Add database size metric

beacon_node/client/src/lib.rs

@@ -128,6 +128,7 @@ where
                 executor,
                 network_send,
                 beacon_chain.clone(),
+                config.db_name.clone(),
                 metrics_registry,
                 &log,
             ))

beacon_node/http_server/src/key.rs

@@ -3,6 +3,7 @@ use beacon_chain::{BeaconChain, BeaconChainTypes};
 use iron::typemap::Key;
 use prometheus::Registry;
 use std::marker::PhantomData;
+use std::path::PathBuf;
 use std::sync::Arc;
 
 pub struct BeaconChainKey<T> {
@@ -24,3 +25,9 @@ pub struct LocalMetricsKey;
 impl Key for LocalMetricsKey {
     type Value = LocalMetrics;
 }
+
+pub struct DBPathKey;
+
+impl Key for DBPathKey {
+    type Value = PathBuf;
+}

beacon_node/http_server/src/lib.rs

@@ -9,6 +9,7 @@ use network::NetworkMessage;
 use prometheus::Registry;
 use router::Router;
 use slog::{info, o, warn};
+use std::path::PathBuf;
 use std::sync::Arc;
 use tokio::runtime::TaskExecutor;
 
@@ -32,6 +33,7 @@ impl Default for HttpServerConfig {
 /// Build the `iron` HTTP server, defining the core routes.
 pub fn create_iron_http_server<T: BeaconChainTypes + 'static>(
     beacon_chain: Arc<BeaconChain<T>>,
+    db_path: PathBuf,
     metrics_registry: Registry,
 ) -> Iron<Router> {
     let mut router = Router::new();
@@ -39,7 +41,7 @@ pub fn create_iron_http_server<T: BeaconChainTypes + 'static>(
     // A `GET` request to `/metrics` is handled by the `metrics` module.
     router.get(
         "/metrics",
-        metrics::build_handler(beacon_chain.clone(), metrics_registry),
+        metrics::build_handler(beacon_chain.clone(), db_path, metrics_registry),
         "metrics",
     );
 
@@ -55,6 +57,7 @@ pub fn start_service<T: BeaconChainTypes + 'static>(
     executor: &TaskExecutor,
     _network_chan: crossbeam_channel::Sender<NetworkMessage>,
     beacon_chain: Arc<BeaconChain<T>>,
+    db_path: PathBuf,
     metrics_registry: Registry,
     log: &slog::Logger,
 ) -> exit_future::Signal {
@@ -66,7 +69,7 @@ pub fn start_service<T: BeaconChainTypes + 'static>(
     let (shutdown_trigger, wait_for_shutdown) = exit_future::signal();
 
     // Create an `iron` http, without starting it yet.
-    let iron = create_iron_http_server(beacon_chain, metrics_registry);
+    let iron = create_iron_http_server(beacon_chain, db_path, metrics_registry);
 
     // Create a HTTP server future.
     //

beacon_node/http_server/src/metrics.rs

@@ -1,5 +1,5 @@
 use crate::{
-    key::{BeaconChainKey, LocalMetricsKey, MetricsRegistryKey},
+    key::{BeaconChainKey, DBPathKey, LocalMetricsKey, MetricsRegistryKey},
     map_persistent_err_to_500,
 };
 use beacon_chain::{BeaconChain, BeaconChainTypes};
@@ -7,6 +7,7 @@ use iron::prelude::*;
 use iron::{status::Status, Handler, IronResult, Request, Response};
 use persistent::Read;
 use prometheus::{Encoder, Registry, TextEncoder};
+use std::path::PathBuf;
 use std::sync::Arc;
 
 pub use local_metrics::LocalMetrics;
@@ -16,6 +17,7 @@ mod local_metrics;
 /// Yields a handler for the metrics endpoint.
 pub fn build_handler<T: BeaconChainTypes + 'static>(
     beacon_chain: Arc<BeaconChain<T>>,
+    db_path: PathBuf,
     metrics_registry: Registry,
 ) -> impl Handler {
     let mut chain = Chain::new(handle_metrics::<T>);
@@ -26,6 +28,7 @@ pub fn build_handler<T: BeaconChainTypes + 'static>(
     chain.link(Read::<BeaconChainKey<T>>::both(beacon_chain));
     chain.link(Read::<MetricsRegistryKey>::both(metrics_registry));
     chain.link(Read::<LocalMetricsKey>::both(local_metrics));
+    chain.link(Read::<DBPathKey>::both(db_path));
 
     chain
 }
@@ -46,8 +49,12 @@ fn handle_metrics<T: BeaconChainTypes + 'static>(req: &mut Request) -> IronResul
         .get::<Read<LocalMetricsKey>>()
         .map_err(map_persistent_err_to_500)?;
 
+    let db_path = req
+        .get::<Read<DBPathKey>>()
+        .map_err(map_persistent_err_to_500)?;
+
     // Update metrics that are calculated on each scrape.
-    local_metrics.update(&beacon_chain);
+    local_metrics.update(&beacon_chain, &db_path);
 
     let mut buffer = vec![];
     let encoder = TextEncoder::new();

beacon_node/http_server/src/metrics/local_metrics.rs

@@ -1,6 +1,8 @@
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use prometheus::{IntGauge, Opts, Registry};
 use slot_clock::SlotClock;
+use std::path::PathBuf;
+use std::fs::File;
 use types::Slot;
 
 // If set to `true` will iterate and sum the balances of all validators in the state for each
@@ -14,6 +16,7 @@ pub struct LocalMetrics {
     justified_epoch: IntGauge,
     finalized_epoch: IntGauge,
     validator_balances_sum: IntGauge,
+    database_size: IntGauge,
 }
 
 impl LocalMetrics {
@@ -44,6 +47,10 @@ impl LocalMetrics {
                 let opts = Opts::new("validator_balances_sum", "sum_of_all_validator_balances");
                 IntGauge::with_opts(opts)?
             },
+            database_size: {
+                let opts = Opts::new("database_size", "size_of_on_disk_db_in_mb");
+                IntGauge::with_opts(opts)?
+            },
         })
     }
 
@@ -55,12 +62,13 @@ impl LocalMetrics {
         registry.register(Box::new(self.finalized_epoch.clone()))?;
         registry.register(Box::new(self.justified_epoch.clone()))?;
         registry.register(Box::new(self.validator_balances_sum.clone()))?;
+        registry.register(Box::new(self.database_size.clone()))?;
 
         Ok(())
     }
 
     /// Update the metrics in `self` to the latest values.
-    pub fn update<T: BeaconChainTypes>(&self, beacon_chain: &BeaconChain<T>) {
+    pub fn update<T: BeaconChainTypes>(&self, beacon_chain: &BeaconChain<T>, db_path: &PathBuf) {
         let state = &beacon_chain.head().beacon_state;
 
         let present_slot = beacon_chain
@@ -77,5 +85,10 @@ impl LocalMetrics {
         if SHOULD_SUM_VALIDATOR_BALANCES {
             self.validator_balances_sum.set(state.validator_balances.iter().sum::<u64>() as i64);
         }
+        let db_size = File::open(db_path)
+            .and_then(|f| f.metadata())
+            .and_then(|m| Ok(m.len()))
+            .unwrap_or(0);
+        self.database_size.set(db_size as i64);
     }
 }