Configuration Reference

Prefix: korvet. · Env prefix: KORVET_

Top-level Korvet runtime settings: namespace, runtime service selection, and the entry points into each sub-system.

Env var: KORVET_NAMESPACE · Type: string · Default: korvet

Logical namespace applied to all storage and registry state this Korvet instance owns. Must not contain whitespace or the : delimiter — colons are appended internally to compose sub-namespaces.

Prefix: korvet.broker. · Env prefix: KORVET_BROKER_

Kafka-wire broker listener and group coordinator: bind address, TLS, request limits, backpressure, and rebalance tuning.

Env var: KORVET_BROKER_ADVERTISED_HOST · Type: string

Hostname advertised to clients via the Kafka metadata response. Leave unset (null) to fall back to host; blank/whitespace values are rejected.

Env var: KORVET_BROKER_ADVERTISED_PORT · Type: integer

Port advertised to clients via the Kafka metadata response. Defaults to port when unset.

Env var: KORVET_BROKER_BOSS_THREADS · Type: integer · Default: 1

Netty boss (accept) thread count.

Env var: KORVET_BROKER_CERT_FILE · Type: file path

PEM-encoded server certificate (or chain). Required when tls=true.

Env var: KORVET_BROKER_CLIENT_AUTH_REQUIRED · Type: boolean · Default: false

Require clients to present a certificate (mTLS).

Env var: KORVET_BROKER_ENABLED · Type: boolean · Default: false

Enable the broker listener.

Env var: KORVET_BROKER_FETCH_MAX_WAIT · Type: duration · Default: 500ms

Maximum time a fetch request will block waiting for fetch.min.bytes to be satisfied.

Env var: KORVET_BROKER_FETCH_PARTITION_MAX_BYTES · Type: data size · Default: 1MB

Default upper bound on per-partition bytes returned by a fetch.

Env var: KORVET_BROKER_HOST · Type: string · Default: 0.0.0.0

Listener host (interface to bind to).

Env var: KORVET_BROKER_ID · Type: integer · Default: 0

Numeric broker id advertised to Kafka clients. Must be unique across a multi-node deployment.

Env var: KORVET_BROKER_KEY_FILE · Type: file path

PEM-encoded server private key. Required when tls=true.

Env var: KORVET_BROKER_KEY_PASSWORD · Type: secret

Passphrase protecting keyFile, if encrypted.

Env var: KORVET_BROKER_MAX_PENDING_BYTES · Type: data size · Default: 100MB

Backpressure threshold: pause reads from the wire once this many bytes are pending outbound.

Env var: KORVET_BROKER_MAX_REQUEST_BYTES · Type: data size · Default: 100MB

Maximum size of a single inbound Kafka request. Requests larger than this are rejected.

Env var: KORVET_BROKER_PORT · Type: integer · Default: 9092

Listener TCP port.

Env var: KORVET_BROKER_REBALANCE_DELAY · Type: duration · Default: 3s

Grace period before triggering a consumer-group rebalance after a member joins or leaves.

Env var: KORVET_BROKER_REBALANCE_THREADS · Type: integer · Default: max(2, available CPU cores)

Scheduler thread-pool size for the group coordinator.

Env var: KORVET_BROKER_RESUME_PENDING_BYTES · Type: data size · Default: 50MB

Backpressure release threshold: resume reads once pending bytes drop below this. Must be < maxPendingBytes.

Env var: KORVET_BROKER_TLS · Type: boolean · Default: false

Enable TLS on the listener. When true, certFile and keyFile are required.

Env var: KORVET_BROKER_TRUST_CERT_FILE · Type: file path

PEM-encoded CA trust store for verifying client certificates (mTLS). Required when clientAuthRequired=true.

Env var: KORVET_BROKER_WORKER_THREADS · Type: integer · Default: 0

Netty worker (IO) thread count. 0 lets Netty pick a default based on CPU count.

Prefix: korvet.maintenance. · Env prefix: KORVET_MAINTENANCE_

Consolidated background maintenance worker (replaces the archiver+trimmer pair) — leader-locked periodic task that catches up on missed archives, enforces retention, and runs cold-tier housekeeping (snapshot expiry, orphan-file sweep, manifest compaction).

Env var: KORVET_MAINTENANCE_CATCHUP_ARCHIVE_AFTER · Type: duration · Default: 5m

Sealed-LOCAL segments older than this are picked up by the catch-up archive sweep. The inline-archive happy path handles writers' own rolls; this only mops up crashes.

Env var: KORVET_MAINTENANCE_ENABLED · Type: boolean · Default: false

Enable the maintenance worker. The Redis leader lock ensures at most one enabled instance runs at a time across the cluster.

Env var: KORVET_MAINTENANCE_EXPIRE_SNAPSHOTS_INTERVAL · Type: duration · Default: 1d

Cadence for Iceberg ExpireSnapshots on the cold-tier table.

Env var: KORVET_MAINTENANCE_LEASE_DURATION · Type: duration · Default: 2m

Redis leader-lock lease duration. Must exceed tickInterval so a slow tick does not let the lease expire mid-flight.

Env var: KORVET_MAINTENANCE_REMOVE_ORPHAN_FILES_INTERVAL · Type: duration · Default: 1h

Cadence for Iceberg RemoveOrphanFiles on the cold-tier table.

Env var: KORVET_MAINTENANCE_REWRITE_MANIFESTS_INTERVAL · Type: duration · Default: 1d

Cadence for Iceberg RewriteManifests on the cold-tier table.

Env var: KORVET_MAINTENANCE_SCAN_PAGE_SIZE · Type: integer · Default: 10000

Page size for XREAD when streaming a sealed segment into cold storage.

Env var: KORVET_MAINTENANCE_TICK_INTERVAL · Type: duration · Default: 1m

Tick cadence for the maintenance loop.

Prefix: korvet.redis. · Env prefix: KORVET_REDIS_

Primary Redis client used by the broker, registries, and (unless overridden) storage.

Env var: KORVET_REDIS_CLUSTER · Type: boolean · Default: false

Env var: KORVET_REDIS_HOST · Type: string · Default: localhost

Env var: KORVET_REDIS_IO_THREADS · Type: integer · Default: available CPU cores

Env var: KORVET_REDIS_PASSWORD · Type: secret

Env var: KORVET_REDIS_PORT · Type: integer · Default: 6379

Env var: KORVET_REDIS_TIMEOUT · Type: duration · Default: 1m

Env var: KORVET_REDIS_URI · Type: string

Env var: KORVET_REDIS_USERNAME · Type: string

Prefix: korvet.schema-registry. · Env prefix: KORVET_SCHEMA_REGISTRY_

Embedded Confluent-compatible schema-registry HTTP endpoint.

Env var: KORVET_SCHEMA_REGISTRY_DEFAULT_COMPATIBILITY · Type: none, backward, backward_transitive, forward, forward_transitive, full, full_transitive · Default: backward

Default compatibility level applied to newly-created subjects.

Env var: KORVET_SCHEMA_REGISTRY_ENABLED · Type: boolean · Default: true

Enable the embedded schema-registry HTTP endpoint.

Env var: KORVET_SCHEMA_REGISTRY_VALIDATE_PRODUCE · Type: boolean · Default: true

Reject produce requests whose payload doesn’t validate against the subject’s latest schema.

Prefix: korvet.storage. · Env prefix: KORVET_STORAGE_

Storage settings: Redis-backed local tier and optional object-store cold tier (opt-in via remote-path).

Env var: KORVET_STORAGE_REMOTE_PATH · Type: string

Object-store path for the cold-tier Iceberg table (e.g. s3://bucket/korvet/cold). Absent/blank disables the cold tier — Korvet runs local-only on Redis Streams. The URI scheme picks the Iceberg FileIO: s3:// → S3FileIO. (Future: gs:// → GCSFileIO, abfs:///abfss:// → ADLSFileIO.)

The korvet.topics list is order-sensitive: each entry is a glob pattern plus optional field overrides, evaluated top-to-bottom with first-non-null-wins semantics. Fields not set by any matching pattern fall back to the built-in defaults defined in TopicConfig. Per-topic admin-set overrides beat patterns.

The per-element fields (korvet.topics[n].partitions, retention-time, compression, etc.) live on TopicConfig in a separate module and are not enumerated in the tables above. The full list:

See the configuration guide for examples.

Every property can be set via an environment variable using Spring Boot’s relaxed binding: uppercase the property name, replace . and - with _. For example:

The exact env-var name for every property is listed in the tables above.

The property layout was reorganized in the KorvetProperties refactor. There are no compatibility aliases — old names are rejected by strict binding and must be updated at the same time as the upgrade.