Struct PrometheusMetrics 

pub struct PrometheusMetrics {

    pub nodes_created: IntCounter,
    pub edges_created: IntCounter,
    pub prompts_submitted: IntCounter,
    pub responses_generated: IntCounter,
    pub tools_invoked: IntCounter,
    pub agent_handoffs: IntCounter,
    pub template_instantiations: IntCounter,
    pub queries_executed: IntCounter,
    pub write_latency: Histogram,
    pub read_latency: Histogram,
    pub query_duration: Histogram,
    pub tool_duration: Histogram,
    pub batch_size: Histogram,
    pub active_sessions: IntGauge,
    pub total_nodes: IntGauge,
    pub total_edges: IntGauge,
    pub cache_size_bytes: IntGauge,
    pub buffer_size: IntGauge,
    pub grpc_requests_total: IntCounterVec,
    pub grpc_request_duration: HistogramVec,
    pub grpc_active_streams: IntGauge,
    pub plugin_executions_total: IntCounterVec,
    pub plugin_duration: HistogramVec,
    pub plugin_errors_total: IntCounterVec,
    pub registry_calls_total: IntCounterVec,
    pub vault_archives_total: IntCounter,
    pub vault_retrievals_total: IntCounter,
    pub vault_errors_total: IntCounter,
}

Prometheus metrics for MemoryGraph monitoring

Provides comprehensive production-grade metrics across multiple categories:

• 8 Counters for tracking operations
• 5 Histograms for latency and size distributions
• 5 Gauges for current state monitoring
• 7 Production metrics (gRPC, Plugin, Integration)

Fields

nodes_created: IntCounter

Total number of nodes created

edges_created: IntCounter

Total number of edges created

prompts_submitted: IntCounter

Total number of prompts submitted

responses_generated: IntCounter

Total number of responses generated

tools_invoked: IntCounter

Total number of tools invoked

agent_handoffs: IntCounter

Total number of agent handoffs

template_instantiations: IntCounter

Total number of template instantiations

queries_executed: IntCounter

Total number of queries executed

write_latency: Histogram

Write operation latency distribution (seconds)

read_latency: Histogram

Read operation latency distribution (seconds)

query_duration: Histogram

Query execution duration distribution (seconds)

tool_duration: Histogram

Tool execution duration distribution (seconds)

batch_size: Histogram

Batch operation size distribution

active_sessions: IntGauge

Number of currently active sessions

total_nodes: IntGauge

Total number of nodes in the graph

total_edges: IntGauge

Total number of edges in the graph

cache_size_bytes: IntGauge

Current cache size in bytes

buffer_size: IntGauge

Current event buffer size

grpc_requests_total: IntCounterVec

Total gRPC requests by method and status

grpc_request_duration: HistogramVec

gRPC request duration by method

grpc_active_streams: IntGauge

Number of active gRPC streams

plugin_executions_total: IntCounterVec

Total plugin executions by plugin name and hook

plugin_duration: HistogramVec

Plugin execution duration by plugin and hook

plugin_errors_total: IntCounterVec

Total plugin errors by plugin and error type

registry_calls_total: IntCounterVec

Total LLM-Registry API calls by operation and status

vault_archives_total: IntCounter

Total sessions archived to Data-Vault

vault_retrievals_total: IntCounter

Total sessions retrieved from Data-Vault

vault_errors_total: IntCounter

Total Data-Vault errors

Implementations

impl PrometheusMetrics

pub fn new(registry: &Registry) -> Result<Self>

Create and register all metrics with the provided registry

Arguments

• registry - Prometheus registry to register metrics with

Returns

Returns a new PrometheusMetrics instance with all metrics registered

Errors

Returns an error if metric registration fails

pub fn with_namespace(registry: &Registry, _namespace: &str) -> Result<Self>

Create metrics with a custom namespace prefix

pub fn record_node_created(&self)

Record a node creation

pub fn record_nodes_created(&self, count: u64)

Record multiple node creations

pub fn record_edge_created(&self)

Record an edge creation

pub fn record_edges_created(&self, count: u64)

Record multiple edge creations

pub fn record_prompt_submitted(&self)

Record a prompt submission

pub fn record_response_generated(&self)

Record a response generation

pub fn record_tool_invoked(&self)

Record a tool invocation

pub fn record_agent_handoff(&self)

Record an agent handoff

pub fn record_template_instantiation(&self)

Record a template instantiation

pub fn record_query_executed(&self)

Record a query execution

pub fn record_write_latency(&self, duration_secs: f64)

Record write operation latency in seconds

pub fn record_read_latency(&self, duration_secs: f64)

Record read operation latency in seconds

pub fn record_query_duration(&self, duration_secs: f64)

Record query execution duration in seconds

pub fn record_tool_duration(&self, duration_secs: f64)

Record tool execution duration in seconds

pub fn record_batch_size(&self, size: usize)

Record batch operation size

pub fn set_active_sessions(&self, count: i64)

Set the number of active sessions

pub fn inc_active_sessions(&self)

Increment active sessions count

pub fn dec_active_sessions(&self)

Decrement active sessions count

pub fn set_total_nodes(&self, count: i64)

Set the total number of nodes

pub fn inc_total_nodes(&self)

Increment total nodes count

pub fn inc_total_nodes_by(&self, count: i64)

Increment total nodes by amount

pub fn set_total_edges(&self, count: i64)

Set the total number of edges

pub fn inc_total_edges(&self)

Increment total edges count

pub fn inc_total_edges_by(&self, count: i64)

Increment total edges by amount

pub fn set_cache_size_bytes(&self, size: i64)

Set cache size in bytes

pub fn set_buffer_size(&self, size: i64)

Set event buffer size

pub fn record_grpc_request(&self, method: &str, status: &str)

Record a gRPC request with method and status

pub fn record_grpc_request_duration(&self, method: &str, duration_secs: f64)

Record gRPC request duration for a method

pub fn inc_grpc_active_streams(&self)

Increment active gRPC streams count

pub fn dec_grpc_active_streams(&self)

Decrement active gRPC streams count

pub fn set_grpc_active_streams(&self, count: i64)

Set the number of active gRPC streams

pub fn record_plugin_execution(&self, plugin: &str, hook: &str)

Record a plugin execution

pub fn record_plugin_duration( &self, plugin: &str, hook: &str, duration_secs: f64, )

Record plugin execution duration

pub fn record_plugin_error(&self, plugin: &str, error_type: &str)

Record a plugin error

pub fn record_registry_call(&self, operation: &str, status: &str)

Record an LLM-Registry API call

pub fn record_vault_archive(&self)

Record a successful vault archive operation

pub fn record_vault_archives(&self, count: u64)

Record multiple vault archive operations

pub fn record_vault_retrieval(&self)

Record a successful vault retrieval operation

pub fn record_vault_retrievals(&self, count: u64)

Record multiple vault retrieval operations

pub fn record_vault_error(&self)

Record a vault error

pub fn record_vault_errors(&self, count: u64)

Record multiple vault errors

pub fn get_counter_snapshot(&self) -> MetricsCounterSnapshot

Get a snapshot of all counter values

pub fn get_gauge_snapshot(&self) -> MetricsGaugeSnapshot

Get a snapshot of all gauge values

pub fn get_grpc_snapshot(&self) -> GrpcMetricsSnapshot

Get a snapshot of gRPC metrics

pub fn get_vault_snapshot(&self) -> VaultMetricsSnapshot

Get a snapshot of vault metrics

Trait Implementations

impl Clone for PrometheusMetrics

fn clone(&self) -> PrometheusMetrics

Returns a duplicate of the value.

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

Performs copy-assignment from source.