Only forward to p2p nodes that are in sync

src/ripple/app/reporting/ETLHelpers.h

@@ -43,7 +43,7 @@ class NetworkValidatedLedgers
 
     mutable std::mutex m_;
 
-    std::condition_variable cv_;
+    mutable std::condition_variable cv_;
 
     bool stopping_ = false;
 
@@ -64,13 +64,23 @@ public:
     /// @return sequence of most recently validated ledger. empty optional if
     /// the datastructure has been stopped
     std::optional<uint32_t>
-    getMostRecent()
+    getMostRecent() const
     {
         std::unique_lock lck(m_);
         cv_.wait(lck, [this]() { return max_ || stopping_; });
         return max_;
     }
 
+    /// Get most recently validated sequence.
+    /// @return sequence of most recently validated ledger, or empty optional
+    /// if no ledgers are known to have been validated.
+    std::optional<uint32_t>
+    tryGetMostRecent() const
+    {
+        std::unique_lock lk(m_);
+        return max_;
+    }
+
     /// Waits for the sequence to be validated by the network
     /// @param sequence to wait for
     /// @return true if sequence was validated, false otherwise

src/ripple/app/reporting/ETLSource.cpp

@@ -760,13 +760,24 @@ ETLLoadBalancer::forwardToP2p(RPC::JsonContext& context) const
     srand((unsigned)time(0));
     auto sourceIdx = rand() % sources_.size();
     auto numAttempts = 0;
+
+    auto mostRecent = etl_.getNetworkValidatedLedgers().tryGetMostRecent();
     while (numAttempts < sources_.size())
     {
-        res = sources_[sourceIdx]->forwardToP2p(context);
-        if (!res.isMember("forwarded") || res["forwarded"] != true)
-        {
+        auto increment = [&]() {
             sourceIdx = (sourceIdx + 1) % sources_.size();
             ++numAttempts;
+        };
+        auto& src = sources_[sourceIdx];
+        if (mostRecent && !src->hasLedger(*mostRecent))
+        {
+            increment();
+            continue;
+        }
+        res = src->forwardToP2p(context);
+        if (!res.isMember("forwarded") || res["forwarded"] != true)
+        {
+            increment();
             continue;
         }
         return res;