Creating a file registry service

Table of Contents

• Overview
• Creating a file registry service

Overview

A file registry service is a simple store of key-values pairs where keys are files (i.e., wrench::WorkflowFile) and values are file locations (i.e., wrench::FileLocation). It is used to keep track of the location of file copies. In real-world deployments, this service is often called a "replica catalog".

Creating a file registry service

In WRENCH, a file registry service is defined by the wrench::FileRegistryService class, an instantiation of which requires the following parameters:

• The name of a host on which to start the service; and
• Maps (std::map) of configurable properties (wrench::NetworkProximityServiceProperty) and configurable message payloads (wrench::NetworkProximityServiceMessagePayload).

The example below creates an instance that runs on host ReplicaCatalog. Furthermore, the service is configured so that looking up an entry takes 100 flops of computation, and so that the message sent to the service to lookup an entry is 1KiB:

auto fr_service = simulation->add(
          new wrench::FileRegistryService("ReplicaCatalog",
                                       {{wrench::FileRegistryServiceProperty::LOOKUP_COMPUTE_COST, "0.1"}},
                                       {{wrench::BareMetalComputeServiceMessagePayload::FILE_LOOKUP_REQUEST_MESSAGE_PAYLOAD, 1024}});

See the documentation of wrench::FileRegistryServiceProperty and wrench::FileRegistryServiceMessagePayload for all possible configuration options.