struct Logit::Event

• Logit::Event
• Struct
• Value
• Object

Overview

A structured log event with OpenTelemetry-compatible fields.

Events are the core data structure passed to backends for logging. Each event contains:

• Trace context (trace_id, span_id, parent_span_id)
• Timing information (timestamp, duration)
• Source location (file, line, method, class)
• Structured attributes
• Exception information (if applicable)

Events are created automatically by the instrumentation system. You typically interact with events through the Span API or by implementing custom formatters/backends.

OpenTelemetry Semantic Conventions

Events provide helper methods for setting OpenTelemetry semantic attributes:

if span = Logit::Span.current?
  # HTTP attributes
  span.attributes.set("http.method", "POST")
  span.attributes.set("http.route", "/api/users")
  span.attributes.set("http.status_code", 200_i64)

  # Database attributes
  span.attributes.set("db.system", "postgresql")
  span.attributes.set("db.statement", "SELECT * FROM users")
end

JSON Serialization

Events serialize to JSON in an OpenTelemetry-compatible format:

{
  "trace_id": "abc123...",
  "span_id": "def456...",
  "timestamp": "2024-01-15T10:30:00.000000Z",
  "duration_ms": 42,
  "name": "find_user",
  "level": "info",
  "code": {
    "file": "user_service.cr",
    "line": 15,
    "function": "find_user",
    "namespace": "UserService"
  },
  "attributes": { ... }
}

Defined in:

logit/events/attributes.cr
logit/events/event.cr

Constructors

• .new(trace_id : String, span_id : String, name : String, level : Logit::LogLevel, code_file : String, code_line : Int32, method_name : String, class_name : String, parent_span_id : Nil | String = nil)

  Creates a new event with the given parameters.

Instance Method Summary

• #attributes : Event::Attributes

  Structured attributes attached to this event.

• #attributes=(attributes : Event::Attributes)

  Structured attributes attached to this event.

• #class_name : String

  Fully-qualified class name containing the instrumented method.

• #class_name=(class_name : String)

  Fully-qualified class name containing the instrumented method.

• #code_file : String

  Source file where the instrumented method is defined.

• #code_file=(code_file : String)

  Source file where the instrumented method is defined.

• #code_line : Int32

  Line number where the instrumented method is defined.

• #code_line=(code_line : Int32)

  Line number where the instrumented method is defined.

• #duration_ms : Int64

  Duration of the operation in milliseconds.

• #duration_ms=(duration_ms : Int64)

  Duration of the operation in milliseconds.

• #exception : ExceptionInfo | Nil

  Exception information if an error occurred.

• #exception=(exception : ExceptionInfo | Nil)

  Exception information if an error occurred.

• #level : LogLevel

  Log level of this event.

• #level=(level : LogLevel)

  Log level of this event.

• #method_name : String

  Name of the instrumented method.

• #method_name=(method_name : String)

  Name of the instrumented method.

• #name : String

  Name of this event (typically the method name).

• #name=(name : String)

  Name of this event (typically the method name).

• #parent_span_id : String | Nil

  Span ID of the parent span, or nil if this is a root span.

• #parent_span_id=(parent_span_id : String | Nil)

  Span ID of the parent span, or nil if this is a root span.

• #set_code_function(function : String) : Nil

  Code attributes

• #set_code_namespace(namespace : String) : Nil
• #set_db_name(name : String) : Nil
• #set_db_operation(operation : String) : Nil
• #set_db_statement(statement : String) : Nil
• #set_db_system(system : String) : Nil

  Database attributes

• #set_exception_message(message : String) : Nil
• #set_exception_type(type : String) : Nil

  Exception attributes

• #set_http_method(method : String) : Nil

  Sets the HTTP request method (e.g., "GET", "POST").

• #set_http_request_body_size(size : Int64) : Nil
• #set_http_route(route : String) : Nil
• #set_http_status_code(code : Int32) : Nil
• #set_service_name(name : String) : Nil

  Service attributes

• #set_service_version(version : String) : Nil
• #set_user_id(id : String | Int64) : Nil

  User attributes

• #set_user_role(role : String) : Nil
• #span_events : Array(Logit::SpanEvent)

  Span events that occurred during the operation.

• #span_events=(span_events : Array(Logit::SpanEvent))

  Span events that occurred during the operation.

• #span_id : String

  Unique identifier for the span that generated this event.

• #span_id=(span_id : String)

  Unique identifier for the span that generated this event.

• #status : Status

  Status of the operation (Ok or Error).

• #status=(status : Status)

  Status of the operation (Ok or Error).

• #timestamp : Time

  When this event was created.

• #timestamp=(timestamp : Time)

  When this event was created.

• #to_json(json : JSON::Builder) : Nil

  Serialize to JSON

• #to_json : String
• #trace_id : String

  W3C trace ID (128-bit hex string) shared across all spans in a trace.

• #trace_id=(trace_id : String)

  W3C trace ID (128-bit hex string) shared across all spans in a trace.

Constructor Detail

Instance Method Detail