Reduce slot duration and consecutive leader slots (#4838)

* change consecutive leader slots to 4

* reduce polling frequency for transaction signature confirmation

* adjust wait time for transaction signature confirmation

* fix nominal test

* fix flakiness in wallet pay test

client/src/rpc_client.rs

@@ -446,17 +446,27 @@ impl RpcClient {
     ) -> io::Result<()> {
         let mut now = Instant::now();
         let mut confirmed_blocks = 0;
+        let mut wait_time = 15;
         loop {
             let response = self.get_num_blocks_since_signature_confirmation(signature);
             match response {
                 Ok(count) => {
                     if confirmed_blocks != count {
                         info!(
-                            "signature {} confirmed {} out of {}",
+                            "signature {} confirmed {} out of {} after {} ms",
-                            signature, count, min_confirmed_blocks
+                            signature,
+                            count,
+                            min_confirmed_blocks,
+                            now.elapsed().as_millis()
                         );
                         now = Instant::now();
                         confirmed_blocks = count;
+                        // If the signature has been confirmed once, wait extra while reconfirming it
+                        // One confirmation means the transaction has been seen by the network, so
+                        // next confirmation (for a higher block count) should come through.
+                        // Returning an error prematurely will cause a valid transaction to be deemed
+                        // as failure.
+                        wait_time = 30;
                     }
                     if count >= min_confirmed_blocks {
                         break;
@@ -466,11 +476,18 @@ impl RpcClient {
                     debug!("check_confirmations request failed: {:?}", err);
                 }
             };
-            if now.elapsed().as_secs() > 15 {
+            if now.elapsed().as_secs() > wait_time {
+                info!(
+                    "signature {} confirmed {} out of {} failed after {} ms",
+                    signature,
+                    confirmed_blocks,
+                    min_confirmed_blocks,
+                    now.elapsed().as_millis()
+                );
                 // TODO: Return a better error.
                 return Err(io::Error::new(io::ErrorKind::Other, "signature not found"));
             }
-            sleep(Duration::from_millis(250));
+            sleep(Duration::from_secs(1));
         }
         Ok(())
     }

ledger-tool/tests/basic.rs

@@ -4,6 +4,7 @@ extern crate solana;
 use assert_cmd::prelude::*;
 use solana::blocktree::create_new_tmp_ledger;
 use solana::genesis_utils::create_genesis_block;
+use std::cmp;
 use std::process::Command;
 use std::process::Output;
 
@@ -47,10 +48,12 @@ fn nominal() {
     assert!(output.status.success());
     assert_eq!(count_newlines(&output.stdout), ticks);
 
-    // Only print the first 5 items
+    // Only print the first N items
-    let output = run_ledger_tool(&["-l", &ledger_path, "-n", "5", "print"]);
+    let count = cmp::min(genesis_block.ticks_per_slot, 5);
+    let output = run_ledger_tool(&["-l", &ledger_path, "-n", &count.to_string(), "print"]);
+    println!("{:?}", output);
     assert!(output.status.success());
-    assert_eq!(count_newlines(&output.stdout), 5);
+    assert_eq!(count_newlines(&output.stdout), count as usize);
 
     // Skip entries with no hashes
     let output = run_ledger_tool(&["-l", &ledger_path, "-h", "1", "print"]);

sdk/src/timing.rs

@@ -6,14 +6,14 @@ use std::time::{SystemTime, UNIX_EPOCH};
 // rate at any given time should be expected to drift
 pub const DEFAULT_NUM_TICKS_PER_SECOND: u64 = 10;
 
-// At 10 ticks/s, 8 ticks per slot implies that leader rotation and voting will happen
+// At 10 ticks/s, 4 ticks per slot implies that leader rotation and voting will happen
-// every 800 ms. A fast voting cadence ensures faster finality and convergence
+// every 400 ms. A fast voting cadence ensures faster finality and convergence
-pub const DEFAULT_TICKS_PER_SLOT: u64 = 8;
+pub const DEFAULT_TICKS_PER_SLOT: u64 = 4;
 
-// 1 Epoch = 800 * 4096 ms ~= 55 minutes
+// 1 Epoch = 400 * 8192 ms ~= 55 minutes
-pub const DEFAULT_SLOTS_PER_EPOCH: u64 = 4096;
+pub const DEFAULT_SLOTS_PER_EPOCH: u64 = 8192;
 
-pub const NUM_CONSECUTIVE_LEADER_SLOTS: u64 = 8;
+pub const NUM_CONSECUTIVE_LEADER_SLOTS: u64 = 4;
 
 /// The time window of recent block hash values that the bank will track the signatures
 /// of over. Once the bank discards a block hash, it will reject any transactions that use
@@ -32,11 +32,11 @@ pub const MAX_PROCESSING_AGE: usize = MAX_RECENT_BLOCKHASHES / 2;
 /// This is maximum time consumed in forwarding a transaction from one node to next, before
 /// it can be processed in the target node
 #[cfg(feature = "cuda")]
-pub const MAX_TRANSACTION_FORWARDING_DELAY: usize = 4;
+pub const MAX_TRANSACTION_FORWARDING_DELAY: usize = 2;
 
 /// More delay is expected if CUDA is not enabled (as signature verification takes longer)
 #[cfg(not(feature = "cuda"))]
-pub const MAX_TRANSACTION_FORWARDING_DELAY: usize = 12;
+pub const MAX_TRANSACTION_FORWARDING_DELAY: usize = 6;
 
 pub fn duration_as_ns(d: &Duration) -> u64 {
     d.as_secs() * 1_000_000_000 + u64::from(d.subsec_nanos())

wallet/tests/pay.rs

@@ -12,10 +12,20 @@ use std::sync::mpsc::channel;
 
 #[cfg(test)]
 use solana::validator::new_validator_for_tests;
+use std::thread::sleep;
+use std::time::Duration;
 
 fn check_balance(expected_balance: u64, client: &RpcClient, pubkey: &Pubkey) {
-    let balance = client.retry_get_balance(pubkey, 1).unwrap().unwrap();
+    (0..5).for_each(|tries| {
-    assert_eq!(balance, expected_balance);
+        let balance = client.retry_get_balance(pubkey, 1).unwrap().unwrap();
+        if balance == expected_balance {
+            return;
+        }
+        if tries == 4 {
+            assert_eq!(balance, expected_balance);
+        }
+        sleep(Duration::from_millis(500));
+    });
 }
 
 #[test]