Configuration Management

kiok resolves configuration through a priority chain, so the same distribution runs unchanged across laptops, containers, and production hosts.

Priority order

Highest to lowest:

1. System properties — -D flags passed on the command line, e.g. -Dkiok.master.admin.port=8080.
2. Environment variables — the property name uppercased with dots replaced by underscores: kiok.master.admin.port → KIOK_MASTER_ADMIN_PORT.
3. Bundled defaults — the kiok.properties defaults shipped inside the distribution.

A value set at a higher level overrides the same key set lower down.

Variable substitution

Properties may reference other properties with ${...} — for example the RocksDB stores all derive from one base directory:

kiok.base.data.dir=./data
kiok.metadata.rocksdb.path=${kiok.base.data.dir}/metadata

Key settings

Property	Purpose
kiok.zk.serverList	ZooKeeper connect string
kiok.master.admin.port	Admin UI / REST API port (default 8080)
kiok.master.internal.port	Master internal protocol port (default 19999)
kiok.worker.internal.port	Worker internal protocol port (default 19998)
kiok.worker.task.slots	Concurrent task slots per Worker (default 8)
kiok.scheduler.tick.interval.ms	Scheduler evaluation interval
kiok.scheduler.default.task.timeout.ms	Default per-task timeout
kiok.kms.master.key.env	Env var holding the master key (KIOK_MASTER_KEY)
kiok.gitsync.interval.ms	Git Sync pull interval
kiok.joblog.s3.*	Job-log S3 archival destination
kiok.python.path	Python binary for python tasks

The bundled kiok.properties is the full reference — every key is listed there with its default and a comment.