A network driver for a distributed system. More...

#include <DistributedSystem.hpp>

Collaboration diagram for samchon::protocol::master::DistributedSystem:

[legend]

Public Member Functions
	DistributedSystem ()
	Default Constructor. More...

virtual void	construct (std::shared_ptr< library::XML >) override
	Construct data of the Entity from an XML object. More...

virtual void	sendData (std::shared_ptr< Invoke >) override
	Sends message to a related system. More...

virtual void	replyData (std::shared_ptr< Invoke >) override
	Handling replied message from an external system. More...

virtual auto	toXML () const -> std::shared_ptr< library::XML > override
	Get an XML object represents the EntityGroup. More...

Public Member Functions inherited from samchon::protocol::ExternalSystem
	ExternalSystem ()
	Default Constructor. More...

virtual void	start ()=0
	Start interaction. More...

virtual auto	key () const -> std::string override
	Get a key that can identify the Entity uniquely. More...

virtual auto	TAG () const -> std::string override
	A tag name when represented by XML. More...

virtual auto	CHILD_TAG () const -> std::string override
	A tag name of children. More...

Public Member Functions inherited from samchon::protocol::EntityGroup< _Container, _ETy, T >
	EntityGroup ()
	Default Constructor. More...

auto	has (const std::string &key) const -> bool
	Indicates whether a container has an object having the specified identifier. More...

auto	get (const std::string &key) -> value_type &
	Access the element by specified identifier(key). More...

auto	get (const std::string &key) const -> const value_type &
	Access the const element by specified identifier(key). More...

Public Member Functions inherited from samchon::protocol::Entity
	Entity ()
	Default Constructor. More...

Public Member Functions inherited from samchon::protocol::IEntityGroup
	IEntityGroup ()
	Default Constructor. More...

Public Member Functions inherited from samchon::protocol::IClient
	IClient ()
	Default Constructor. More...

virtual void	listen ()
	Listens message from a related system. More...

Public Member Functions inherited from samchon::protocol::IProtocol
	IProtocol ()
	Default Constructor. More...

Protected Member Functions
virtual auto	createChild (std::shared_ptr< library::XML >) -> ExternalSystemRole *override
	Factory method of a child Entity. More...

Protected Member Functions inherited from samchon::protocol::IClient
virtual auto	BUFFER_SIZE () const -> size_t
	Buffer size of network I/O. More...

virtual void	_replyData (std::shared_ptr< Invoke >)
	A method for pre-processing replied Invoke message. More...

Protected Attributes
size_t	inProgress
	A number of processes running on the distributed system. More...

size_t	processed
	A number of processed have runned. More...

double	avgElapsedTime
	Average of elapsed time. More...

double	performance
	A performance index. More...

DSRoleHistoryList *	roleHistoryList
	A list of history log for role allocations. More...

DSInvokeHistoryArray *	invokeHistoryArray
	A list of history log for reported Invoke messages. More...

Protected Attributes inherited from samchon::protocol::ExternalSystem
std::string	name
	A name can identify an external system. More...

std::string	ip
	An ip address of an external system. More...

int	port
	A port number of an external system. More...

Protected Attributes inherited from samchon::protocol::IClient
Socket *	socket
	Socket for network I/O. More...

std::mutex *	sendMtx
	A mutex for sending message. More...

Detailed Description

A network driver for a distributed system.

DistributedSystem class is an ExternalSystem having role as DistributedSystemRole objects with performance index and history log allocation of DistributedSystemRole objects and have requsted Invoke message to related external system.

The greatest difference between DistributedSystem and ExternalSystem is, unlike the ExternalSystem class which having is ExternalSystemRole objects exclusively, DistributedSystem does not monopoly a DistributedSystemRole. The DistributedSystemRole can allocatedto multiple DistributedSystem.

DistributedSystem and DistributedSystemRole classes have performance index and history log archiving what they've requested to the related distributed system. Allocating DistributedSystemRole objects to DistributedSyste will be determined those performance index and history log for optimize distribution of elasped time about each Invoke message processing.

Todo:

[Inherited]

ExternalSystem is a boundary class interacting with an external system by network communication. Also, ExternalSystem is an abstract class that a network role, which one is server and which one is client, is not determined yet.

The ExternalSystem has ExternalSystemRole(s) groupped methods, handling Invoke message interacting with the external system, by subject or unit of a moudle. The ExternalSystemRole is categorized in a 'control'.

Example Sources

example::interaction

Note

The ExternalSystem class takes a role of interaction with external system in network level. However, within a framework of Samchon Framework, a boundary class like the ExternalSystem is not such important. You can find some evidence in a relationship between ExternalSystemArray, ExternalSystem and ExternalSystemRole.

Of course, the ExternalSystemRole is belonged to an ExternalSystem. However, if you access an ExternalSystemRole from an ExternalSystemArray directly, not passing by a belonged ExternalSystem, and send an Invoke message even you're not knowing which ExternalSystem is related in, it's called "Proxy pattern".

Like the explanation of "Proxy pattern", you can utilize an ExternalSystemRole as a proxy of an ExternalSystem. With the pattern, you can only concentrate on ExternalSystemRole itself, what to do with Invoke message, irrespective of the ExternalSystemRole is belonged to which ExternalSystem.

See also: samchon::protocol

Author: Jeongho Nam http://samchon.org

Definition at line 44 of file DistributedSystem.hpp.

Constructor & Destructor Documentation

DistributedSystem::DistributedSystem ( )

Default Constructor.

Definition at line 19 of file DistributedSystem.cpp.

References invokeHistoryArray.

Member Function Documentation

void DistributedSystem::construct ( std::shared_ptr< library::XML > xml )

overridevirtual

Construct data of the Entity from an XML object.

Constructs the EntityGroup's own member variables only from the input XML object.

Do not consider about constructing children Entity objects' data in EntityGroup::construct(). Those children Entity objects' data will constructed by their own construct() method. Even insertion of XML objects representing children are done by abstract method of EntityGroup::toXML().

Constructs only data of EntityGroup's own.

[Inherited]: Construct data of the Entity from an XML object.

Overrides the construct() method and fetch data of member variables from the XML.

By recommended guidance, data representing member variables are contained in properties of the put XML object.

Parameters

xml	An xml used to construct data of entity

Reimplemented from samchon::protocol::ExternalSystem.

Reimplemented in samchon::protocol::master::DistributedServer.

Definition at line 29 of file DistributedSystem.cpp.

References samchon::protocol::ExternalSystem::construct(), and performance.

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auto DistributedSystem::createChild ( std::shared_ptr< library::XML > ) -> ExternalSystemRole *override

overrideprotectedvirtual

Factory method of a child Entity.

EntityGroup::createChild() is a factory method creating a new child Entity which is belonged to the EntityGroup. This method is called by EntityGroup::construct(). The children construction methods Entity::construct() will be called by abstract method of the EntityGroup::construct().

Returns: A new child Entity belongs to EntityGroup.

Implements samchon::protocol::EntityGroup< _Container, _ETy, T >.

Definition at line 36 of file DistributedSystem.cpp.

void DistributedSystem::sendData ( std::shared_ptr< Invoke > )

overridevirtual

Sends message to a related system.

Parameters

invoke Invoke message to send

Reimplemented from samchon::protocol::IClient.

Definition at line 49 of file DistributedSystem.cpp.

References invokeHistoryArray, and samchon::protocol::IClient::sendData().

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void DistributedSystem::replyData ( std::shared_ptr< Invoke > )

overridevirtual

Handling replied message from an external system.

If there's a related ExternalSystemRole, shifts responsibility to the ExternalSystemRole.

Parameters

invoke Replied Invoke message

Reimplemented from samchon::protocol::ExternalSystem.

Definition at line 67 of file DistributedSystem.cpp.

auto DistributedSystem::toXML ( ) const -> std::shared_ptr<library::XML>

overridevirtual

Get an XML object represents the EntityGroup.

Archives the EntityGroup's own member variables only to the returned XML object.

Do not consider about archiving children Entity objects' data in EntityGroup::toXML(). Those children Entity objects will converted to XML object by their own toXML() method. The insertion of XML objects representing children are done by abstract method of EntityGroup::toXML().

Archives only data of EntityGroup's own.

[Inherited]: Get an XML object represents the Entity.

Returns an XML object that can represents the Entity containing member variables into properties.

A member variable (not object, but atomic value like number, string or date) is categorized as a property within the framework of entity side. Thus, when overriding a toXML() method and archiving member variables to an XML object to return, puts each variable to be a property belongs to only an XML object.

Don't archive the member variable of atomic value to XML::value causing enormouse creation of XML objects to number of member variables. An Entity must be represented by only an XML instance (tag).

Standard Usage	Non-standard usage abusing value
<memberList> <member id='jhnam88' name='Jeongho+Nam' birthdate='1988-03-11' /> <member id='master' name='Administartor' birthdate='2011-07-28' /> </memberList>	<member> <id>jhnam88</id> <name>Jeongho+Nam</name> <birthdate>1988-03-11</birthdate> </member>

Returns: An XML object representing the Entity.

Reimplemented from samchon::protocol::ExternalSystem.

Reimplemented in samchon::protocol::master::DistributedServer.

Definition at line 75 of file DistributedSystem.cpp.

References invokeHistoryArray, performance, samchon::protocol::ExternalSystem::toXML(), and samchon::protocol::EntityGroup< _Container, _ETy, T >::toXML().

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Member Data Documentation

size_t samchon::protocol::master::DistributedSystem::inProgress

protected

A number of processes running on the distributed system.

Adds one count when sendData() is called and minus one count if a DSInvokeHistory, which means reported Invoke history, was reported by replyData().

If an DistributedSystemRole is allocated to multiple DistributedSystem objects, which DistributedSystem will be used is determined by the process size and performance index of the ExternalSystemRole.

Definition at line 67 of file DistributedSystem.hpp.

size_t samchon::protocol::master::DistributedSystem::processed

protected

A number of processed have runned.

Definition at line 72 of file DistributedSystem.hpp.

double samchon::protocol::master::DistributedSystem::avgElapsedTime

protected

Average of elapsed time.

Average elapsed time of handling Invoke message (request) in frame work of tbe related distributed system. Not in frame work of distributed system's driver, DistributeDSystem.

The ultimate optimization target of distributed processing system is to minimizing standard deviation of the average elapsed time of the DistributedSystem.

Definition at line 84 of file DistributedSystem.hpp.

double samchon::protocol::master::DistributedSystem::performance

protected

A performance index.

A performance index z is calculated by normalization calculating reverse number of whole distributed system's average elapsed times and its z value between the normal distribution.

X = (�� + z��)

If a distributed system has no history of handling Invoke message, then set the performance index to 0 as default. The performance index will be re-calcuated whenever re-allocation of roles is done (DistributedSystem::allocateRoles()).

Definition at line 103 of file DistributedSystem.hpp.

Referenced by construct(), and toXML().

DSRoleHistoryList* samchon::protocol::master::DistributedSystem::roleHistoryList

protected

A list of history log for role allocations.

Definition at line 108 of file DistributedSystem.hpp.

DSInvokeHistoryArray* samchon::protocol::master::DistributedSystem::invokeHistoryArray

protected

A list of history log for reported Invoke messages.

Definition at line 113 of file DistributedSystem.hpp.

Referenced by DistributedSystem(), sendData(), and toXML().

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

D:/OneDrive/Project/Samchon/framework/cpp/samchon/protocol/master/DistributedSystem.hpp
D:/OneDrive/Project/Samchon/framework/cpp/samchon/protocol/master/DistributedSystem.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation