Struct SqliteMetricsBackend 

pub struct SqliteMetricsBackend { /* private fields */ }

Durable SQLite metrics storage in the spectra_metrics table.

new opens the database file and applies the required DDL. Use a separate file from the events backend when following the standard Spectra wiring.

Examples

Facade wiring through Spectra::builder() (requires the spectra crate with the sqlite feature):

use std::sync::Arc;
use spectra::{Spectra, SqliteEventsBackend, SqliteMetricsBackend};

let dir = std::env::temp_dir().join("spectra-example");
let spectra = Spectra::builder()
    .metrics_backend(Arc::new(SqliteMetricsBackend::new(dir.join("metrics.db"))?))
    .events_backend(Arc::new(SqliteEventsBackend::new(dir.join("events.db"))?))
    .embedded()
    .build()?;

Direct backend usage:

use chrono::{Duration, Utc};
use serde_json::json;
use spectra_backend_sqlite::SqliteMetricsBackend;
use spectra_core::{MetricsQueryRange, MetricsStorageBackend};

let dir = tempfile::tempdir()?;
let backend = SqliteMetricsBackend::new(dir.path().join("metrics.db"))?;
let now = Utc::now();
backend.record_counter("cache_hits", &json!({}), 1, now).await?;

let points = backend.query_range(MetricsQueryRange {
    metric_name: "cache_hits".into(),
    start: now - Duration::seconds(1),
    end: now + Duration::seconds(1),
    label_matchers: vec![],
}).await?;
assert_eq!(points.len(), 1);

Implementations

impl SqliteMetricsBackend

pub fn new(path: impl AsRef<Path>) -> Result<Self>

Open or create a SQLite database at path and apply metrics DDL migrations.

The constructor is synchronous. Parent directories must already exist. Use a separate database file from the events backend when following the standard Spectra wiring.

Examples

use spectra_backend_sqlite::SqliteMetricsBackend;

let backend = SqliteMetricsBackend::new("/tmp/spectra-metrics.db")?;
assert!(backend.path().ends_with("spectra-metrics.db"));

pub fn path(&self) -> &Path

Filesystem path of the backing SQLite database.

Trait Implementations

impl Clone for SqliteMetricsBackend

fn clone(&self) -> SqliteMetricsBackend

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl MetricsStorageBackend for SqliteMetricsBackend

fn engine_type(&self) -> StorageEngineType

Returns the engine type for this backend.

fn record_counter<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, name: &'life1 str, labels: &'life2 Value, delta: i64, ts: DateTime<Utc>, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Records a counter increment.

fn record_gauge<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, name: &'life1 str, labels: &'life2 Value, value: f64, ts: DateTime<Utc>, ) -> Pin<Box<dyn Future<Output = Result<()>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Records a gauge sample.

fn query_range<'life0, 'async_trait>( &'life0 self, query: MetricsQueryRange, ) -> Pin<Box<dyn Future<Output = Result<Vec<MetricPoint>>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Queries a time range of metric points.

fn record_metrics_batch<'life0, 'life1, 'async_trait>( &'life0 self, rows: &'life1 [MetricWriteRow], ) -> Pin<Box<dyn Future<Output = Result<(), Error>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Self: 'async_trait,

Batch write metrics (default: per-row dispatch).