Struct MetricsRegistry 

pub struct MetricsRegistry {
    pub prometheus_registry: Arc<RwLock<Registry>>,
    pub prometheus_update_callbacks: Arc<RwLock<Vec<PrometheusUpdateCallback>>>,
    pub prometheus_expfmt_callbacks: Arc<RwLock<Vec<PrometheusExpositionFormatCallback>>>,
    /* private fields */
}

Structure to hold Prometheus registries and associated callbacks for a given hierarchy.

All fields are Arc-wrapped, so cloning shares state. This ensures metrics registered on cloned instances (e.g., cloned Client/Endpoint) are visible to the original.

Fields

prometheus_registry: Arc<RwLock<Registry>>

The Prometheus registry for this hierarchy. Arc-wrapped so clones share the same registry (metrics registered on clones are visible everywhere).

prometheus_update_callbacks: Arc<RwLock<Vec<PrometheusUpdateCallback>>>

Update callbacks invoked before metrics are scraped. Wrapped in Arc to preserve callbacks across clones (prevents callback loss when MetricsRegistry is cloned).

prometheus_expfmt_callbacks: Arc<RwLock<Vec<PrometheusExpositionFormatCallback>>>

Callbacks that return Prometheus exposition text appended to metrics output. Wrapped in Arc to preserve callbacks across clones (e.g., vLLM callbacks registered at Endpoint remain accessible at DRT).

Implementations

impl MetricsRegistry

pub fn new() -> Self

Create a new metrics registry with an empty Prometheus registry and callback lists

pub fn add_child_registry(&self, child: &MetricsRegistry)

Add a child registry to be included in combined /metrics output.

Dedup is by underlying Prometheus registry pointer, so repeated registration via clones is safe.

pub fn prometheus_expfmt_combined(&self) -> Result<String>

Combine metrics across this registry and all registered children into one Prometheus exposition output.

• Families are merged by name; HELP and TYPE must match.
• Multiple series for the same name are allowed if labels differ.
• Exact duplicate series (same name + identical label pairs) are warned and dropped.

pub fn add_update_callback(&self, callback: PrometheusUpdateCallback)

Add a callback function that receives a reference to any MetricsHierarchy

pub fn add_expfmt_callback(&self, callback: PrometheusExpositionFormatCallback)

Add an exposition text callback that returns Prometheus text

pub fn execute_update_callbacks(&self) -> Vec<Result<()>>

Execute all update callbacks and return their results

pub fn execute_expfmt_callbacks(&self) -> String

Execute all exposition text callbacks and return their concatenated text

pub fn add_metric(&self, collector: Box<dyn Collector>) -> Result<()>

Add a Prometheus metric collector to this registry

pub fn get_prometheus_registry(&self) -> RwLockReadGuard<'_, Registry>

Get a read guard to the Prometheus registry for scraping

pub fn has_metric_named(&self, metric_name: &str) -> bool

Returns true if a metric with the given name already exists in the Prometheus registry

Trait Implementations

impl Clone for MetricsRegistry

fn clone(&self) -> MetricsRegistry

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MetricsRegistry

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for MetricsRegistry

fn default() -> Self

Returns the “default value” for a type.