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Understanding Resources
Contents
- About LSF Resources
- How Resources are Classified
- How LSF Uses Resources
- Load Indices
- Static Resources
- Automatic Detection of Hardware Reconfiguration
About LSF Resources
The LSF system uses built-in and configured resources to track job resource requirements and schedule jobs according to the resources available on individual hosts.
View available resources
View cluster resources (lsinfo)
- Use
lsinfo
to list the resources available in your cluster.The
lsinfo
command lists all the resource names and their descriptions.lsinfo
RESOURCE_NAME TYPE ORDER DESCRIPTION r15s Numeric Inc 15-second CPU run queue length r1m Numeric Inc 1-minute CPU run queue length (alias:cpu) r15m Numeric Inc 15-minute CPU run queue length ut Numeric Inc 1-minute CPU utilization (0.0 to 1.0) pg Numeric Inc Paging rate (pages/second) io Numeric Inc Disk IO rate (Kbytes/second) ls Numeric Inc Number of login sessions (alias: login) it Numeric Dec Idle time (minutes) (alias: idle) tmp Numeric Dec Disk space in /tmp (Mbytes) swp Numeric Dec Available swap space (Mbytes) (alias:swap) mem Numeric Dec Available memory (Mbytes) ncpus Numeric Dec Number of CPUs nprocs Numeric Dec Number of physical processors ncores Numeric Dec Number of cores per physical processor nthreads Numeric Dec Number of threads per processor corendisks Numeric Dec Number of local disks maxmem Numeric Dec Maximum memory (Mbytes) maxswp Numeric Dec Maximum swap space (Mbytes) maxtmp Numeric Dec Maximum /tmp space (Mbytes) cpuf Numeric Dec CPU factor ...View host resources (lshosts)
- Run
lshosts
to get a list of the resources defined on a specific host:lshosts hostA
HOST_NAME type model cpuf ncpus maxmem maxswp server RESOURCES hostA SOL732 Ultra2 20.2 2 256M 679M Yes ()View host load by resource
- Run
lshosts -s
to view host load by shared resource:lshosts -s
RESOURCE VALUE LOCATION tot_lic 5 host1 host2 tot_scratch 500 host1 host2The above output indicates that 5 licenses are available, and that the shared scratch directory currently contains 500 MB of space.
The VALUE field indicates the amount of that resource. The LOCATION column shows the hosts which share this resource. The
lshosts -s
command displays static shared resources. Thelsload -s
command displays dynamic shared resources.How Resources are Classified
Resource categories
By values
By the way values change
By definitions
By scope
Boolean resources
Boolean resources (for example,
server
to denote LSF server hosts) have a value of one (1) if they are defined for a host, and zero (0) if they are not defined for the host. Use Boolean resources to configure host attributes to be used in selecting hosts to run jobs. For example:
- Machines may have different types and versions of operating systems.
- Machines may play different roles in the system, such as file server or compute server.
- Some machines may have special-purpose devices needed by some applications.
- Certain software packages or licenses may be available only on some of the machines.
Specify a Boolean resource in a resource requirement selection string of a job to select only hosts that can run the job.
Some examples of Boolean resources:
Shared resources
Shared resources are configured resources that are not tied to a specific host, but are associated with the entire cluster, or a specific subset of hosts within the cluster. For example:
- Floating licenses for software packages
- Disk space on a file server which is mounted by several machines
- The physical network connecting the hosts
LSF does not contain any built-in shared resources. All shared resources must be configured by the LSF administrator. A shared resource may be configured to be dynamic or static. In the above example, the total space on the shared disk may be static while the amount of space currently free is dynamic. A site may also configure the shared resource to report numeric, string or Boolean values.
An application may use a shared resource by running on any host from which that resource is accessible. For example, in a cluster in which each host has a local disk but can also access a disk on a file server, the disk on the file server is a shared resource, and the local disk is a host-based resource. In contrast to host-based resources such as memory or swap space, using a shared resource from one machine affects the availability of that resource as seen by other machines. There will be one value for the entire cluster which measures the utilization of the shared resource, but each host-based resource is measured separately.
The following restrictions apply to the use of shared resources in LSF products.
- A shared resource cannot be used as a load threshold in the
Hosts
section of thelsf.cluster.
cluster_name
file.- A shared resource cannot be used in the
loadSched
/loadStop
thresholds, or in the STOP_COND or RESUME_COND parameters in the queue definition in thelsb.queues
file.View shared resources for hosts
- Run
bhosts -s
to view shared resources for hosts. For example:bhosts -s
RESOURCE TOTAL RESERVED LOCATION tot_lic 5 0.0 hostA hostB tot_scratch 00 0.0 hostA hostB avail_lic 2 3.0 hostA hostB avail_scratch 100 400.0 hostA hostBThe
TOTAL
column displays the value of the resource. For dynamic resources, theRESERVED
column displays the amount that has been reserved by running jobs.How LSF Uses Resources
Jobs submitted through the LSF system will have the resources they use monitored while they are running. This information is used to enforce resource usage limits and load thresholds as well as for fairshare scheduling.
LSF collects information such as:
- Total CPU time consumed by all processes in the job
- Total resident memory usage in KB of all currently running processes in a job
- Total virtual memory usage in KB of all currently running processes in a job
- Currently active process group ID in a job
- Currently active processes in a job
On UNIX, job-level resource usage is collected through a special process called PIM (Process Information Manager). PIM is managed internally by LSF.
Viewing job resource usage
The
-l
option of thebjobs
command displays the current resource usage of the job. The usage information is sampled by PIM every 30 seconds and collected bysbatchd
at a maximum frequency of every SBD_SLEEP_TIME (configured in thelsb.params
file) and sent tombatchd
. The update is done only if the value for the CPU time, resident memory usage, or virtual memory usage has changed by more than 10 percent from the previous update, or if a new process or process group has been created.
tip:
The parameterLSF_PIM_LINUX_ENHANCE
inlsf.conf
enables the enhanced PIM, returning the exact memory usage of processes using shared memory on Linux operating systems. By default memory shared between jobs may be counted more than once.View load on a host
- Run
bhosts -l
to check the load levels on the host, and adjust the suspending conditions of the host or queue if necessary.The
bhosts -l
command gives the most recent load values used for the scheduling of jobs. A dash (-
) in the output indicates that the particular threshold is not defined.bhosts -l hostB
HOST: hostB STATUS CPUF JL/U MAX NJOBS RUN SSUSP USUSP RSV ok 20.00 2 2 0 0 0 0 0 CURRENT LOAD USED FOR SCHEDULING: r15s r1m r15m ut pg io ls t tmp swp mem Total 0.3 0.8 0.9 61% 3.8 72 26 0 6M 253 M 297M Reserved 0.0 0.0 0.0 0% 0.0 0 0 0 0M 0M 0M LOAD THRESHOLD USED FOR SCHEDULING: r15s r1m r15m ut pg io ls it tmp swp mem loadSched - - - - - - - - - - - loadStop - - - - - - - - - - - cpuspeed bandwidth loadSched - - loadStop - -Load Indices
Load indices are built-in resources that measure the availability of static or dynamic, non-shared resources on hosts in the LSF cluster.
Load indices built into the LIM are updated at fixed time intervals.
External load indices
are defined and configured by the LSF administrator, who writes an external load information manager (elim
) executable. Theelim
collects the values of the external load indices and sends these values to the LIM.Load indices collected by LIM
Status
The
status
index is a string indicating the current status of the host. This status applies to the LIM and RES.The possible values for
status
are:
note:
The termavailable
is frequently used in command output titles and headings.Available
means a host is in any state exceptunavail
. This means anavailable
host could beunlicensed
,locked
,busy
, orok
.CPU run queue lengths (r15s, r1m, r15m)
The
r15s
,r1m
andr15m
load indices are the 15-second, 1-minute and 15-minute average CPU run queue lengths. This is the average number of processes ready to use the CPU during the given interval.On UNIX, run queue length indices are not necessarily the same as the load averages printed by the
uptime(1)
command;uptime
load averages on some platforms also include processes that are in short-term wait states (such as paging or disk I/O).Effective run queue length
On multiprocessor systems, more than one process can execute at a time. LSF scales the run queue value on multiprocessor systems to make the CPU load of uniprocessors and multiprocessors comparable. The scaled value is called the effective run queue length.
Use
lsload -E
to view the effective run queue length.Normalized run queue length
LSF also adjusts the CPU run queue based on the relative speeds of the processors (the CPU factor). The normalized run queue length is adjusted for both number of processors and CPU speed. The host with the lowest normalized run queue length will run a CPU-intensive job the fastest.
Use
lsload -N
to view the normalized CPU run queue lengths.CPU utilization (ut)
The
ut
index measures CPU utilization, which is the percentage of time spent running system and user code. A host with no process running has aut
value of 0 percent; a host on which the CPU is completely loaded has aut
of 100 percent.Paging rate (pg)
The
pg
index gives the virtual memory paging rate in pages per second. This index is closely tied to the amount of available RAM memory and the total size of the processes running on a host; if there is not enough RAM to satisfy all processes, the paging rate will be high. Paging rate is a good measure of how a machine will respond to interactive use; a machine that is paging heavily feels very slow.Login sessions (ls)
The
ls
index gives the number of users logged in. Each user is counted once, no matter how many times they have logged into the host.Interactive idle time (it)
On UNIX, the
it
index is the interactive idle time of the host, in minutes. Idle time is measured from the last input or output on a directly attached terminal or a network pseudo-terminal supporting a login session. This does not include activity directly through the X server such as CAD applications oremacs
windows, except on Solaris and HP-UX systems.On Windows, the
it
index is based on the time a screen saver has been active on a particular host.Temporary directories (tmp)
The
tmp
index is the space available in MB on the file system that contains the temporary directory:
/tmp
on UNIXC:\temp
on WindowsSwap space (swp)
The
swp
index gives the currently available virtual memory (swap space) in MB. This represents the largest process that can be started on the host.Memory (mem)
The
mem
index is an estimate of the real memory currently available to user processes. This represents the approximate size of the largest process that could be started on a host without causing the host to start paging.LIM reports the amount of free memory available. LSF calculates free memory as a sum of physical free memory, cached memory, buffered memory and an adjustment value. The command
vmstat
also reports free memory but displays these values separately. There may be a difference between the free memory reported by LIM and the free memory reported byvmstat
because of virtual memory behavior variations among operating systems. You can write an ELIM that overrides the free memory values returned by LIM.I/O rate (io)
The
io
index measures I/O throughput to disks attached directly to this host, in KB per second. It does not include I/O to disks that are mounted from other hosts.Viewing information about load indices
lsinfo -l
The
lsinfo -l
command displays all information available about load indices in the system. You can also specify load indices on the command line to display information about selected indices:lsinfo -l swp
RESOURCE_NAME: swp DESCRIPTION: Available swap space (Mbytes) (alias: swap) TYPE ORDER INTERVAL BUILTIN DYNAMIC RELEASE Numeric Dec 60 Yes Yes NOlsload -l
The
lsload -l
command displays the values of all load indices. External load indices are configured by your LSF administrator:lsload
HOST_NAME status r15s r1m r15m ut pg ls it tmp swp mem hostN ok 0.0 0.0 0.1 1% 0.0 1 224 43M 67M 3M hostK -ok 0.0 0.0 0.0 3% 0.0 3 0 38M 40M 7M hostF busy 0.1 0.1 0.3 7% *17 6 0 9M 23M 28M hostG busy *6.2 6.9 9.5 85% 1.1 30 0 5M 400M 385M hostV unavailStatic Resources
Static resources are built-in resources that represent host information that does not change over time, such as the maximum RAM available to user processes or the number of processors in a machine. Most static resources are determined by the LIM at start-up time, or when LSF detects hardware configuration changes.
Static resources can be used to select appropriate hosts for particular jobs based on binary architecture, relative CPU speed, and system configuration.
The resources
ncpus
,nprocs
,ncores
,nthreads
,maxmem
,maxswp
, andmaxtmp
are not static on UNIX hosts that support dynamic hardware reconfiguration.Static resources reported by LIM
Host type (type)
Host type is a combination of operating system and CPU architecture. All computers that run the same operating system on the same computer architecture are of the same type. You can add custom host types in the HostType section of
lsf.shared
. This alphanumeric value can be up to 39 characters long.An example of host type is
LINUX86
.Host model (model)
Host model is the combination of host type and CPU speed (CPU factor) of your machine. All hosts of the same relative type and speed are assigned the same host model. You can add custom host models in the HostModel section of
lsf.shared
. This alphanumeric value can be up to 39 characters long.An example of host model is
Intel_IA64
.Host name (hname)
Host name specifies the name with which the host identifies itself.
CPU factor (cpuf)
The CPU factor (frequently shortened to cpuf) represents the speed of the host CPU relative to other hosts in the cluster. For example, if one processor is twice the speed of another, its CPU factor should be twice as large. For multiprocessor hosts, the CPU factor is the speed of a single processor; LSF automatically scales the host CPU load to account for additional processors. The CPU factors are detected automatically or defined by the administrator.
Server
The
server
static resource is Boolean. It has the following values:
- 1 if the host is configured to run jobs from other hosts
- 0 if the host is an LSF client for submitting jobs to other hosts
Number of CPUs (ncpus)
By default, the number of CPUs represents the number of physical processors a machine has. As most CPUs consist of multiple cores, threads, and processors,
ncpus
can be defined by the cluster administrator (either globally or per-host) to consider one of the following:
- Processors
- Processors and cores
- Processors, cores, and threads
Globally, this definition is controlled by the parameter
EGO_DEFINE_NCPUS
inlsf.conf
orego.conf
. The default behavior forncpus
is to consider only the number of physical processors (EGO_DEFINE_NCPUS=procs
).
note:
- On a machine running AIX, ncpus detection is different. Under AIX, the number of detected physical processors is always 1, whereas the number of detected cores is the number of cores across all physical processors. Thread detection is the same as other operating systems (the number of threads per core).
- When
PARALLEL_SCHED_BY_SLOT=Y
inlsb.params
, the resource requirement string keywordncpus
refers to the number of slots instead of the number of processors, howeverlshosts
output will continue to showncpus
as defined byEGO_DEFINE_NCPUS
inlsf.conf
.Number of disks (ndisks)
The number of disks specifies the number of local disks a machine has, determined by the LIM.
Maximum memory (maxmem)
Maximum memory is the total available memory of a machine, measured in megabytes (MB).
Maximum swap (maxswp)
Maximum swap is the total available swap space a machine has, measured in megabytes (MB).
Maximum temporary space (maxtmp)
Maximum temporary space is the total temporary space a machine has, measured in megabytes (MB).
How LIM detects cores, threads and processors
Traditionally, the value of
ncpus
has been equal to the number of physical CPUs. However, many CPUs consist of multiple cores and threads, so the traditional 1:1 mapping is no longer useful. A more useful approach is to setncpus
to equal one of the following:
- The number of processors (this is the ncpus default setting)
- Cores-the number of cores (per processor) * the number of processors
- Threads-the number of threads (per core) * the number of cores (per processor) * the number of processors
A cluster administrator globally defines how
ncpus
is computed using the EGO_DEFINE_NCPUS parameter inlsf.conf
orego.conf
(instead of LSF_ENABLE_DUALCORE inlsf.conf
, or EGO_ENABLE_DUALCORE inego.conf
).See Define ncpus-processors, cores, or threads for details.
LIM detects and stores the number of processors, cores, and threads for all supported architectures. The following diagram illustrates the flow of information between daemons, CPUs, and other components.
![]()
Although the
ncpus
computation is applied globally, it can be overridden on a per-host basis. See Override the global configuration of ncpus computation for details.To correctly detect processors, cores, and threads, LIM assumes that all physical processors on a single machine are of the same type.
In cases where CPU architectures and operating system combinations may not support accurate processor, core, thread detection, LIM uses the defaults of 1 processor, 1 core per physical processor, and 1 thread per core. If LIM detects that it is running in a virtual environment (for example, VMwareŽ), each detected processor is similarly reported (as a single-core, single-threaded, physical processor).
LIM only detects hardware that is recognized by the operating system. LIM detection uses processor- or OS-specific techniques (for example, the Intel CPUID instruction, or Solaris
kstat()
/core_id
). If the operating system does not recognize a CPU or core (for example, if an older OS does not recognize a quad-core processor and instead detects it as dual-core), then LIM will not recognize it either.
note:
RQL normalization never considers threads. Consider a hyper-thread enabled Pentium: Threads are not full-fledged CPUs, so considering them as CPUs would artificially lower the system load.ncpus detection on AIX
On a machine running AIX, detection of
ncpus
is different. Under AIX, the number of detected physical processors is always 1, whereas the number of detected cores is always the number of cores across all physical processors. Thread detection is the same as other operating systems (the number of threads per core).Define ncpus-processors, cores, or threads
A cluster administrator must define how
ncpus
is computed. Usually, the number of available job slots is equal to the value ofncpus
; however, slots can be redefined at the EGO resource group level. Thencpus
definition is globally applied across the cluster.
- Open
lsf.conf
orego.conf
.
- UNIX and Linux:
LSF_CONFDIR/lsf.conf
LSF_CONFDIR/ego/
cluster_name
/kernel/ego.conf
- Windows:
LSF_CONFDIR\lsf.conf
LSF_CONFDIR\ego\
cluster_name
\kernel\ego.conf
important:
You can set EGO_DEFINE_NCPUS in ego.conf only if EGO is enabled in the LSF cluster. If EGO is not enabled, you must set EGO_DEFINE_NCPUS in lsf.conf.- Define the parameter
EGO_DEFINE_NCPUS=[procs | cores | threads]
.Set it to one of the following:
procs
(wherencpus
=procs
)cores
(wherencpus
=procs
*cores
)threads
(where ncpus=procs
*cores
*threads
)By default,
ncpus
is set toprocs
(number of processors).
note:
In clusters with older LIMs that do not recognize cores and threads, EGO_DEFINE_NCPUS is ignored. In clusters where only the master LIM recognizes cores and threads, the master LIM assigns default values (for example, in Platform LSF 6.2: 1 core, -1 thread).- Save and close
lsf.conf
orego.conf
.
tip:
As a best practice, set EGO_DEFINE_NCPUS instead of EGO_ENABLE_DUALCORE. The functionality of EGO_ENABLE_DUALCORE=y is preserved by setting EGO_DEFINE_NCPUS=cores.Interaction with LSF_LOCAL_RESOURCES in lsf.conf
If EGO is enabled, and EGO_LOCAL_RESOURCES is set in
ego.conf
and LSF_LOCAL_RESOURCES is set inlsf.conf
, EGO_LOCAL_RESOURCES takes precedence.Platform LSF
Override the global configuration of ncpus computation
The cluster administrator globally defines how the
ncpus
resource is computed. Thencpus
global definition can be overridden on specified dynamic and static hosts in the cluster.Defining computation of ncpus on dynamic hosts
- Open
lsf.conf
orego.conf
.
- UNIX and Linux:
LSF_CONFDIR/lsf.conf
LSF_CONFDIR/ego/
cluster_name
/kernel/ego.conf
- Windows:
LSF_CONFDIR\lsf.conf
LSF_CONFDIR\ego\
cluster_name
\kernel\ego.conf
important:
You can set EGO_LOCAL_RESOURCES in ego.conf only if EGO is enabled in the LSF cluster. If EGO is not enabled, you must set EGO_LOCAL_RESOURCES in lsf.conf.- Define the parameter
EGO_LOCAL_RESOURCES
="[resource
resource_name
]".Set
resource_name
to one of the following:
define_ncpus_procs
define_ncpus_cores
define_ncpus_threads
note:
Resource definitions are mutually exclusive. Choose only one resource definition per host.For example:
- Windows:
EGO_LOCAL_RESOURCES="[type NTX86] [resource define_ncpus_procs]"
- Linux:
EGO_LOCAL_RESOURCES="[resource define_ncpus_cores]"
- Save and close
ego.conf
.
note:
In multi-cluster environments, if ncpus is defined on a per-host basis (thereby overriding the global setting) the definition is applied toall
clusters that the host is a part of. In contrast, globally defined ncpus settingsonly
take effect within the cluster for which EGO_DEFINE_NCPUS is defined.Defining computation of ncpus on static hosts
- Open
lsf.cluster.
cluster_name
.
- Linux:
LSF_CONFDIR/lsf.cluster.
cluster_name
- Windows:
LSF_CONFDIR\lsf.cluster.
cluster_name
- Find the host you for which you want to define ncpus computation. In the
RESOURCES
column, add one of the following definitions:
define_ncpus_procs
define_ncpus_cores
define_ncpus_threads
note:
Resource definitions are mutually exclusive. Choose only one resource definition per host.For example:
Begin Host HOSTNAME model type r1m mem swp RESOURCES #Keywords #lemon PC200 LINUX86 3.5 1 2 (linux) #plum ! NTX86 3.5 1 2 (nt) Host_name ! NTX86 - - - (define_ncpus_procs) End Host- Save and close
lsf.cluster.
cluster_name
.- Restart the master host.
note:
In multi-cluster environments, if ncpus is defined on a per-host basis (thereby overriding the global setting) the definition is applied toall
clusters that the host is a part of. In contrast, globally defined ncpus settingsonly
take effect within the cluster for which EGO_DEFINE_NCPUS is defined.Interaction with LSF_LOCAL_RESOURCES in lsf.conf
If EGO is enabled, and EGO_LOCAL_RESOURCES is set in
ego.conf
and LSF_LOCAL_RESOURCES is set inlsf.conf
, EGO_LOCAL_RESOURCES takes precedence.Platform LSF
Automatic Detection of Hardware Reconfiguration
Some UNIX operating systems support dynamic hardware reconfiguration-that is, the attaching or detaching of system boards in a live system without having to reboot the host.
Supported platforms
LSF is able to recognize changes in
ncpus
,maxmem
,maxswp
,maxtmp
in the following platforms:
- Sun Solaris 2.5+
- HP-UX 10.10+
- IBM AIX 4.0+
- SGI IRIX 6.2+
Dynamic changes in ncpus
LSF is able to automatically detect a change in the number of processors in systems that support dynamic hardware reconfiguration.
The local LIM checks if there is a change in the number of processors at an internal interval of 2 minutes. If it detects a change in the number of processors, the local LIM also checks
maxmem
,maxswp
,maxtmp
. The local LIM then sends this new information to the master LIM.Dynamic changes in maxmem, maxswp, maxtmp
If you dynamically change
maxmem
,maxswp
, ormaxtmp
without changing the number of processors, you need to restart the local LIM with the commandlsadmin
limrestart
so that it can recognize the changes.If you dynamically change the number of processors and any of
maxmem
,maxswp
, ormaxtmp
, the change will be automatically recognized by LSF. When it detects a change in the number of processors, the local LIM also checksmaxmem
,maxswp
,maxtmp
.Viewing dynamic hardware changes
lsxxx Commands
There may be a 2 minute delay before the changes are recognized by
lsxxx
commands (for example, beforelshosts
displays the changes).bxxx Commands
There may be at most a 2 + 10 minute delay before the changes are recognized by
bxxx
commands (for example, beforebhosts
-l
displays the changes).This is because
mbatchd
contacts the master LIM at an internal interval of 10 minutes.Platform MultiCluster
Configuration changes from a local cluster are communicated from the master LIM to the remote cluster at an interval of 2 * CACHE_INTERVAL. The parameter CACHE_INTERVAL is configured in
lsf.cluster.
cluster_name
and is by default 60 seconds.This means that for changes to be recognized in a remote cluster there is a maximum delay of 2 minutes + 2*CACHE_INTERVAL.
How dynamic hardware changes affect LSF
LSF uses
ncpus
,maxmem
,maxswp
,maxtmp
to make scheduling and load decisions.When processors are added or removed, LSF licensing is affected because LSF licenses are based on the number of processors.
If you put a processor offline:
- Per host or per-queue load thresholds may be exceeded sooner. This is because LSF uses the number of CPUS and relative CPU speeds to calculate effective run queue length.
- The value of CPU run queue lengths (
r15s
,r1m
, andr15m
) increases.- Jobs may also be suspended or not dispatched because of load thresholds.
- Per-processor job slot limit (PJOB_LIMIT in
lsb.queues
) may be exceeded sooner.If you put a new processor online:
- Load thresholds may be reached later.
- The value of CPU run queue lengths (r15s, r1m, and r15m) is decreased.
- Jobs suspended due to load thresholds may be resumed.
Per-processor job slot limit (PJOB_LIMIT in
lsb.queues
) may be reached later.Set the external static LIM
Use the external static LIM to automatically detect the operating system type and version of hosts.
- In
lsf.shared
, remove the comment from the indices you want detected.- In $
LSF_SERVERDIR
, renametmp.eslim.<
extension
>
toeslim.
extension
.- Set
EGO_ESLIM_TIMEOUT
inlsf.conf
orego.conf
.- Restart the lim on all hosts.
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