21 KiB
SciMesh Workload SDK v1
SciMesh now ships a public Python SDK under scimesh.sdk. The implemented
authoring profile is core-batch-v1: installed and digest-pinned workload
definitions, strict JSON manifests, typed artifact ports and collections, a
static map/reduce workflow, CPU/memory/scratch eligibility, atomic local
resource reservation, exact/canonical/numeric verifier primitives, and a
compatibility adapter for the existing DistributedWorkload protocol. Its
local executor is deliberately a trusted, in-process conformance harness; the
production subprocess/lease sandbox remains a coordinator/Worker milestone.
The full target contract remains in
scimesh-sdk-contract.md. Dynamic expansion,
streaming, accelerators, gang execution, and side effects have typed bounded
declarations, but the current coordinator/Worker runtime does not advertise
their features. Compatibility negotiation therefore rejects those workflows
before planner code runs.
SDK versus workloads
scimesh.sdk is the framework only: strict manifests, plans, artifacts,
registry, verifiers, and the local conformance executor. It contains no
scientific workload code. Workloads are user Python scripts and packages that
import the SDK and live outside it. The built-in SciMesh workloads are under
scimesh/workloads/:
scimesh/workloads/search/— SDK-builtsimilarity-search@1.0.0;scimesh/workloads/graph/— SDK-builtsimilarity-graph@1.0.0;scimesh/workloads/descriptors/— SDK-builtdescriptor-batch@1.0.0;scimesh/workloads/molwt_filter/— SDK-builtmolwt-filter@1.0.0, the minimal authoring example: it only declares identity, parameters, ports, and thecompute_shardhook, using the scaffold's default sharding and concatenation;scimesh/workloads/library.py— the built-in library wiring: a default registry containing all three definitions and a runtime advertising their capabilities;- the plain
scimesh/workloads/*.pymodules remain the local CLI scientific cores and theirWorkloadregistry.
Each SDK-built workload is a small package with core.py (scientific code)
and definition.py (manifest plus planner/runner/reducer handlers). A future
external workload library can follow the same shape: its own distribution, one
scimesh.workloads entry point per workload version, and an administrator
allowlist.
What authors import
The stable authoring surface is exported from scimesh.sdk:
WorkloadManifest,WorkloadId,VersionRange,PackageSpec, andEnvironmentSpecpin identity and compatibility;ArtifactSchema,PortSpec,ArtifactRef, andArtifactCollectiondefine immutable data boundaries without transport URLs or local paths;WorkflowSpec,StageSpec,ArtifactEdge,TaskSpec, andWorkflowPlandefine a typed acyclic plan and pin package/manifest digests plus trust mode;ResourceRequirementsandExecutionProfileseparate per-task resources from Agentmax_concurrency;Planner,Runner,Reducer, andVerifierare the package handler protocols;OutputManifestandProvenancedescribe sealed durable results;WorkloadRegistryresolves an exact name, version, package digest, runtime, environment, and feature set. It never selects an implicit latest version;MapReduceWorkloadis the primary authoring scaffold forcore-batch-v1: a subclass declares its identity, parameter schema, artifact ports, and three scientific hooks (partition, compute, merge), and the SDK assembles the manifest, map/reduce stages, workflow, digest-pinned handlers, and the exact-artifact verifier. See "Authoring a workload" below.
Persisted manifests, requests, plans, tasks, expansions, outputs, candidates, decisions, and failures are frozen, recursively immutable, JSON-safe, canonically serialized, and strict about unknown fields; their enclosing wire contracts carry schema versions. Artifact identities contain a coordinator-owned UUID, schema, checksum, media type, and bounds; a scientific handler never persists a filesystem path.
Try the built-in SDK workloads
This example runs the SDK-built similarity-search without starting
PostgreSQL or the coordinator:
from pathlib import Path
from scimesh.sdk import (
ArtifactCollection,
JobRequest,
LocalArtifactStore,
LocalCoreBatchExecutor,
)
from scimesh.workloads.library import (
default_sdk_registry,
default_sdk_runtime,
similarity_search_sdk_definition,
)
root = Path("sdk-run")
store = LocalArtifactStore(root / "artifacts")
workload = similarity_search_sdk_definition(shard_rows=1_000)
dataset = store.import_file(
Path("chembl_37_chemreps.txt"),
declaration=workload.manifest.inputs["input"].schema,
)
request = JobRequest(
workload=workload.manifest.workload,
parameters={"query_smiles": "CCO", "top_k": 20},
inputs={"input": ArtifactCollection.single(dataset)},
)
result = LocalCoreBatchExecutor(
default_sdk_registry(shard_rows=1_000),
default_sdk_runtime(),
store,
root / "attempts",
).execute(request, workload.manifest.package.digest)
result_ref = result.outputs["result"].items[0].artifact
print(store.materialize(result_ref))
LocalCoreBatchExecutor is a correctness/conformance runtime, not a substitute
for coordinator leases or multi-machine scheduling. It accepts only
TrustMode.TRUSTED, NetworkPolicy.TRUSTED, single-process/single-threaded CPU
map/reduce stages without secrets, checkpoints, retries, gangs, or
accelerators. It does not claim network, timeout, process, or credential
isolation. Unsupported declarations are rejected before a handler runs. The
harness runs the SDK-built workload handlers themselves, and their parity
against the single-process references is covered by automated tests.
The descriptor-batch reference workload
descriptor-batch@1.0.0 is the first SDK-native reference workload: it is
built directly on the manifest/planner/runner/reducer contracts, and it is
the intended first untrusted_quorum candidate
(byte_exact plus exact-artifact@1). Its scientific contract is pinned:
- one output CSV row per valid input molecule, in input order, with RDKit canonical SMILES recomputed by RDKit;
- an explicit 81-name pinned RDKit 2D descriptor set (see
scimesh/workloads/descriptors/core.py), validated against the installed RDKit at definition build time; %.6ffloat formatting,utf-8CSV with one header, and row-bounded deterministic shards;skip_invalidis the only parameter (defaulttrue): invalid SMILES rows are counted and skipped, or fail the run whenfalse;- the reducer concatenates shard partials by shard index with exactly one header, so the distributed output is byte-identical to the single-process reference for the same input rows.
from pathlib import Path
from scimesh.sdk import (
ArtifactCollection,
JobRequest,
LocalArtifactStore,
LocalCoreBatchExecutor,
WorkloadRegistry,
)
from scimesh.workloads.descriptors import descriptor_batch_sdk_definition
from scimesh.workloads.library import default_sdk_runtime
root = Path("descriptor-run")
store = LocalArtifactStore(root / "artifacts")
workload = descriptor_batch_sdk_definition(shard_rows=1_000)
dataset = store.import_file(
Path("chembl_37_chemreps.txt"),
declaration=workload.manifest.inputs["input"].schema,
)
request = JobRequest(
workload=workload.manifest.workload,
parameters={"skip_invalid": True},
inputs={"input": ArtifactCollection.single(dataset)},
)
registry = WorkloadRegistry()
registry.register(workload.definition(), enabled=True)
result = LocalCoreBatchExecutor(
registry,
default_sdk_runtime(),
store,
root / "attempts",
).execute(request, workload.manifest.package.digest)
result_ref = result.outputs["result"].items[0].artifact
print(store.materialize(result_ref))
The descriptor-batch entry point descriptor-batch@1.0.0 is declared in
pyproject.toml; discovery loads it only when an administrator supplies a
matching AllowedPackage allowlist entry. Its manifest declares both
trusted and untrusted_quorum trust modes and the exact-artifact verifier,
so the same definition can later run under coordinator quorum once protocol-v2
leases exist.
The SDK-built similarity workloads
similarity-search@1.0.0 and similarity-graph@1.0.0 are SDK-built workloads
under scimesh/workloads/search/ and scimesh/workloads/graph/; both reuse
the local scientific cores from scimesh/workloads/similarity_search.py and
similarity_graph.py and declare byte_exact + exact-artifact@1:
- the search workload resolves
query_idexactly once at plan time, shards the input deterministically, computes a local top-k per shard with the reference heap, and merges the sorted partials with the same tie-breakers, so the final CSV is byte-identical to the single-process CLI output; - the graph workload parses molecules once into deterministic row-ordered
blocks, plans one map task per block pair
(i, j)withi <= j, and its reducer enforces the pair-coverage invariant (every unordered molecule pair compared exactly once, no duplicates) before emitting the same deterministically sorted edge list as the local brute-force reference, for either threshold direction and any block size; - the v1 worker executes SDK-built workloads directly:
scimesh/worker/runners.pyis a workload-generic wire bridge that builds aTaskSpecwith the workload's own pins, negotiates against a runtime derived from the loaded definitions, reserves resources, seals the partial through a content-addressed store, and uploads the resulting CSV over the unchanged coordinator contract. The worker loads workloads fromSCIMESH_WORKLOAD_ALLOWLIST(a JSON array of{distribution, name, version, digest}entries matched against installedscimesh.workloadsentry points) or falls back to the built-insimilarity-search; advertised capabilities come fromSCIMESH_CAPABILITIES. Workloads whose map stage needs more than one input port are rejected with a clear message until the coordinator contract supports them.
Authoring a workload
A workload is a user script that imports the SDK. For the standard
core-batch-v1 shape (one input dataset, shards, partials, one merged result)
subclass MapReduceWorkload and implement the three scientific hooks; the
framework provides everything else:
from pathlib import Path
from typing import Any, Mapping, Sequence
from scimesh.sdk import (
ArtifactSchema,
ComponentRef,
MapReduceWorkload,
PortSpec,
SchemaRef,
WorkloadId,
)
class CountRowsWorkload(MapReduceWorkload):
workload_id = WorkloadId("count-rows", "1.0.0")
description = "Count TSV data rows per shard and concatenate the counts."
parameters_schema = {
"type": "object",
"additionalProperties": False,
"properties": {"prefix": {"type": "string", "minLength": 1, "maxLength": 50}},
}
input_port = PortSpec(ArtifactSchema(
SchemaRef("molecule-table", 1), "text/tab-separated-values", "utf-8",
max_bytes=10**9, validator=ComponentRef("delimited-table", 1),
validator_configuration={"required_columns": ["canonical_smiles", "chembl_id"]},
))
partial_port = output_port = PortSpec(ArtifactSchema(
SchemaRef("count-table", 1), "text/csv", "utf-8",
max_bytes=10**9, validator=ComponentRef("delimited-table", 1),
validator_configuration={"columns": ["id", "rows"]},
))
map_parameter_names = ("prefix",)
def partition_input(self, input_path, parameters, workspace): # -> list[Path]
... # deterministic shard files, one per map task
def compute_shard(self, inputs, parameters, output_path): # -> Mapping[str, int|float]
... # one map task; inputs maps each map port to a materialized file
def reduce_partials(self, partial_paths, parameters, output_path): # -> Mapping[str, int|float]
... # deterministic merge of the accepted partials
The base class then provides validate, plan, run, reduce, and
definition(). For workloads whose map output is a simple filtered or
transformed table, the scaffold's defaults already cover partitioning
(row-bounded shards that keep the header) and reduction (concatenation with
one header), so only compute_shard has to be written — that is exactly what
the built-in molwt-filter workload does. The registry, negotiation, resource
reservation, verification, and the local conformance executor treat the
result like any other workload:
from scimesh.sdk import (
ArtifactCollection,
JobRequest,
LocalArtifactStore,
LocalCoreBatchExecutor,
WorkloadRegistry,
)
from scimesh.workloads.library import default_sdk_runtime
workload = CountRowsWorkload(package_digest=..., environment_digest=...)
registry = WorkloadRegistry()
registry.register(workload.definition(), enabled=True)
store = LocalArtifactStore(Path("artifacts"))
artifact = store.import_file(Path("tiny.tsv"), declaration=workload.manifest.inputs["input"].schema)
request = JobRequest(workload=workload.manifest.workload, parameters={"prefix": "x"},
inputs={"input": ArtifactCollection.single(artifact)})
result = LocalCoreBatchExecutor(registry, default_sdk_runtime(), store, Path("work")) \
.execute(request, workload.manifest.package.digest)
Hooks you can override beyond the three scientific ones:
domain_validate(parameters)— extra job-parameter validation (the JSON schema already ran);resolved_parameters(request)/resolved_parameters_for_plan(job, input_path, resolved)— values persisted into the plan (for example one-time query resolution);plan_tasks(...)— custom task construction (the graph workload uses this to plan one task per block pair with two block inputs);parse_partial_key(key)/validate_partial_keys(parsed)— partial-key policy (default:map.<eight-digit-index>, contiguous; the graph workload parsesmap.<i>x<j>and enforces the pair-coverage invariant);map_stage_inputs— a map stage with more than one input port (each extra port must share the external input schema).
Anything outside this model uses the lower-level SDK value objects directly. Authoring rules: keep the scientific core callable without a coordinator, inline a strict JSON parameter schema, declare artifact schemas with bounds, return only sink-sealed artifacts, and select a verifier compatible with determinism and trust.
To run a workload from the command line without writing any program code:
scimesh workload list
scimesh workload run count-rows --input tiny.tsv --params '{"prefix": "x"}' -o result.csv
scimesh workload is a generic SDK tool; it contains no workload-specific
logic, so new workloads do not require changes to the CLI or any other part of
the program.
Package shape and registration
A workload distribution provides one explicit entry point per workload
version. The built-in workloads are part of the scimesh distribution:
[project.entry-points."scimesh.workloads"]
"similarity-search@1.0.0" = "scimesh.workloads.search:workload_definition"
"similarity-graph@1.0.0" = "scimesh.workloads.graph:workload_definition"
"descriptor-batch@1.0.0" = "scimesh.workloads.descriptors:workload_definition"
The factory returns a WorkloadDefinition containing its manifest and handler
objects. An administrator supplies an AllowedPackage with the same
distribution, exact WorkloadId, and sha256: package digest. Discovery
filters installed metadata before importing an entry point and fails
transactionally if an allowlisted definition is missing or mismatched. Job
parameters cannot name a module, entry point, package path, or executable.
The measured digest covers package payload files and installed entry-point
declarations and is checked before and after loading. It is a content pin, not
a signature or image attestation; production discovery should run in a fresh
trusted control-plane process so a pre-populated Python module cache is not an
integrity boundary.
Direct registration is useful for tests and embedded deployments:
registry = WorkloadRegistry()
registry.register(definition, enabled=False)
registry.enable(
definition.manifest.workload.name,
definition.manifest.workload.version,
definition.manifest.package.digest,
)
Both version and digest are required when resolving or planning. Upgrading an installed definition does not change the identity of an existing Job.
Authoring rules
- Keep the scientific core callable without a coordinator.
- Inline a strict JSON parameter schema with
type: objectandadditionalProperties: false; the planner still performs domain validation. - Give every external and stage port an
ArtifactSchemawith a media type, schema version, and byte/record/dimension bounds. - Connect stage ports with
ArtifactEdgevalues.WorkflowSpecchecks source and target schemas, complete input bindings, declared dependencies, and acyclicity. - Declare one
ResourceRequirementsandExecutionProfileper stage. A task cannot run until its entire request is eligible and atomically reserved. - Return only sink-sealed artifacts in
OutputManifest; the local harness binds task key/provenance itself and rejects fabricated references, unexpected/missing ports, wrong schema/media type, and cumulative output or artifact-limit violations. - Select a verifier compatible with determinism and trust. SDK v1 permits
untrusted_quorumonly forbyte_exactplusexact-artifact@1. - Add golden fixtures, local/distributed parity, retry/completion-order, and verifier failure tests before enabling a package.
ArtifactSink and ArtifactCatalog are bridge-owned protocols. They let
scientific handlers materialize verified inputs and seal outputs without bearer
tokens, database credentials, upload URLs, or durable local paths.
Verification
The SDK includes:
ExactArtifactVerifier: compares logical port/collection/schema/content digests while ignoring coordinator UUIDs, timestamps, metrics, and worker identity. Quorum inputs use coordinator-createdCandidateOutputenvelopes, count at most one vote per owner, and require aVerificationBindingfor the exact task, inputs, parameters, package, manifest, and environment;CanonicalRecordVerifier: applies a package-owned bounded canonicalizer and compares length-framed canonical records;NumericToleranceVerifier: recursively checks structure plus explicit absolute, relative, ULP, and NaN policy, returning bounded sanitized evidence.
Canonical and numeric objects expose direct bounded comparison methods. To use
them as manifest Verifier handlers, the package supplies an artifact-to-record
or artifact-to-structured-value loader; without one, verification returns
inconclusive rather than accepting bytes it did not parse.
A decision is accepted, rejected, or inconclusive; only accepted
satisfies a stage. Evidence is limited to 16 KiB and cannot contain local paths
or transport URLs.
Resources and current runtime boundary
ResourcePool provides a lock-protected all-or-nothing local reservation for
CPU cores, memory, scratch, and accelerator device/partition IDs, including
whole-device versus partition conflict fencing. It enforces aggregate capacity
and execution-slot count. ExecutionProfile produces only
allocation-derived OpenMP/BLAS and device-visibility values; credentials never
belong to scientific parameters.
The current protocol-v1 coordinator stores one input/result per flat task and does not persist resource requirements, device allocations, stage edges, or package versions. The production Worker also remains serial. Consequently:
- SDK
core-batch-v1can be authored, validated, tested, discovered, and run through the trusted local conformance harness now; - existing production
similarity-searchremains on its compatible v1 wire path and is not renamed; - real concurrent claims, GPU scheduling, multi-output DAG execution, dynamic
loops, streaming, and gang leases require the versioned coordinator/Worker
changes listed in
scimesh-sdk-roadmap.md; - merely declaring a GPU or gang request never enables it. Missing runtime features or inventory fail before the planner executes.
Conformance commands
Install development tools and run the SDK suite:
pip install -e '.[dev]'
pytest tests/test_sdk_models.py \
tests/test_sdk_resources.py \
tests/test_sdk_verification.py \
tests/test_sdk_compatibility.py \
tests/test_sdk_registry.py \
tests/test_sdk_descriptors.py \
tests/test_sdk_search.py \
tests/test_sdk_graph.py
Run pytest for the full Worker, local-science, and SDK regression suite. Package authors can reuse LocalArtifactStore,
LocalCoreBatchExecutor, and assert_manifest_round_trip in their own golden
tests.