Systems configuration

Each DIRAC system has its corresponding section in the Configuration namespace.

Note

The configuration options for services and agents are being moved to the Code Documentation. You can find the options for each service and agent on the individual documentation page of the respective agent or service.

Default structure

In each system, per setup, you normally find the following sections:

  • Agents: definition of each agent
  • Services: definition of each service
  • Databases: definition of each db
  • URLs: Resolution of the URL of a given Service (like ‘DataManagement/FileCatalog’) to a list of real urls (like ‘dips://<host>:<port>/DataManagement/FileCatalog’). They are tried in a random order.
  • FailoverURLs: Like URLs, but they are only tried if no server in URLs was successfully contacted.

Main Servers

There might be setup in which all services are installed behind one or several dns alias(es) or gateways (typically orchestrator like Mesos/Kubernetes). When this is the case, it can be bothering to redefine the very same URL everywhere, especially the day the machine name changes.

For this reason, there is the possibility to define a entry in the Operation section which contains the list of servers:

Operations/<Setup>/MainServers = server1, server2

There should be no port, no protocol. In the system configuration, one can then write:

System
{
  URLs
  {
    Service = dips://$MAINSERVERS$:1234/System/Service
  }
}

This will resolve in the following 2 urls:

dips://server1:1234/System/Service, dips://server2:1234/System/Service

Using together the FailoverURLs section, it can be interesting for orchestrator’s setup, where there is a risk for the whole cluster to go down:

System
{
  URLs
  {
    Service = dips://$MAINSERVERS$:1234/System/Service
  }
  FailoverURLs
  {
    Service = dips://failover1:1234/System/Service,dips://failover2:1234/System/Service
  }
}
Operations
{
  Defaults
  {
    MainServers = gateway1, gateway2
  }
}

This results in all calls going to gateway1 and gateway2, which could be frontend to your orchestrator, and only if none of them answers, then do we use failover1 and failover2, which can be installed on separate machines, independent from the orchestrator