intercede 0.0.1a1

Unified interfaces to Computing Elements and batch systems for DIRAC / DiracX

Unified interfaces to Computing Elements and batch systems for DIRAC / DiracX and beyond —
submit, monitor, retrieve — validated against containerized backends.

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What is interCEde?

interCEde sits between Workload Management Systems, such as DiracX and the many resources where jobs actually run. It provides a single, consistent interface for talking to Computing Elements (CEs) and batch systems — submitting jobs, querying their status, and retrieving their outputs — regardless of which backend is on the other end.

The name is the job description: the library intercedes on WMS' behalf, acting between two parties so the rest of the stack never has to know whether it is talking to ARC, HTCondor, Slurm over SSH, or a process on the local machine.

Every interface ships with integration tests that run against containerized instances of the real backends, so a given CE type is verified against multiple versions and configurations rather than against a mock that drifts from reality.

Why it exists

• One contract, many backends. Calling code submits a job the same way everywhere; the backend-specific quirks live behind the interface.
• Composable resources. Backends combine — SSH + Slurm, SSH + HTCondor, ARC + HTCondor, or a plain local runner — and each combination is just another implementation of the same interface.
• Tested against the real thing. Containerized Slurm, HTCondor, and ARC instances are spun up in CI so behavior is checked against actual schedulers, not stubs.
• Version coverage. The same test suite runs across a matrix of backend versions to catch incompatibilities before they reach production.

Relationship to DIRAC / DiracX

interCEde is part of the DIRACGrid ecosystem and is designed to back the Computing Element layer used by DiracX. It can also be used standalone wherever a uniform interface to heterogeneous CEs and batch systems is useful.