Introduce new experimental parallel ledger close flag

Author: marta-lokhova

src/ledger/LedgerManagerImpl.h

@@ -94,7 +94,8 @@ class LedgerManagerImpl : public LedgerManager
                  std::unique_ptr<LedgerCloseMetaFrame> const& ledgerCloseMeta,
                  uint32_t initialLedgerVers);
 
-    void storeCurrentLedger(LedgerHeader const& header, bool storeHeader, bool appendToCheckpoint);
+    void storeCurrentLedger(LedgerHeader const& header, bool storeHeader,
+                            bool appendToCheckpoint);
     static void
     prefetchTransactionData(AbstractLedgerTxnParent& rootLtx,
                             std::vector<TransactionFrameBasePtr> const& txs,

src/ledger/LedgerTxn.cpp

@@ -2597,6 +2597,11 @@ LedgerTxnRoot::Impl::addChild(AbstractLedgerTxn& child, TransactionMode mode)
 
     if (mode == TransactionMode::READ_WRITE_WITH_SQL_TXN)
     {
+        if (mApp.getConfig().EXPERIMENTAL_PARALLEL_LEDGER_CLOSE)
+        {
+            mSession =
+                std::make_unique<soci::session>(mApp.getDatabase().getPool());
+        }
         mTransaction =
             std::make_unique<soci::transaction>(getSession().session());
     }

src/main/Config.cpp

@@ -164,6 +164,7 @@ Config::Config() : NODE_SEED(SecretKey::random())
     CATCHUP_RECENT = 0;
     EXPERIMENTAL_PRECAUTION_DELAY_META = false;
     EXPERIMENTAL_BACKGROUND_OVERLAY_PROCESSING = false;
+    EXPERIMENTAL_PARALLEL_LEDGER_CLOSE = false;
     DEPRECATED_SQL_LEDGER_STATE = false;
     BUCKETLIST_DB_INDEX_PAGE_SIZE_EXPONENT = 14; // 2^14 == 16 kb
     BUCKETLIST_DB_INDEX_CUTOFF = 20;             // 20 mb
@@ -1071,6 +1072,10 @@ Config::processConfig(std::shared_ptr<cpptoml::table> t)
                      EXPERIMENTAL_BACKGROUND_OVERLAY_PROCESSING =
                          readBool(item);
                  }},
+                {"EXPERIMENTAL_PARALLEL_LEDGER_CLOSE",
+                 [&]() {
+                     EXPERIMENTAL_PARALLEL_LEDGER_CLOSE = readBool(item);
+                 }},
                 {"BACKGROUND_EVICTION_SCAN",
                  [&]() { BACKGROUND_EVICTION_SCAN = readBool(item); }},
                 // TODO: Flag is no longer supported, remove in next release.
@@ -1989,6 +1994,10 @@ Config::logBasicInfo()
              "EXPERIMENTAL_BACKGROUND_OVERLAY_PROCESSING="
              "{}",
              EXPERIMENTAL_BACKGROUND_OVERLAY_PROCESSING ? "true" : "false");
+    LOG_INFO(DEFAULT_LOG,
+             "EXPERIMENTAL_PARALLEL_LEDGER_CLOSE="
+             "{}",
+             EXPERIMENTAL_PARALLEL_LEDGER_CLOSE ? "true" : "false");
 }
 
 void

src/main/Config.h

@@ -409,6 +409,9 @@ class Config : public std::enable_shared_from_this<Config>
     // Enable parallel processing of overlay operations (experimental)
     bool EXPERIMENTAL_BACKGROUND_OVERLAY_PROCESSING;
 
+    // Enable parallel block application (experimental)
+    bool EXPERIMENTAL_PARALLEL_LEDGER_CLOSE;
+
     // When set to true, BucketListDB indexes are persisted on-disk so that the
     // BucketList does not need to be reindexed on startup. Defaults to true.
     // This should only be set to false for testing purposes

src/test/TxTests.cpp

@@ -591,17 +591,12 @@ closeLedgerOn(Application& app, uint32 ledgerSeq, time_t closeTime,
 {
     app.getHerder().externalizeValue(txSet, ledgerSeq, closeTime,
                                      emptyUpgradeSteps);
-<<<<<<< HEAD
-
-    auto& lm = static_cast<LedgerManagerImpl&>(app.getLedgerManager());
-    auto z1 = lm.mLatestTxResultSet;
-=======
     while (app.getLedgerManager().getLastClosedLedgerNum() != ledgerSeq)
     {
         app.getClock().crank(true);
     }
-    auto z1 = getTransactionHistoryResults(app.getDatabase(), ledgerSeq);
->>>>>>> a5c5de098 (Allow ledger close path to run async during externalize)
+    auto& lm = static_cast<LedgerManagerImpl&>(app.getLedgerManager());
+    auto z1 = lm.mLatestTxResultSet;
 
     REQUIRE(app.getLedgerManager().getLastClosedLedgerNum() == ledgerSeq);