LoadbalanceWriter Class Reference

The LoadbalanceWriter writes out information about the programs load balance. More...

#include <LoadBalanceWriter.h>

Inheritance diagram for LoadbalanceWriter:

Public Member Functions
void	readXML (XMLfileUnits &xmlconfig) override
	Read in XML configuration for LoadbalanceWriter. More...
void	init (ParticleContainer *particleContainer, DomainDecompBase *domainDecomp, Domain *domain) override
	Method init will be called at the begin of the simulation. More...
void	endStep (ParticleContainer *particleContainer, DomainDecompBase *domainDecomp, Domain *domain, unsigned long simstep) override
	Method endStep will be called at the end of each time step. More...
void	finish (ParticleContainer *particleContainer, DomainDecompBase *domainDecomp, Domain *domain) override
	Method finish will be called at the end of the simulation. More...
std::string	getPluginName () override
	return the name of the plugin More...
Public Member Functions inherited from PluginBase
	PluginBase ()
	Subclasses should use their constructur to pass parameters (e.g. filenames)
virtual void	beforeEventNewTimestep (ParticleContainer *particleContainer, DomainDecompBase *domainDecomp, unsigned long simstep)
	Method will be called first thing in a new timestep. More...
virtual void	beforeForces (ParticleContainer *particleContainer, DomainDecompBase *domainDecomp, unsigned long simstep)
	Method beforeForces will be called before forcefields have been applied no alterations w.r.t. Forces shall be made here. More...
virtual void	siteWiseForces (ParticleContainer *particleContainer, DomainDecompBase *domainDecomp, unsigned long simstep)
	Method siteWiseForces will be called before forcefields have been applied alterations to sitewise forces and fullMolecule forces can be made here. More...
virtual void	afterForces (ParticleContainer *particleContainer, DomainDecompBase *domainDecomp, unsigned long simstep)
	Method afterForces will be called after forcefields have been applied no sitewise Forces can be applied here. More...
virtual void	registerCallbacks (std::map< std::string, FunctionWrapper > &callbackMap)
virtual void	accessAllCallbacks (const std::map< std::string, FunctionWrapper > &callbackMap)

Static Public Member Functions
static PluginBase *	createInstance ()

Detailed Description

The LoadbalanceWriter writes out information about the programs load balance.

The LoadbalanceWriter writes out load balance information for MPI processes based on timers. The 'default' timer used measures the time between invocations of this plugin. Additional timers used in the program and registered in the Simulation can be added to compute the load balance of specific code parts.

The output file will include for each time step in the simulation one line. In each line the following values are stored for each LB timer:

• min, max times over all processes
• the factor max/min
• the imbalance 1 - average / max. This describes lost performance due to imbalances for the current time step.
• an averaged imbalance. Compared to the step-wise imbalance, the time-values are averaged for averageLength time steps. In the first few steps, this averaging is not fully possible, thus only the average of the first steps is taken. The averaged imbalance aims to reduce imbalances caused by noise and performance fluctuations and is thus a more accurate measure for the quality of the partitioning. It is (in average) lower than the step-wise imbalance. In addition, when comparing the step-wise imbalance and the averaged imbalance, information about the fluctuations can be retrieved.

Note

Warning thresholds (level) (for the ratio max / min) for each timer can be set (see documentation of readXML()) which will output a warning to the logfile if the ratio max_time / min_time is above the threshold. This warning level should be bigger than 1.!

Todo:

This plugin may be extended to threads

Member Function Documentation

endStep()

void LoadbalanceWriter::endStep ( ParticleContainer *  particleContainer, DomainDecompBase *  domainDecomp, Domain *  domain, unsigned long  simstep  )

overridevirtual

Method endStep will be called at the end of each time step.

This method will be called every time step passing the simstep as an additional parameter. It can be used e.g. to write per time step data to a file or perform additional computations.

Parameters

particleContainer	particle container storing the (local) molecules
domainDecomp	domain decomposition in use
domain

Implements PluginBase.

finish()

void LoadbalanceWriter::finish ( ParticleContainer *  particleContainer, DomainDecompBase *  domainDecomp, Domain *  domain  )

inlineoverridevirtual

Method finish will be called at the end of the simulation.

This method will be called once at the end of the simulation. It can be used e.g. to closing output files or writing final statistics.

Parameters

particleContainer	particle container storing the (local) molecules
domainDecomp	domain decomposition in use
domain

Implements PluginBase.

getPluginName()

std::string LoadbalanceWriter::getPluginName ( )

inlineoverridevirtual

return the name of the plugin

Implements PluginBase.

init()

void LoadbalanceWriter::init ( ParticleContainer *  particleContainer, DomainDecompBase *  domainDecomp, Domain *  domain  )

overridevirtual

Method init will be called at the begin of the simulation.

This method will be called once at the begin of the simulation just right before the main time step loop. It can be used e.g. to open output files or initialize statistics.

Parameters

particleContainer	particle container storing the (local) molecules
domainDecomp	domain decomposition in use
domain

Implements PluginBase.

readXML()

void LoadbalanceWriter::readXML ( XMLfileUnits &  xmlconfig )

overridevirtual

Read in XML configuration for LoadbalanceWriter.

The following xml object structure is handled by this method: parameters: name: name of the timer warninglevel: warnings will be printed if "max time / min time > warninglevel" incremental: specifies whether the timer is incremental or not, e.g., a timer just measuring the time for the current time step is not incremental, but one measuring the time since the first time step is incremental.

<outputplugin name="LoadbalanceWriter">
  <writefrequency>INTEGER</writefrequency>
  <averageLength>INTEGER</averageLength>
  <outputfilename>STRING</outputfilename>
  <timers> <!-- additional timers -->
     <timer> <name>LoadbalanceWriter_default</name> <warninglevel>DOUBLE</warninglevel> </timer>
     <timer> <name>STRING</name> <warninglevel>DOUBLE</warninglevel> <incremental>BOOL</incremental> </timer>
     <!-- ... -->
  </timers>
</outputplugin>

Implements PluginBase.

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The documentation for this class was generated from the following files:

• src/io/LoadBalanceWriter.h
• src/io/LoadBalanceWriter.cpp