graphprotocol · lutter · Jul 3, 2020 · Jun 26, 2020 · Jun 26, 2020 · Jun 26, 2020
diff --git a/docs/environment-variables.md b/docs/environment-variables.md
@@ -112,3 +112,16 @@ those.
   Due to implementation details, this value may not be strictly adhered to. Defaults to 10.
 - `GRAPH_LOG_POI_EVENTS`: Logs Proof of Indexing events deterministically.
   This may be useful for debugging.
+- `GRAPH_LOAD_WINDOW_SIZE`, `GRAPH_LOAD_BIN_SIZE`: Load can be
+  automatically throttled if load measurements over a time period of
+  `GRAPH_LOAD_WINDOW_SIZE` seconds exceed a threshold. Measurements within
+  each window are binned into bins of `GRAPH_LOAD_BIN_SIZE` seconds. The
+  variables default to 300s and 1s
+- `GRAPH_LOAD_THRESHOLD`: If wait times for getting database connections go
+  above this threshold, throttle queries until the wait times fall below
+  the threshold. Value is in milliseconds, and defaults to 0 which
+  turns throttling off and any associated statistics collection off.
+- `GRAPH_LOAD_JAIL_THRESHOLD`: When the system is overloaded, any query
+  that causes more than this fraction of the effort will be rejected for as
+  long as the process is running (i.e., even after the overload situation
+  is resolved) Defaults to 0.1
diff --git a/graph/src/components/graphql.rs b/graph/src/components/graphql.rs
@@ -1,5 +1,6 @@
 use futures::prelude::*;
 
+use crate::data::graphql::effort::LoadManager;
 use crate::data::query::{Query, QueryError, QueryResult};
 use crate::data::subscription::{Subscription, SubscriptionError, SubscriptionResult};
 
@@ -8,6 +9,7 @@ use failure::format_err;
 use failure::Error;
 use futures03::compat::Future01CompatExt;
 use graphql_parser::query as q;
+use std::sync::Arc;
 
 /// Future for query results.
 pub type QueryResultFuture = Box<dyn Future<Item = QueryResult, Error = QueryError> + Send>;
@@ -47,4 +49,6 @@ pub trait GraphQlRunner: Send + Sync + 'static {
                 }
             })
     }
+
+    fn load_manager(&self) -> Arc<LoadManager>;
 }
diff --git a/graph/src/components/store.rs b/graph/src/components/store.rs
@@ -11,7 +11,7 @@ use std::env;
 use std::fmt;
 use std::str::FromStr;
 use std::sync::atomic::{AtomicUsize, Ordering};
-use std::sync::Arc;
+use std::sync::{Arc, RwLock};
 use std::time::{Duration, Instant};
 use web3::types::{Address, H256};
 
@@ -1214,6 +1214,10 @@ mock! {
     }
 }
 
+// The type that the connection pool uses to track wait times for
+// connection checkouts
+pub type PoolWaitStats = Arc<RwLock<MovingStats>>;
+
 // The store trait must be implemented manually because mockall does not support async_trait, nor borrowing from arguments.
 impl Store for MockStore {
     fn block_ptr(