Faster dedup

core/src/sigverify_stage.rs

@@ -7,13 +7,11 @@
 
 use {
     crate::sigverify,
-    core::time::Duration,
     crossbeam_channel::{Receiver, RecvTimeoutError, SendError, Sender},
     itertools::Itertools,
-    solana_bloom::bloom::{AtomicBloom, Bloom},
     solana_measure::measure::Measure,
     solana_perf::packet::PacketBatch,
-    solana_perf::sigverify::dedup_packets,
+    solana_perf::sigverify::Deduper,
     solana_sdk::timing,
     solana_streamer::streamer::{self, PacketBatchReceiver, StreamerError},
     std::{
@@ -214,7 +212,7 @@ impl SigVerifyStage {
     }
 
     fn verifier<T: SigVerifier>(
-        bloom: &AtomicBloom<&[u8]>,
+        deduper: &Deduper,
         recvr: &PacketBatchReceiver,
         sendr: &Sender<Vec<PacketBatch>>,
         verifier: &T,
@@ -229,18 +227,19 @@ impl SigVerifyStage {
             num_packets,
         );
 
-        let mut dedup_time = Measure::start("sigverify_dedup_time");
-        let dedup_fail = dedup_packets(bloom, &mut batches) as usize;
-        dedup_time.stop();
-        let valid_packets = num_packets.saturating_sub(dedup_fail);
-
+        //50ns per packet with a single core
         let mut discard_time = Measure::start("sigverify_discard_time");
-        if valid_packets > MAX_SIGVERIFY_BATCH {
+        if num_packets > MAX_SIGVERIFY_BATCH {
             Self::discard_excess_packets(&mut batches, MAX_SIGVERIFY_BATCH)
         };
-        let excess_fail = valid_packets.saturating_sub(MAX_SIGVERIFY_BATCH);
+        let excess_fail = num_packets.saturating_sub(MAX_SIGVERIFY_BATCH);
         discard_time.stop();
 
+        //100ns per packet with N cores
+        let mut dedup_time = Measure::start("sigverify_dedup_time");
+        let dedup_fail = deduper.dedup_packets(&mut batches) as usize;
+        dedup_time.stop();
+
         let mut verify_batch_time = Measure::start("sigverify_batch_time");
         let batches = verifier.verify_batches(batches);
         sendr.send(batches)?;
@@ -289,25 +288,16 @@ impl SigVerifyStage {
         let verifier = verifier.clone();
         let mut stats = SigVerifierStats::default();
         let mut last_print = Instant::now();
-        const MAX_BLOOM_AGE: Duration = Duration::from_millis(2_000);
-        const MAX_BLOOM_ITEMS: usize = 1_000_000;
-        const MAX_BLOOM_FAIL: f64 = 0.0001;
-        const MAX_BLOOM_BITS: usize = 8 << 22;
+        const MAX_DEDUPER_AGE_MS: u64 = 2_000;
+        const MAX_DEDUPER_ITEMS: u32 = 1_000_000;
         Builder::new()
             .name("solana-verifier".to_string())
             .spawn(move || {
-                let mut bloom =
-                    Bloom::random(MAX_BLOOM_ITEMS, MAX_BLOOM_FAIL, MAX_BLOOM_BITS).into();
-                let mut bloom_age = Instant::now();
+                let mut deduper = Deduper::new(MAX_DEDUPER_ITEMS, MAX_DEDUPER_AGE_MS);
                 loop {
-                    let now = Instant::now();
-                    if now.duration_since(bloom_age) > MAX_BLOOM_AGE {
-                        bloom =
-                            Bloom::random(MAX_BLOOM_ITEMS, MAX_BLOOM_FAIL, MAX_BLOOM_BITS).into();
-                        bloom_age = now;
-                    }
+                    deduper.reset();
                     if let Err(e) = Self::verifier(
-                        &bloom,
+                        &deduper,
                         &packet_receiver,
                         &verified_sender,
                         &verifier,

perf/benches/dedup.rs

@@ -5,7 +5,6 @@ extern crate test;
 
 use {
     rand::prelude::*,
-    solana_bloom::bloom::{AtomicBloom, Bloom},
     solana_perf::{
         packet::{to_packet_batches, PacketBatch},
         sigverify,
@@ -22,20 +21,14 @@ fn test_packet_with_size(size: usize, rng: &mut ThreadRng) -> Vec<u8> {
 
 fn do_bench_dedup_packets(bencher: &mut Bencher, mut batches: Vec<PacketBatch>) {
     // verify packets
-    let mut bloom: AtomicBloom<&[u8]> = Bloom::random(1_000_000, 0.0001, 8 << 22).into();
+    let mut deduper = sigverify::Deduper::new(1_000_000, 2_000);
     bencher.iter(|| {
-        // bench
-        sigverify::dedup_packets(&bloom, &mut batches);
-
-        // reset
-        bloom.clear_for_tests();
-        batches.iter_mut().for_each(|batch| {
-            batch
-                .packets
-                .iter_mut()
-                .for_each(|p| p.meta.set_discard(false))
-        });
-    })
+        let _ans = deduper.dedup_packets(&mut batches);
+        deduper.reset();
+        batches
+            .iter_mut()
+            .for_each(|b| b.packets.iter_mut().for_each(|p| p.meta.set_discard(false)));
+    });
 }
 
 #[bench]
@@ -97,3 +90,12 @@ fn bench_dedup_diff_big_packets(bencher: &mut Bencher) {
 
     do_bench_dedup_packets(bencher, batches);
 }
+
+#[bench]
+#[ignore]
+fn bench_dedup_reset(bencher: &mut Bencher) {
+    let mut deduper = sigverify::Deduper::new(1_000_000, 0);
+    bencher.iter(|| {
+        deduper.reset();
+    });
+}

perf/src/sigverify.rs

@@ -4,7 +4,6 @@
 //! to the GPU.
 //!
 
-use solana_bloom::bloom::AtomicBloom;
 #[cfg(test)]
 use solana_sdk::transaction::Transaction;
 use {
@@ -24,7 +23,11 @@ use {
         short_vec::decode_shortu16_len,
         signature::Signature,
     },
-    std::sync::atomic::{AtomicU64, Ordering},
+    std::collections::hash_map::RandomState,
+    std::hash::BuildHasher,
+    std::hash::Hasher,
+    std::sync::atomic::{AtomicBool, AtomicU64, Ordering},
+    std::time::{Duration, Instant},
     std::{convert::TryFrom, mem::size_of},
 };
 
@@ -420,34 +423,80 @@ pub fn generate_offsets(
     )
 }
 
-fn dedup_packet(count: &AtomicU64, packet: &mut Packet, bloom: &AtomicBloom<&[u8]>) {
-    // If this packet was already marked as discard, drop it
-    if packet.meta.discard() {
-        return;
+pub struct Deduper {
+    filter: Vec<AtomicU64>,
+    seed: RandomState,
+    age: Instant,
+    max_age: Duration,
+    saturated: AtomicBool,
+}
+
+impl Deduper {
+    pub fn new(size: u32, max_age_ms: u64) -> Self {
+        let mut filter: Vec<AtomicU64> = Vec::with_capacity(size as usize);
+        filter.resize_with(size as usize, Default::default);
+        let seed = RandomState::new();
+        Self {
+            filter,
+            seed,
+            age: Instant::now(),
+            max_age: Duration::from_millis(max_age_ms),
+            saturated: AtomicBool::new(false),
+        }
     }
 
-    // If this packet was not newly added, it's a dup and should be discarded
-    if !bloom.add(&&packet.data.as_slice()[0..packet.meta.size]) {
-        packet.meta.set_discard(true);
-        count.fetch_add(1, Ordering::Relaxed);
+    pub fn reset(&mut self) {
+        let now = Instant::now();
+        //this should reset every 500k unique packets per 1m sized deduper
+        //false positive rate is 1/1000 at that point
+        let saturated = self.saturated.load(Ordering::Relaxed);
+        if saturated || now.duration_since(self.age) > self.max_age {
+            for i in &self.filter {
+                i.store(0, Ordering::Relaxed);
+            }
+            self.seed = RandomState::new();
+            self.age = now;
+            self.saturated.store(false, Ordering::Relaxed);
+        }
     }
-}
 
-pub fn dedup_packets(bloom: &AtomicBloom<&[u8]>, batches: &mut [PacketBatch]) -> u64 {
-    use rayon::prelude::*;
-    let packet_count = count_packets_in_batches(batches);
-    // machine specific random offset to read the u64 from the packet signature
-    let count = AtomicU64::new(0);
-    PAR_THREAD_POOL.install(|| {
-        batches.into_par_iter().for_each(|batch| {
-            batch
-                .packets
-                .par_iter_mut()
-                .for_each(|p| dedup_packet(&count, p, bloom))
-        })
-    });
-    inc_new_counter_debug!("dedup_packets_total", packet_count);
-    count.load(Ordering::Relaxed)
+    fn dedup_packet(&self, count: &AtomicU64, packet: &mut Packet) {
+        // If this packet was already marked as discard, drop it
+        if packet.meta.discard() {
+            return;
+        }
+        let mut hasher = self.seed.build_hasher();
+        hasher.write(&packet.data[0..packet.meta.size]);
+        let hash = hasher.finish();
+        let len = self.filter.len();
+        let pos = (usize::try_from(hash).unwrap()).wrapping_rem(len);
+        // saturate each position with or
+        let prev = self.filter[pos].fetch_or(hash, Ordering::Relaxed);
+        if prev == u64::MAX {
+            self.saturated.store(true, Ordering::Relaxed);
+            //reset this value
+            self.filter[pos].store(hash, Ordering::Relaxed);
+        }
+        if hash == prev & hash {
+            packet.meta.set_discard(true);
+            count.fetch_add(1, Ordering::Relaxed);
+        }
+    }
+
+    pub fn dedup_packets(&self, batches: &mut [PacketBatch]) -> u64 {
+        use rayon::prelude::*;
+        // machine specific random offset to read the u64 from the packet signature
+        let count = AtomicU64::new(0);
+        PAR_THREAD_POOL.install(|| {
+            batches.into_par_iter().for_each(|batch| {
+                batch
+                    .packets
+                    .par_iter_mut()
+                    .for_each(|p| self.dedup_packet(&count, p))
+            })
+        });
+        count.load(Ordering::Relaxed)
+    }
 }
 
 pub fn ed25519_verify_cpu(batches: &mut [PacketBatch], reject_non_vote: bool) {
@@ -634,7 +683,6 @@ mod tests {
             test_tx::{new_test_vote_tx, test_multisig_tx, test_tx},
         },
         bincode::{deserialize, serialize},
-        solana_bloom::bloom::{AtomicBloom, Bloom},
         solana_sdk::{
             instruction::CompiledInstruction,
             message::{Message, MessageHeader},
@@ -1299,26 +1347,55 @@ mod tests {
     fn test_dedup_same() {
         let tx = test_tx();
 
-        // generate packet vector
         let mut batches =
             to_packet_batches(&std::iter::repeat(tx).take(1024).collect::<Vec<_>>(), 128);
         let packet_count = sigverify::count_packets_in_batches(&batches);
-        let bloom: AtomicBloom<&[u8]> = Bloom::random(1_000_000, 0.0001, 8 << 20).into();
-        let discard = sigverify::dedup_packets(&bloom, &mut batches) as usize;
-        // because dedup uses a threadpool, there maybe up to N threads of txs that go through
-        let n = get_thread_count();
-        assert!(packet_count < discard + n * 2);
+        let filter = Deduper::new(1_000_000, 0);
+        let discard = filter.dedup_packets(&mut batches) as usize;
+        assert_eq!(packet_count, discard + 1);
     }
 
     #[test]
     fn test_dedup_diff() {
-        // generate packet vector
+        let mut filter = Deduper::new(1_000_000, 0);
         let mut batches = to_packet_batches(&(0..1024).map(|_| test_tx()).collect::<Vec<_>>(), 128);
 
-        let bloom: AtomicBloom<&[u8]> = Bloom::random(1_000_000, 0.0001, 8 << 20).into();
-        let discard = sigverify::dedup_packets(&bloom, &mut batches) as usize;
+        let discard = filter.dedup_packets(&mut batches) as usize;
         // because dedup uses a threadpool, there maybe up to N threads of txs that go through
-        let n = get_thread_count();
-        assert!(discard < n * 2);
+        assert_eq!(discard, 0);
+        filter.reset();
+        for i in filter.filter {
+            assert_eq!(i.load(Ordering::Relaxed), 0);
+        }
+    }
+
+    #[test]
+    #[ignore]
+    fn test_dedup_saturated() {
+        let filter = Deduper::new(1_000_000, 0);
+        let mut discard = 0;
+        assert!(!filter.saturated.load(Ordering::Relaxed));
+        for i in 0..1000 {
+            let mut batches =
+                to_packet_batches(&(0..1000).map(|_| test_tx()).collect::<Vec<_>>(), 128);
+            discard += filter.dedup_packets(&mut batches) as usize;
+            println!("{} {}", i, discard);
+            if filter.saturated.load(Ordering::Relaxed) {
+                break;
+            }
+        }
+        assert!(filter.saturated.load(Ordering::Relaxed));
+    }
+    #[test]
+    fn test_dedup_false_positive() {
+        let filter = Deduper::new(1_000_000, 0);
+        let mut discard = 0;
+        for i in 0..10 {
+            let mut batches =
+                to_packet_batches(&(0..1024).map(|_| test_tx()).collect::<Vec<_>>(), 128);
+            discard += filter.dedup_packets(&mut batches) as usize;
+            println!("false positive rate: {}/{}", discard, i * 1024);
+        }
+        assert!(discard < 1);
     }
 }