Bundles #20

buffalu · 2022-03-30T15:15:12Z

Problem

Validator can't guarantee sequential, all-or-nothing transaction bundle processing.

Summary of Changes

TX Flow

Added BankingStage::bundle_stage thread.
Checks poh + drops bundles if not leader.
Attempts to grab most sequential locks it can, then executes and saves account results to a HashMap cache. Runs several iterations sequentially until the entire bundle is executed.
Commits entire bundle to poh, all-or-nothing and if the entire bundle succeeds recording, commits the results to the bank.

PoH

Changed PoH to work with many mixins and versioned transactions per record so that the entire thing can be treated as a bundle that gets processed all-or-nothing.
All-or-nothing processing added to broadcast stage such that no piece of the shred gets dropped.

entry/src/poh.rs

bootstrap

mev/src/blocking_proxy_client.rs

mev/src/lib.rs

mev/src/mev_stage.rs

poh/src/poh_recorder.rs

buffalu · 2022-04-07T16:35:35Z

poh/src/poh_service.rs

-                ))
-                .is_err()
-            {
+        if let Ok((record, sender)) = record {


revert some of this

runtime/src/bank.rs

runtime/src/accounts.rs

buffalu · 2022-04-07T16:37:25Z

runtime/src/accounts.rs

+                            tx_account_locks.writable,
+                            tx_account_locks.readonly,
+                        );
+                        if matches!(locked, Err(TransactionError::AccountInUse)) {


double check there can't be other errors; need to ensure contiguous batch

core/src/banking_stage.rs

segfaultdoc · 2022-04-17T23:23:10Z

core/src/banking_stage.rs

+        }
+    }
+
+    fn get_bundle_txs(bundle: Bundle, bank: &Arc<Bank>) -> Vec<SanitizedTransaction> {


wdyt about adding this as a method on the Bundle object ++ rename to something like get_txs, extract_txs etc.?

I guess it's just a wrapper around transactions_from_packets which set precedent on defining here; your call

segfaultdoc · 2022-04-17T23:24:13Z

core/src/banking_stage.rs

+            } = &*working_bank_start.unwrap();
+
+            // Process + send one bundle at a time
+            // TODO (LB): probably want to lock all the other tx procesing pipelines (except votes) until this is done


Is locking what would theoretically guarantee top of block inclusion?

I think so, without locking other stages seems like you may have a situation where a bundle is fragmented within a block

locking mainly about preventing other reads and writes that would invalidate cache. bundle will never be fragmented bc its written in a batch to poh

core/src/banking_stage.rs

entry/src/poh.rs

segfaultdoc · 2022-04-18T00:27:54Z

entry/src/poh.rs

+                self.num_hashes = 0;
+                self.remaining_hashes -= 1;
+                PohEntry {
+                    num_hashes,


after the first iteration this will always be 1, is that the desired behavior? also it's not immediately clear to me why it was set to 0 in the base branch revision, mind giving some color offline or here?

segfaultdoc · 2022-04-18T00:29:38Z

entry/src/poh.rs

+                self.hash = hashv(&[self.hash.as_ref(), m.as_ref()]);
+                let num_hashes = self.num_hashes + 1;
+                self.num_hashes = 0;
+                self.remaining_hashes -= 1;


micro-optimization, but why not just move this outside the map and just self.remaining_hashes -= mixins.len()

if optimized at all haha, just tryna squeeze out some juice

poh/src/poh_recorder.rs

Previously TPU and TPU forward addresses were passed via CLI args, now the validator requests TPU addresses from the validator interface it connects to.

@whistlinwilly

TPU Proxy Receiver (#10) credits to @whistlinwilly Fetch TPU proxy address on connection (#20) Previously TPU and TPU forward addresses were passed via CLI args, now the validator requests TPU addresses from the validator interface it connects to. removed submodule fixes

- Add support for bundles. - Add support for bundles through PoH. - Add account caching to account override - Add QoS and QoS rollback for bundles that fail to execute fully

- Add support for bundles. - Add support for bundles through PoH. - Add account caching to account override - Add QoS and QoS rollback for bundles that fail to execute fully - Add tips to validator

buffalu changed the title ~~Don't review~~ Bundles Apr 6, 2022