Admin interface

[MarkWolters]

JMX Runtime Configuration for Graph Index Builder

Introduces GraphIndexBuilderConfig, a JMX-managed singleton that exposes GraphIndexBuilder construction parameters as runtime-tunable attributes. Before this change, options such as addHierarchy, refineFinalGraph, parallelBuild, and build-time compression type could only be set at the call site and required a code change or restart to modify.

What's new

• management package — GraphIndexBuilderConfigMBean declares 8 managed attributes across four groups (graph topology, write path, build compression type, PQ parameters); GraphIndexBuilderConfig is the singleton implementation registered under io.github.jbellis.jvector:type=GraphIndexBuilderConfig. CompressionType enum (NONE, PQ, BQ) drives build-time scoring compression selection.

• GraphIndexBuilder — New constructor (RandomAccessVectorValues, VectorSimilarityFunction, …) reads addHierarchy, refineFinalGraph, and compression type from GraphIndexBuilderConfig at construction time. Existing constructors that accept those booleans explicitly are deprecated but unchanged in behavior. The new getBuildScoreProvider helper wires PQ and BQ build-time compression end-to-end using the JMX-configured parameters.

• RandomAccessOnDiskGraphIndexWriter.Builder — Unified builder replaces the separate OnDiskGraphIndexWriter.Builder. Reads GraphIndexBuilderConfig.isParallelBuild() at build time to select OnDiskParallelGraphIndexWriter or OnDiskGraphIndexWriter. Both produce an identical on-disk format, so the flag can be toggled without re-indexing.

• No breaking changes — All existing API call sites continue to compile and behave identically; deprecated constructors are retained and honor caller-supplied values.

Attributes managed via JMX

Attribute	Type	Default
AddHierarchy	boolean	true
RefineFinalGraph	boolean	true
ParallelBuild	boolean	false
BuildCompressionType	String	"NONE"
PqMFactor	int	8
PqK	int	256
PqCenterData	boolean	false
PqAnisotropicThreshold	float	-1.0

All attributes are @Experimental. MBean registration is best-effort — failure logs a warning but does not affect normal operation.

[github-actions]

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[jshook]

I don't mind JMX being added for these things but I do want to see there be a better way. As in if JMX is supported, it should probably be based on a better internal interface.
If you are open to this, we can discuss before pushing forward on this change.

[MarkWolters]

I don't mind JMX being added for these things but I do want to see there be a better way. As in if JMX is supported, it should probably be based on a better internal interface. If you are open to this, we can discuss before pushing forward on this change.

Updated PR to include flexible management registry allowing for other implementations but keeping jmx as the default

[jshook]

Looks good