Pick an RPC node at random to avoid getting stuck on a bad RPC node

(cherry picked from commit ad4d41e)

validator/Cargo.toml

@@ -15,6 +15,7 @@ chrono = { version = "0.4.10", features = ["serde"] }
 console = "0.9.1"
 log = "0.4.8"
 indicatif = "0.13.0"
+rand = "0.6.5"
 reqwest = { version = "0.9.22", default-features = false }
 serde_json = "1.0.41"
 solana-clap-utils = { path = "../clap-utils", version = "0.21.8" }

validator/src/main.rs

@@ -3,6 +3,7 @@ use clap::{crate_description, crate_name, value_t, value_t_or_exit, App, Arg};
 use console::{style, Emoji};
 use indicatif::{ProgressBar, ProgressStyle};
 use log::*;
+use rand::{thread_rng, Rng};
 use solana_clap_utils::{
     input_parsers::pubkey_of,
     input_validators::{is_keypair, is_pubkey_or_keypair},
@@ -217,15 +218,16 @@ fn get_rpc_addr(
             .any(|contact_info| contact_info.gossip == *entrypoint_gossip);
 
         if found_entrypoint & !rpc_peers.is_empty() {
-            // Prefer the entrypoint's RPC service it it has one, otherwise pick the first RPC
-            // service found
+            // Prefer the entrypoint's RPC service if present, otherwise pick a node at random
             if let Some(contact_info) = rpc_peers
                 .iter()
                 .find(|contact_info| contact_info.gossip == *entrypoint_gossip)
             {
                 break (contact_info.id, contact_info.rpc);
             }
-            break (rpc_peers[0].id, rpc_peers[0].rpc);
+
+            let i = thread_rng().gen_range(0, rpc_peers.len());
+            break (rpc_peers[i].id, rpc_peers[i].rpc);
         }
 
         sleep(Duration::from_secs(1));