below.

Please also note that some of these variables may also be provided by the VO factory clients.

Specifies whether preemption is allowed to occur on this glidein.

Name

Type

Default Value

Description

GLIDEIN_Site String Entry name

Logical name of the Grid site where the glidein is running. This information is published both in the startd ClassAd and in the user job environment.

GLIDEIN_Hold Exp (Bool) True

Condor expression to use to specify when a user job in the glideins should be held. If any expression is true, the glidein is held. This is usually done to specify "bad" jobs, such as those that claim too much memory.

GLIDEIN_Entry_PREEMPT Exp (Bool) True
GLIDEIN_PREEMPT Exp (Bool) True

Condor expression to use to specify when a user job in the glideins should be preempted. If any expression is true, the glidein is preempted. This is usually done to specify custom preemption policies for user jobs.

GLIDEIN_Rank Exp (Int) 1

Used in calculating the Condor RANK

They are summed together, and the user job with the largest rank will run first.

GLIDEIN_Entry_Rank Exp (Int) 1
GLIDEIN_Max_Idle Int 1200
(20 mins)

Max amount of time a condor_startd will wait to be matched before giving up and terminating.

GLIDEIN_Max_Tail Int 400
(6 mins)

Max amount of time a condor_startd will wait after having already completed a job to be matched again. (i.e. the tail of a job).

GLIDEIN_Retire_Time Int 21600
(6 hours)

How long the condor_startd be running before no longer accepting jobs.
The random spread is used to improve the efficiencies, so the actual value used by Condor will be anywhere between GRT-GRTS and GRT.

GLIDEIN_Retire_Time_Spread Int 7200
(2 hours)
GLIDEIN_Max_Walltime Int N/A

Max allowed time for the glidein.
This variable is optional. If you specify this variable, then Condor startup scripts will calculate the GLIDEIN_Retire_Time for the glidein as GLIDEIN_MAX_Walltime - GLIDEIN_Job_Max_Time. If GLIDEIN_Retire_Time is also specified, it will be ignored and only the calculated value is used. Note that if GLIDEIN_Job_Max_Time is specified but is greater than GLIDEIN_Max_Walltime or does not allow enough time for graceful shutdown, it will be reduced by the glidein. See Lifetime of a glidein for details.

GLIDEIN_Graceful_Shutdown Int 120

Once DAEMON_SHUTDOWN is reached and the glidein pilot enters the Retiring state, this amount passes to allow the startd and job to gracefully shutdown before forcefully terminating the glidein. See Lifetime of a glidein for details.

PREEMPT Bool False 1
PREEMPT_GRACE_TIME Int 10000000 This value affects the condor value "MaxJobRetirementtime" and is an integer value representing the number of seconds a preempted job will be allowed to run before being evicted. This only affects behaviour if PREEMPT=True.
HOLD_GRACE_TIME Int 0 This value affects the condor value "MaxJobRetirementtime" and is an integer value representing the number of seconds a job that triggers WANT_HOLD will be allowed to run before being evicted. This only affects behaviour if GLIDEIN_HOLD, GLIDEIN_Entry_HOLD, GLIDECLIENT_HOLD, or GLIDECLIENT_Group_HOLD are specified and become true. By default, these "bad" jobs are immediately evicted.
GLIDEIN_Monitoring_Enabled Bool True

Ability to control whether the pseduo-interactive monitoring slot is started on the worker node. Set to False if you do not want the monitoring slot started.

GLIDEIN_Resource_Slots String None

Special purpose slots added to the glidein. These slots will never be available for the regular jobs. This string is a semicolon separated list of comma separated resource descriptions. Each resource description contains the name and optionally the number of resources (default is 1), the total memory reserved (default is 128MB time the number of resources) and an option to say if the resource slots are partitionable or static (default is partitionable, unless there is only one slot).

Jobs submission must use require_RESOURCE=N with N>0 to use these slots, e.g. require_ioslot=1

Examples:

  • value="ioslot,2,200,static" creates statically partitioned 2 ioslot resources with 100MB memory each.
  • value="ioslot" creates 1 ioslot resource with 128MB
  • value="ioslot,2;monitor" creates (1) partitionable slot with 2 ioslot resources and 256MB total memory (2) 1 monitor slot resource with 128MB memory

GLEXEC_BIN String None

If set, Condor will launch all user jobs via glexec, thus running the job under the appropriate local account. This is important both for glideinWMS security and for accounting purposes.
A special value of "OSG" can be used to automatically find the locally installed gLExec on OSG worker nodes.

This variable is renamed to GLEXEC in the condor config.

GLEXEC_JOB Bool False

If set to False, the condor_starter is run sharing the same UID as the user job. This has security implications.

If running Condor 7.1.3 or later, it is recommended to turn this on and have the condor_starter be protected from the user jobs.

GLIDEIN_Use_PGroups Bool False

Should process group monitoring be enabled?

This is a Condor optimization parameter. Unfortunately, it negatively interferes with the batch systems used by the Grid sites, so it should not be turned on unless you have a very good reason to do so.

UPDATE_COLLECTOR_WITH_TCP Bool True

If True, forces the glidein to use TCP updates.
The collector must be configured in the same way for this to work.

Also see the Condor documentation for implications and side effects.

WANT_UDP_COMMAND_SOCKET Bool False

If True, enable the startd UDP command socket (Condor default).

Using the UDP command socket is a Condor optimization that makes working over firewalls and NATs very difficult. It is thus recommended you leave it disabled in the glideins.

Please note if you leave it disabled, that you must configure the schedd with
SCHEDD_SEND_VACATE_VIA_TCP = True
and the negotiator with
NEGOTIATOR_INFORM_STARTD = False
to have a functional system.

STARTD_SENDS_ALIVES Bool True

If set to False, the schedd will be sending keepalives to the startd.

Setting this to True instructs the startd to send keepalives to the schedd. This improves the glidein behavior when running behind a firewall or a NAT.

Please note that the schedd must be configured in the same way for this to work.

SEC_DEFAULT_INTEGRITY Exp REQUIRED

Security related settings. Please notice that the glideins always require GSI authentication.

For more details see the configuration page or the Condor manual.

SEC_DEFAULT_ENCRYPTION Exp OPTIONAL
USE_MATCH_AUTH Bool False

Another security setting.

If set to True, the schedd and the startd will use a low overhead protocol. See the configuration page or the Condor manual.

MAX_MASTER_LOG Int 1M

What is the maximum size the logs should grow.

Setting them too low will made debugging difficult.
Setting them too high may fill up the disk in anomalous situations, both on the work nodes and on the glidein factory.

MAX_STARTD_LOG Int 10M
MAX_STARTER_LOG Int 10M
GCB_LIST List -

Configure GCB.

GCB was needed to run glideins on worker nodes behind a firewall or a NAT in older versions of HTCondor.
Note: Newer versions of HTCondor do not support it anymore.

For more information, see the configuration page.

GCB_ORDER String
GCB_MIN_FREE Int
GCB_REMAP_ROUTE String
MASTER_GCB_RECONNECT_TIMEOUT Int 1200
(20 mins)

Specifies how long should a glidein wait before giving up on a GCB, if network connectivity is lost.

USE_CCB Bool False

If set to True, it will enable HTCondor Connection Brokering (CCB), which is needed if the glideins are behind a firewall or a NAT.

USE_SHARED_PORT Bool False

If set to True, it will enable the shared port daemon, which will reduce the number of connections between the glidein and the collectors.

GLIDEIN_CPUS Int 1

Number of CPUs glidein should use. GLIDEIN_CPUS is used to set NUM_CPUS for the HTCondor started by the glidein. Use "auto" to let glidein determine this from the worker node, set a value to force a different number. In case of static partitioning, glidein will create GLIDEIN_CPUS number of slots. In case of dynamic partitioning, the slots will be created automatically based on the CPUs required by the job and GLIDEIN_CPUS is the sum of the slots made available. Refer to HTCondor manual for info on NUM_CPUS

GLIDEIN_MaxMemMBs Int None

Amount of memory glidein should use. If set, GLIDEIN_MaxMemMBs is used to set total MEMORY used for the HTCondor and Startd and jobs started by the glidein. If not GLIDEIN_MaxMemMBs is not set and GLIDEIN_MaxMemMBs_Estimate is TRUE, GLIDEIN_MaxMemMBs is calculated based on the memory available on the worker node. If GLIDEIN_MaxMemMBs is not set and GLIDEIN_MaxMemMBs_Estimate is not TRUE, glidein lets HTCondor decide the amount of memory. Refer to HTCondor manual for info on MEMORY

GLIDEIN_MaxMemMBs_Estimate Bool False

Used in conjunction with GLIDEIN_MaxMemMBs. See GLIDEIN_MaxMemMBs for the description.

GLIDEIN_Factory_Report_Failed String ALIVEONLY

This attribute regulates advertising of validation failures to the Factory collector.

  • NEVER - The glidein will just fail, and do nothing.
  • ALIVEONLY - The glidein will advertise a Master ClassAd in Drained state and Retiring activity for the lifetime of the glidein script.
  • ALWAYS - Similar to ALIVEONLY, but will also send a final ClassAd in Drained state and Killing activity just before dying.

When advertised, the classad is flagged GLIDEIN_Failed=True, the error is recorded in the GLIDEIN_FAILURE_REASON and GLIDEIN_EXIT_CODE attributes, and the failing script is recorded in the GLIDEIN_LAST_SCRIPT attribute.

Factory config xml - configuration

The second set of variables comes from values the Glidein Factory administrator defined to make the factory to work. They are generated based on xml tags in the factory configuration (most in the entry tag). They cannot be changed by an administrator in any other way.

Name Type Source Description
GLIDEIN_Factory String <glidein factory_name="value">

Logical name of the Glidein Factory machine (like “osg1”).

GLIDEIN_Name String <glidein glidein_name="value">

Identification name of the Glidein Factory instance (like “v1_0”).

GLIDEIN_Entry_Name String ...<entries><entry name=”value”>

Identification name of the entry point (like “ucsd5”).

GLIDEIN_GridType String ...<entries><entry gridtype=“value”>

Type of Grid resource (like “gt2”).

GLIDEIN_Gatekeeper String ...<entries><entry gatekeeper=“value”>

URI of the Grid gatekeeper (like “osg1.ucsd.edu/jobmanager-pbs”)

GLIDEIN_GlobusRSL String ...<entries><entry rsl=“value”>

Optional RSL string (like "(condor_submit=('+ProdSlot' 'TRUE'))")

PROXY_URL String ...<entries><entry proxy_url=“value”>

Optional URL of the site Web proxy.

A special value “OSG” can be used to automatically discover the local Web proxy on OSG worker nodes.

This variable is exported as GLIDEIN_Proxy_URL to the use job environment.

DEBUG_MODE String ...<entries><entry verbosity=“value”>

This setting can be either:

  • “std” - Default mode, where all interesting debug information is reported back to the Glidein Factory and the glidein will wait 20 minutes on a worker node that failed validation to minimize the black hole effect.

  • “nodebug” - Disable most diagnostic messages. This can be useful for very stable setups. The glidein still waits 20 minutes on a worker node that failed validation to minimize the black hole effect.

  • Fast – All debugging is enabled and the glidein waits only 2 minutes on a worker node that failed validation. This mode is useful when debugging a misbehaving Grid site.

Frontend Client Variables

The third set of values comes from the Glidein Frontend clients. While a client can set any number of variables, the ones described below ar the most often used.

Name Type Description
GLIDEIN_Client String

Identification name of the VO frontend request (like “ucsd5@v1_0@osg1@cms4”).

GLIDEIN_Collector List

List of Collector URIs used by the VO Condor pool (like “cc.cms.edu:9620,cc.cms.edu:9621”).

One of the URIs in the list will be selected and used as HEAD_NODE in the condor_config.

GLIDECLIENT_Hold Exp (Bool)

Condor expression to use to specify when a user job in the glideins should be held. If any expression is true, the glidein is held. This is usually done to specify "bad" jobs, such as those that claim too much memory.

GLIDECLIENT_Group_Hold Exp (Bool)
GLIDECLIENT_PREEMPT Exp (Bool)

Condor expression to use to specify when a user job in the glideins should be preempted. If any expression is true, the glidein is preempted. This is usually done to specify custom preemption policies.

GLIDECLIENT_Group_PREEMPT Exp (Bool)
GLIDECLIENT_Rank Exp (Int)

Used in calculating the Condor RANK

They are summed together, and the user job with the largest rank will run first.

GLIDECLIENT_Group_Rank Exp (Int)
GLIDEIN_Job_Max_Time Int

Max allowed time for the job to end.
This is used by the condor_startd. Once the GLIDEIN_Retire_Time expires, the glidein will allow the job to run for this amount of time before activating DAEMON_SHUTDOWN and killing the job. Note that, if GLIDEIN_Max_Walltime is specified, this variable could be reduced by the glidein in order to fit within Glidein_Max_Walltime. See Lifetime of a glidein for details.

GLIDEIN_Expose_Grid_Env Exp (Bool)

If False, the user job environment will contain only glidein factory provided variables.

If True, the user job environment will also contain the environment variables defined at glidein startup.

See JOB_INHERITS_STARTER_ENVIRONMENT documentation for more details.

GLIDEIN_Expose_X509 Exp (Bool)

By default, the glidein will unset the variable X509_USER_PROXY for security reasons to prevent the user jobs from accessing the pilot proxy. Setting this to true will override this behavior and keep the X509_USER_PROXY in the environment.

SLOTS_LAYOUT String Defines how multi-core glideins should split their resources.

There are only two legal values: The default behavior is defined by the factory, but it has historically been set to "fixed".

Note: This variable MUST NOT be passed as a parameter, or the glideins will fail!
FORCE_PARTITIONABLE String (Bool) By default, single core glideins will never be configured as partitionable, independently of the value of SLOTS_LAYOUT.

If partitionable slots are desired also for single-core glideins, set this variable to "True".
GLIDEIN_Report_Failed String

This attribute regulates advertising of validation failures to the user collector.

  • NEVER - The glidein will just fail, and do nothing. (default)
  • ALIVEONLY - The glidein will advertise a Machine ClassAd in Drained state and Retiring activity for the lifetime of the glidein script.
  • ALWAYS - Similar to ALIVEONLY, but will also send a final ClassAd in Drained state and Killing activity just before dying.

When advertised, the classad is flagged GLIDEIN_Failed=True, the error is recorded in the GLIDEIN_FAILURE_REASON and GLIDEIN_EXIT_CODE attributes, and the failing script is recorded in the GLIDEIN_LAST_SCRIPT attribute.

GLIDEIN_CLAIM_WORKLIFE Int

CLAIM_WORKLIFE for non-dynamic slots. Defaults to -1 i.e. HTCondor will treat this as an infinite claim worklife and schedd will hold claim to the slot until jobs are preempted or user runs out of jobs.

GLIDEIN_CLAIM_WORKLIFE_DYNAMIC Int

CLAIM_WORKLIFE for dynamically partitionable slots. Defaults to 3600. This controls how frequently the dynamically partionable slots will coalesce.

Cloud VM specific Variables

The following variables are only applicable to Cloud VMs.

These variables can be either configured by factory or the frontend

Name

Type

Default Value

Description

VM_MAX_LIFETIME Int 172800
(48 hours)

Max lifetime of the VM. When this timer is reached the glideinwms-pilot service will terminate and glidein process, shutdown the glideinwms-pilot service and issue a VM shutdown

VM_DISABLE_SHUTDOWN Bool False

Disables VM from automatically shutting down after the glideinwms-pilot service has exited.
NOTE: This variable is for debugging purposes only and should not be set to True in the Production environment. Disabling auto shutdown could result in accumulating financial charges in case of paid clouds.

Dynamically generated variables

The following variables are being dynamically generated and/or modified by glideinWMS processes. The glideinWMS administrators cannot directly change them.

The first set of variables comes from the Glidein Factory.

Name Type Description
GLIDEIN_Signature String

These variables contain the SHA1 signature of the signature files.

These signatures are used as a base to ensure the integrity of all the data downloaded in the glidein startup scripts, but they also provide a fingerprint of the configuration used by the glidein.

These variables are published both in the glidein ClassAd and in the user job environenmt.

GLIDEIN_Entry_Signature String
CONDORG_SCHEDD String

The schedd used by the Glidein Factory to submit the glidein.

This variables is exported a GLIDEIN_Schedd both in the glidein ClassAd and to the user job environment.

CONDORG_CLUSTER Int

The cluster and process id assigned by the Glidein Factory schedd to this glidein.

These variables are exported as GLIDEIN_ClusterId and GLIDEIN_ProcId both in the glidein ClassAd and to the user job environment.

CONDORG_SUBCLUSTER Int

Directory Path Variables

The next set contains the location of files and/or directories downloaded or created by the glidein. Most of them are located under the working directory specified by

<entry work_dir=“value”>
Name Description
TMP_DIR

Path to the directory that admin-provided scripts and user jobs can use for storing temporary data.

This variable is exported as GLIDEIN_Tmp_Dir both to the glidein ClassAd and to the user job environment.

GLIDEIN_LOCAL_TMP_DIR

Path to the directory on the local file system for storing temporary data.
Note: Only use for things that absolutely need the guarantee of residing in the local file system. Prefer TMP_DIR above for everything else.

This variable is exported to the user job environment.

CONDOR_VARS_FILE

File path to the condor vars files.

Admin-provided scripts may want to add entries to these files.

CONDOR_VARS_ENTRY_FILE
ADD_CONFIG_LINE_SOURCE

File path to the script containing the add_config_line and add_confir_vars line functions.

X509_USER_PROXY

File path to the glidein proxy file.

X509_CONDORMAP

File path to the Condor mapfile used by the glidein.

X509_CERT_DIR

Path to the directory containing the trusted CAs' public keys and RSLs.

CONDOR_DIR

Directory where the glidein Condor binary distribution have been installed.

WRAPPER_LIST

File path to the list of wrapper scripts used by the glidein.

GLIDEIN_WRAPPER_EXEC

This is the executable that glideins will run (ie what to put after "exec" in the condor job wrapper). By default, glideins will perform exec "\$@" to run the pilot. For other modes of execution, you may need different arguments. For example, to run a program under parrot, you may need exec "$GLIDEIN_PARROT/parrot_run" -t "$parrot_tmp" "$@" .
Note, the syntax of this command is very sensitiv This needs to be double-escaped in order to function correctly. For the two examples listed above, you would need:

  • "\\\"\\\$@\\\""
  • "\\\"\\\$GLIDEIN_PARROT/parrot_run\\\" -t \\\"$parrot_tmp\\\" \\\"\\\$@\\\""

Glidein Script Variables (dynamic)

The last set contains various variables generated by the glidein startup scripts.

Name Type Description
X509_GRIDMAP_DNS String

List of DNs trusted by the glidein.

X509_EXPIRE time_t

When is the proxy expected to expire.

GLEXEC_STARTER Bool If gLExec is used and this is set to True, the condor_starter will be run sharing the same UID as the user job.

ALTERNATIVE_SHELL String

If gLExec is used, this variable points to a trusted copy of a shell.

GLEXEC_USER_DIR String If gLExec is used, this variable points to the working directory under which all user jobs will be started.

Lifetime of a Glidein

All the various variables in the glidein configuration can be confusing. The above diagram illustrates the lifetime of a glidein pilot that has a long-running job.

  • Green: For the first GLIDEIN_Retire_Time seconds (modified by a random spread GLIDEIN_Retire_Spread to smooth out glideins all ending simultaneously), jobs can start on the glidein pilot.
  • Yellow: During the yellow period, START will evauluate to FALSE, so no new jobs will start. However, already running jobs will continue to run for GLIDEIN_Job_Max_Time. (Note that the glideins will end during this period if the job ends. They will not idle afterwards since no new jobs can start anyway).
  • Once this period is done, the DAEMON_SHUTDOWN variable will be true.
  • Orange: There can be a delay of up to UPDATE_INTERVAL (usually about 5 minutes) between when DAEMON_SHUTDOWN becomes true and when it is actually updated in the collector. This is because the collector only reevaluates this expression periodically.
  • Red: Once DAEMON_SHUTDOWN is true, condor gives a short grace period of GLIDEIN_Graceful_Shutdown before forcefully terminating everything and shutting down. All of these periods are totalled and calculated to fit within GLIDEIN_MAX_WALLTIME if specified.

Note that if a job ends early in the green period, a new job will start. If a job ends after this period, then the glidein will shut down and end early. This can be seen in the example below with two jobs below:

  • Orange: A glidein first starts up.
  • Yellow: After starting up, the glidein will wait for Glidein_Max_Idle for its initial matching. If it is Idle for longer than this, it will assume no jobs are available and will shutdown.
  • Green: A job runs (subject to the maximum limits in the previous diagram).
  • Yellow: Once a job runs, it will wait for Glidein_Max_Tail for another job.
  • Green: Another matching job runs.
  • Yellow: Once the job finishes, it will wait for Glidein_Max_Tail for another job. If cannot find one, it will shutdown.
Note that for GlideinWMS versions before 3.2.7 or for glidins using HTCondor pre 8.2, the idle limits are cumulative (it counts total idle time), so that the total idle times in all the yellow zones above will be counted towards GLIDEIN_Max_Tail. Not so for GlideinWMS 3.2.7 and HTCondor 8.2 or later, where Glidein_Max_Tail counts the idle time after the previous job ends, as specified above.