From 3589e3c4ab5680e19df6756b6ccb68be2ad73122 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Wed, 17 Jan 2024 18:20:07 +0100
Subject: [PATCH 01/15] Insertion of the first version of the code.

---
 Cargo.lock                          |   1 +
 linera-views/Cargo.toml             |   1 +
 linera-views/src/lib.rs             |   3 +
 linera-views/src/metered_wrapper.rs | 156 ++++++++++++++++++++++++++++
 4 files changed, 161 insertions(+)
 create mode 100644 linera-views/src/metered_wrapper.rs

diff --git a/Cargo.lock b/Cargo.lock
index 6d36105630ef..632c9343164f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3542,6 +3542,7 @@ dependencies = [
  "aws-smithy-types",
  "aws-types",
  "bcs",
+ "convert_case 0.6.0",
  "futures",
  "generic-array",
  "hex",
diff --git a/linera-views/Cargo.toml b/linera-views/Cargo.toml
index a2be0d7260cb..f3fa912ff391 100644
--- a/linera-views/Cargo.toml
+++ b/linera-views/Cargo.toml
@@ -22,6 +22,7 @@ db_timings = []
 metrics = ["dep:hex"]
 
 [dependencies]
+convert_case = { workspace = true }
 anyhow = { workspace = true }
 async-graphql = { workspace = true }
 async-lock = { workspace = true }
diff --git a/linera-views/src/lib.rs b/linera-views/src/lib.rs
index 5e030069d87a..50b3d4ef7cf5 100644
--- a/linera-views/src/lib.rs
+++ b/linera-views/src/lib.rs
@@ -62,6 +62,9 @@ pub mod common;
 /// The code to turn a `DirectKeyValueStore` into a `KeyValueStore` by adding journaling.
 pub mod journaling;
 
+/// The code for encapsulating one key_value store into another that does metric
+pub mod metered_wrapper;
+
 /// The code for handling big values by splitting them into several small ones.
 pub mod value_splitting;
 
diff --git a/linera-views/src/metered_wrapper.rs b/linera-views/src/metered_wrapper.rs
new file mode 100644
index 000000000000..b3e5b7dd9d4f
--- /dev/null
+++ b/linera-views/src/metered_wrapper.rs
@@ -0,0 +1,156 @@
+// Copyright (c) Zefchain Labs, Inc.
+// SPDX-License-Identifier: Apache-2.0
+
+//use std::time::{Duration, Instant};
+//use linera_base::sync::Lazy;
+use convert_case::{Case, Casing};
+use prometheus::HistogramVec;
+use prometheus::register_histogram_vec;
+use crate::common::KeyValueStore;
+use async_trait::async_trait;
+use std::future::Future;
+use std::time::{Instant};
+use crate::common::ReadableKeyValueStore;
+use crate::common::WritableKeyValueStore;
+use crate::batch::Batch;
+
+#[derive(Clone)]
+struct MeteredCounter {
+    read_value_bytes: HistogramVec,
+    contains_key: HistogramVec,
+    read_multi_values_bytes: HistogramVec,
+    find_keys_by_prefix: HistogramVec,
+    find_key_values_by_prefix: HistogramVec,
+    write_batch: HistogramVec,
+    clear_journal: HistogramVec,
+}
+
+
+impl MeteredCounter {
+    fn new(name: String) -> Self {
+        // name can be "rocks db". Then var_name = "rocks_db" and title_name = "RocksDb"
+        let var_name = name.replace(" ", "_");
+        let title_name = name.to_case(Case::Snake);
+
+        let read_value1 = format!("{}_read_value_bytes", var_name);
+        let read_value2 = format!("{} read value bytes", title_name);
+        let read_value_bytes = register_histogram_vec!(read_value1, read_value2, &[])
+            .expect("Counter creation should not fail");
+
+        let contains_key1 = format!("{}_contains_key", var_name);
+        let contains_key2 = format!("{} contains key", title_name);
+        let contains_key = register_histogram_vec!(contains_key1, contains_key2, &[])
+            .expect("Counter creation should not fail");
+
+        let read_multi_values1 = format!("{}_read_multi_value_bytes", var_name);
+        let read_multi_values2 = format!("{} read multi value bytes", title_name);
+        let read_multi_values_bytes = register_histogram_vec!(read_multi_values1, read_multi_values2, &[])
+            .expect("Counter creation should not fail");
+
+        let find_keys1 = format!("{}_find_keys_by_prefix", var_name);
+        let find_keys2 = format!("{} find keys by prefix", title_name);
+        let find_keys_by_prefix = register_histogram_vec!(find_keys1, find_keys2, &[])
+            .expect("Counter creation should not fail");
+
+        let find_key_values1 = format!("{}_find_key_values_by_prefix", var_name);
+        let find_key_values2 = format!("{} find key values by prefix", title_name);
+        let find_key_values_by_prefix = register_histogram_vec!(find_key_values1, find_key_values2, &[])
+            .expect("Counter creation should not fail");
+
+        let write_batch1 = format!("{}_write_batch", var_name);
+        let write_batch2 = format!("{} write batch", title_name);
+        let write_batch = register_histogram_vec!(write_batch1, write_batch2, &[])
+            .expect("Counter creation should not fail");
+
+        let clear_journal1 = format!("{}_clear_journal", var_name);
+        let clear_journal2 = format!("{} clear journal", title_name);
+        let clear_journal = register_histogram_vec!(clear_journal1, clear_journal2, &[])
+            .expect("Counter creation should not fail");
+
+        MeteredCounter { read_value_bytes, contains_key, read_multi_values_bytes, find_keys_by_prefix, find_key_values_by_prefix, write_batch, clear_journal }
+    }
+}
+
+#[derive(Clone)]
+struct MeteredStore<K> {
+    /// the metrics being stored
+    pub counter: MeteredCounter,
+    /// The underlying store of the metered store
+    pub store: K,
+}
+
+async fn prometheus_async<F, O>(f: F, hist: &HistogramVec) -> O
+where
+    F: Future<Output = O>,
+{
+    let start = Instant::now();
+    let out = f.await;
+    let duration = start.elapsed();
+    hist.with_label_values(&[])
+        .observe(duration.as_micros() as f64);
+    out
+}
+
+
+#[async_trait]
+impl<K> ReadableKeyValueStore<K::Error> for MeteredStore<K>
+where
+    K: KeyValueStore + Send + Sync,
+{
+    const MAX_KEY_SIZE: usize = K::MAX_KEY_SIZE;
+    type Keys = K::Keys;
+    type KeyValues = K::KeyValues;
+
+    fn max_stream_queries(&self) -> usize {
+        self.store.max_stream_queries()
+    }
+
+    async fn read_value_bytes(&self, key: &[u8]) -> Result<Option<Vec<u8>>, K::Error> {
+        prometheus_async(self.store.read_value_bytes(key), &self.counter.read_value_bytes).await
+    }
+
+    async fn contains_key(&self, key: &[u8]) -> Result<bool, K::Error> {
+        prometheus_async(self.store.contains_key(key), &self.counter.contains_key).await
+    }
+
+    async fn read_multi_values_bytes(
+        &self,
+        keys: Vec<Vec<u8>>,
+    ) -> Result<Vec<Option<Vec<u8>>>, K::Error> {
+        prometheus_async(self.store.read_multi_values_bytes(keys), &self.counter.read_multi_values_bytes).await
+    }
+
+    async fn find_keys_by_prefix(&self, key_prefix: &[u8]) -> Result<Self::Keys, K::Error> {
+        prometheus_async(self.store.find_keys_by_prefix(key_prefix), &self.counter.find_keys_by_prefix).await
+    }
+
+    async fn find_key_values_by_prefix(
+        &self,
+        key_prefix: &[u8],
+    ) -> Result<Self::KeyValues, K::Error> {
+        prometheus_async(self.store.find_key_values_by_prefix(key_prefix), &self.counter.find_key_values_by_prefix).await
+    }
+}
+
+#[async_trait]
+impl<K> WritableKeyValueStore<K::Error> for MeteredStore<K>
+where
+    K: KeyValueStore + Send + Sync,
+{
+    const MAX_VALUE_SIZE: usize = K::MAX_VALUE_SIZE;
+
+    async fn write_batch(&self, batch: Batch, base_key: &[u8]) -> Result<(), K::Error> {
+        prometheus_async(self.store.write_batch(batch, base_key), &self.counter.write_batch).await
+    }
+
+    async fn clear_journal(&self, base_key: &[u8]) -> Result<(), K::Error> {
+        prometheus_async(self.store.clear_journal(base_key), &self.counter.clear_journal).await
+    }
+}
+
+impl<K> KeyValueStore for MeteredStore<K>
+where
+    K: KeyValueStore + Send + Sync,
+{
+    type Error = K::Error;
+}

From d1e0f518a7ec0f73f24fc9e35a8d0a90e7479037 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Wed, 17 Jan 2024 19:03:12 +0100
Subject: [PATCH 02/15] Generalize a little bit the code.

---
 linera-views/src/metered_wrapper.rs | 34 ++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/linera-views/src/metered_wrapper.rs b/linera-views/src/metered_wrapper.rs
index b3e5b7dd9d4f..f859cd8b80be 100644
--- a/linera-views/src/metered_wrapper.rs
+++ b/linera-views/src/metered_wrapper.rs
@@ -13,6 +13,7 @@ use std::time::{Instant};
 use crate::common::ReadableKeyValueStore;
 use crate::common::WritableKeyValueStore;
 use crate::batch::Batch;
+use crate::journaling::DirectWritableKeyValueStore;
 
 #[derive(Clone)]
 struct MeteredCounter {
@@ -25,9 +26,8 @@ struct MeteredCounter {
     clear_journal: HistogramVec,
 }
 
-
 impl MeteredCounter {
-    fn new(name: String) -> Self {
+    pub fn new(name: String) -> Self {
         // name can be "rocks db". Then var_name = "rocks_db" and title_name = "RocksDb"
         let var_name = name.replace(" ", "_");
         let title_name = name.to_case(Case::Snake);
@@ -93,9 +93,9 @@ where
 
 
 #[async_trait]
-impl<K> ReadableKeyValueStore<K::Error> for MeteredStore<K>
+impl<K, E> ReadableKeyValueStore<E> for MeteredStore<K>
 where
-    K: KeyValueStore + Send + Sync,
+    K: ReadableKeyValueStore<E> + Send + Sync,
 {
     const MAX_KEY_SIZE: usize = K::MAX_KEY_SIZE;
     type Keys = K::Keys;
@@ -105,45 +105,45 @@ where
         self.store.max_stream_queries()
     }
 
-    async fn read_value_bytes(&self, key: &[u8]) -> Result<Option<Vec<u8>>, K::Error> {
+    async fn read_value_bytes(&self, key: &[u8]) -> Result<Option<Vec<u8>>, E> {
         prometheus_async(self.store.read_value_bytes(key), &self.counter.read_value_bytes).await
     }
 
-    async fn contains_key(&self, key: &[u8]) -> Result<bool, K::Error> {
+    async fn contains_key(&self, key: &[u8]) -> Result<bool, E> {
         prometheus_async(self.store.contains_key(key), &self.counter.contains_key).await
     }
 
     async fn read_multi_values_bytes(
         &self,
         keys: Vec<Vec<u8>>,
-    ) -> Result<Vec<Option<Vec<u8>>>, K::Error> {
+    ) -> Result<Vec<Option<Vec<u8>>>, E> {
         prometheus_async(self.store.read_multi_values_bytes(keys), &self.counter.read_multi_values_bytes).await
     }
 
-    async fn find_keys_by_prefix(&self, key_prefix: &[u8]) -> Result<Self::Keys, K::Error> {
+    async fn find_keys_by_prefix(&self, key_prefix: &[u8]) -> Result<Self::Keys, E> {
         prometheus_async(self.store.find_keys_by_prefix(key_prefix), &self.counter.find_keys_by_prefix).await
     }
 
     async fn find_key_values_by_prefix(
         &self,
         key_prefix: &[u8],
-    ) -> Result<Self::KeyValues, K::Error> {
+    ) -> Result<Self::KeyValues, E> {
         prometheus_async(self.store.find_key_values_by_prefix(key_prefix), &self.counter.find_key_values_by_prefix).await
     }
 }
 
 #[async_trait]
-impl<K> WritableKeyValueStore<K::Error> for MeteredStore<K>
+impl<K, E> WritableKeyValueStore<E> for MeteredStore<K>
 where
-    K: KeyValueStore + Send + Sync,
+    K: WritableKeyValueStore<E> + Send + Sync,
 {
     const MAX_VALUE_SIZE: usize = K::MAX_VALUE_SIZE;
 
-    async fn write_batch(&self, batch: Batch, base_key: &[u8]) -> Result<(), K::Error> {
+    async fn write_batch(&self, batch: Batch, base_key: &[u8]) -> Result<(), E> {
         prometheus_async(self.store.write_batch(batch, base_key), &self.counter.write_batch).await
     }
 
-    async fn clear_journal(&self, base_key: &[u8]) -> Result<(), K::Error> {
+    async fn clear_journal(&self, base_key: &[u8]) -> Result<(), E> {
         prometheus_async(self.store.clear_journal(base_key), &self.counter.clear_journal).await
     }
 }
@@ -154,3 +154,11 @@ where
 {
     type Error = K::Error;
 }
+
+impl<K> MeteredStore<K> {
+    pub fn new(name: String, store: K) -> Self {
+        let counter = MeteredCounter::new(name);
+        Self { counter, store }
+    }
+}
+

From e35beebbde07b2c4c0854209859cc42702520961 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Wed, 17 Jan 2024 19:26:50 +0100
Subject: [PATCH 03/15] Introduce the metering software in DynamoDb.

---
 linera-views/src/dynamo_db.rs       | 36 +++++++++++++++++++++--------
 linera-views/src/lib.rs             |  1 +
 linera-views/src/metered_wrapper.rs |  4 +++-
 3 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/linera-views/src/dynamo_db.rs b/linera-views/src/dynamo_db.rs
index 8016bdd12b4c..4d3b64821b6d 100644
--- a/linera-views/src/dynamo_db.rs
+++ b/linera-views/src/dynamo_db.rs
@@ -40,6 +40,10 @@ use linera_base::ensure;
 use std::{collections::HashMap, env, str::FromStr, sync::Arc};
 use thiserror::Error;
 
+#[cfg(feature = "metrics")]
+use crate::metered_wrapper::MeteredStore;
+
+
 #[cfg(any(test, feature = "test"))]
 use {
     crate::lru_caching::TEST_CACHE_SIZE,
@@ -945,6 +949,9 @@ impl DirectKeyValueStore for DynamoDbStoreInternal {
 /// A shared DB client for DynamoDb implementing LruCaching
 #[derive(Clone)]
 pub struct DynamoDbStore {
+    #[cfg(feature = "metrics")]
+    store: MeteredStore<LruCachingStore<MeteredStore<ValueSplittingStore<MeteredStore<JournalingKeyValueStore<DynamoDbStoreInternal>>>>>>,
+    #[cfg(not(feature = "metrics"))]
     store: LruCachingStore<ValueSplittingStore<JournalingKeyValueStore<DynamoDbStoreInternal>>>,
 }
 
@@ -1007,6 +1014,23 @@ impl KeyValueStore for DynamoDbStore {
 }
 
 impl DynamoDbStore {
+    #[cfg(not(feature = "metrics"))]
+    fn get_complete_store(store: JournalingKeyValueStore<DynamoDbStoreInternal>, cache_size: usize) -> Self {
+        let store = ValueSplittingStore::new(store);
+        let store = LruCachingStore::new(store, cache_size);
+        Self { store }
+    }
+
+    #[cfg(feature = "metrics")]
+    fn get_complete_store(store: JournalingKeyValueStore<DynamoDbStoreInternal>, cache_size: usize) -> Self {
+        let store = MeteredStore::new("DynamoDbInternal".to_string(), store);
+        let store = ValueSplittingStore::new(store);
+        let store = MeteredStore::new("ValueSplitting".to_string(), store);
+        let store = LruCachingStore::new(store, cache_size);
+        let store = MeteredStore::new("LruCaching".to_string(), store);
+        Self { store }
+    }
+
     /// Creates a `DynamoDbStore` from scratch with an LRU cache
     #[cfg(any(test, feature = "test"))]
     pub async fn new_for_testing(
@@ -1016,9 +1040,7 @@ impl DynamoDbStore {
         let (simple_store, table_status) =
             DynamoDbStoreInternal::new_for_testing(store_config).await?;
         let store = JournalingKeyValueStore::new(simple_store);
-        let store = ValueSplittingStore::new(store);
-        let store = LruCachingStore::new(store, cache_size);
-        let store = Self { store };
+        let store = Self::get_complete_store(store, cache_size);
         Ok((store, table_status))
     }
 
@@ -1029,9 +1051,7 @@ impl DynamoDbStore {
         let cache_size = store_config.common_config.cache_size;
         let simple_store = DynamoDbStoreInternal::initialize(store_config).await?;
         let store = JournalingKeyValueStore::new(simple_store);
-        let store = ValueSplittingStore::new(store);
-        let store = LruCachingStore::new(store, cache_size);
-        let store = Self { store };
+        let store = Self::get_complete_store(store, cache_size);
         Ok(store)
     }
 
@@ -1068,9 +1088,7 @@ impl DynamoDbStore {
         let cache_size = store_config.common_config.cache_size;
         let (simple_store, table_name) = DynamoDbStoreInternal::new(store_config).await?;
         let store = JournalingKeyValueStore::new(simple_store);
-        let store = ValueSplittingStore::new(store);
-        let store = LruCachingStore::new(store, cache_size);
-        let store = Self { store };
+        let store = Self::get_complete_store(store, cache_size);
         Ok((store, table_name))
     }
 }
diff --git a/linera-views/src/lib.rs b/linera-views/src/lib.rs
index 50b3d4ef7cf5..0fd1c8ad9501 100644
--- a/linera-views/src/lib.rs
+++ b/linera-views/src/lib.rs
@@ -63,6 +63,7 @@ pub mod common;
 pub mod journaling;
 
 /// The code for encapsulating one key_value store into another that does metric
+#[cfg(feature = "metrics")]
 pub mod metered_wrapper;
 
 /// The code for handling big values by splitting them into several small ones.
diff --git a/linera-views/src/metered_wrapper.rs b/linera-views/src/metered_wrapper.rs
index f859cd8b80be..0caecab4af6b 100644
--- a/linera-views/src/metered_wrapper.rs
+++ b/linera-views/src/metered_wrapper.rs
@@ -71,8 +71,9 @@ impl MeteredCounter {
     }
 }
 
+/// A metered wrapper that keeps track of every operation
 #[derive(Clone)]
-struct MeteredStore<K> {
+pub struct MeteredStore<K> {
     /// the metrics being stored
     pub counter: MeteredCounter,
     /// The underlying store of the metered store
@@ -156,6 +157,7 @@ where
 }
 
 impl<K> MeteredStore<K> {
+    /// Creates a new Metered store
     pub fn new(name: String, store: K) -> Self {
         let counter = MeteredCounter::new(name);
         Self { counter, store }

From 7c0e3584348eb611e9c8ce32e40dd4589e30d43c Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Wed, 17 Jan 2024 20:26:26 +0100
Subject: [PATCH 04/15] Some corrections + adding the support for the
 rocksdb/scylladb.

---
 linera-views/src/metered_wrapper.rs |  4 ++--
 linera-views/src/rocks_db.rs        | 28 +++++++++++++++++++---
 linera-views/src/scylla_db.rs       | 36 ++++++++++++++++++++++++-----
 3 files changed, 57 insertions(+), 11 deletions(-)

diff --git a/linera-views/src/metered_wrapper.rs b/linera-views/src/metered_wrapper.rs
index 0caecab4af6b..4d64be69f5fe 100644
--- a/linera-views/src/metered_wrapper.rs
+++ b/linera-views/src/metered_wrapper.rs
@@ -13,7 +13,7 @@ use std::time::{Instant};
 use crate::common::ReadableKeyValueStore;
 use crate::common::WritableKeyValueStore;
 use crate::batch::Batch;
-use crate::journaling::DirectWritableKeyValueStore;
+//use crate::journaling::DirectWritableKeyValueStore;
 
 #[derive(Clone)]
 struct MeteredCounter {
@@ -75,7 +75,7 @@ impl MeteredCounter {
 #[derive(Clone)]
 pub struct MeteredStore<K> {
     /// the metrics being stored
-    pub counter: MeteredCounter,
+    counter: MeteredCounter,
     /// The underlying store of the metered store
     pub store: K,
 }
diff --git a/linera-views/src/rocks_db.rs b/linera-views/src/rocks_db.rs
index 0e4a5e1803a9..eacc22e23286 100644
--- a/linera-views/src/rocks_db.rs
+++ b/linera-views/src/rocks_db.rs
@@ -19,6 +19,10 @@ use std::{
     sync::Arc,
 };
 use thiserror::Error;
+
+#[cfg(feature = "metrics")]
+use crate::metered_wrapper::MeteredStore;
+
 #[cfg(any(test, feature = "test"))]
 use {crate::lru_caching::TEST_CACHE_SIZE, tempfile::TempDir};
 
@@ -231,6 +235,9 @@ impl KeyValueStore for RocksDbStoreInternal {
 /// A shared DB client for RocksDB implementing LruCaching
 #[derive(Clone)]
 pub struct RocksDbStore {
+    #[cfg(feature = "metrics")]
+    store: MeteredStore<LruCachingStore<MeteredStore<ValueSplittingStore<MeteredStore<RocksDbStoreInternal>>>>>,
+    #[cfg(not(feature = "metrics"))]
     store: LruCachingStore<ValueSplittingStore<RocksDbStoreInternal>>,
 }
 
@@ -295,6 +302,23 @@ impl RocksDbStore {
         Ok(client)
     }
 
+    #[cfg(not(feature = "metrics"))]
+    fn get_complete_store(store: RocksDbStoreInternal, cache_size: usize) -> Self {
+        let store = ValueSplittingStore::new(store);
+        let store = LruCachingStore::new(store, cache_size);
+        Self { store }
+    }
+
+    #[cfg(feature = "metrics")]
+    fn get_complete_store(store: RocksDbStoreInternal, cache_size: usize) -> Self {
+        let store = MeteredStore::new("RocksDbInternal".to_string(), store);
+        let store = ValueSplittingStore::new(store);
+        let store = MeteredStore::new("ValueSplitting".to_string(), store);
+	let store = LruCachingStore::new(store, cache_size);
+        let store = MeteredStore::new("LruCaching".to_string(), store);
+	Self { store }
+    }
+
     /// Creates a RocksDB database from a specified path.
     async fn new_internal(
         store_config: RocksDbStoreConfig,
@@ -328,9 +352,7 @@ impl RocksDbStore {
             db: Arc::new(db),
             max_stream_queries,
         };
-        let store = ValueSplittingStore::new(store);
-        let store = LruCachingStore::new(store, cache_size);
-        let store = Self { store };
+        let store = Self::get_complete_store(store, cache_size);
         Ok((store, table_status))
     }
 }
diff --git a/linera-views/src/scylla_db.rs b/linera-views/src/scylla_db.rs
index 5af23e9dba31..d6905c440324 100644
--- a/linera-views/src/scylla_db.rs
+++ b/linera-views/src/scylla_db.rs
@@ -15,6 +15,9 @@
 //! [trait1]: common::KeyValueStore
 //! [trait2]: common::Context
 
+#[cfg(feature = "metrics")]
+use crate::metered_wrapper::MeteredStore;
+
 #[cfg(any(test, feature = "test"))]
 use crate::{lru_caching::TEST_CACHE_SIZE, test_utils::get_table_name};
 
@@ -673,6 +676,9 @@ impl ScyllaDbStoreInternal {
 /// A shared DB store for ScyllaDB implementing LruCaching
 #[derive(Clone)]
 pub struct ScyllaDbStore {
+    #[cfg(feature = "metrics")]
+    store: MeteredStore<LruCachingStore<MeteredStore<JournalingKeyValueStore<ScyllaDbStoreInternal>>>>,
+    #[cfg(not(feature = "metrics"))]
     store: LruCachingStore<JournalingKeyValueStore<ScyllaDbStoreInternal>>,
 }
 
@@ -749,10 +755,31 @@ impl KeyValueStore for ScyllaDbStore {
 
 impl ScyllaDbStore {
     /// Gets the table name of the ScyllaDB store.
+    #[cfg(not(feature = "metrics"))]
     pub async fn get_table_name(&self) -> String {
         self.store.store.store.get_table_name().await
     }
 
+    /// Gets the table name of the ScyllaDB store.
+    #[cfg(feature = "metrics")]
+    pub async fn get_table_name(&self) -> String {
+        self.store.store.store.store.store.get_table_name().await
+    }
+
+    #[cfg(not(feature = "metrics"))]
+    fn get_complete_store(store: JournalingKeyValueStore<ScyllaDbStoreInternal>, cache_size: usize) -> Self {
+	let store = LruCachingStore::new(store, cache_size);
+        Self { store }
+    }
+
+    #[cfg(feature = "metrics")]
+    fn get_complete_store(store: JournalingKeyValueStore<ScyllaDbStoreInternal>, cache_size: usize) -> Self {
+	let store = MeteredStore::new("DynamoDbInternal".to_string(), store);
+        let store = LruCachingStore::new(store, cache_size);
+	let store = MeteredStore::new("LruCaching".to_string(), store);
+        Self { store }
+    }
+
     /// Creates a [`ScyllaDbStore`] from the input parameters.
     #[cfg(any(test, feature = "test"))]
     pub async fn new_for_testing(
@@ -762,8 +789,7 @@ impl ScyllaDbStore {
         let (simple_store, table_status) =
             ScyllaDbStoreInternal::new_for_testing(store_config).await?;
         let store = JournalingKeyValueStore::new(simple_store);
-        let store = LruCachingStore::new(store, cache_size);
-        let store = ScyllaDbStore { store };
+        let store = Self::get_complete_store(store, cache_size);
         Ok((store, table_status))
     }
 
@@ -774,8 +800,7 @@ impl ScyllaDbStore {
         let cache_size = store_config.common_config.cache_size;
         let simple_store = ScyllaDbStoreInternal::initialize(store_config).await?;
         let store = JournalingKeyValueStore::new(simple_store);
-        let store = LruCachingStore::new(store, cache_size);
-        let store = ScyllaDbStore { store };
+        let store = Self::get_complete_store(store, cache_size);
         Ok(store)
     }
 
@@ -812,8 +837,7 @@ impl ScyllaDbStore {
         let cache_size = store_config.common_config.cache_size;
         let (simple_store, table_status) = ScyllaDbStoreInternal::new(store_config).await?;
         let store = JournalingKeyValueStore::new(simple_store);
-        let store = LruCachingStore::new(store, cache_size);
-        let store = ScyllaDbStore { store };
+        let store = Self::get_complete_store(store, cache_size);
         Ok((store, table_status))
     }
 }

From 340560113ac6308eaa2415240477615e05e51d58 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Wed, 17 Jan 2024 21:16:54 +0100
Subject: [PATCH 05/15] Renaming.

---
 linera-views/src/dynamo_db.rs | 6 +++---
 linera-views/src/rocks_db.rs  | 6 +++---
 linera-views/src/scylla_db.rs | 4 ++--
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/linera-views/src/dynamo_db.rs b/linera-views/src/dynamo_db.rs
index 4d3b64821b6d..8441a361a0c6 100644
--- a/linera-views/src/dynamo_db.rs
+++ b/linera-views/src/dynamo_db.rs
@@ -1023,11 +1023,11 @@ impl DynamoDbStore {
 
     #[cfg(feature = "metrics")]
     fn get_complete_store(store: JournalingKeyValueStore<DynamoDbStoreInternal>, cache_size: usize) -> Self {
-        let store = MeteredStore::new("DynamoDbInternal".to_string(), store);
+        let store = MeteredStore::new("dynamo db internal".to_string(), store);
         let store = ValueSplittingStore::new(store);
-        let store = MeteredStore::new("ValueSplitting".to_string(), store);
+        let store = MeteredStore::new("value splitting".to_string(), store);
         let store = LruCachingStore::new(store, cache_size);
-        let store = MeteredStore::new("LruCaching".to_string(), store);
+        let store = MeteredStore::new("lru caching".to_string(), store);
         Self { store }
     }
 
diff --git a/linera-views/src/rocks_db.rs b/linera-views/src/rocks_db.rs
index eacc22e23286..5d32861a77ce 100644
--- a/linera-views/src/rocks_db.rs
+++ b/linera-views/src/rocks_db.rs
@@ -311,11 +311,11 @@ impl RocksDbStore {
 
     #[cfg(feature = "metrics")]
     fn get_complete_store(store: RocksDbStoreInternal, cache_size: usize) -> Self {
-        let store = MeteredStore::new("RocksDbInternal".to_string(), store);
+        let store = MeteredStore::new("rocks db internal".to_string(), store);
         let store = ValueSplittingStore::new(store);
-        let store = MeteredStore::new("ValueSplitting".to_string(), store);
+        let store = MeteredStore::new("value splitting".to_string(), store);
 	let store = LruCachingStore::new(store, cache_size);
-        let store = MeteredStore::new("LruCaching".to_string(), store);
+        let store = MeteredStore::new("lru caching".to_string(), store);
 	Self { store }
     }
 
diff --git a/linera-views/src/scylla_db.rs b/linera-views/src/scylla_db.rs
index d6905c440324..ca992edaff84 100644
--- a/linera-views/src/scylla_db.rs
+++ b/linera-views/src/scylla_db.rs
@@ -774,9 +774,9 @@ impl ScyllaDbStore {
 
     #[cfg(feature = "metrics")]
     fn get_complete_store(store: JournalingKeyValueStore<ScyllaDbStoreInternal>, cache_size: usize) -> Self {
-	let store = MeteredStore::new("DynamoDbInternal".to_string(), store);
+	let store = MeteredStore::new("scylla db internal".to_string(), store);
         let store = LruCachingStore::new(store, cache_size);
-	let store = MeteredStore::new("LruCaching".to_string(), store);
+	let store = MeteredStore::new("lru caching".to_string(), store);
         Self { store }
     }
 

From a3e5810c535c19f5948e500a1f660af8f3be78c0 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Wed, 17 Jan 2024 21:36:01 +0100
Subject: [PATCH 06/15] Reformatting.

---
 linera-views/src/dynamo_db.rs       | 20 +++++--
 linera-views/src/metered_wrapper.rs | 86 ++++++++++++++++++-----------
 linera-views/src/rocks_db.rs        |  8 ++-
 linera-views/src/scylla_db.rs       | 19 +++++--
 4 files changed, 89 insertions(+), 44 deletions(-)

diff --git a/linera-views/src/dynamo_db.rs b/linera-views/src/dynamo_db.rs
index 8441a361a0c6..0e175a5a0d50 100644
--- a/linera-views/src/dynamo_db.rs
+++ b/linera-views/src/dynamo_db.rs
@@ -43,7 +43,6 @@ use thiserror::Error;
 #[cfg(feature = "metrics")]
 use crate::metered_wrapper::MeteredStore;
 
-
 #[cfg(any(test, feature = "test"))]
 use {
     crate::lru_caching::TEST_CACHE_SIZE,
@@ -948,9 +947,16 @@ impl DirectKeyValueStore for DynamoDbStoreInternal {
 
 /// A shared DB client for DynamoDb implementing LruCaching
 #[derive(Clone)]
+#[allow(clippy::type_complexity)]
 pub struct DynamoDbStore {
     #[cfg(feature = "metrics")]
-    store: MeteredStore<LruCachingStore<MeteredStore<ValueSplittingStore<MeteredStore<JournalingKeyValueStore<DynamoDbStoreInternal>>>>>>,
+    store: MeteredStore<
+        LruCachingStore<
+            MeteredStore<
+                ValueSplittingStore<MeteredStore<JournalingKeyValueStore<DynamoDbStoreInternal>>>,
+            >,
+        >,
+    >,
     #[cfg(not(feature = "metrics"))]
     store: LruCachingStore<ValueSplittingStore<JournalingKeyValueStore<DynamoDbStoreInternal>>>,
 }
@@ -1015,14 +1021,20 @@ impl KeyValueStore for DynamoDbStore {
 
 impl DynamoDbStore {
     #[cfg(not(feature = "metrics"))]
-    fn get_complete_store(store: JournalingKeyValueStore<DynamoDbStoreInternal>, cache_size: usize) -> Self {
+    fn get_complete_store(
+        store: JournalingKeyValueStore<DynamoDbStoreInternal>,
+        cache_size: usize,
+    ) -> Self {
         let store = ValueSplittingStore::new(store);
         let store = LruCachingStore::new(store, cache_size);
         Self { store }
     }
 
     #[cfg(feature = "metrics")]
-    fn get_complete_store(store: JournalingKeyValueStore<DynamoDbStoreInternal>, cache_size: usize) -> Self {
+    fn get_complete_store(
+        store: JournalingKeyValueStore<DynamoDbStoreInternal>,
+        cache_size: usize,
+    ) -> Self {
         let store = MeteredStore::new("dynamo db internal".to_string(), store);
         let store = ValueSplittingStore::new(store);
         let store = MeteredStore::new("value splitting".to_string(), store);
diff --git a/linera-views/src/metered_wrapper.rs b/linera-views/src/metered_wrapper.rs
index 4d64be69f5fe..fa37092889d7 100644
--- a/linera-views/src/metered_wrapper.rs
+++ b/linera-views/src/metered_wrapper.rs
@@ -3,16 +3,14 @@
 
 //use std::time::{Duration, Instant};
 //use linera_base::sync::Lazy;
-use convert_case::{Case, Casing};
-use prometheus::HistogramVec;
-use prometheus::register_histogram_vec;
-use crate::common::KeyValueStore;
+use crate::{
+    batch::Batch,
+    common::{KeyValueStore, ReadableKeyValueStore, WritableKeyValueStore},
+};
 use async_trait::async_trait;
-use std::future::Future;
-use std::time::{Instant};
-use crate::common::ReadableKeyValueStore;
-use crate::common::WritableKeyValueStore;
-use crate::batch::Batch;
+use convert_case::{Case, Casing};
+use prometheus::{register_histogram_vec, HistogramVec};
+use std::{future::Future, time::Instant};
 //use crate::journaling::DirectWritableKeyValueStore;
 
 #[derive(Clone)]
@@ -29,7 +27,7 @@ struct MeteredCounter {
 impl MeteredCounter {
     pub fn new(name: String) -> Self {
         // name can be "rocks db". Then var_name = "rocks_db" and title_name = "RocksDb"
-        let var_name = name.replace(" ", "_");
+        let var_name = name.replace(' ', "_");
         let title_name = name.to_case(Case::Snake);
 
         let read_value1 = format!("{}_read_value_bytes", var_name);
@@ -44,8 +42,9 @@ impl MeteredCounter {
 
         let read_multi_values1 = format!("{}_read_multi_value_bytes", var_name);
         let read_multi_values2 = format!("{} read multi value bytes", title_name);
-        let read_multi_values_bytes = register_histogram_vec!(read_multi_values1, read_multi_values2, &[])
-            .expect("Counter creation should not fail");
+        let read_multi_values_bytes =
+            register_histogram_vec!(read_multi_values1, read_multi_values2, &[])
+                .expect("Counter creation should not fail");
 
         let find_keys1 = format!("{}_find_keys_by_prefix", var_name);
         let find_keys2 = format!("{} find keys by prefix", title_name);
@@ -54,8 +53,9 @@ impl MeteredCounter {
 
         let find_key_values1 = format!("{}_find_key_values_by_prefix", var_name);
         let find_key_values2 = format!("{} find key values by prefix", title_name);
-        let find_key_values_by_prefix = register_histogram_vec!(find_key_values1, find_key_values2, &[])
-            .expect("Counter creation should not fail");
+        let find_key_values_by_prefix =
+            register_histogram_vec!(find_key_values1, find_key_values2, &[])
+                .expect("Counter creation should not fail");
 
         let write_batch1 = format!("{}_write_batch", var_name);
         let write_batch2 = format!("{} write batch", title_name);
@@ -67,7 +67,15 @@ impl MeteredCounter {
         let clear_journal = register_histogram_vec!(clear_journal1, clear_journal2, &[])
             .expect("Counter creation should not fail");
 
-        MeteredCounter { read_value_bytes, contains_key, read_multi_values_bytes, find_keys_by_prefix, find_key_values_by_prefix, write_batch, clear_journal }
+        MeteredCounter {
+            read_value_bytes,
+            contains_key,
+            read_multi_values_bytes,
+            find_keys_by_prefix,
+            find_key_values_by_prefix,
+            write_batch,
+            clear_journal,
+        }
     }
 }
 
@@ -92,7 +100,6 @@ where
     out
 }
 
-
 #[async_trait]
 impl<K, E> ReadableKeyValueStore<E> for MeteredStore<K>
 where
@@ -107,29 +114,39 @@ where
     }
 
     async fn read_value_bytes(&self, key: &[u8]) -> Result<Option<Vec<u8>>, E> {
-        prometheus_async(self.store.read_value_bytes(key), &self.counter.read_value_bytes).await
+        prometheus_async(
+            self.store.read_value_bytes(key),
+            &self.counter.read_value_bytes,
+        )
+        .await
     }
 
     async fn contains_key(&self, key: &[u8]) -> Result<bool, E> {
         prometheus_async(self.store.contains_key(key), &self.counter.contains_key).await
     }
 
-    async fn read_multi_values_bytes(
-        &self,
-        keys: Vec<Vec<u8>>,
-    ) -> Result<Vec<Option<Vec<u8>>>, E> {
-        prometheus_async(self.store.read_multi_values_bytes(keys), &self.counter.read_multi_values_bytes).await
+    async fn read_multi_values_bytes(&self, keys: Vec<Vec<u8>>) -> Result<Vec<Option<Vec<u8>>>, E> {
+        prometheus_async(
+            self.store.read_multi_values_bytes(keys),
+            &self.counter.read_multi_values_bytes,
+        )
+        .await
     }
 
     async fn find_keys_by_prefix(&self, key_prefix: &[u8]) -> Result<Self::Keys, E> {
-        prometheus_async(self.store.find_keys_by_prefix(key_prefix), &self.counter.find_keys_by_prefix).await
+        prometheus_async(
+            self.store.find_keys_by_prefix(key_prefix),
+            &self.counter.find_keys_by_prefix,
+        )
+        .await
     }
 
-    async fn find_key_values_by_prefix(
-        &self,
-        key_prefix: &[u8],
-    ) -> Result<Self::KeyValues, E> {
-        prometheus_async(self.store.find_key_values_by_prefix(key_prefix), &self.counter.find_key_values_by_prefix).await
+    async fn find_key_values_by_prefix(&self, key_prefix: &[u8]) -> Result<Self::KeyValues, E> {
+        prometheus_async(
+            self.store.find_key_values_by_prefix(key_prefix),
+            &self.counter.find_key_values_by_prefix,
+        )
+        .await
     }
 }
 
@@ -141,11 +158,19 @@ where
     const MAX_VALUE_SIZE: usize = K::MAX_VALUE_SIZE;
 
     async fn write_batch(&self, batch: Batch, base_key: &[u8]) -> Result<(), E> {
-        prometheus_async(self.store.write_batch(batch, base_key), &self.counter.write_batch).await
+        prometheus_async(
+            self.store.write_batch(batch, base_key),
+            &self.counter.write_batch,
+        )
+        .await
     }
 
     async fn clear_journal(&self, base_key: &[u8]) -> Result<(), E> {
-        prometheus_async(self.store.clear_journal(base_key), &self.counter.clear_journal).await
+        prometheus_async(
+            self.store.clear_journal(base_key),
+            &self.counter.clear_journal,
+        )
+        .await
     }
 }
 
@@ -163,4 +188,3 @@ impl<K> MeteredStore<K> {
         Self { counter, store }
     }
 }
-
diff --git a/linera-views/src/rocks_db.rs b/linera-views/src/rocks_db.rs
index 5d32861a77ce..67e51ce5c5dd 100644
--- a/linera-views/src/rocks_db.rs
+++ b/linera-views/src/rocks_db.rs
@@ -236,7 +236,9 @@ impl KeyValueStore for RocksDbStoreInternal {
 #[derive(Clone)]
 pub struct RocksDbStore {
     #[cfg(feature = "metrics")]
-    store: MeteredStore<LruCachingStore<MeteredStore<ValueSplittingStore<MeteredStore<RocksDbStoreInternal>>>>>,
+    store: MeteredStore<
+        LruCachingStore<MeteredStore<ValueSplittingStore<MeteredStore<RocksDbStoreInternal>>>>,
+    >,
     #[cfg(not(feature = "metrics"))]
     store: LruCachingStore<ValueSplittingStore<RocksDbStoreInternal>>,
 }
@@ -314,9 +316,9 @@ impl RocksDbStore {
         let store = MeteredStore::new("rocks db internal".to_string(), store);
         let store = ValueSplittingStore::new(store);
         let store = MeteredStore::new("value splitting".to_string(), store);
-	let store = LruCachingStore::new(store, cache_size);
+        let store = LruCachingStore::new(store, cache_size);
         let store = MeteredStore::new("lru caching".to_string(), store);
-	Self { store }
+        Self { store }
     }
 
     /// Creates a RocksDB database from a specified path.
diff --git a/linera-views/src/scylla_db.rs b/linera-views/src/scylla_db.rs
index ca992edaff84..0e1bc0bb84fb 100644
--- a/linera-views/src/scylla_db.rs
+++ b/linera-views/src/scylla_db.rs
@@ -677,7 +677,8 @@ impl ScyllaDbStoreInternal {
 #[derive(Clone)]
 pub struct ScyllaDbStore {
     #[cfg(feature = "metrics")]
-    store: MeteredStore<LruCachingStore<MeteredStore<JournalingKeyValueStore<ScyllaDbStoreInternal>>>>,
+    store:
+        MeteredStore<LruCachingStore<MeteredStore<JournalingKeyValueStore<ScyllaDbStoreInternal>>>>,
     #[cfg(not(feature = "metrics"))]
     store: LruCachingStore<JournalingKeyValueStore<ScyllaDbStoreInternal>>,
 }
@@ -767,16 +768,22 @@ impl ScyllaDbStore {
     }
 
     #[cfg(not(feature = "metrics"))]
-    fn get_complete_store(store: JournalingKeyValueStore<ScyllaDbStoreInternal>, cache_size: usize) -> Self {
-	let store = LruCachingStore::new(store, cache_size);
+    fn get_complete_store(
+        store: JournalingKeyValueStore<ScyllaDbStoreInternal>,
+        cache_size: usize,
+    ) -> Self {
+        let store = LruCachingStore::new(store, cache_size);
         Self { store }
     }
 
     #[cfg(feature = "metrics")]
-    fn get_complete_store(store: JournalingKeyValueStore<ScyllaDbStoreInternal>, cache_size: usize) -> Self {
-	let store = MeteredStore::new("scylla db internal".to_string(), store);
+    fn get_complete_store(
+        store: JournalingKeyValueStore<ScyllaDbStoreInternal>,
+        cache_size: usize,
+    ) -> Self {
+        let store = MeteredStore::new("scylla db internal".to_string(), store);
         let store = LruCachingStore::new(store, cache_size);
-	let store = MeteredStore::new("lru caching".to_string(), store);
+        let store = MeteredStore::new("lru caching".to_string(), store);
         Self { store }
     }
 

From 0a5686e060ba1729490b2ff4f3a6c09dc919bda4 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Thu, 18 Jan 2024 07:46:39 +0100
Subject: [PATCH 07/15] Some correction for linting.

---
 examples/Cargo.lock     | 1 +
 linera-views/Cargo.toml | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/examples/Cargo.lock b/examples/Cargo.lock
index bb4e14fa500c..c8b0899de869 100644
--- a/examples/Cargo.lock
+++ b/examples/Cargo.lock
@@ -1801,6 +1801,7 @@ dependencies = [
  "async-lock",
  "async-trait",
  "bcs",
+ "convert_case 0.6.0",
  "futures",
  "generic-array",
  "hex",
diff --git a/linera-views/Cargo.toml b/linera-views/Cargo.toml
index f3fa912ff391..2f00eff0c184 100644
--- a/linera-views/Cargo.toml
+++ b/linera-views/Cargo.toml
@@ -22,12 +22,12 @@ db_timings = []
 metrics = ["dep:hex"]
 
 [dependencies]
-convert_case = { workspace = true }
 anyhow = { workspace = true }
 async-graphql = { workspace = true }
 async-lock = { workspace = true }
 async-trait = { workspace = true }
 bcs = { workspace = true }
+convert_case = { workspace = true }
 futures = { workspace = true }
 generic-array = { workspace = true }
 hex = { workspace = true, optional = true }

From e6e70d26810b270fe1bb13c364a3b876d8311da9 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Thu, 18 Jan 2024 11:35:06 +0100
Subject: [PATCH 08/15] Make the test pass so that the entries are not
 registered multiple times.

---
 linera-views/src/dynamo_db.rs       | 11 +++++----
 linera-views/src/metered_wrapper.rs | 35 +++++++++++++++++++++++++----
 linera-views/src/rocks_db.rs        | 17 ++++++++------
 linera-views/src/scylla_db.rs       |  8 ++++---
 4 files changed, 53 insertions(+), 18 deletions(-)

diff --git a/linera-views/src/dynamo_db.rs b/linera-views/src/dynamo_db.rs
index 0e175a5a0d50..194172fd21d9 100644
--- a/linera-views/src/dynamo_db.rs
+++ b/linera-views/src/dynamo_db.rs
@@ -41,7 +41,10 @@ use std::{collections::HashMap, env, str::FromStr, sync::Arc};
 use thiserror::Error;
 
 #[cfg(feature = "metrics")]
-use crate::metered_wrapper::MeteredStore;
+use crate::metered_wrapper::{
+    MeteredStore, METERED_COUNTER_DYNAMO_DB, METERED_COUNTER_LRU_CACHING,
+    METERED_COUNTER_VALUE_SPLITTING,
+};
 
 #[cfg(any(test, feature = "test"))]
 use {
@@ -1035,11 +1038,11 @@ impl DynamoDbStore {
         store: JournalingKeyValueStore<DynamoDbStoreInternal>,
         cache_size: usize,
     ) -> Self {
-        let store = MeteredStore::new("dynamo db internal".to_string(), store);
+        let store = MeteredStore::new(&METERED_COUNTER_DYNAMO_DB, store);
         let store = ValueSplittingStore::new(store);
-        let store = MeteredStore::new("value splitting".to_string(), store);
+        let store = MeteredStore::new(&METERED_COUNTER_VALUE_SPLITTING, store);
         let store = LruCachingStore::new(store, cache_size);
-        let store = MeteredStore::new("lru caching".to_string(), store);
+        let store = MeteredStore::new(&METERED_COUNTER_LRU_CACHING, store);
         Self { store }
     }
 
diff --git a/linera-views/src/metered_wrapper.rs b/linera-views/src/metered_wrapper.rs
index fa37092889d7..0b431b6684a6 100644
--- a/linera-views/src/metered_wrapper.rs
+++ b/linera-views/src/metered_wrapper.rs
@@ -9,12 +9,14 @@ use crate::{
 };
 use async_trait::async_trait;
 use convert_case::{Case, Casing};
+use linera_base::sync::Lazy;
 use prometheus::{register_histogram_vec, HistogramVec};
 use std::{future::Future, time::Instant};
 //use crate::journaling::DirectWritableKeyValueStore;
 
 #[derive(Clone)]
-struct MeteredCounter {
+/// The implementation of the `MeteredCounter` for the `KeyValueStore`.
+pub struct MeteredCounter {
     read_value_bytes: HistogramVec,
     contains_key: HistogramVec,
     read_multi_values_bytes: HistogramVec,
@@ -24,7 +26,33 @@ struct MeteredCounter {
     clear_journal: HistogramVec,
 }
 
+/// The metered counter for the "rocks db"
+#[cfg(feature = "rocksdb")]
+pub static METERED_COUNTER_ROCKS_DB: Lazy<MeteredCounter> =
+    Lazy::new(|| MeteredCounter::new("rocks db internal".to_string()));
+
+/// The metered counter for the "dynamo db"
+#[cfg(feature = "aws")]
+pub static METERED_COUNTER_DYNAMO_DB: Lazy<MeteredCounter> =
+    Lazy::new(|| MeteredCounter::new("dynamo db internal".to_string()));
+
+/// The metered counter for the "scylla db"
+#[cfg(feature = "scylladb")]
+pub static METERED_COUNTER_SCYLLA_DB: Lazy<MeteredCounter> =
+    Lazy::new(|| MeteredCounter::new("scylla db internal".to_string()));
+
+/// The metered counter for the "scylla db"
+#[cfg(any(feature = "rocksdb", feature = "aws"))]
+pub static METERED_COUNTER_VALUE_SPLITTING: Lazy<MeteredCounter> =
+    Lazy::new(|| MeteredCounter::new("value splitting".to_string()));
+
+/// The metered counter for the "lru caching"
+#[cfg(any(feature = "rocksdb", feature = "aws", feature = "scylladb"))]
+pub static METERED_COUNTER_LRU_CACHING: Lazy<MeteredCounter> =
+    Lazy::new(|| MeteredCounter::new("lru caching".to_string()));
+
 impl MeteredCounter {
+    /// Creation of a named Metered counter.
     pub fn new(name: String) -> Self {
         // name can be "rocks db". Then var_name = "rocks_db" and title_name = "RocksDb"
         let var_name = name.replace(' ', "_");
@@ -83,7 +111,7 @@ impl MeteredCounter {
 #[derive(Clone)]
 pub struct MeteredStore<K> {
     /// the metrics being stored
-    counter: MeteredCounter,
+    counter: &'static Lazy<MeteredCounter>,
     /// The underlying store of the metered store
     pub store: K,
 }
@@ -183,8 +211,7 @@ where
 
 impl<K> MeteredStore<K> {
     /// Creates a new Metered store
-    pub fn new(name: String, store: K) -> Self {
-        let counter = MeteredCounter::new(name);
+    pub fn new(counter: &'static Lazy<MeteredCounter>, store: K) -> Self {
         Self { counter, store }
     }
 }
diff --git a/linera-views/src/rocks_db.rs b/linera-views/src/rocks_db.rs
index 67e51ce5c5dd..4e6d654fe9b5 100644
--- a/linera-views/src/rocks_db.rs
+++ b/linera-views/src/rocks_db.rs
@@ -21,7 +21,10 @@ use std::{
 use thiserror::Error;
 
 #[cfg(feature = "metrics")]
-use crate::metered_wrapper::MeteredStore;
+use crate::metered_wrapper::{
+    MeteredStore, METERED_COUNTER_LRU_CACHING, METERED_COUNTER_ROCKS_DB,
+    METERED_COUNTER_VALUE_SPLITTING,
+};
 
 #[cfg(any(test, feature = "test"))]
 use {crate::lru_caching::TEST_CACHE_SIZE, tempfile::TempDir};
@@ -263,7 +266,7 @@ impl RocksDbStore {
     #[cfg(any(test, feature = "test"))]
     pub async fn new_for_testing(
         store_config: RocksDbStoreConfig,
-    ) -> Result<(RocksDbStore, TableStatus), RocksDbContextError> {
+    ) -> Result<(Self, TableStatus), RocksDbContextError> {
         let path = store_config.path_buf.as_path();
         fs::remove_dir_all(path)?;
         let create_if_missing = true;
@@ -289,7 +292,7 @@ impl RocksDbStore {
     /// Creates a RocksDB database from a specified path.
     pub async fn new(
         store_config: RocksDbStoreConfig,
-    ) -> Result<(RocksDbStore, TableStatus), RocksDbContextError> {
+    ) -> Result<(Self, TableStatus), RocksDbContextError> {
         let create_if_missing = false;
         Self::new_internal(store_config, create_if_missing).await
     }
@@ -313,11 +316,11 @@ impl RocksDbStore {
 
     #[cfg(feature = "metrics")]
     fn get_complete_store(store: RocksDbStoreInternal, cache_size: usize) -> Self {
-        let store = MeteredStore::new("rocks db internal".to_string(), store);
+        let store = MeteredStore::new(&METERED_COUNTER_ROCKS_DB, store);
         let store = ValueSplittingStore::new(store);
-        let store = MeteredStore::new("value splitting".to_string(), store);
+        let store = MeteredStore::new(&METERED_COUNTER_VALUE_SPLITTING, store);
         let store = LruCachingStore::new(store, cache_size);
-        let store = MeteredStore::new("lru caching".to_string(), store);
+        let store = MeteredStore::new(&METERED_COUNTER_LRU_CACHING, store);
         Self { store }
     }
 
@@ -325,7 +328,7 @@ impl RocksDbStore {
     async fn new_internal(
         store_config: RocksDbStoreConfig,
         create_if_missing: bool,
-    ) -> Result<(RocksDbStore, TableStatus), RocksDbContextError> {
+    ) -> Result<(Self, TableStatus), RocksDbContextError> {
         let kv_name = format!(
             "store_config={:?} create_if_missing={:?}",
             store_config, create_if_missing
diff --git a/linera-views/src/scylla_db.rs b/linera-views/src/scylla_db.rs
index 0e1bc0bb84fb..607f38e92509 100644
--- a/linera-views/src/scylla_db.rs
+++ b/linera-views/src/scylla_db.rs
@@ -16,7 +16,9 @@
 //! [trait2]: common::Context
 
 #[cfg(feature = "metrics")]
-use crate::metered_wrapper::MeteredStore;
+use crate::metered_wrapper::{
+    MeteredStore, METERED_COUNTER_LRU_CACHING, METERED_COUNTER_SCYLLA_DB,
+};
 
 #[cfg(any(test, feature = "test"))]
 use crate::{lru_caching::TEST_CACHE_SIZE, test_utils::get_table_name};
@@ -781,9 +783,9 @@ impl ScyllaDbStore {
         store: JournalingKeyValueStore<ScyllaDbStoreInternal>,
         cache_size: usize,
     ) -> Self {
-        let store = MeteredStore::new("scylla db internal".to_string(), store);
+        let store = MeteredStore::new(&METERED_COUNTER_SCYLLA_DB, store);
         let store = LruCachingStore::new(store, cache_size);
-        let store = MeteredStore::new("lru caching".to_string(), store);
+        let store = MeteredStore::new(&METERED_COUNTER_LRU_CACHING, store);
         Self { store }
     }
 

From 1bf3a915feffe2b665723164ba013f41464d927c Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Fri, 19 Jan 2024 08:45:19 +0100
Subject: [PATCH 09/15] Rename prometheus_async.

---
 linera-views/src/metered_wrapper.rs | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/linera-views/src/metered_wrapper.rs b/linera-views/src/metered_wrapper.rs
index 0b431b6684a6..72af4f69da51 100644
--- a/linera-views/src/metered_wrapper.rs
+++ b/linera-views/src/metered_wrapper.rs
@@ -116,7 +116,7 @@ pub struct MeteredStore<K> {
     pub store: K,
 }
 
-async fn prometheus_async<F, O>(f: F, hist: &HistogramVec) -> O
+async fn run_with_execution_time_metric<F, O>(f: F, hist: &HistogramVec) -> O
 where
     F: Future<Output = O>,
 {
@@ -142,7 +142,7 @@ where
     }
 
     async fn read_value_bytes(&self, key: &[u8]) -> Result<Option<Vec<u8>>, E> {
-        prometheus_async(
+        run_with_execution_time_metric(
             self.store.read_value_bytes(key),
             &self.counter.read_value_bytes,
         )
@@ -150,11 +150,11 @@ where
     }
 
     async fn contains_key(&self, key: &[u8]) -> Result<bool, E> {
-        prometheus_async(self.store.contains_key(key), &self.counter.contains_key).await
+        run_with_execution_time_metric(self.store.contains_key(key), &self.counter.contains_key).await
     }
 
     async fn read_multi_values_bytes(&self, keys: Vec<Vec<u8>>) -> Result<Vec<Option<Vec<u8>>>, E> {
-        prometheus_async(
+        run_with_execution_time_metric(
             self.store.read_multi_values_bytes(keys),
             &self.counter.read_multi_values_bytes,
         )
@@ -162,7 +162,7 @@ where
     }
 
     async fn find_keys_by_prefix(&self, key_prefix: &[u8]) -> Result<Self::Keys, E> {
-        prometheus_async(
+        run_with_execution_time_metric(
             self.store.find_keys_by_prefix(key_prefix),
             &self.counter.find_keys_by_prefix,
         )
@@ -170,7 +170,7 @@ where
     }
 
     async fn find_key_values_by_prefix(&self, key_prefix: &[u8]) -> Result<Self::KeyValues, E> {
-        prometheus_async(
+        run_with_execution_time_metric(
             self.store.find_key_values_by_prefix(key_prefix),
             &self.counter.find_key_values_by_prefix,
         )
@@ -186,7 +186,7 @@ where
     const MAX_VALUE_SIZE: usize = K::MAX_VALUE_SIZE;
 
     async fn write_batch(&self, batch: Batch, base_key: &[u8]) -> Result<(), E> {
-        prometheus_async(
+        run_with_execution_time_metric(
             self.store.write_batch(batch, base_key),
             &self.counter.write_batch,
         )
@@ -194,7 +194,7 @@ where
     }
 
     async fn clear_journal(&self, base_key: &[u8]) -> Result<(), E> {
-        prometheus_async(
+        run_with_execution_time_metric(
             self.store.clear_journal(base_key),
             &self.counter.clear_journal,
         )

From 6d50ddbf69b3301e61da464c320eecfcf9539176 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Fri, 19 Jan 2024 08:48:27 +0100
Subject: [PATCH 10/15] More renaming.

---
 linera-views/src/dynamo_db.rs                        | 2 +-
 linera-views/src/lib.rs                              | 2 +-
 linera-views/src/{metered_wrapper.rs => metering.rs} | 0
 linera-views/src/rocks_db.rs                         | 2 +-
 linera-views/src/scylla_db.rs                        | 2 +-
 5 files changed, 4 insertions(+), 4 deletions(-)
 rename linera-views/src/{metered_wrapper.rs => metering.rs} (100%)

diff --git a/linera-views/src/dynamo_db.rs b/linera-views/src/dynamo_db.rs
index 194172fd21d9..ad0caa97fc07 100644
--- a/linera-views/src/dynamo_db.rs
+++ b/linera-views/src/dynamo_db.rs
@@ -41,7 +41,7 @@ use std::{collections::HashMap, env, str::FromStr, sync::Arc};
 use thiserror::Error;
 
 #[cfg(feature = "metrics")]
-use crate::metered_wrapper::{
+use crate::metering::{
     MeteredStore, METERED_COUNTER_DYNAMO_DB, METERED_COUNTER_LRU_CACHING,
     METERED_COUNTER_VALUE_SPLITTING,
 };
diff --git a/linera-views/src/lib.rs b/linera-views/src/lib.rs
index 0fd1c8ad9501..44cd607b6bc3 100644
--- a/linera-views/src/lib.rs
+++ b/linera-views/src/lib.rs
@@ -64,7 +64,7 @@ pub mod journaling;
 
 /// The code for encapsulating one key_value store into another that does metric
 #[cfg(feature = "metrics")]
-pub mod metered_wrapper;
+pub mod metering;
 
 /// The code for handling big values by splitting them into several small ones.
 pub mod value_splitting;
diff --git a/linera-views/src/metered_wrapper.rs b/linera-views/src/metering.rs
similarity index 100%
rename from linera-views/src/metered_wrapper.rs
rename to linera-views/src/metering.rs
diff --git a/linera-views/src/rocks_db.rs b/linera-views/src/rocks_db.rs
index 4e6d654fe9b5..8cf2ec8062e8 100644
--- a/linera-views/src/rocks_db.rs
+++ b/linera-views/src/rocks_db.rs
@@ -21,7 +21,7 @@ use std::{
 use thiserror::Error;
 
 #[cfg(feature = "metrics")]
-use crate::metered_wrapper::{
+use crate::metering::{
     MeteredStore, METERED_COUNTER_LRU_CACHING, METERED_COUNTER_ROCKS_DB,
     METERED_COUNTER_VALUE_SPLITTING,
 };
diff --git a/linera-views/src/scylla_db.rs b/linera-views/src/scylla_db.rs
index 607f38e92509..9f55612a2d40 100644
--- a/linera-views/src/scylla_db.rs
+++ b/linera-views/src/scylla_db.rs
@@ -16,7 +16,7 @@
 //! [trait2]: common::Context
 
 #[cfg(feature = "metrics")]
-use crate::metered_wrapper::{
+use crate::metering::{
     MeteredStore, METERED_COUNTER_LRU_CACHING, METERED_COUNTER_SCYLLA_DB,
 };
 

From 855afbc4f1aaae00f5328497fde406365abed818 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Fri, 19 Jan 2024 08:57:06 +0100
Subject: [PATCH 11/15] Another rename.

---
 linera-views/src/metering.rs | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/linera-views/src/metering.rs b/linera-views/src/metering.rs
index 72af4f69da51..14e584e306af 100644
--- a/linera-views/src/metering.rs
+++ b/linera-views/src/metering.rs
@@ -15,8 +15,8 @@ use std::{future::Future, time::Instant};
 //use crate::journaling::DirectWritableKeyValueStore;
 
 #[derive(Clone)]
-/// The implementation of the `MeteredCounter` for the `KeyValueStore`.
-pub struct MeteredCounter {
+/// The implementation of the `KeyValueStoreMetrics` for the `KeyValueStore`.
+pub struct KeyValueStoreMetrics {
     read_value_bytes: HistogramVec,
     contains_key: HistogramVec,
     read_multi_values_bytes: HistogramVec,
@@ -28,30 +28,30 @@ pub struct MeteredCounter {
 
 /// The metered counter for the "rocks db"
 #[cfg(feature = "rocksdb")]
-pub static METERED_COUNTER_ROCKS_DB: Lazy<MeteredCounter> =
-    Lazy::new(|| MeteredCounter::new("rocks db internal".to_string()));
+pub static METERED_COUNTER_ROCKS_DB: Lazy<KeyValueStoreMetrics> =
+    Lazy::new(|| KeyValueStoreMetrics::new("rocks db internal".to_string()));
 
 /// The metered counter for the "dynamo db"
 #[cfg(feature = "aws")]
-pub static METERED_COUNTER_DYNAMO_DB: Lazy<MeteredCounter> =
-    Lazy::new(|| MeteredCounter::new("dynamo db internal".to_string()));
+pub static METERED_COUNTER_DYNAMO_DB: Lazy<KeyValueStoreMetrics> =
+    Lazy::new(|| KeyValueStoreMetrics::new("dynamo db internal".to_string()));
 
 /// The metered counter for the "scylla db"
 #[cfg(feature = "scylladb")]
-pub static METERED_COUNTER_SCYLLA_DB: Lazy<MeteredCounter> =
-    Lazy::new(|| MeteredCounter::new("scylla db internal".to_string()));
+pub static METERED_COUNTER_SCYLLA_DB: Lazy<KeyValueStoreMetrics> =
+    Lazy::new(|| KeyValueStoreMetrics::new("scylla db internal".to_string()));
 
 /// The metered counter for the "scylla db"
 #[cfg(any(feature = "rocksdb", feature = "aws"))]
-pub static METERED_COUNTER_VALUE_SPLITTING: Lazy<MeteredCounter> =
-    Lazy::new(|| MeteredCounter::new("value splitting".to_string()));
+pub static METERED_COUNTER_VALUE_SPLITTING: Lazy<KeyValueStoreMetrics> =
+    Lazy::new(|| KeyValueStoreMetrics::new("value splitting".to_string()));
 
 /// The metered counter for the "lru caching"
 #[cfg(any(feature = "rocksdb", feature = "aws", feature = "scylladb"))]
-pub static METERED_COUNTER_LRU_CACHING: Lazy<MeteredCounter> =
-    Lazy::new(|| MeteredCounter::new("lru caching".to_string()));
+pub static METERED_COUNTER_LRU_CACHING: Lazy<KeyValueStoreMetrics> =
+    Lazy::new(|| KeyValueStoreMetrics::new("lru caching".to_string()));
 
-impl MeteredCounter {
+impl KeyValueStoreMetrics {
     /// Creation of a named Metered counter.
     pub fn new(name: String) -> Self {
         // name can be "rocks db". Then var_name = "rocks_db" and title_name = "RocksDb"
@@ -95,7 +95,7 @@ impl MeteredCounter {
         let clear_journal = register_histogram_vec!(clear_journal1, clear_journal2, &[])
             .expect("Counter creation should not fail");
 
-        MeteredCounter {
+        KeyValueStoreMetrics {
             read_value_bytes,
             contains_key,
             read_multi_values_bytes,
@@ -111,7 +111,7 @@ impl MeteredCounter {
 #[derive(Clone)]
 pub struct MeteredStore<K> {
     /// the metrics being stored
-    counter: &'static Lazy<MeteredCounter>,
+    counter: &'static Lazy<KeyValueStoreMetrics>,
     /// The underlying store of the metered store
     pub store: K,
 }
@@ -211,7 +211,7 @@ where
 
 impl<K> MeteredStore<K> {
     /// Creates a new Metered store
-    pub fn new(counter: &'static Lazy<MeteredCounter>, store: K) -> Self {
+    pub fn new(counter: &'static Lazy<KeyValueStoreMetrics>, store: K) -> Self {
         Self { counter, store }
     }
 }

From 5d10281b13ec4527c5327f8ec479154c2ed8afa0 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Fri, 19 Jan 2024 09:00:58 +0100
Subject: [PATCH 12/15] More renaming.

---
 linera-views/src/metering.rs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/linera-views/src/metering.rs b/linera-views/src/metering.rs
index 14e584e306af..cba53229901c 100644
--- a/linera-views/src/metering.rs
+++ b/linera-views/src/metering.rs
@@ -26,27 +26,27 @@ pub struct KeyValueStoreMetrics {
     clear_journal: HistogramVec,
 }
 
-/// The metered counter for the "rocks db"
+/// The metrics for the "rocks db"
 #[cfg(feature = "rocksdb")]
 pub static METERED_COUNTER_ROCKS_DB: Lazy<KeyValueStoreMetrics> =
     Lazy::new(|| KeyValueStoreMetrics::new("rocks db internal".to_string()));
 
-/// The metered counter for the "dynamo db"
+/// The metrics for the "dynamo db"
 #[cfg(feature = "aws")]
 pub static METERED_COUNTER_DYNAMO_DB: Lazy<KeyValueStoreMetrics> =
     Lazy::new(|| KeyValueStoreMetrics::new("dynamo db internal".to_string()));
 
-/// The metered counter for the "scylla db"
+/// The metrics for the "scylla db"
 #[cfg(feature = "scylladb")]
 pub static METERED_COUNTER_SCYLLA_DB: Lazy<KeyValueStoreMetrics> =
     Lazy::new(|| KeyValueStoreMetrics::new("scylla db internal".to_string()));
 
-/// The metered counter for the "scylla db"
+/// The metrics for the "scylla db"
 #[cfg(any(feature = "rocksdb", feature = "aws"))]
 pub static METERED_COUNTER_VALUE_SPLITTING: Lazy<KeyValueStoreMetrics> =
     Lazy::new(|| KeyValueStoreMetrics::new("value splitting".to_string()));
 
-/// The metered counter for the "lru caching"
+/// The metrics for the "lru caching"
 #[cfg(any(feature = "rocksdb", feature = "aws", feature = "scylladb"))]
 pub static METERED_COUNTER_LRU_CACHING: Lazy<KeyValueStoreMetrics> =
     Lazy::new(|| KeyValueStoreMetrics::new("lru caching".to_string()));

From 3ddec71425dc7333d258a942cacda60ec4362739 Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Fri, 19 Jan 2024 09:07:00 +0100
Subject: [PATCH 13/15] formatting.

---
 linera-views/src/metering.rs  | 3 ++-
 linera-views/src/scylla_db.rs | 4 +---
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/linera-views/src/metering.rs b/linera-views/src/metering.rs
index cba53229901c..2579e78e7e17 100644
--- a/linera-views/src/metering.rs
+++ b/linera-views/src/metering.rs
@@ -150,7 +150,8 @@ where
     }
 
     async fn contains_key(&self, key: &[u8]) -> Result<bool, E> {
-        run_with_execution_time_metric(self.store.contains_key(key), &self.counter.contains_key).await
+        run_with_execution_time_metric(self.store.contains_key(key), &self.counter.contains_key)
+            .await
     }
 
     async fn read_multi_values_bytes(&self, keys: Vec<Vec<u8>>) -> Result<Vec<Option<Vec<u8>>>, E> {
diff --git a/linera-views/src/scylla_db.rs b/linera-views/src/scylla_db.rs
index 9f55612a2d40..2651ed29b05c 100644
--- a/linera-views/src/scylla_db.rs
+++ b/linera-views/src/scylla_db.rs
@@ -16,9 +16,7 @@
 //! [trait2]: common::Context
 
 #[cfg(feature = "metrics")]
-use crate::metering::{
-    MeteredStore, METERED_COUNTER_LRU_CACHING, METERED_COUNTER_SCYLLA_DB,
-};
+use crate::metering::{MeteredStore, METERED_COUNTER_LRU_CACHING, METERED_COUNTER_SCYLLA_DB};
 
 #[cfg(any(test, feature = "test"))]
 use crate::{lru_caching::TEST_CACHE_SIZE, test_utils::get_table_name};

From ac7790a0ecfdafff467709812fbb20b4b27cfdef Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Fri, 19 Jan 2024 20:44:46 +0100
Subject: [PATCH 14/15] Simplification of the names.

---
 linera-views/src/dynamo_db.rs |  9 ++++-----
 linera-views/src/metering.rs  | 10 +++++-----
 linera-views/src/rocks_db.rs  |  9 ++++-----
 linera-views/src/scylla_db.rs |  6 +++---
 4 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/linera-views/src/dynamo_db.rs b/linera-views/src/dynamo_db.rs
index ad0caa97fc07..301f386381ee 100644
--- a/linera-views/src/dynamo_db.rs
+++ b/linera-views/src/dynamo_db.rs
@@ -42,8 +42,7 @@ use thiserror::Error;
 
 #[cfg(feature = "metrics")]
 use crate::metering::{
-    MeteredStore, METERED_COUNTER_DYNAMO_DB, METERED_COUNTER_LRU_CACHING,
-    METERED_COUNTER_VALUE_SPLITTING,
+    MeteredStore, DYNAMO_DB_METRICS, LRU_CACHING_METRICS, VALUE_SPLITTING_METRICS,
 };
 
 #[cfg(any(test, feature = "test"))]
@@ -1038,11 +1037,11 @@ impl DynamoDbStore {
         store: JournalingKeyValueStore<DynamoDbStoreInternal>,
         cache_size: usize,
     ) -> Self {
-        let store = MeteredStore::new(&METERED_COUNTER_DYNAMO_DB, store);
+        let store = MeteredStore::new(&DYNAMO_DB_METRICS, store);
         let store = ValueSplittingStore::new(store);
-        let store = MeteredStore::new(&METERED_COUNTER_VALUE_SPLITTING, store);
+        let store = MeteredStore::new(&VALUE_SPLITTING_METRICS, store);
         let store = LruCachingStore::new(store, cache_size);
-        let store = MeteredStore::new(&METERED_COUNTER_LRU_CACHING, store);
+        let store = MeteredStore::new(&LRU_CACHING_METRICS, store);
         Self { store }
     }
 
diff --git a/linera-views/src/metering.rs b/linera-views/src/metering.rs
index 2579e78e7e17..6233d5b1892c 100644
--- a/linera-views/src/metering.rs
+++ b/linera-views/src/metering.rs
@@ -28,27 +28,27 @@ pub struct KeyValueStoreMetrics {
 
 /// The metrics for the "rocks db"
 #[cfg(feature = "rocksdb")]
-pub static METERED_COUNTER_ROCKS_DB: Lazy<KeyValueStoreMetrics> =
+pub static ROCKS_DB_METRICS: Lazy<KeyValueStoreMetrics> =
     Lazy::new(|| KeyValueStoreMetrics::new("rocks db internal".to_string()));
 
 /// The metrics for the "dynamo db"
 #[cfg(feature = "aws")]
-pub static METERED_COUNTER_DYNAMO_DB: Lazy<KeyValueStoreMetrics> =
+pub static DYNAMO_DB_METRICS: Lazy<KeyValueStoreMetrics> =
     Lazy::new(|| KeyValueStoreMetrics::new("dynamo db internal".to_string()));
 
 /// The metrics for the "scylla db"
 #[cfg(feature = "scylladb")]
-pub static METERED_COUNTER_SCYLLA_DB: Lazy<KeyValueStoreMetrics> =
+pub static SCYLLA_DB_METRICS: Lazy<KeyValueStoreMetrics> =
     Lazy::new(|| KeyValueStoreMetrics::new("scylla db internal".to_string()));
 
 /// The metrics for the "scylla db"
 #[cfg(any(feature = "rocksdb", feature = "aws"))]
-pub static METERED_COUNTER_VALUE_SPLITTING: Lazy<KeyValueStoreMetrics> =
+pub static VALUE_SPLITTING_METRICS: Lazy<KeyValueStoreMetrics> =
     Lazy::new(|| KeyValueStoreMetrics::new("value splitting".to_string()));
 
 /// The metrics for the "lru caching"
 #[cfg(any(feature = "rocksdb", feature = "aws", feature = "scylladb"))]
-pub static METERED_COUNTER_LRU_CACHING: Lazy<KeyValueStoreMetrics> =
+pub static LRU_CACHING_METRICS: Lazy<KeyValueStoreMetrics> =
     Lazy::new(|| KeyValueStoreMetrics::new("lru caching".to_string()));
 
 impl KeyValueStoreMetrics {
diff --git a/linera-views/src/rocks_db.rs b/linera-views/src/rocks_db.rs
index 8cf2ec8062e8..3ed7fd76c9df 100644
--- a/linera-views/src/rocks_db.rs
+++ b/linera-views/src/rocks_db.rs
@@ -22,8 +22,7 @@ use thiserror::Error;
 
 #[cfg(feature = "metrics")]
 use crate::metering::{
-    MeteredStore, METERED_COUNTER_LRU_CACHING, METERED_COUNTER_ROCKS_DB,
-    METERED_COUNTER_VALUE_SPLITTING,
+    MeteredStore, LRU_CACHING_METRICS, ROCKS_DB_METRICS, VALUE_SPLITTING_METRICS,
 };
 
 #[cfg(any(test, feature = "test"))]
@@ -316,11 +315,11 @@ impl RocksDbStore {
 
     #[cfg(feature = "metrics")]
     fn get_complete_store(store: RocksDbStoreInternal, cache_size: usize) -> Self {
-        let store = MeteredStore::new(&METERED_COUNTER_ROCKS_DB, store);
+        let store = MeteredStore::new(&ROCKS_DB_METRICS, store);
         let store = ValueSplittingStore::new(store);
-        let store = MeteredStore::new(&METERED_COUNTER_VALUE_SPLITTING, store);
+        let store = MeteredStore::new(&VALUE_SPLITTING_METRICS, store);
         let store = LruCachingStore::new(store, cache_size);
-        let store = MeteredStore::new(&METERED_COUNTER_LRU_CACHING, store);
+        let store = MeteredStore::new(&LRU_CACHING_METRICS, store);
         Self { store }
     }
 
diff --git a/linera-views/src/scylla_db.rs b/linera-views/src/scylla_db.rs
index 2651ed29b05c..edf030576062 100644
--- a/linera-views/src/scylla_db.rs
+++ b/linera-views/src/scylla_db.rs
@@ -16,7 +16,7 @@
 //! [trait2]: common::Context
 
 #[cfg(feature = "metrics")]
-use crate::metering::{MeteredStore, METERED_COUNTER_LRU_CACHING, METERED_COUNTER_SCYLLA_DB};
+use crate::metering::{MeteredStore, LRU_CACHING_METRICS, SCYLLA_DB_METRICS};
 
 #[cfg(any(test, feature = "test"))]
 use crate::{lru_caching::TEST_CACHE_SIZE, test_utils::get_table_name};
@@ -781,9 +781,9 @@ impl ScyllaDbStore {
         store: JournalingKeyValueStore<ScyllaDbStoreInternal>,
         cache_size: usize,
     ) -> Self {
-        let store = MeteredStore::new(&METERED_COUNTER_SCYLLA_DB, store);
+        let store = MeteredStore::new(&SCYLLA_DB_METRICS, store);
         let store = LruCachingStore::new(store, cache_size);
-        let store = MeteredStore::new(&METERED_COUNTER_LRU_CACHING, store);
+        let store = MeteredStore::new(&LRU_CACHING_METRICS, store);
         Self { store }
     }
 

From e1ed7c67b508815a0d211fa9926d3d30ad0ecb4f Mon Sep 17 00:00:00 2001
From: Mathieu Dutour Sikiric <mathieu.dutour@gmail.com>
Date: Fri, 19 Jan 2024 20:53:39 +0100
Subject: [PATCH 15/15] Remove unused includes.

---
 linera-views/src/metering.rs | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/linera-views/src/metering.rs b/linera-views/src/metering.rs
index 6233d5b1892c..d867f68e27bc 100644
--- a/linera-views/src/metering.rs
+++ b/linera-views/src/metering.rs
@@ -1,8 +1,6 @@
 // Copyright (c) Zefchain Labs, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-//use std::time::{Duration, Instant};
-//use linera_base::sync::Lazy;
 use crate::{
     batch::Batch,
     common::{KeyValueStore, ReadableKeyValueStore, WritableKeyValueStore},
@@ -12,7 +10,6 @@ use convert_case::{Case, Casing};
 use linera_base::sync::Lazy;
 use prometheus::{register_histogram_vec, HistogramVec};
 use std::{future::Future, time::Instant};
-//use crate::journaling::DirectWritableKeyValueStore;
 
 #[derive(Clone)]
 /// The implementation of the `KeyValueStoreMetrics` for the `KeyValueStore`.