| name | ivg-arno |
| description | Arno (libarno_callout.so) Rust acceleration for IVG — BFS, Leiden community detection, PPR. Load when working on large-graph operations with ivg-iris-enterprise container. |
| managed_by | iris-vector-graph |
| source | intersystems-community/iris-vector-graph |
| tags | ["iris","graph","arno","rust","bfs","ppr","performance"] |
ivg-arno — Arno Rust Acceleration for IVG
What It Is
Arno (libarno_callout.so) is a Rust callout library that accelerates IVG's most
compute-intensive graph operations. It replaces Python-side BFS and community detection
with native Rust implementations invoked via IRIS $ZF(-5) callout.
When It Matters
| Operation | Without Arno | With Arno | Threshold |
|---|
| BFS / multi-hop traversal | LazyKG Python (~seconds at scale) | Rust BFS (~ms) | > ~10K nodes |
| Leiden community detection | leidenalg Python | leiden-rs Rust crate | > ~5K nodes |
| PPR (Personalized PageRank) | Not available | Available | Any size |
| Graph serialization to Rust | ~944ms (20K Native-API hops) | ~9–60ms (1 SQL round-trip) | > ~2K edges |
For small graphs (< 5K nodes) the Python fallback is fast enough. Use Arno when
running production workloads, benchmarks, or Shaarpec/FHIR-scale data.
How to Enable
Arno requires the enterprise container (ivg-iris-enterprise):
scripts/enterprise-container.sh up
python - <<'EOF'
import iris
conn = iris.connect("localhost", 31972, "USER", "_SYSTEM", "SYS")
from iris_vector_graph.engine import IRISGraphEngine
engine = IRISGraphEngine(conn)
print("arno:", engine._detect_arno())
EOF
The up command runs tcp-load-arno which streams docker/enterprise/libarno_callout.so
into the container via TCP and calls Graph.KG.ArnoAccel.Load to register it.
ASQ Query Syntax vs Cypher
IVG exposes two query languages:
| Cypher | ASQ |
|---|
| Syntax | MATCH (a)-[:REL]->(b) RETURN b | JSON/structured adjacency spec |
| Surface | engine.execute_cypher(q) | engine.execute_asq(q) |
| Multi-hop | [*1..N] variable-length | native BFS depth parameter |
| When Arno helps | Routes to Rust BFS internally | Direct Rust BFS |
| Best for | Ad-hoc queries, Cypher-fluent callers | Programmatic traversal, bulk BFS |
ASQ example:
result = engine.execute_asq({
"start": "gene:TP53",
"direction": "out",
"max_depth": 3,
"rel_filter": ["INTERACTS_WITH", "REGULATES"],
})
Fixtures in Tests
Tests that require Arno use the arno_iris_connection fixture (port 31972).
They auto-skip when the enterprise container is not running — they never hard-fail
on Community-only machines.
class TestMyArnoFeature:
@pytest.fixture(autouse=True)
def setup(self, arno_master_cleanup, arno_iris_connection):
from iris_vector_graph.engine import IRISGraphEngine
self.engine = IRISGraphEngine(arno_iris_connection)
self.engine.initialize_schema()
yield
Key ObjectScript Classes
| Class | Purpose |
|---|
Graph.KG.ArnoAccel | Callout bridge — Load, BFS, PPR, Leiden |
Graph.KG.NKGAccel | Integer-keyed adjacency operations over ^NKG |
Graph.KG.NKGAccelTraversal | Traversal methods (BFS, k-hop) on ^NKG |
Graph.KG.NKGAccelCentrality | Closeness/eigenvector/betweenness on ^NKG |
Deploy / Recompile
If ObjectScript classes change, redeploy to the enterprise container:
scripts/enterprise-container.sh tcp-deploy
scripts/enterprise-container.sh tcp-load-arno
Direct irispython or docker cp won't work — the enterprise container uses a NoPWS
HealthShare image where TCP and irispython route to different database files (dual-DB
split). Always use the tcp-deploy subcommand.
