From b170ecc9903b9cb5076fb51862cd2120c3bf0eca Mon Sep 17 00:00:00 2001
From: CJ Cobb <ccobb@ripple.com>
Date: Wed, 9 Feb 2022 15:17:46 +0000
Subject: [PATCH] make sync interval for Cassandra configurable

---
 src/backend/CassandraBackend.cpp |  6 ++++
 src/backend/CassandraBackend.h   | 53 +++++++++++++++++++-------------
 2 files changed, 38 insertions(+), 21 deletions(-)

diff --git a/src/backend/CassandraBackend.cpp b/src/backend/CassandraBackend.cpp
index 00a0a4698..3112fe2a5 100644
--- a/src/backend/CassandraBackend.cpp
+++ b/src/backend/CassandraBackend.cpp
@@ -916,6 +916,12 @@ CassandraBackend::open(bool readOnly)
     if (getInt("max_requests_outstanding"))
         maxRequestsOutstanding = *getInt("max_requests_outstanding");
 
+    if (getInt("sync_interval"))
+        syncInterval_ = *getInt("sync_interval");
+    BOOST_LOG_TRIVIAL(info)
+        << __func__ << " sync interval is " << syncInterval_
+        << ". max requests outstanding is " << maxRequestsOutstanding;
+
     cass_cluster_set_request_timeout(cluster, 10000);
 
     rc = cass_cluster_set_queue_size_io(
diff --git a/src/backend/CassandraBackend.h b/src/backend/CassandraBackend.h
index cbbd6bae2..ad53074c7 100644
--- a/src/backend/CassandraBackend.h
+++ b/src/backend/CassandraBackend.h
@@ -609,6 +609,9 @@ private:
     CassandraPreparedStatement selectLatestLedger_;
     CassandraPreparedStatement selectLedgerRange_;
 
+    uint32_t syncInterval_ = 1;
+    uint32_t lastSync_ = 0;
+
     // maximum number of concurrent in flight requests. New requests will wait
     // for earlier requests to finish if this limit is exceeded
     std::uint32_t maxRequestsOutstanding = 10000;
@@ -691,30 +694,38 @@ public:
     bool
     doFinishWrites() const override
     {
-        // wait for all other writes to finish
-        sync();
-        // write range
-        if (!range)
+        if (!range || lastSync_ == 0 ||
+            ledgerSequence_ - syncInterval_ == lastSync_)
         {
+            // wait for all other writes to finish
+            sync();
+            // write range
+            if (!range)
+            {
+                CassandraStatement statement{updateLedgerRange_};
+                statement.bindNextInt(ledgerSequence_);
+                statement.bindNextBoolean(false);
+                statement.bindNextInt(ledgerSequence_);
+                executeSyncWrite(statement);
+            }
             CassandraStatement statement{updateLedgerRange_};
             statement.bindNextInt(ledgerSequence_);
-            statement.bindNextBoolean(false);
-            statement.bindNextInt(ledgerSequence_);
-            executeSyncWrite(statement);
+            statement.bindNextBoolean(true);
+            if (lastSync_ == 0)
+                statement.bindNextInt(ledgerSequence_ - 1);
+            else
+                statement.bindNextInt(lastSync_);
+            if (!executeSyncUpdate(statement))
+            {
+                BOOST_LOG_TRIVIAL(warning)
+                    << __func__ << " Update failed for ledger "
+                    << std::to_string(ledgerSequence_) << ". Returning";
+                return false;
+            }
+            BOOST_LOG_TRIVIAL(info) << __func__ << " Committed ledger "
+                                    << std::to_string(ledgerSequence_);
+            lastSync_ = ledgerSequence_;
         }
-        CassandraStatement statement{updateLedgerRange_};
-        statement.bindNextInt(ledgerSequence_);
-        statement.bindNextBoolean(true);
-        statement.bindNextInt(ledgerSequence_ - 1);
-        if (!executeSyncUpdate(statement))
-        {
-            BOOST_LOG_TRIVIAL(warning)
-                << __func__ << " Update failed for ledger "
-                << std::to_string(ledgerSequence_) << ". Returning";
-            return false;
-        }
-        BOOST_LOG_TRIVIAL(debug) << __func__ << " Committed ledger "
-                                 << std::to_string(ledgerSequence_);
         return true;
     }
     void
@@ -911,7 +922,7 @@ public:
             std::unique_lock<std::mutex> lck(throttleMutex_);
             if (!canAddRequest())
             {
-                BOOST_LOG_TRIVIAL(trace)
+                BOOST_LOG_TRIVIAL(info)
                     << __func__ << " : "
                     << "Max outstanding requests reached. "
                     << "Waiting for other requests to finish";