Class ObservableBackend`Internal`

Observable Backend - Unified backend for logging and metrics

This is the internal backend that handles both logging and metrics operations. It replaces the separate PluginLogging and PluginMetrics classes with a single unified implementation.

Example

// Internal use only - plugins use Observable interface
const backend = new ObservableBackend(
  'development',
  'my-app',
  'my-plugin',
  sbObservable
);

Index

Constructors

constructor

Methods

debug info warn error createCounter createGauge createHistogram createTrace createSpan createTimer

Constructors

constructor

new ObservableBackend(
    mode: DEBUG_MODE,
    appId: string,
    pluginName: string,
    bus: ObservableBus,
): ObservableBackend
Create an ObservableBackend instance
Parameters
- mode: DEBUG_MODE
  Debug mode setting
- appId: string
  Application ID
- pluginName: string
  Plugin name
- bus: ObservableBus
  Observable bus for emitting events
Returns ObservableBackend
- Defined in src/base/ObservableBackend.ts:313

Methods

debug

debug<T extends string>(
    trace: DTrace,
    message: T,
    ...meta: SmartLogMeta<T>,
): void
Logs a debug message
Type Parameters
- T extends string
Parameters
- trace: DTrace
  The trace to associate with the log
- message: T
  The message to log
- ...meta: SmartLogMeta<T>
  Additional information to log with the message
Returns void
nothing
Example
```
backend.debug(trace, "This is a debug log");
backend.debug(trace, "This is a debug {key}", {"key": "log"});
```
- Defined in src/base/ObservableBackend.ts:338

info

info<T extends string>(
    trace: DTrace,
    message: T,
    ...meta: SmartLogMeta<T>,
): void
Logs an info message
Type Parameters
- T extends string
Parameters
- trace: DTrace
  The trace to associate with the log
- message: T
  The message to log
- ...meta: SmartLogMeta<T>
  Additional information to log with the message
Returns void
nothing
Example
```
backend.info(trace, "This is an info log");
backend.info(trace, "This is an info {key}", {"key": "log"});
```
- Defined in src/base/ObservableBackend.ts:357

warn

warn<T extends string>(
    trace: DTrace,
    message: T,
    ...meta: SmartLogMeta<T>,
): void
Logs a warn message
Type Parameters
- T extends string
Parameters
- trace: DTrace
  The trace to associate with the log
- message: T
  The message to log
- ...meta: SmartLogMeta<T>
  Additional information to log with the message
Returns void
nothing
Example
```
backend.warn(trace, "This is a warn log");
backend.warn(trace, "This is a warn {key}", {"key": "log"});
```
- Defined in src/base/ObservableBackend.ts:375

error

error<T extends string>(
    trace: DTrace,
    message: T,
    ...meta: SmartLogMeta<T>,
): void
Logs an error message
Type Parameters
- T extends string
Parameters
- trace: DTrace
  The trace to associate with the log
- message: T
  The message to log
- ...meta: SmartLogMeta<T>
  Additional information to log with the message
Returns void
nothing
Example
```
backend.error(trace, "This is an error log");
backend.error(trace, "This is an error {key}", {"key": "log"});
```
```
backend.error(new BSBError(trace, "error-key", "This is an error log"));
backend.error(new BSBError(trace, "error-key", "This is an error {key}", {"key": "log"}));
```
- Defined in src/base/ObservableBackend.ts:397

error<T extends string>(error: BSBError<T>): void

Logs an error message

Type Parameters

T extends string

Parameters

error: BSBError<T>

Returns void

nothing

Example

backend.error(trace, "This is an error log");
backend.error(trace, "This is an error {key}", {"key": "log"});

backend.error(new BSBError(trace, "error-key", "This is an error log"));
backend.error(new BSBError(trace, "error-key", "This is an error {key}", {"key": "log"}));

createCounter

createCounter<LABELS extends string | undefined>(
    name: string,
    description: string,
    help: string,
    labels?: LABELS[],
): Counter<LABELS>
Create a counter metric

Counters are monotonically increasing values used to track cumulative totals. Common uses: request counts, error counts, bytes processed.
Type Parameters
- LABELS extends string | undefined
Parameters
- name: string
  Metric name (e.g., "requests_total")
- description: string
  Short description
- help: string
  Detailed help text
- Optionallabels: LABELS[]
  Optional label names for dimensional metrics
Returns Counter<LABELS>
Counter instance with increment method
Example
```
const requests = backend.createCounter(
  "http_requests_total",
  "Total HTTP requests",
  "Count of all HTTP requests received",
  ["method", "status"]
);
requests.increment(1, { method: "GET", status: "200" });
```
- Defined in src/base/ObservableBackend.ts:458

createGauge

createGauge<LABELS extends string | undefined>(
    name: string,
    description: string,
    help: string,
    labels?: LABELS[],
): Gauge<LABELS>
Create a gauge metric

Gauges represent point-in-time values that can go up or down. Common uses: memory usage, active connections, queue depth, temperature.
Type Parameters
- LABELS extends string | undefined
Parameters
- name: string
  Metric name (e.g., "active_connections")
- description: string
  Short description
- help: string
  Detailed help text
- Optionallabels: LABELS[]
  Optional label names for dimensional metrics
Returns Gauge<LABELS>
Gauge instance with set, increment, and decrement methods
Example
```
const activeConns = backend.createGauge(
  "active_connections",
  "Active connections",
  "Number of currently active connections"
);
activeConns.set(42);
activeConns.increment(1);
activeConns.decrement(1);
```
- Defined in src/base/ObservableBackend.ts:494

createHistogram

createHistogram<LABELS extends string | undefined>(
    name: string,
    description: string,
    help: string,
    boundaries?: number[],
    labels?: LABELS[],
): Histogram<LABELS>
Create a histogram metric

Histograms track the distribution of values over time. Common uses: request duration, response size, batch size.
Type Parameters
- LABELS extends string | undefined
Parameters
- name: string
  Metric name (e.g., "request_duration_ms")
- description: string
  Short description
- help: string
  Detailed help text
- Optionalboundaries: number[]
  Optional bucket boundaries (default: [0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10])
- Optionallabels: LABELS[]
  Optional label names for dimensional metrics
Returns Histogram<LABELS>
Histogram instance with record method
Example
```
const duration = backend.createHistogram(
  "request_duration_ms",
  "Request duration",
  "Duration of HTTP requests in milliseconds",
  [10, 50, 100, 500, 1000, 5000],
  ["method"]
);
duration.record(125, { method: "GET" });
```
- Defined in src/base/ObservableBackend.ts:539

createTrace

createTrace(
name: string,
attributes?: Record<string, string | number | boolean>,
): Trace
Create a new distributed trace

Creates a root trace with no parent. Use this when starting a new request or operation that should be tracked independently.
Parameters
- name: string
  Name of the trace/span (e.g., "http-request")
- Optionalattributes: Record<string, string | number | boolean>
  Optional attributes to attach to the trace
Returns Trace
Trace instance
Example
```
const trace = backend.createTrace("process-batch", {
  "batch.size": 100
});
// ... do work ...
trace.end({ "batch.processed": 100 });
```
- Defined in src/base/ObservableBackend.ts:570

createSpan

createSpan(
    trace: DTrace,
    name: string,
    attributes?: Record<string, string | number | boolean>,
): Trace
Create a child span within an existing trace

Creates a child span that inherits the trace ID from the parent. This is used internally by Observable.startSpan().
Parameters
- trace: DTrace
  Parent DTrace object
- name: string
  Name of the span (e.g., "database-query")
- Optionalattributes: Record<string, string | number | boolean>
  Optional attributes to attach to the span
Returns Trace
Trace instance representing the child span
Example
```
// Usually accessed via Observable
const childSpan = backend.createSpan(trace, "database-query");
// ... do work ...
childSpan.end();
```
- Defined in src/base/ObservableBackend.ts:596

createTimer

createTimer(): Timer
Create a high-resolution timer

Returns a timer that can measure elapsed time in milliseconds with sub-millisecond precision using Node.js hrtime.

Returns Timer
Timer instance with stop method
Example
```
const timer = backend.createTimer();
await performOperation();
const elapsed = timer.stop();
```
- Defined in src/base/ObservableBackend.ts:618

Class ObservableBackendInternal

Example

Index

Constructors

Methods

Constructors

constructor

Parameters

Returns ObservableBackend

Methods

debug

Type Parameters

Parameters

Returns void

Example

info

Type Parameters

Parameters

Returns void

Example

warn

Type Parameters

Parameters

Returns void

Example

error

Type Parameters

Parameters

Returns void

Example

Type Parameters

Parameters

Returns void

Example

createCounter

Type Parameters

Parameters

Returns Counter<LABELS>

Example

createGauge

Type Parameters

Parameters

Returns Gauge<LABELS>

Example

createHistogram

Type Parameters

Parameters

Returns Histogram<LABELS>

Example

createTrace

Parameters

Returns Trace

Example

createSpan

Parameters

Returns Trace

Example

createTimer

Returns Timer

Example

Settings

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Class ObservableBackend`Internal`