feat: cleanup the spanner pool managers

- ignore deadpool's Status::available negative values for PoolState
- kill no longer used DB_THREAD_POOL_SIZE

Closes #794

src/db/mod.rs

@@ -57,9 +57,6 @@ pub const FIRST_CUSTOM_COLLECTION_ID: i32 = 101;
 /// Rough guesstimate of the maximum reasonable life span of a batch
 pub const BATCH_LIFETIME: i64 = 2 * 60 * 60 * 1000; // 2 hours, in milliseconds
 
-/// DbPools' worker ThreadPool size
-pub const DB_THREAD_POOL_SIZE: usize = 50;
-
 type DbFuture<'a, T> = LocalBoxFuture<'a, Result<T, ApiError>>;
 
 #[async_trait(?Send)]

src/db/mysql/pool.rs

@@ -17,7 +17,11 @@ use diesel::{
 use super::models::{MysqlDb, Result};
 #[cfg(test)]
 use super::test::TestTransactionCustomizer;
-use crate::db::{error::DbError, results, Db, DbPool, STD_COLLS};
+use crate::db::{
+    error::DbError,
+    results::{self, PoolState},
+    Db, DbPool, STD_COLLS,
+};
 use crate::error::{ApiError, ApiResult};
 use crate::server::metrics::Metrics;
 use crate::settings::Settings;
@@ -105,8 +109,10 @@ impl DbPool for MysqlDbPool {
 }
 
 impl fmt::Debug for MysqlDbPool {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "MysqlDbPool {{ coll_cache: {:?} }}", self.coll_cache)
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt.debug_struct("MysqlDbPool")
+            .field("coll_cache", &self.coll_cache)
+            .finish()
     }
 }
 
@@ -175,3 +181,12 @@ impl Default for CollectionCache {
         }
     }
 }
+
+impl From<diesel::r2d2::State> for PoolState {
+    fn from(state: diesel::r2d2::State) -> PoolState {
+        PoolState {
+            connections: state.connections,
+            idle_connections: state.idle_connections,
+        }
+    }
+}

src/db/results.rs

@@ -76,33 +76,6 @@ pub struct PoolState {
     pub idle_connections: u32,
 }
 
-impl From<diesel::r2d2::State> for PoolState {
-    fn from(state: diesel::r2d2::State) -> PoolState {
-        PoolState {
-            connections: state.connections,
-            idle_connections: state.idle_connections,
-        }
-    }
-}
-
-impl From<bb8::State> for PoolState {
-    fn from(state: bb8::State) -> PoolState {
-        PoolState {
-            connections: state.connections,
-            idle_connections: state.idle_connections,
-        }
-    }
-}
-
-impl From<deadpool::Status> for PoolState {
-    fn from(status: deadpool::Status) -> PoolState {
-        PoolState {
-            connections: status.size as u32,
-            idle_connections: status.available as u32,
-        }
-    }
-}
-
 #[cfg(test)]
 pub type GetCollectionId = i32;
 

src/db/spanner/manager/bb8.rs

@@ -1,26 +1,25 @@
 use std::marker::PhantomData;
 use std::{fmt, sync::Arc};
 
-use actix_web::web::block;
 use async_trait::async_trait;
-use bb8::ManageConnection;
-use googleapis_raw::spanner::v1::{
-    spanner::{CreateSessionRequest, GetSessionRequest, Session},
-    spanner_grpc::SpannerClient,
-};
-use grpcio::{
-    CallOption, ChannelBuilder, ChannelCredentials, EnvBuilder, Environment, MetadataBuilder,
-};
+use bb8::{ManageConnection, PooledConnection};
+use grpcio::{EnvBuilder, Environment};
 
 use crate::{
-    db::error::{DbError, DbErrorKind},
+    db::{
+        error::{DbError, DbErrorKind},
+        results::PoolState,
+    },
     server::metrics::Metrics,
     settings::Settings,
 };
 
-pub const SPANNER_ADDRESS: &str = "spanner.googleapis.com:443";
+use super::session::{create_spanner_session, recycle_spanner_session, SpannerSession};
 
-pub struct SpannerConnectionManager<T> {
+#[allow(dead_code)]
+pub type Conn<'a> = PooledConnection<'a, SpannerSessionManager<SpannerSession>>;
+
+pub struct SpannerSessionManager<T> {
     database_name: String,
     /// The gRPC environment
     env: Arc<Environment>,
@@ -29,30 +28,30 @@ pub struct SpannerConnectionManager<T> {
     phantom: PhantomData<T>,
 }
 
-impl<_T> fmt::Debug for SpannerConnectionManager<_T> {
+impl<_T> fmt::Debug for SpannerSessionManager<_T> {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt.debug_struct("SpannerConnectionManager")
+        fmt.debug_struct("bb8::SpannerSessionManager")
             .field("database_name", &self.database_name)
             .field("test_transactions", &self.test_transactions)
             .finish()
     }
 }
 
-impl<T> SpannerConnectionManager<T> {
+impl<T> SpannerSessionManager<T> {
+    #[allow(dead_code)]
     pub fn new(settings: &Settings, metrics: &Metrics) -> Result<Self, DbError> {
-        let url = &settings.database_url;
-        if !url.starts_with("spanner://") {
-            Err(DbErrorKind::InvalidUrl(url.to_owned()))?;
-        }
-        let database_name = url["spanner://".len()..].to_owned();
+        let database_name = settings
+            .spanner_database_name()
+            .ok_or_else(|| DbErrorKind::InvalidUrl(settings.database_url.to_owned()))?
+            .to_owned();
         let env = Arc::new(EnvBuilder::new().build());
 
         #[cfg(not(test))]
         let test_transactions = false;
         #[cfg(test)]
         let test_transactions = settings.database_use_test_transactions;
 
-        Ok(SpannerConnectionManager::<T> {
+        Ok(SpannerSessionManager::<T> {
             database_name,
             env,
             metrics: metrics.clone(),
@@ -62,67 +61,23 @@ impl<T> SpannerConnectionManager<T> {
     }
 }
 
-pub struct SpannerSession {
-    pub client: SpannerClient,
-    pub session: Session,
-
-    pub(in crate::db::spanner) use_test_transactions: bool,
-}
-
 #[async_trait]
-impl<T: std::marker::Send + std::marker::Sync + 'static> ManageConnection
-    for SpannerConnectionManager<T>
-{
+impl<T: Send + Sync + 'static> ManageConnection for SpannerSessionManager<T> {
     type Connection = SpannerSession;
     type Error = DbError;
 
     async fn connect(&self) -> Result<Self::Connection, Self::Error> {
-        let env = self.env.clone();
-        let mut metrics = self.metrics.clone();
-        // XXX: issue732: Could google_default_credentials (or
-        // ChannelBuilder::secure_connect) block?!
-        let chan = block(move || -> Result<grpcio::Channel, grpcio::Error> {
-            metrics.start_timer("storage.pool.grpc_auth", None);
-            // Requires
-            // GOOGLE_APPLICATION_CREDENTIALS=/path/to/service-account.json
-            let creds = ChannelCredentials::google_default_credentials()?;
-            Ok(ChannelBuilder::new(env)
-                .max_send_message_len(100 << 20)
-                .max_receive_message_len(100 << 20)
-                .secure_connect(SPANNER_ADDRESS, creds))
-        })
+        create_spanner_session(
+            Arc::clone(&self.env),
+            self.metrics.clone(),
+            &self.database_name,
+            self.test_transactions,
+        )
         .await
-        .map_err(|e| match e {
-            actix_web::error::BlockingError::Error(e) => e.into(),
-            actix_web::error::BlockingError::Canceled => {
-                DbError::internal("web::block Manager operation canceled")
-            }
-        })?;
-        let client = SpannerClient::new(chan);
-
-        // Connect to the instance and create a Spanner session.
-        let session = create_session(&client, &self.database_name).await?;
-
-        Ok(SpannerSession {
-            client,
-            session,
-            use_test_transactions: self.test_transactions,
-        })
     }
 
     async fn is_valid(&self, mut conn: Self::Connection) -> Result<Self::Connection, Self::Error> {
-        let mut req = GetSessionRequest::new();
-        req.set_name(conn.session.get_name().to_owned());
-        if let Err(e) = conn.client.get_session_async(&req)?.await {
-            match e {
-                grpcio::Error::RpcFailure(ref status)
-                    if status.status == grpcio::RpcStatusCode::NOT_FOUND =>
-                {
-                    conn.session = create_session(&conn.client, &self.database_name).await?;
-                }
-                _ => return Err(e.into()),
-            }
-        }
+        recycle_spanner_session(&mut conn, &self.database_name).await?;
         Ok(conn)
     }
 
@@ -131,15 +86,11 @@ impl<T: std::marker::Send + std::marker::Sync + 'static> ManageConnection
     }
 }
 
-pub async fn create_session(
-    client: &SpannerClient,
-    database_name: &str,
-) -> Result<Session, grpcio::Error> {
-    let mut req = CreateSessionRequest::new();
-    req.database = database_name.to_owned();
-    let mut meta = MetadataBuilder::new();
-    meta.add_str("google-cloud-resource-prefix", database_name)?;
-    meta.add_str("x-goog-api-client", "gcp-grpc-rs")?;
-    let opt = CallOption::default().headers(meta.build());
-    client.create_session_async_opt(&req, opt)?.await
+impl From<bb8::State> for PoolState {
+    fn from(state: bb8::State) -> PoolState {
+        PoolState {
+            connections: state.connections,
+            idle_connections: state.idle_connections,
+        }
+    }
 }