Bedrock.SystemKeys (bedrock v0.7.0)

The \xFF/system keys Bedrock writes and reads.

Every key defined here has a named purpose: shard_keys/<end_key> feeds each commit proxy's routing view (through resolver metadata windows) and the next recovery's materializer bootstrap; materializers/<tag>/<worker_id> entries feed the client-facing routing projection served by commit proxies (FDB's serverList/ analogue - interfaces ride the keyspace), answer worker rejoin validation, and give recovery's materializer bootstrap its re-adoption input (read_prior_refs) and the persistence phase's diff base. To clients the members are hints, unverified and cached; to recovery they are durable state. distributor_lock/{owner, write} is the distributor's write fence (FDB's MoveKeys lock, bedrock-q67.21): opaque UIDs read-checked-written inside every mutating distributor transaction, so ownership is enforced by the commit pipeline itself. A system key without a reader is inventory, not communication - unread MACHINERY is deleted, while durable observability keys stay by decision, named as such; families return here when their readers do (config authority with bedrock-q67.25).

Summary

Functions

distributor_lock_owner()

Distributor write-fence owner UID: distributor_lock/owner (FDB's moveKeysLockOwnerKey)

distributor_lock_write()

Distributor write-fence write UID: distributor_lock/write (FDB's moveKeysLockWriteKey)

materializer_key(tag, worker_id)

Membership entry: materializers/<tag>/<worker_id> -> node string.

materializer_tag_prefix(tag)

Prefix covering one tag's members.

materializers_prefix()

Prefix covering every materializer membership entry

parse_key(arg1)

Parses a system key into its family. Unknown system keys parse as :unknown (forward compatibility); non-system keys as :error.

placeholder_worker_id()

The reserved worker id the distributor's placeholder registers under.

shard_key(end_key)

Shard boundary entry: shard_keys/<end_key> -> {tag, start_key} (ceiling search)

shard_keys_prefix()

Prefix covering every shard boundary entry

Functions

distributor_lock_owner()

@spec distributor_lock_owner() :: Bedrock.key()

Distributor write-fence owner UID: distributor_lock/owner (FDB's moveKeysLockOwnerKey)

distributor_lock_write()

@spec distributor_lock_write() :: Bedrock.key()

Distributor write-fence write UID: distributor_lock/write (FDB's moveKeysLockWriteKey)

materializer_key(tag, worker_id)

@spec materializer_key(Bedrock.range_tag(), Bedrock.Service.Worker.id()) ::
  Bedrock.key()

Membership entry: materializers/<tag>/<worker_id> -> node string.

Tag-major with the worker id IN the key, so one family answers both questions FDB needs two for: a prefix scan over a tag gives the shard's members (FDB's range-major keyServers/<range> -> team), and each member is individually addressable for removal (FDB's server-major serverKeys/<server>/<range>). A worker owns exactly one shard and notices broadcast on the shard's tag, so no per-worker index is needed. Membership is expressed by key PRESENCE; removal is a clear.

materializer_tag_prefix(tag)

@spec materializer_tag_prefix(Bedrock.range_tag()) :: Bedrock.key()

Prefix covering one tag's members.

The family's standard triple mirrors FDB's (SystemData.cpp): materializers_prefix/0 is serverKeysRange, materializer_key/2 is serverKeysKey, and this is serverKeysPrefixFor — the scan that answers "who serves this shard" without decoding the whole family.

materializers_prefix()

@spec materializers_prefix() :: Bedrock.key()

Prefix covering every materializer membership entry

parse_key(arg1)

@spec parse_key(Bedrock.key()) ::
  {:shard_key, Bedrock.key()}
  | {:materializer_key, Bedrock.range_tag(), Bedrock.Service.Worker.id()}
  | {:distributor_lock, :owner | :write}
  | :unknown
  | :error

Parses a system key into its family. Unknown system keys parse as :unknown (forward compatibility); non-system keys as :error.

placeholder_worker_id()

@spec placeholder_worker_id() :: Bedrock.Service.Worker.id()

The reserved worker id the distributor's placeholder registers under.

A keyspace-level convention, not a distributor detail: routing reads it to prefer real coverage over parking, so it belongs where the family's semantics are defined rather than behind a control-plane module.

shard_key(end_key)

@spec shard_key(Bedrock.key()) :: Bedrock.key()

Shard boundary entry: shard_keys/<end_key> -> {tag, start_key} (ceiling search)

shard_keys_prefix()

@spec shard_keys_prefix() :: Bedrock.key()

Prefix covering every shard boundary entry