async write to keys and books with recovery and warnings

handlers/BookOffers.cpp

@@ -324,7 +324,7 @@ doBookOffers(
     }
 
     auto start = std::chrono::system_clock::now();
-    auto [offers, retCursor] =
+    auto [offers, retCursor, warning] =
         backend.fetchBookOffers(bookBase, *ledgerSequence, limit, cursor);
     auto end = std::chrono::system_clock::now();
 
@@ -361,6 +361,11 @@ doBookOffers(
                                << ((end - start).count() / 1000000000.0);
     if (retCursor)
         response["cursor"] = ripple::strHex(*retCursor);
+    if (warning)
+        response["warning"] =
+            "Periodic database update in progress. Data for this book as of "
+            "this ledger "
+            "may be incomplete. Data should be complete within one minute";
 
     return response;
 }

handlers/LedgerData.cpp

@@ -100,6 +100,16 @@ doLedgerData(
     response["num_results"] = results.size();
     response["db_time"] = time;
     response["time_per_result"] = time / (results.size() ? results.size() : 1);
+    if (page.warning)
+    {
+        response["warning"] =
+            "Periodic database update in progress. Data for this ledger may be "
+            "incomplete. Data should be complete "
+            "within a few minutes. Other RPC calls are not affected, "
+            "regardless of ledger. This "
+            "warning is only present on the first "
+            "page of the ledger";
+    }
     return response;
 }
 

reporting/BackendIndexer.cpp

@@ -49,7 +49,9 @@ BackendIndexer::clearCaches()
     booksCumulative = {};
 }
 void
-BackendIndexer::populateCaches(BackendInterface const& backend)
+BackendIndexer::populateCaches(
+    BackendInterface const& backend,
+    std::optional<uint32_t> sequence)
 {
     if (keysCumulative.size() > 0)
     {
@@ -57,16 +59,27 @@ BackendIndexer::populateCaches(BackendInterface const& backend)
             << __func__ << " caches already populated. returning";
         return;
     }
-    auto tip = backend.fetchLatestLedgerSequence();
+    if (!sequence)
-    if (!tip)
+        sequence = backend.fetchLatestLedgerSequence();
+    if (!sequence)
         return;
     std::optional<ripple::uint256> cursor;
     while (true)
     {
         try
         {
-            auto [objects, curCursor] =
+            auto [objects, curCursor, warning] =
-                backend.fetchLedgerPage(cursor, *tip, 2048);
+                backend.fetchLedgerPage(cursor, *sequence, 2048);
+            if (warning)
+            {
+                BOOST_LOG_TRIVIAL(warning)
+                    << __func__ << " performing index repair";
+                uint32_t lower = (*sequence - 1) >> shift_ << shift_;
+                populateCaches(backend, lower);
+                writeNext(lower, backend);
+                clearCaches();
+                continue;
+            }
             BOOST_LOG_TRIVIAL(debug) << __func__ << " fetched a page";
             cursor = curCursor;
             for (auto& obj : objects)
@@ -106,16 +119,23 @@ BackendIndexer::writeNext(
 
     if (isFlag)
     {
-        uint32_t nextSeq =
+        auto booksCopy = booksCumulative;
-            ((ledgerSequence >> shift_ << shift_) + (1 << shift_));
+        auto keysCopy = keysCumulative;
-        BOOST_LOG_TRIVIAL(info)
+        boost::asio::post(ioc_, [=, &backend]() {
-            << __func__ << " actually doing the write. keysCumulative.size() = "
+            uint32_t nextSeq =
-            << std::to_string(keysCumulative.size());
+                ((ledgerSequence >> shift_ << shift_) + (1 << shift_));
-        backend.writeKeys(keysCumulative, nextSeq);
+            ripple::uint256 zero = {};
-        BOOST_LOG_TRIVIAL(info) << __func__ << " wrote keys";
+            BOOST_LOG_TRIVIAL(info) << __func__ << " booksCumulative.size() = "
-
+                                    << std::to_string(booksCumulative.size());
-        backend.writeBooks(booksCumulative, nextSeq);
+            backend.writeBooks(booksCopy, nextSeq);
-        BOOST_LOG_TRIVIAL(info) << __func__ << " wrote books";
+            backend.writeBooks({{zero, {zero}}}, nextSeq);
+            BOOST_LOG_TRIVIAL(info) << __func__ << " wrote books";
+            BOOST_LOG_TRIVIAL(info) << __func__ << " keysCumulative.size() = "
+                                    << std::to_string(keysCumulative.size());
+            backend.writeKeys(keysCopy, nextSeq);
+            backend.writeKeys({zero}, nextSeq);
+            BOOST_LOG_TRIVIAL(info) << __func__ << " wrote keys";
+        });
     }
 }
 

reporting/BackendInterface.h

@@ -26,6 +26,13 @@ struct LedgerPage
 {
     std::vector<LedgerObject> objects;
     std::optional<ripple::uint256> cursor;
+    std::optional<std::string> warning;
+};
+struct BookOffersPage
+{
+    std::vector<LedgerObject> offers;
+    std::optional<ripple::uint256> cursor;
+    std::optional<std::string> warning;
 };
 struct TransactionAndMetadata
 {
@@ -74,7 +81,9 @@ public:
     ~BackendIndexer();
 
     void
-    populateCaches(BackendInterface const& backend);
+    populateCaches(
+        BackendInterface const& backend,
+        std::optional<uint32_t> sequence = {});
     void
     clearCaches();
 
@@ -160,7 +169,8 @@ public:
         std::uint32_t ledgerSequence,
         std::uint32_t limit) const = 0;
 
-    virtual std::pair<std::vector<LedgerObject>, std::optional<ripple::uint256>>
+    // TODO add warning for incomplete data
+    virtual BookOffersPage
     fetchBookOffers(
         ripple::uint256 const& book,
         uint32_t ledgerSequence,

reporting/CassandraBackend.cpp

@@ -530,6 +530,8 @@ CassandraBackend::fetchLedgerPage(
                 page.objects.push_back({std::move(key), std::move(obj)});
             }
         }
+        if (keys.size() && keys[0].isZero())
+            page.warning = "Data may be incomplete";
         return page;
     }
     return {{}, {}};
@@ -568,7 +570,7 @@ CassandraBackend::fetchLedgerObjects(
         << "Fetched " << numKeys << " records from Cassandra";
     return results;
 }
-std::pair<std::vector<LedgerObject>, std::optional<ripple::uint256>>
+BookOffersPage
 CassandraBackend::fetchBookOffers(
     ripple::uint256 const& book,
     uint32_t sequence,
@@ -613,8 +615,14 @@ CassandraBackend::fetchBookOffers(
             if (objs[i].size() != 0)
                 results.push_back({keys[i], objs[i]});
         }
-        if (keys.size())
+        std::optional<std::string> warning;
-            return {results, keys[keys.size() - 1]};
+        if (keys[0].isZero())
+            warning = "Data may be incomplete";
+        if (keys.size() == limit)
+            return {results, keys[keys.size() - 1], warning};
+        else
+            return {results, {}, warning};
+
         return {{}, {}};
     }
 

reporting/CassandraBackend.h

@@ -977,7 +977,7 @@ public:
             ripple::uint256,
             std::unordered_set<ripple::uint256>> const& books,
         uint32_t ledgerSequence) const override;
-    std::pair<std::vector<LedgerObject>, std::optional<ripple::uint256>>
+    BookOffersPage
     fetchBookOffers(
         ripple::uint256 const& book,
         uint32_t sequence,

reporting/PostgresBackend.cpp

@@ -338,7 +338,7 @@ PostgresBackend::fetchLedgerPage(
     sql << "SELECT key FROM keys WHERE ledger_seq = " << std::to_string(*index);
     if (cursor)
         sql << " AND key < \'\\x" << ripple::strHex(*cursor) << "\'";
-    sql << " ORDER BY key DESC LIMIT " << std::to_string(limit);
+    sql << " ORDER BY key ASC LIMIT " << std::to_string(limit);
     BOOST_LOG_TRIVIAL(debug) << __func__ << sql.str();
     auto res = pgQuery(sql.str().data());
     BOOST_LOG_TRIVIAL(debug) << __func__ << " fetched keys";
@@ -362,12 +362,14 @@ PostgresBackend::fetchLedgerPage(
                 results.push_back({keys[i], objs[i]});
             }
         }
+        if (keys[0].isZero())
+            return {results, returnCursor, "Data may be incomplete"};
         return {results, returnCursor};
     }
     return {};
 }
 
-std::pair<std::vector<LedgerObject>, std::optional<ripple::uint256>>
+BookOffersPage
 PostgresBackend::fetchBookOffers(
     ripple::uint256 const& book,
     uint32_t ledgerSequence,
@@ -392,6 +394,9 @@ PostgresBackend::fetchBookOffers(
         {
             keys.push_back(res.asUInt256(i, 0));
         }
+        std::optional<std::string> warning;
+        if (keys[0].isZero())
+            warning = "Data may be incomplete";
         std::vector<Blob> blobs = fetchLedgerObjects(keys, ledgerSequence);
 
         std::vector<LedgerObject> results;
@@ -409,10 +414,10 @@ PostgresBackend::fetchBookOffers(
             BOOST_LOG_TRIVIAL(debug)
                 << __func__ << " : " << ripple::strHex(results[0].key) << " : "
                 << ripple::strHex(results[results.size() - 1].key);
-            return {results, results[results.size() - 1].key};
+            return {results, results[results.size() - 1].key, warning};
         }
         else
-            return {results, {}};
+            return {results, {}, warning};
     }
     return {{}, {}};
 }

reporting/PostgresBackend.h

@@ -50,7 +50,7 @@ public:
         std::uint32_t ledgerSequence,
         std::uint32_t limit) const override;
 
-    std::pair<std::vector<LedgerObject>, std::optional<ripple::uint256>>
+    BookOffersPage
     fetchBookOffers(
         ripple::uint256 const& book,
         uint32_t ledgerSequence,