Telemetry event definitions and emission helpers for terminusdb_ex.
Every public operation emits a [:start] and [:stop] event of the form:
[:terminusdb, <area>, :start]
[:terminusdb, <area>, :stop]where <area> is one of :database, :document, :query, :branch,
:merge, :diff, :commit, :woql, :graphql, :prefix, :triples,
:remote, or :connection.
Measurements
start:%{system_time: System.monotonic_time()}stop:%{duration: native_time, system_time: System.monotonic_time()}
duration is in :native time units; convert in handlers with
System.convert_time_unit(duration, :native, :millisecond).
Metadata
Both events carry %{config: redacted_config, method: atom, path: String.t(), area: atom}
plus, on :stop, status: pos_integer | nil and error: TerminusDB.Error.t() | nil.
The caller (typically TerminusDB.Client) is responsible for redacting the config via
TerminusDB.Config.redact/1 before placing it in the meta, so credentials never leak.
Attaching
:telemetry.attach_many(
"my-handler",
[[:terminusdb, :database, :stop], [:terminusdb, :query, :stop]],
fn event, measurements, meta, _ctx ->
# log slow queries, push metrics, ...
end,
nil
)Summary
Functions
Returns the event name for a given area and stage (:start or :stop).
Emits the [:start] event for area with the given metadata.
Emits the [:stop] event for area, computing duration from start_monotonic.
Types
Functions
Returns the event name for a given area and stage (:start or :stop).
iex> TerminusDB.Telemetry.event_name(:database, :start)
[:terminusdb, :database, :start]@spec start(area(), map(), TerminusDB.Config.t()) :: integer() | nil
Emits the [:start] event for area with the given metadata.
Returns the monotonic time captured for the measurement, so callers can pass it to
stop/4. No-op when config.telemetry is false.
Examples
iex> config = TerminusDB.Config.new(endpoint: "http://localhost:6363")
iex> meta = %{path: "db/admin/mydb", method: :post}
iex> start_time = TerminusDB.Telemetry.start(:database, meta, config)
iex> is_integer(start_time)
true@spec stop(area(), map(), integer() | nil, TerminusDB.Config.t(), keyword()) :: :ok | nil
Emits the [:stop] event for area, computing duration from start_monotonic.
Accepts an optional status (HTTP status code) and error (TerminusDB.Error.t())
to include in the metadata. No-op when config.telemetry is false.
Examples
iex> config = TerminusDB.Config.new(endpoint: "http://localhost:6363")
iex> meta = %{path: "db/admin/mydb", method: :post, config: TerminusDB.Config.redact(config)}
iex> start_time = TerminusDB.Telemetry.start(:database, meta, config)
iex> :ok = TerminusDB.Telemetry.stop(:database, meta, start_time, config, status: 200, error: nil)
iex> :ok
:ok