From 78db947e6e65f4d0960ca5b9340305c663856244 Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Sun, 11 Aug 2019 18:28:57 +1000
Subject: [PATCH] Add beacon chain persistence metric

---
 beacon_node/beacon_chain/src/beacon_chain.rs | 4 ++++
 beacon_node/beacon_chain/src/metrics.rs      | 6 ++++++
 2 files changed, 10 insertions(+)

diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index 6f9a2b414..96ff339a6 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -199,6 +199,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
 
     /// Attempt to save this instance to `self.store`.
     pub fn persist(&self) -> Result<(), Error> {
+        let timer = metrics::start_timer(&metrics::PERSIST_CHAIN);
+
         let p: PersistedBeaconChain<T> = PersistedBeaconChain {
             canonical_head: self.canonical_head.read().clone(),
             op_pool: PersistedOperationPool::from_operation_pool(&self.op_pool),
@@ -209,6 +211,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         let key = Hash256::from_slice(&BEACON_CHAIN_DB_KEY.as_bytes());
         self.store.put(&key, &p)?;
 
+        metrics::stop_timer(timer);
+
         Ok(())
     }
 
diff --git a/beacon_node/beacon_chain/src/metrics.rs b/beacon_node/beacon_chain/src/metrics.rs
index 34f359ad8..b91125463 100644
--- a/beacon_node/beacon_chain/src/metrics.rs
+++ b/beacon_node/beacon_chain/src/metrics.rs
@@ -138,4 +138,10 @@ lazy_static! {
      */
     pub static ref UPDATE_HEAD_TIMES: Result<Histogram> =
         try_create_histogram("update_head_times", "Time taken to update the canonical head");
+
+    /*
+     * Persisting BeaconChain to disk
+     */
+    pub static ref PERSIST_CHAIN: Result<Histogram> =
+        try_create_histogram("persist_chain", "Time taken to update the canonical head");
 }