Add --rpc-threads argument

Cargo.lock

@@ -5115,6 +5115,7 @@ dependencies = [
  "indicatif",
  "libc",
  "log 0.4.11",
+ "num_cpus",
  "rand 0.7.3",
  "serde_json",
  "signal-hook",

core/Cargo.toml

@@ -38,7 +38,6 @@ log = "0.4.11"
 lru = "0.6.1"
 miow = "0.2.2"
 net2 = "0.2.37"
-num_cpus = "1.13.0"
 num-traits = "0.2"
 rand = "0.7.0"
 rand_chacha = "0.2.2"
@@ -88,6 +87,7 @@ trees = "0.2.1"
 
 [dev-dependencies]
 matches = "0.1.6"
+num_cpus = "1.13.0"
 reqwest = { version = "0.10.8", default-features = false, features = ["blocking", "rustls-tls", "json"] }
 serial_test = "0.4.0"
 serial_test_derive = "0.4.0"

core/src/rpc.rs

@@ -112,6 +112,7 @@ pub struct JsonRpcConfig {
     pub enable_bigtable_ledger_upload: bool,
     pub max_multiple_accounts: Option<usize>,
     pub account_indexes: HashSet<AccountIndex>,
+    pub rpc_threads: usize,
 }
 
 #[derive(Clone)]

core/src/rpc_service.rs

@@ -273,6 +273,7 @@ impl JsonRpcService {
     ) -> Self {
         info!("rpc bound to {:?}", rpc_addr);
         info!("rpc configuration: {:?}", config);
+        let rpc_threads = 1.max(config.rpc_threads);
 
         let health = Arc::new(RpcHealth::new(
             cluster_info.clone(),
@@ -374,7 +375,7 @@ impl JsonRpcService {
                     io,
                     move |_req: &hyper::Request<hyper::Body>| request_processor.clone(),
                 )
-                .threads(num_cpus::get())
+                .threads(rpc_threads)
                 .cors(DomainsValidation::AllowOnly(vec![
                     AccessControlAllowOrigin::Any,
                 ]))

validator/Cargo.toml

@@ -19,6 +19,7 @@ core_affinity = "0.5.10"
 fd-lock = "1.1.1"
 indicatif = "0.15.0"
 log = "0.4.11"
+num_cpus = "1.13.0"
 rand = "0.7.0"
 serde_json = "1.0.56"
 solana-clap-utils = { path = "../clap-utils", version = "1.6.0" }

validator/src/main.rs

@@ -826,6 +826,7 @@ pub fn main() {
     let default_rpc_send_transaction_leader_forward_count = ValidatorConfig::default()
         .send_transaction_leader_forward_count
         .to_string();
+    let default_rpc_threads = num_cpus::get().to_string();
 
     let matches = App::new(crate_name!()).about(crate_description!())
         .version(solana_version::version!())
@@ -1277,6 +1278,15 @@ pub fn main() {
                 .validator(solana_net_utils::is_host)
                 .help("IP address to bind the RPC port [default: use --bind-address]"),
         )
+        .arg(
+            Arg::with_name("rpc_threads")
+                .long("rpc-threads")
+                .value_name("NUMBER")
+                .validator(is_parsable::<usize>)
+                .takes_value(true)
+                .default_value(&default_rpc_threads)
+                .help("Number of threads to use for servicing RPC requests"),
+        )
         .arg(
             Arg::with_name("rpc_pubsub_enable_vote_subscription")
                 .long("rpc-pubsub-enable-vote-subscription")
@@ -1550,6 +1560,7 @@ pub fn main() {
                 "health_check_slot_distance",
                 u64
             ),
+            rpc_threads: value_t_or_exit!(matches, "rpc_threads", usize),
             account_indexes: account_indexes.clone(),
         },
         rpc_addrs: value_t!(matches, "rpc_port", u16).ok().map(|rpc_port| {