wrench::CompoundStorageService

class CompoundStorageService : public wrench::StorageService

An abstract storage service which holds a collection of concrete storage services (eg. SimpleStorageServices). It does not provide direct access to any storage resource. It is meant to be used as a way to postpone the selection of a storage service for a file action (read, write, copy, etc) until a later time in the simulation, rather than during job definition. A typical use for the CompoundStorageService is to select a definitive SimpleStorageService for each action of a job during its scheduling in a BatchScheduler class. This should never receive messages for I/O operations, as any standard storage service (File Read/Write/Delete/Copy/Lookup requests), instead, it overides the main functions of StorageService (readFile / writeFile /…) and will craft messages intended for one or many of its underlying storage services.

Public Functions

CompoundStorageService(const std::string &hostname, std::set<std::shared_ptr<StorageService>> storage_services, StorageSelectionStrategyCallback storage_selection, WRENCH_PROPERTY_COLLECTION_TYPE property_list = {}, WRENCH_MESSAGE_PAYLOADCOLLECTION_TYPE messagepayload_list = {})

Constructor for the case where the user provides a callback (StorageSelectionStrategyCallback) which will be used by the CompoundStorageService any time it receives a file write or file copy request, in order to determine which underlying StorageService to use for the (potentially) new file in the request. Note that nothing prevents the user from also intercepting some actions (see use case for other constructor), but resulting behaviour is undefined.

Parameters:

• hostname – the name of the host on which this service will run

• storage_services – subordinate storage services

• storage_selection – the storage selection strategy callback

• property_list – the configurable properties

• messagepayload_list – the configurable message payloads

CompoundStorageService(const std::string &hostname, std::set<std::shared_ptr<StorageService>> storage_services, WRENCH_PROPERTY_COLLECTION_TYPE property_list = {}, WRENCH_MESSAGE_PAYLOADCOLLECTION_TYPE messagepayload_list = {})

Constructor for the case where no request message (for I/O operations) should ever reach the CompoundStorageService. This use case suppose that any action making use of a FileLocation referencing this CompoundStorageService will be intercepted before its execution (in a scheduler for instance) and updated with one of the StorageServices known to this CompoundStorageService.

Parameters:

• hostname – the name of the host on which this service will run

• storage_services – subordinate storage services

• property_list – the configurable properties

• messagepayload_list – the configurable message payloads