impliment book offers for async etl

handlers/BookOffers.cpp

@@ -280,16 +280,16 @@ doBookOffers(
     }
 
     auto start = std::chrono::system_clock::now();
-    std::cout << "getting Book Offers" << std::endl;
+    auto [offers, retCursor, warning] =
-    auto [offers, retCursor] =
         backend.fetchBookOffers(bookBase, *ledgerSequence, limit, cursor);
-    std::cout << "got Book Offers" << std::endl;
-
     auto end = std::chrono::system_clock::now();
 
-    BOOST_LOG_TRIVIAL(warning) << "Time loading books from Postgres: "
+    BOOST_LOG_TRIVIAL(warning) << "Time loading books: "
                                << ((end - start).count() / 1000000000.0);
 
+    if(warning)
+        response["warning"] = *warning;
+
     response["offers"] = boost::json::value(boost::json::array_kind);
     boost::json::array& jsonOffers = response.at("offers").as_array();
 
@@ -324,6 +324,11 @@ 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

@@ -17,13 +17,23 @@ BackendIndexer::~BackendIndexer()
 void
 BackendIndexer::addKey(ripple::uint256 const& key)
 {
+    std::unique_lock lck(mtx);
     keys.insert(key);
     keysCumulative.insert(key);
 }
 void
+BackendIndexer::addKeyAsync(ripple::uint256 const& key)
+{
+    std::unique_lock lck(mtx);
+    keysCumulative.insert(key);
+}
+void
 BackendIndexer::deleteKey(ripple::uint256 const& key)
 {
+    std::unique_lock lck(mtx);
     keysCumulative.erase(key);
+    if (populatingCacheAsync)
+        deletedKeys.insert(key);
 }
 
 void
@@ -31,15 +41,87 @@ BackendIndexer::addBookOffer(
     ripple::uint256 const& book,
     ripple::uint256 const& offerKey)
 {
+    std::unique_lock lck(mtx);
     books[book].insert(offerKey);
     booksCumulative[book].insert(offerKey);
 }
 void
+BackendIndexer::addBookOfferAsync(
+    ripple::uint256 const& book,
+    ripple::uint256 const& offerKey)
+{
+    std::unique_lock lck(mtx);
+    booksCumulative[book].insert(offerKey);
+}
+void
 BackendIndexer::deleteBookOffer(
     ripple::uint256 const& book,
     ripple::uint256 const& offerKey)
 {
+    std::unique_lock lck(mtx);
     booksCumulative[book].erase(offerKey);
+    if (populatingCacheAsync)
+        deletedBooks[book].insert(offerKey);
+}
+
+void
+writeFlagLedger(
+    uint32_t ledgerSequence,
+    uint32_t shift,
+    BackendInterface const& backend,
+    std::unordered_set<ripple::uint256> const& keys,
+    std::unordered_map<
+        ripple::uint256,
+        std::unordered_set<ripple::uint256>> const& books)
+
+{
+    uint32_t nextFlag = ((ledgerSequence >> shift << shift) + (1 << shift));
+    ripple::uint256 zero = {};
+    BOOST_LOG_TRIVIAL(info)
+        << __func__
+        << " starting. ledgerSequence = " << std::to_string(ledgerSequence)
+        << " nextFlag = " << std::to_string(nextFlag)
+        << " keys.size() = " << std::to_string(keys.size())
+        << " books.size() = " << std::to_string(books.size());
+    while (true)
+    {
+        try
+        {
+            auto [objects, curCursor, warning] =
+                backend.fetchLedgerPage({}, nextFlag, 1);
+            if (!(warning || objects.size() == 0))
+            {
+                BOOST_LOG_TRIVIAL(warning)
+                    << __func__ << " flag ledger already written. sequence = "
+                    << std::to_string(ledgerSequence)
+                    << " next flag = " << std::to_string(nextFlag)
+                    << "returning";
+                return;
+            }
+            break;
+        }
+        catch (DatabaseTimeout& t)
+        {
+            ;
+        }
+    }
+    auto start = std::chrono::system_clock::now();
+    backend.writeBooks(books, nextFlag);
+    backend.writeBooks({{zero, {zero}}}, nextFlag);
+
+    BOOST_LOG_TRIVIAL(debug) << __func__ << " wrote books. writing keys ...";
+
+    backend.writeKeys(keys, nextFlag);
+    backend.writeKeys({zero}, nextFlag);
+    auto end = std::chrono::system_clock::now();
+    BOOST_LOG_TRIVIAL(info)
+        << __func__
+        << " finished. ledgerSequence = " << std::to_string(ledgerSequence)
+        << " nextFlag = " << std::to_string(nextFlag)
+        << " keys.size() = " << std::to_string(keys.size())
+        << " books.size() = " << std::to_string(books.size()) << " time = "
+        << std::chrono::duration_cast<std::chrono::seconds>(end - start)
+               .count();
 }
 
 void
@@ -48,34 +130,47 @@ BackendIndexer::clearCaches()
     keysCumulative = {};
     booksCumulative = {};
 }
+
 void
-BackendIndexer::populateCaches(BackendInterface const& backend)
+BackendIndexer::populateCaches(
+    BackendInterface const& backend,
+    std::optional<uint32_t> sequence)
 {
-    if (keysCumulative.size() > 0)
+    if (!sequence)
     {
-        BOOST_LOG_TRIVIAL(info)
+        auto rng = backend.fetchLedgerRangeNoThrow();
-            << __func__ << " caches already populated. returning";
+        if (!rng)
-        return;
+            return;
+        sequence = rng->maxSequence;
     }
-    auto tip = backend.fetchLatestLedgerSequence();
+    BOOST_LOG_TRIVIAL(info)
-    if (!tip)
+        << __func__ << " sequence = " << std::to_string(*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);
+                writeFlagLedger(
+                    lower, shift_, backend, keysCumulative, booksCumulative);
+                clearCaches();
+            }
             BOOST_LOG_TRIVIAL(debug) << __func__ << " fetched a page";
             cursor = curCursor;
             for (auto& obj : objects)
             {
-                keysCumulative.insert(obj.key);
+                addKeyAsync(obj.key);
                 if (isOffer(obj.blob))
                 {
                     auto book = getBook(obj.blob);
-                    booksCumulative[book].insert(obj.key);
+                    addBookOfferAsync(book, obj.key);
                 }
             }
             if (!cursor)
@@ -88,51 +183,113 @@ BackendIndexer::populateCaches(BackendInterface const& backend)
             std::this_thread::sleep_for(std::chrono::seconds(2));
         }
     }
+    // Do reconcilation. Remove anything from keys or books that shouldn't
+    // be there
+    {
+        std::unique_lock lck(mtx);
+        populatingCacheAsync = false;
+    }
+    auto tip = backend.fetchLatestLedgerSequence();
+    for (auto& key : deletedKeys)
+    {
+        deleteKey(key);
+    }
+    for (auto& book : deletedBooks)
+    {
+        for (auto& offer : book.second)
+        {
+            deleteBookOffer(book.first, offer);
+        }
+    }
+    {
+        std::unique_lock lck(mtx);
+        deletedKeys = {};
+        deletedBooks = {};
+        cv_.notify_one();
+    }
+    BOOST_LOG_TRIVIAL(info)
+        << __func__
+        << " finished. keys.size() = " << std::to_string(keysCumulative.size());
+}
+void
+BackendIndexer::populateCachesAsync(
+    BackendInterface const& backend,
+    std::optional<uint32_t> sequence)
+{
+    if (keysCumulative.size() > 0)
+    {
+        BOOST_LOG_TRIVIAL(info)
+            << __func__ << " caches already populated. returning";
+        return;
+    }
+    {
+        std::unique_lock lck(mtx);
+        populatingCacheAsync = true;
+    }
+    BOOST_LOG_TRIVIAL(info)
+        << __func__ << " seq = " << (sequence ? std::to_string(*sequence) : "");
+    boost::asio::post(ioc_, [this, sequence, &backend]() {
+        populateCaches(backend, sequence);
+    });
 }
 
 void
-BackendIndexer::writeNext(
+BackendIndexer::waitForCaches()
+{
+    std::unique_lock lck(mtx);
+    cv_.wait(lck, [this]() {
+        return !populatingCacheAsync && deletedKeys.size() == 0;
+    });
+}
+
+void
+BackendIndexer::writeFlagLedgerAsync(
     uint32_t ledgerSequence,
     BackendInterface const& backend)
 {
     BOOST_LOG_TRIVIAL(info)
         << __func__
         << " starting. sequence = " << std::to_string(ledgerSequence);
-    bool isFlag = (ledgerSequence % (1 << shift_)) == 0;
-    if (!backend.fetchLedgerRange())
-    {
-        isFlag = true;
-    }
 
-    if (isFlag)
+    waitForCaches();
-    {
+    auto booksCopy = booksCumulative;
-        uint32_t nextSeq =
+    auto keysCopy = keysCumulative;
-            ((ledgerSequence >> shift_ << shift_) + (1 << shift_));
+    boost::asio::post(ioc_, [=, this, &backend]() {
-        BOOST_LOG_TRIVIAL(info)
+        writeFlagLedger(ledgerSequence, shift_, backend, keysCopy, booksCopy);
-            << __func__ << " actually doing the write. keysCumulative.size() = "
+    });
-            << std::to_string(keysCumulative.size());
+    BOOST_LOG_TRIVIAL(info)
-        backend.writeKeys(keysCumulative, nextSeq);
+        << __func__
-        BOOST_LOG_TRIVIAL(info) << __func__ << " wrote keys";
+        << " finished. sequence = " << std::to_string(ledgerSequence);
-
-        backend.writeBooks(booksCumulative, nextSeq);
-        BOOST_LOG_TRIVIAL(info) << __func__ << " wrote books";
-    }
 }
 
 void
 BackendIndexer::finish(uint32_t ledgerSequence, BackendInterface const& backend)
 {
-    bool isFlag = ledgerSequence % (1 << shift_) == 0;
+    BOOST_LOG_TRIVIAL(info)
-    if (!backend.fetchLedgerRange())
+        << __func__
+        << " starting. sequence = " << std::to_string(ledgerSequence);
+    bool isFirst = false;
+    uint32_t index = getIndexOfSeq(ledgerSequence);
+    auto rng = backend.fetchLedgerRangeNoThrow();
+    if (!rng || rng->minSequence == ledgerSequence)
     {
-        isFlag = true;
+        isFirst = true;
+        index = ledgerSequence;
+    }
+    backend.writeKeys(keys, index);
+    backend.writeBooks(books, index);
+    if (isFirst)
+    {
+        ripple::uint256 zero = {};
+        backend.writeBooks({{zero, {zero}}}, ledgerSequence);
+        backend.writeKeys({zero}, ledgerSequence);
+        writeFlagLedgerAsync(ledgerSequence, backend);
     }
-    uint32_t nextSeq = ((ledgerSequence >> shift_ << shift_) + (1 << shift_));
-    uint32_t curSeq = isFlag ? ledgerSequence : nextSeq;
-    backend.writeKeys(keys, curSeq);
     keys = {};
-    backend.writeBooks(books, curSeq);
     books = {};
+    BOOST_LOG_TRIVIAL(info)
+        << __func__
+        << " finished. sequence = " << std::to_string(ledgerSequence);
 
 }  // namespace Backend
 }  // namespace Backend

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
 {
@@ -63,28 +70,51 @@ class BackendIndexer
     std::thread ioThread_;
     uint32_t shift_ = 16;
     std::unordered_set<ripple::uint256> keys;
-    std::unordered_map<ripple::uint256, std::unordered_set<ripple::uint256>>
-        books;
     std::unordered_set<ripple::uint256> keysCumulative;
+    std::unordered_map<ripple::uint256, std::unordered_set<ripple::uint256>>
+        books;
     std::unordered_map<ripple::uint256, std::unordered_set<ripple::uint256>>
         booksCumulative;
+    bool populatingCacheAsync = false;
+    // These are only used when the cache is being populated asynchronously
+    std::unordered_set<ripple::uint256> deletedKeys;
+    std::unordered_map<ripple::uint256, std::unordered_set<ripple::uint256>>
+        deletedBooks;
+    std::mutex mtx;
+    std::condition_variable cv_;
+
+    void
+    addKeyAsync(ripple::uint256 const& key);
+    void
+    addBookOfferAsync(
+        ripple::uint256 const& book,
+        ripple::uint256 const& offerKey);
 
 public:
     BackendIndexer(boost::json::object const& config);
     ~BackendIndexer();
 
     void
-    populateCaches(BackendInterface const& backend);
+    populateCachesAsync(
+        BackendInterface const& backend,
+        std::optional<uint32_t> sequence = {});
+    void
+    populateCaches(
+        BackendInterface const& backend,
+        std::optional<uint32_t> sequence = {});
     void
     clearCaches();
+    // Blocking, possibly for minutes
+    void
+    waitForCaches();
 
     void
     addKey(ripple::uint256 const& key);
     void
     deleteKey(ripple::uint256 const& key);
-
     void
     addBookOffer(ripple::uint256 const& book, ripple::uint256 const& offerKey);
+
     void
     deleteBookOffer(
         ripple::uint256 const& book,
@@ -93,12 +123,27 @@ public:
     void
     finish(uint32_t ledgerSequence, BackendInterface const& backend);
     void
-    writeNext(uint32_t ledgerSequence, BackendInterface const& backend);
+    writeFlagLedgerAsync(
+        uint32_t ledgerSequence,
+        BackendInterface const& backend);
     uint32_t
     getShift()
     {
         return shift_;
     }
+    uint32_t
+    getIndexOfSeq(uint32_t seq) const
+    {
+        if (isFlagLedger(seq))
+            return seq;
+        auto incr = (1 << shift_);
+        return (seq >> shift_ << shift_) + incr;
+    }
+    bool
+    isFlagLedger(uint32_t ledgerSequence) const
+    {
+        return (ledgerSequence % (1 << shift_)) == 0;
+    }
 };
 
 class BackendInterface
@@ -121,15 +166,27 @@ public:
     std::optional<uint32_t>
     getIndexOfSeq(uint32_t seq) const
     {
-        if (!fetchLedgerRange())
+        if (indexer_.isFlagLedger(seq))
+            return seq;
+        auto rng = fetchLedgerRange();
+        if (!rng)
             return {};
-        if (fetchLedgerRange()->minSequence == seq)
+        if (rng->minSequence == seq)
             return seq;
-        uint32_t shift = indexer_.getShift();
+        return indexer_.getIndexOfSeq(seq);
-        uint32_t incr = (1 << shift);
+    }
-        if ((seq % incr) == 0)
+
-            return seq;
+    bool
-        return (seq >> shift << shift) + incr;
+    finishWrites(uint32_t ledgerSequence) const
+    {
+        indexer_.finish(ledgerSequence, *this);
+        auto commitRes = doFinishWrites();
+        if (commitRes)
+        {
+            if (indexer_.isFlagLedger(ledgerSequence))
+                indexer_.writeFlagLedgerAsync(ledgerSequence, *this);
+        }
+        return commitRes;
     }
 
     virtual std::optional<uint32_t>
@@ -141,6 +198,22 @@ public:
     virtual std::optional<LedgerRange>
     fetchLedgerRange() const = 0;
 
+    std::optional<LedgerRange>
+    fetchLedgerRangeNoThrow() const
+    {
+        while (true)
+        {
+            try
+            {
+                return fetchLedgerRange();
+            }
+            catch (DatabaseTimeout& t)
+            {
+                ;
+            }
+        }
+    }
+
     virtual std::optional<Blob>
     fetchLedgerObject(ripple::uint256 const& key, uint32_t sequence) const = 0;
 
@@ -160,7 +233,8 @@ 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,
@@ -243,7 +317,8 @@ public:
     // other database methods
 
     // Open the database. Set up all of the necessary objects and
-    // datastructures. After this call completes, the database is ready for use.
+    // datastructures. After this call completes, the database is ready for
+    // use.
     virtual void
     open(bool readOnly) = 0;
 
@@ -254,13 +329,6 @@ public:
     virtual void
     startWrites() const = 0;
 
-    bool
-    finishWrites(uint32_t ledgerSequence) const
-    {
-        indexer_.finish(ledgerSequence, *this);
-        indexer_.writeNext(ledgerSequence, *this);
-        return doFinishWrites();
-    }
     virtual bool
     doFinishWrites() const = 0;
 

reporting/CassandraBackend.cpp

@@ -24,24 +24,27 @@ processAsyncWriteResponse(T& requestParams, CassFuture* fut, F func)
     auto rc = cass_future_error_code(fut);
     if (rc != CASS_OK)
     {
-        BOOST_LOG_TRIVIAL(error)
-            << "ERROR!!! Cassandra insert error: " << rc << ", "
-            << cass_error_desc(rc) << ", retrying ";
         // exponential backoff with a max wait of 2^10 ms (about 1 second)
         auto wait = std::chrono::milliseconds(
             lround(std::pow(2, std::min(10u, requestParams.currentRetries))));
+        BOOST_LOG_TRIVIAL(error)
+            << "ERROR!!! Cassandra ETL insert error: " << rc << ", "
+            << cass_error_desc(rc) << ", retrying in " << wait.count()
+            << " milliseconds";
         ++requestParams.currentRetries;
         std::shared_ptr<boost::asio::steady_timer> timer =
             std::make_shared<boost::asio::steady_timer>(
                 backend.getIOContext(),
                 std::chrono::steady_clock::now() + wait);
-        timer->async_wait([timer, &requestParams, &func](
+        timer->async_wait([timer, &requestParams, func](
                               const boost::system::error_code& error) {
             func(requestParams, true);
         });
     }
     else
     {
+        BOOST_LOG_TRIVIAL(trace)
+            << __func__ << " Succesfully inserted a record";
         backend.finishAsyncWrite();
         int remaining = --requestParams.refs;
         if (remaining == 0)
@@ -63,16 +66,6 @@ flatMapWriteCallback(CassFuture* fut, void* cbData)
     processAsyncWriteResponse(requestParams, fut, func);
 }
 
-// void
-// flatMapWriteBookCallback(CassFuture* fut, void* cbData)
-// {
-//     CassandraBackend::WriteCallbackData& requestParams =
-//         *static_cast<CassandraBackend::WriteCallbackData*>(cbData);
-//     auto func = [](auto& params, bool retry) {
-//         params.backend->writeBook(params, retry);
-//     };
-//     processAsyncWriteResponse(requestParams, fut, func);
-// }
 /*
 
 void
@@ -286,73 +279,6 @@ CassandraBackend::fetchAllTransactionHashesInLedger(
     return hashes;
 }
 
-LedgerPage
-CassandraBackend::fetchLedgerPage2(
-    std::optional<ripple::uint256> const& cursor,
-    std::uint32_t ledgerSequence,
-    std::uint32_t limit) const
-{
-    BOOST_LOG_TRIVIAL(trace) << __func__;
-    std::optional<ripple::uint256> currentCursor = cursor;
-    std::vector<LedgerObject> objects;
-    uint32_t curLimit = limit;
-    while (objects.size() < limit)
-    {
-        CassandraStatement statement{selectLedgerPage_};
-
-        int64_t intCursor = INT64_MIN;
-        if (currentCursor)
-        {
-            auto token = getToken(currentCursor->data());
-            if (token)
-                intCursor = *token;
-        }
-        BOOST_LOG_TRIVIAL(debug)
-            << __func__ << " - cursor = " << std::to_string(intCursor)
-            << " , sequence = " << std::to_string(ledgerSequence)
-            << ", - limit = " << std::to_string(limit);
-        statement.bindInt(intCursor);
-        statement.bindInt(ledgerSequence);
-        statement.bindUInt(curLimit);
-
-        CassandraResult result = executeSyncRead(statement);
-
-        if (!!result)
-        {
-            BOOST_LOG_TRIVIAL(debug)
-                << __func__ << " - got keys - size = " << result.numRows();
-
-            size_t prevSize = objects.size();
-            do
-            {
-                std::vector<unsigned char> object = result.getBytes();
-                if (object.size())
-                {
-                    objects.push_back({result.getUInt256(), std::move(object)});
-                }
-            } while (result.nextRow());
-            size_t prevBatchSize = objects.size() - prevSize;
-            BOOST_LOG_TRIVIAL(debug)
-                << __func__ << " - added to objects. size = " << objects.size();
-            if (result.numRows() < curLimit)
-            {
-                currentCursor = {};
-                break;
-            }
-            if (objects.size() < limit)
-            {
-                curLimit = 2048;
-            }
-            assert(objects.size());
-            currentCursor = objects[objects.size() - 1].key;
-        }
-    }
-    if (objects.size())
-        return {objects, currentCursor};
-
-    return {{}, {}};
-}
-
 struct ReadDiffCallbackData
 {
     CassandraBackend const& backend;
@@ -477,12 +403,12 @@ CassandraBackend::fetchLedgerPage(
     if (!index)
         return {};
     LedgerPage page;
-    if (cursor)
-        BOOST_LOG_TRIVIAL(debug)
-            << __func__ << " - Cursor = " << ripple::strHex(*cursor);
     BOOST_LOG_TRIVIAL(debug)
         << __func__ << " ledgerSequence = " << std::to_string(ledgerSequence)
         << " index = " << std::to_string(*index);
+    if (cursor)
+        BOOST_LOG_TRIVIAL(debug)
+            << __func__ << " - Cursor = " << ripple::strHex(*cursor);
     CassandraStatement statement{selectKeys_};
     statement.bindInt(*index);
     if (cursor)
@@ -494,10 +420,9 @@ CassandraBackend::fetchLedgerPage(
     }
     statement.bindUInt(limit);
     CassandraResult result = executeSyncRead(statement);
-    BOOST_LOG_TRIVIAL(debug) << __func__ << " Using base ledger. Got keys";
     if (!!result)
     {
-        BOOST_LOG_TRIVIAL(debug)
+        BOOST_LOG_TRIVIAL(trace)
             << __func__ << " - got keys - size = " << result.numRows();
         std::vector<ripple::uint256> keys;
 
@@ -505,17 +430,14 @@ CassandraBackend::fetchLedgerPage(
         {
             keys.push_back(result.getUInt256());
         } while (result.nextRow());
-        BOOST_LOG_TRIVIAL(debug) << __func__ << " Using base ledger. Read keys";
         auto objects = fetchLedgerObjects(keys, ledgerSequence);
-        BOOST_LOG_TRIVIAL(debug)
-            << __func__ << " Using base ledger. Got objects";
         if (objects.size() != keys.size())
             throw std::runtime_error("Mismatch in size of objects and keys");
         if (keys.size() == limit)
             page.cursor = keys[keys.size() - 1];
 
         if (cursor)
-            BOOST_LOG_TRIVIAL(debug)
+            BOOST_LOG_TRIVIAL(trace)
                 << __func__ << " Cursor = " << ripple::strHex(*page.cursor);
 
         for (size_t i = 0; i < objects.size(); ++i)
@@ -527,6 +449,8 @@ CassandraBackend::fetchLedgerPage(
                 page.objects.push_back({std::move(key), std::move(obj)});
             }
         }
+        if (keys.size() && !cursor && !keys[0].isZero())
+            page.warning = "Data may be incomplete";
         return page;
     }
     return {{}, {}};
@@ -565,39 +489,39 @@ 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,
     std::uint32_t limit,
     std::optional<ripple::uint256> const& cursor) const
 {
-    CassandraStatement statement{selectBook_};
-
     auto rng = fetchLedgerRange();
     
     if(!rng)
         return {{},{}};
 
-    std::vector<ripple::uint256> keys;
     uint32_t upper = sequence;
     auto lastPage = rng->maxSequence - (rng->maxSequence % 256);
 
-    if (sequence != rng->minSequence)
+    auto readBooks = [this](
+            ripple::uint256 const& book, 
+            std::uint32_t seq,
+            std::optional<ripple::uint256> const& cursor) 
+            -> std::vector<std::pair<std::uint64_t, ripple::uint256>>
     {
-        upper = (sequence >> 8) << 8;
+        CassandraStatement statement{this->selectBook_};
-        if (upper != sequence)
+        std::vector<std::pair<std::uint64_t, ripple::uint256>> keys = {};
-            upper += (1 << 8);
     
         statement.bindBytes(book.data(), 24);
-        statement.bindInt(upper);
+        statement.bindInt(seq);
 
-        BOOST_LOG_TRIVIAL(info) << __func__ << " upper = " << std::to_string(upper)
+        BOOST_LOG_TRIVIAL(info) << __func__ << " upper = " << std::to_string(seq)
                                 << " book = " << ripple::strHex(std::string((char*)book.data(), 24));
 
         if (cursor)
         {
-            auto object = fetchLedgerObject(*cursor, sequence);
+            auto object = this->fetchLedgerObject(*cursor, seq);
 
             if(!object)
                 return {{}, {}};
@@ -617,7 +541,7 @@ CassandraBackend::fetchBookOffers(
         }
 
         // statement.bindUInt(limit);
-        CassandraResult result = executeSyncRead(statement);
+        CassandraResult result = this->executeSyncRead(statement);
 
         BOOST_LOG_TRIVIAL(debug) << __func__ << " - got keys";
         if (!result)
@@ -628,32 +552,72 @@ CassandraBackend::fetchBookOffers(
 
         do
         {
-            auto index = result.getBytesTuple().second;
+            auto [quality, index] = result.getBytesTuple();
-            keys.push_back(ripple::uint256::fromVoid(index.data()));
+            std::uint64_t q = 0;
+            memcpy(&q, quality.data(), 8);
+            keys.push_back({q, ripple::uint256::fromVoid(index.data())});
+
         } while (result.nextRow());
+
+        return keys;
+    };
+
+    std::vector<std::pair<std::uint64_t, ripple::uint256>> quality_keys;
+    if (sequence != rng->minSequence)
+    {
+        upper = (sequence >> 8) << 8;
+        if (upper != sequence)
+            upper += (1 << 8);
+
+        quality_keys = readBooks(book, upper, cursor);
     }
 
     BOOST_LOG_TRIVIAL(debug)
-        << __func__ << " - populated keys. num keys = " << keys.size();
+        << __func__ << " - populated keys. num keys = " << quality_keys.size();
 
-    std::cout << keys.size() << std::endl;
+    std::cout << "KEYS SIZE: " << quality_keys.size() << std::endl;
-    if (!keys.size())
+    if (!quality_keys.size())
         return {{}, {}};
 
+    std::optional<std::string> warning = {};
+    if (quality_keys[0].second.isZero())
+    {
+        warning = "Data may be incomplete";
+
+        std::uint32_t lower = (sequence >> 8) << 8;
+        auto originalKeys = std::move(quality_keys);
+        auto otherKeys = readBooks(book, lower, cursor);
+        quality_keys.reserve(originalKeys.size() + otherKeys.size());
+
+        std::merge(originalKeys.begin(), originalKeys.end(),
+                          otherKeys.begin(), otherKeys.end(),
+                          std::back_inserter(quality_keys),
+                          [](auto pair1, auto pair2) 
+                          {
+                              return pair1.first < pair2.first;
+                          });
+    }
+
+    std::vector<ripple::uint256> keys(quality_keys.size());
+    std::transform(quality_keys.begin(), quality_keys.end(),
+                   std::back_inserter(keys),
+                   [](auto pair) { return pair.second; });
+
     std::vector<LedgerObject> results;
     std::vector<Blob> objs = fetchLedgerObjects(keys, sequence);
+
     for (size_t i = 0; i < objs.size(); ++i)
     {
         if (objs[i].size() != 0)
         {
             if (results.size() == limit)
-                return {results, keys[i]}; 
+                return {results, keys[i], warning}; 
 
             results.push_back({keys[i], objs[i]});
         }
     }
 
-    return {results, {}}; 
+    return {results, {}, warning}; 
 }
 struct WriteBookCallbackData
 {
@@ -662,7 +626,7 @@ struct WriteBookCallbackData
     ripple::uint256 offerKey;
     uint32_t ledgerSequence;
     std::condition_variable& cv;
-    std::atomic_uint32_t& numRemaining;
+    std::atomic_uint32_t& numOutstanding;
     std::mutex& mtx;
     uint32_t currentRetries = 0;
     WriteBookCallbackData(
@@ -672,14 +636,14 @@ struct WriteBookCallbackData
         uint32_t ledgerSequence,
         std::condition_variable& cv,
         std::mutex& mtx,
-        std::atomic_uint32_t& numRemaining)
+        std::atomic_uint32_t& numOutstanding)
         : backend(backend)
         , book(book)
         , offerKey(offerKey)
         , ledgerSequence(ledgerSequence)
         , cv(cv)
         , mtx(mtx)
-        , numRemaining(numRemaining)
+        , numOutstanding(numOutstanding)
 
     {
     }
@@ -687,7 +651,7 @@ struct WriteBookCallbackData
 void
 writeBookCallback(CassFuture* fut, void* cbData);
 void
-writeBook2(WriteBookCallbackData& cb)
+writeBook(WriteBookCallbackData& cb)
 {
     CassandraStatement statement{cb.backend.getInsertBookPreparedStatement()};
     statement.bindBytes(cb.book.data(), 24);
@@ -707,12 +671,13 @@ writeBookCallback(CassFuture* fut, void* cbData)
     auto rc = cass_future_error_code(fut);
     if (rc != CASS_OK)
     {
-        BOOST_LOG_TRIVIAL(error)
-            << "ERROR!!! Cassandra insert key error: " << rc << ", "
-            << cass_error_desc(rc) << ", retrying ";
         // exponential backoff with a max wait of 2^10 ms (about 1 second)
         auto wait = std::chrono::milliseconds(
             lround(std::pow(2, std::min(10u, requestParams.currentRetries))));
+        BOOST_LOG_TRIVIAL(error)
+            << "ERROR!!! Cassandra insert book error: " << rc << ", "
+            << cass_error_desc(rc) << ", retrying in " << wait.count()
+            << " milliseconds";
         ++requestParams.currentRetries;
         std::shared_ptr<boost::asio::steady_timer> timer =
             std::make_shared<boost::asio::steady_timer>(
@@ -720,15 +685,15 @@ writeBookCallback(CassFuture* fut, void* cbData)
                 std::chrono::steady_clock::now() + wait);
         timer->async_wait(
             [timer, &requestParams](const boost::system::error_code& error) {
-                writeBook2(requestParams);
+                writeBook(requestParams);
             });
     }
     else
     {
-        BOOST_LOG_TRIVIAL(trace) << __func__ << "Finished a write request";
+        BOOST_LOG_TRIVIAL(trace) << __func__ << " Successfully inserted a book";
         {
             std::lock_guard lck(requestParams.mtx);
-            --requestParams.numRemaining;
+            --requestParams.numOutstanding;
             requestParams.cv.notify_one();
         }
     }
@@ -781,12 +746,13 @@ writeKeyCallback(CassFuture* fut, void* cbData)
     auto rc = cass_future_error_code(fut);
     if (rc != CASS_OK)
     {
-        BOOST_LOG_TRIVIAL(error)
-            << "ERROR!!! Cassandra insert key error: " << rc << ", "
-            << cass_error_desc(rc) << ", retrying ";
-        // exponential backoff with a max wait of 2^10 ms (about 1 second)
         auto wait = std::chrono::milliseconds(
             lround(std::pow(2, std::min(10u, requestParams.currentRetries))));
+        BOOST_LOG_TRIVIAL(error)
+            << "ERROR!!! Cassandra insert key error: " << rc << ", "
+            << cass_error_desc(rc) << ", retrying in " << wait.count()
+            << " milliseconds";
+        // exponential backoff with a max wait of 2^10 ms (about 1 second)
         ++requestParams.currentRetries;
         std::shared_ptr<boost::asio::steady_timer> timer =
             std::make_shared<boost::asio::steady_timer>(
@@ -799,7 +765,7 @@ writeKeyCallback(CassFuture* fut, void* cbData)
     }
     else
     {
-        BOOST_LOG_TRIVIAL(trace) << __func__ << "Finished a write request";
+        BOOST_LOG_TRIVIAL(trace) << __func__ << " Successfully inserted a key";
         {
             std::lock_guard lck(requestParams.mtx);
             --requestParams.numRemaining;
@@ -815,13 +781,15 @@ CassandraBackend::writeKeys(
 {
     BOOST_LOG_TRIVIAL(info)
         << __func__ << " Ledger = " << std::to_string(ledgerSequence)
-        << " . num keys = " << std::to_string(keys.size());
+        << " . num keys = " << std::to_string(keys.size())
+        << " . concurrentLimit = "
+        << std::to_string(indexerMaxRequestsOutstanding);
     std::atomic_uint32_t numRemaining = keys.size();
     std::condition_variable cv;
     std::mutex mtx;
     std::vector<std::shared_ptr<WriteKeyCallbackData>> cbs;
     cbs.reserve(keys.size());
-    uint32_t concurrentLimit = maxRequestsOutstanding;
+    uint32_t concurrentLimit = indexerMaxRequestsOutstanding;
     uint32_t numSubmitted = 0;
     for (auto& key : keys)
     {
@@ -868,7 +836,7 @@ CassandraBackend::writeBooks(
     std::condition_variable cv;
     std::mutex mtx;
     std::vector<std::shared_ptr<WriteBookCallbackData>> cbs;
-    uint32_t concurrentLimit = maxRequestsOutstanding / 2;
+    uint32_t concurrentLimit = indexerMaxRequestsOutstanding;
     std::atomic_uint32_t numOutstanding = 0;
     size_t count = 0;
     auto start = std::chrono::system_clock::now();
@@ -886,7 +854,7 @@ CassandraBackend::writeBooks(
                 cv,
                 mtx,
                 numOutstanding));
-            writeBook2(*cbs.back());
+            writeBook(*cbs.back());
             BOOST_LOG_TRIVIAL(trace) << __func__ << "Submitted a write request";
             std::unique_lock<std::mutex> lck(mtx);
             BOOST_LOG_TRIVIAL(trace) << __func__ << "Got the mutex";
@@ -1416,14 +1384,14 @@ CassandraBackend::open(bool readOnly)
             continue;
 
         query.str("");
-        query << "CREATE TABLE IF NOT EXISTS " << tablePrefix << "books2"
+        query << "CREATE TABLE IF NOT EXISTS " << tablePrefix << "books"
               << " ( book blob, sequence bigint, quality_key tuple<blob, blob>, PRIMARY KEY "
                  "((book, sequence), quality_key)) WITH CLUSTERING ORDER BY (quality_key "
                  "ASC)";
         if (!executeSimpleStatement(query.str()))
             continue;
         query.str("");
-        query << "SELECT * FROM " << tablePrefix << "books2"
+        query << "SELECT * FROM " << tablePrefix << "books"
               << " LIMIT 1";
         if (!executeSimpleStatement(query.str()))
             continue;
@@ -1508,7 +1476,7 @@ CassandraBackend::open(bool readOnly)
             continue;
 
         query.str("");
-        query << "INSERT INTO " << tablePrefix << "books2"
+        query << "INSERT INTO " << tablePrefix << "books"
               << " (book, sequence, quality_key) VALUES (?, ?, (?, ?))";
         if (!insertBook2_.prepareStatement(query, session_.get()))
             continue;
@@ -1516,7 +1484,7 @@ CassandraBackend::open(bool readOnly)
 
         query.str("");
         query << "SELECT key FROM " << tablePrefix << "keys"
-              << " WHERE sequence = ? AND key > ? ORDER BY key ASC LIMIT ?";
+              << " WHERE sequence = ? AND key >= ? ORDER BY key ASC LIMIT ?";
         if (!selectKeys_.prepareStatement(query, session_.get()))
             continue;
 
@@ -1583,7 +1551,7 @@ CassandraBackend::open(bool readOnly)
             continue;
 
         query.str("");
-        query << "SELECT quality_key FROM " << tablePrefix << "books2 "
+        query << "SELECT quality_key FROM " << tablePrefix << "books "
               << " WHERE book = ? AND sequence = ?"
               << " AND quality_key >= (?, ?)"
                  " ORDER BY quality_key ASC";
@@ -1690,6 +1658,11 @@ CassandraBackend::open(bool readOnly)
     {
         maxRequestsOutstanding = config_["max_requests_outstanding"].as_int64();
     }
+    if (config_.contains("indexer_max_requests_outstanding"))
+    {
+        indexerMaxRequestsOutstanding =
+            config_["indexer_max_requests_outstanding"].as_int64();
+    }
     /*
     if (config_.contains("run_indexer"))
     {

reporting/CassandraBackend.h

@@ -662,6 +662,9 @@ private:
     // maximum number of concurrent in flight requests. New requests will wait
     // for earlier requests to finish if this limit is exceeded
     uint32_t maxRequestsOutstanding = 10000;
+    // we keep this small because the indexer runs in the background, and we
+    // don't want the database to be swamped when the indexer is running
+    uint32_t indexerMaxRequestsOutstanding = 10;
     mutable std::atomic_uint32_t numRequestsOutstanding_ = 0;
 
     // mutex and condition_variable to limit the number of concurrent in flight
@@ -826,6 +829,14 @@ public:
     {
         // wait for all other writes to finish
         sync();
+        auto rng = fetchLedgerRangeNoThrow();
+        if (rng && rng->maxSequence >= ledgerSequence_)
+        {
+            BOOST_LOG_TRIVIAL(warning)
+                << __func__ << " Ledger " << std::to_string(ledgerSequence_)
+                << " already written. Returning";
+            return false;
+        }
         // write range
         if (isFirstLedger_)
         {
@@ -839,7 +850,16 @@ public:
         statement.bindInt(ledgerSequence_);
         statement.bindBoolean(true);
         statement.bindInt(ledgerSequence_ - 1);
-        return executeSyncUpdate(statement);
+        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
     writeLedger(
@@ -973,11 +993,6 @@ public:
         return {{result.getBytes(), result.getBytes(), result.getUInt32()}};
     }
     LedgerPage
-    fetchLedgerPage2(
-        std::optional<ripple::uint256> const& cursor,
-        std::uint32_t ledgerSequence,
-        std::uint32_t limit) const;
-    LedgerPage
     fetchLedgerPage(
         std::optional<ripple::uint256> const& cursor,
         std::uint32_t ledgerSequence,
@@ -1005,58 +1020,13 @@ 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,
         std::uint32_t limit,
         std::optional<ripple::uint256> const& cursor) const override;
 
-    std::pair<std::vector<LedgerObject>, std::optional<ripple::uint256>>
-    fetchBookOffers2(
-        ripple::uint256 const& book,
-        uint32_t sequence,
-        std::uint32_t limit,
-        std::optional<ripple::uint256> const& cursor) const
-    {
-        CassandraStatement statement{getBook_};
-        statement.bindBytes(book);
-        statement.bindInt(sequence);
-        statement.bindInt(sequence);
-        if (cursor)
-            statement.bindBytes(*cursor);
-        else
-        {
-            ripple::uint256 zero = {};
-            statement.bindBytes(zero);
-        }
-        statement.bindUInt(limit);
-        CassandraResult result = executeSyncRead(statement);
-
-        BOOST_LOG_TRIVIAL(debug) << __func__ << " - got keys";
-        std::vector<ripple::uint256> keys;
-        if (!result)
-            return {{}, {}};
-        do
-        {
-            keys.push_back(result.getUInt256());
-        } while (result.nextRow());
-
-        BOOST_LOG_TRIVIAL(debug)
-            << __func__ << " - populated keys. num keys = " << keys.size();
-        if (keys.size())
-        {
-            std::vector<LedgerObject> results;
-            std::vector<Blob> objs = fetchLedgerObjects(keys, sequence);
-            for (size_t i = 0; i < objs.size(); ++i)
-            {
-                results.push_back({keys[i], objs[i]});
-            }
-            return {results, results[results.size() - 1].key};
-        }
-
-        return {{}, {}};
-    }
     bool
     canFetchBatch()
     {
@@ -1213,18 +1183,29 @@ public:
         {
         }
     };
+
     struct WriteAccountTxCallbackData
     {
         CassandraBackend const* backend;
-        AccountTransactionsData data;
+        ripple::AccountID account;
+        uint32_t ledgerSequence;
+        uint32_t transactionIndex;
+        ripple::uint256 txHash;
 
         uint32_t currentRetries = 0;
-        std::atomic<int> refs;
+        std::atomic<int> refs = 1;
 
         WriteAccountTxCallbackData(
             CassandraBackend const* f,
-            AccountTransactionsData&& in)
+            ripple::AccountID&& account,
-            : backend(f), data(std::move(in)), refs(data.accounts.size())
+            uint32_t lgrSeq,
+            uint32_t txIdx,
+            ripple::uint256&& hash)
+            : backend(f)
+            , account(std::move(account))
+            , ledgerSequence(lgrSeq)
+            , transactionIndex(txIdx)
+            , txHash(std::move(hash))
         {
         }
     };
@@ -1242,55 +1223,6 @@ public:
         }
     }
 
-    /*
-    void
-    writeDeletedKey(WriteCallbackData& data, bool isRetry) const
-    {
-        CassandraStatement statement{insertKey_};
-        statement.bindBytes(data.key);
-        statement.bindInt(data.createdSequence);
-        statement.bindInt(data.sequence);
-        executeAsyncWrite(statement, flatMapWriteKeyCallback, data, isRetry);
-    }
-
-    void
-    writeKey(WriteCallbackData& data, bool isRetry) const
-    {
-        if (data.isCreated)
-        {
-            CassandraStatement statement{insertKey_};
-            statement.bindBytes(data.key);
-            statement.bindInt(data.sequence);
-            statement.bindInt(INT64_MAX);
-
-            executeAsyncWrite(
-                statement, flatMapWriteKeyCallback, data, isRetry);
-        }
-        else if (data.isDeleted)
-        {
-            CassandraStatement statement{getCreated_};
-
-            executeAsyncWrite(
-                statement, flatMapGetCreatedCallback, data, isRetry);
-        }
-    }
-    */
-
-    // void
-    // writeBook(WriteCallbackData& data, bool isRetry) const
-    // {
-    //     assert(data.isCreated or data.isDeleted);
-    //     assert(data.book);
-    //     CassandraStatement statement{
-    //         (data.isCreated ? insertBook_ : deleteBook_)};
-    //     statement.bindBytes(*data.book);
-    //     statement.bindBytes(data.key);
-    //     statement.bindInt(data.sequence);
-    //     if (data.isCreated)
-    //         statement.bindInt(INT64_MAX);
-    //     executeAsyncWrite(statement, flatMapWriteBookCallback, data, isRetry);
-    // }
-
     void
     doWriteLedgerObject(
         std::string&& key,
@@ -1320,26 +1252,30 @@ public:
     {
         for (auto& record : data)
         {
-            WriteAccountTxCallbackData* cbData =
+            for (auto& account : record.accounts)
-                new WriteAccountTxCallbackData(this, std::move(record));
+            {
-            writeAccountTx(*cbData, false);
+                WriteAccountTxCallbackData* cbData =
+                    new WriteAccountTxCallbackData(
+                        this,
+                        std::move(account),
+                        record.ledgerSequence,
+                        record.transactionIndex,
+                        std::move(record.txHash));
+                writeAccountTx(*cbData, false);
+            }
         }
     }
 
     void
     writeAccountTx(WriteAccountTxCallbackData& data, bool isRetry) const
     {
-        for (auto const& account : data.data.accounts)
+        CassandraStatement statement(insertAccountTx_);
-        {
+        statement.bindBytes(data.account);
-            CassandraStatement statement(insertAccountTx_);
+        statement.bindIntTuple(data.ledgerSequence, data.transactionIndex);
-            statement.bindBytes(account);
+        statement.bindBytes(data.txHash);
-            statement.bindIntTuple(
-                data.data.ledgerSequence, data.data.transactionIndex);
-            statement.bindBytes(data.data.txHash);
 
-            executeAsyncWrite(
+        executeAsyncWrite(
-                statement, flatMapWriteAccountTxCallback, data, isRetry);
+            statement, flatMapWriteAccountTxCallback, data, isRetry);
-        }
     }
 
     struct WriteTransactionCallbackData
@@ -1562,6 +1498,7 @@ public:
     bool
     executeSyncUpdate(CassandraStatement const& statement) const
     {
+        bool timedOut = false;
         CassFuture* fut;
         CassError rc;
         do
@@ -1570,8 +1507,9 @@ public:
             rc = cass_future_error_code(fut);
             if (rc != CASS_OK)
             {
+                timedOut = true;
                 std::stringstream ss;
-                ss << "Cassandra sync write error";
+                ss << "Cassandra sync update error";
                 ss << ", retrying";
                 ss << ": " << cass_error_desc(rc);
                 BOOST_LOG_TRIVIAL(warning) << ss.str();
@@ -1599,7 +1537,15 @@ public:
             return false;
         }
         cass_result_free(res);
-        return success == cass_true;
+        if (success != cass_true && timedOut)
+        {
+            BOOST_LOG_TRIVIAL(warning)
+                << __func__ << " Update failed, but timedOut is true";
+        }
+        // if there was a timeout, the update may have succeeded in the
+        // background. We can't differentiate between an async success and
+        // another writer, so we just return true here
+        return success == cass_true || timedOut;
     }
 
     CassandraResult

reporting/ETLHelpers.h

@@ -156,6 +156,20 @@ public:
             cv_.notify_all();
         return ret;
     }
+    /// @return element popped from queue. Will block until queue is non-empty
+    std::optional<T>
+    tryPop()
+    {
+        std::unique_lock lck(m_);
+        if (queue_.empty())
+            return {};
+        T ret = std::move(queue_.front());
+        queue_.pop();
+        // if queue has a max size, unblock any possible pushers
+        if (maxSize_)
+            cv_.notify_all();
+        return ret;
+    }
 };
 
 /// Parititions the uint256 keyspace into numMarkers partitions, each of equal

reporting/Pg.cpp

@@ -250,6 +250,7 @@ Pg::bulkInsert(char const* table, std::string const& records)
            << ". Postgres insert error: " << res.msg();
         if (res)
             ss << ". Query status not PGRES_COPY_IN: " << res.status();
+        BOOST_LOG_TRIVIAL(error) << __func__ << " " << records;
         throw std::runtime_error(ss.str());
     }
 
@@ -259,6 +260,7 @@ Pg::bulkInsert(char const* table, std::string const& records)
         ss << "bulkInsert to " << table
            << ". PQputCopyData error: " << PQerrorMessage(conn_.get());
         disconnect();
+        BOOST_LOG_TRIVIAL(error) << __func__ << " " << records;
         throw std::runtime_error(ss.str());
     }
 
@@ -268,6 +270,7 @@ Pg::bulkInsert(char const* table, std::string const& records)
         ss << "bulkInsert to " << table
            << ". PQputCopyEnd error: " << PQerrorMessage(conn_.get());
         disconnect();
+        BOOST_LOG_TRIVIAL(error) << __func__ << " " << records;
         throw std::runtime_error(ss.str());
     }
 
@@ -282,7 +285,7 @@ Pg::bulkInsert(char const* table, std::string const& records)
         ss << "bulkInsert to " << table
            << ". PQputCopyEnd status not PGRES_COMMAND_OK: " << status;
         disconnect();
-        BOOST_LOG_TRIVIAL(debug) << __func__ << " " << records;
+        BOOST_LOG_TRIVIAL(error) << __func__ << " " << records;
         throw std::runtime_error(ss.str());
     }
 }

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 (!cursor && !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,

reporting/ReportingETL.cpp

@@ -89,8 +89,8 @@ std::optional<ripple::LedgerInfo>
 ReportingETL::loadInitialLedger(uint32_t startingSequence)
 {
     // check that database is actually empty
-    auto ledger = flatMapBackend_->fetchLedgerBySequence(startingSequence);
+    auto rng = flatMapBackend_->fetchLedgerRangeNoThrow();
-    if (ledger)
+    if (rng)
     {
         BOOST_LOG_TRIVIAL(fatal) << __func__ << " : "
                                  << "Database is not empty";
@@ -156,7 +156,7 @@ ReportingETL::publishLedger(uint32_t ledgerSequence, uint32_t maxAttempts)
     {
         try
         {
-            auto range = flatMapBackend_->fetchLedgerRange();
+            auto range = flatMapBackend_->fetchLedgerRangeNoThrow();
 
             if (!range || range->maxSequence < ledgerSequence)
             {
@@ -327,7 +327,7 @@ ReportingETL::buildNextLedger(org::xrpl::rpc::v1::GetLedgerResponse& rawData)
 std::optional<uint32_t>
 ReportingETL::runETLPipeline(uint32_t startSequence, int numExtractors)
 {
-    if (startSequence > finishSequence_)
+    if (finishSequence_ && startSequence > *finishSequence_)
         return {};
     /*
      * Behold, mortals! This function spawns three separate threads, which talk
@@ -355,15 +355,16 @@ ReportingETL::runETLPipeline(uint32_t startSequence, int numExtractors)
                              << "Starting etl pipeline";
     writing_ = true;
 
-    auto parent = flatMapBackend_->fetchLedgerBySequence(startSequence - 1);
+    auto rng = flatMapBackend_->fetchLedgerRangeNoThrow();
-    if (!parent)
+    if (!rng || rng->maxSequence != startSequence - 1)
     {
         assert(false);
         throw std::runtime_error("runETLPipeline: parent ledger is null");
     }
     BOOST_LOG_TRIVIAL(info) << __func__ << " : "
                             << "Populating caches";
-    flatMapBackend_->getIndexer().populateCaches(*flatMapBackend_);
+
+    flatMapBackend_->getIndexer().populateCachesAsync(*flatMapBackend_);
     BOOST_LOG_TRIVIAL(info) << __func__ << " : "
                             << "Populated caches";
 
@@ -380,19 +381,19 @@ ReportingETL::runETLPipeline(uint32_t startSequence, int numExtractors)
         std::cout << std::to_string((sequence - startSequence) % numExtractors);
         return queues[(sequence - startSequence) % numExtractors];
     };
-    std::vector<std::thread> threads;
+    std::vector<std::thread> extractors;
     for (size_t i = 0; i < numExtractors; ++i)
     {
         auto transformQueue = std::make_shared<QueueType>(maxQueueSize);
         queues.push_back(transformQueue);
         std::cout << "added to queues";
 
-        threads.emplace_back([this,
+        extractors.emplace_back([this,
-                              &startSequence,
+                                 &startSequence,
-                              &writeConflict,
+                                 &writeConflict,
-                              transformQueue,
+                                 transformQueue,
-                              i,
+                                 i,
-                              numExtractors]() {
+                                 numExtractors]() {
             beast::setCurrentThreadName("rippled: ReportingETL extract");
             uint32_t currentSequence = startSequence + i;
 
@@ -403,7 +404,7 @@ ReportingETL::runETLPipeline(uint32_t startSequence, int numExtractors)
             // ETL mechanism should stop. The other stopping condition is if
             // the entire server is shutting down. This can be detected in a
             // variety of ways. See the comment at the top of the function
-            while (currentSequence <= finishSequence_ &&
+            while ((!finishSequence_ || currentSequence <= *finishSequence_) &&
                    networkValidatedLedgers_.waitUntilValidatedByNetwork(
                        currentSequence) &&
                    !writeConflict && !isStopping())
@@ -441,7 +442,7 @@ ReportingETL::runETLPipeline(uint32_t startSequence, int numExtractors)
 
                 transformQueue->push(std::move(fetchResponse));
                 currentSequence += numExtractors;
-                if (currentSequence > finishSequence_)
+                if (finishSequence_ && currentSequence > *finishSequence_)
                     break;
             }
             // empty optional tells the transformer to shut down
@@ -498,7 +499,7 @@ ReportingETL::runETLPipeline(uint32_t startSequence, int numExtractors)
                 lastPublishedSequence = lgrInfo.seq;
             }
             writeConflict = !success;
-            auto range = flatMapBackend_->fetchLedgerRange();
+            auto range = flatMapBackend_->fetchLedgerRangeNoThrow();
             if (onlineDeleteInterval_ && !deleting_ &&
                 range->maxSequence - range->minSequence >
                     *onlineDeleteInterval_)
@@ -515,10 +516,15 @@ ReportingETL::runETLPipeline(uint32_t startSequence, int numExtractors)
         }
     }};
 
-    // wait for all of the threads to stop
-    for (auto& t : threads)
-        t.join();
     transformer.join();
+    for (size_t i = 0; i < numExtractors; ++i)
+    {
+        // pop from each queue that might be blocked on a push
+        getNext(i)->tryPop();
+    }
+    // wait for all of the extractors to stop
+    for (auto& t : extractors)
+        t.join();
     auto end = std::chrono::system_clock::now();
     BOOST_LOG_TRIVIAL(debug)
         << "Extracted and wrote " << *lastPublishedSequence - startSequence
@@ -593,8 +599,8 @@ ReportingETL::monitor()
     {
         if (startSequence_)
         {
-            throw std::runtime_error(
+            BOOST_LOG_TRIVIAL(warning)
-                "start sequence specified but db is already populated");
+                << "start sequence specified but db is already populated";
         }
         BOOST_LOG_TRIVIAL(info)
             << __func__ << " : "

test.py

@@ -510,7 +510,7 @@ async def ledger_data_full(ip, port, ledger, binary, limit, typ=None, count=-1):
                             print(json.dumps(x))
                             blobs.append(x)
                             keys.append(x["index"])
-                if limit != -1 and len(keys) > count:
+                if count != -1 and len(keys) > count:
                     print("stopping early")
                     print(len(keys))
                     print("done")
@@ -598,7 +598,7 @@ async def book_offers(ip, port, ledger, pay_currency, pay_issuer, get_currency,
                     req["cursor"] = cursor
                 await ws.send(json.dumps(req))
                 res = json.loads(await ws.recv())
-                print(json.dumps(res,indent=4,sort_keys=True))
+                #print(json.dumps(res,indent=4,sort_keys=True))
                 if "result" in res:
                     res = res["result"]
                 for x in res["offers"]: