Crate tael_server 

tael-server: OTLP ingest, tiered storage, and the REST/gRPC query API.

Shipped as a library so the tael binary can embed it behind tael serve (a single cargo install), while still being usable as a standalone crate. run is the entrypoint; ServerConfig configures it.

Structs

BlobStore

A local-filesystem content-addressed blob store. The same path layout is a valid object-store key prefix, so a future S3/R2 backend is a swap behind this type (design Phase 9).

DuckDbStore

FanoutStore

A Store that scatters reads across N shard stores and gathers/merges the results. See the module docs for routing vs. fan-out semantics.

LogRecord

MetricPoint

RemoteStore

A Store backed by another tael-server’s REST API over HTTP.

RemoteWalSink

ServerConfig

Span

SpanEvent

TaelBackend

TraceQuery

Enums

LogSeverity

MetricType

SpanKind

Span kind. Mirrors the OpenTelemetry SpanKind, plus a synthetic Llm variant that marks spans carrying a typed [LlmSpan] extension.

SpanStatus

StorageBackend

Selected storage backend. TaelBackend (the purpose-built tiered engine) is the default; pass --storage duckdb or set TAEL_STORAGE=duckdb to use the legacy embedded-DuckDB backend instead.

Traits

Store

Storage backend for all telemetry signals. The server depends on Arc<dyn Store>, so backends (DuckDB today, TaelBackend next) are swappable without touching the API, ingest, or query layers.

WalSink

A replication target for the WAL. The leader hands each appended record’s framed bytes (the wire format below) to every registered sink before its write returns — the replicate-before-ack guarantee that lets a standby survive the leader’s loss, not just its crash (docs/tael-server-scaling-ha.md §5.1). A sink’s append_framed must only return once the record is durable at the sink (a standby ack, an fsync).

Functions

run

Start the server: OTLP gRPC + REST listeners over the configured storage backend, plus the background maintenance task when running on tael-backend. Runs until one of the listeners exits.