Merge branch 'ximinez/online-delete-gaps' into ximinez/online-delete-lastrotated

- First approximation. Good enough and consistent enough for unit tests.
  Not sure about real world, but it'll be an improvement either way.

cfg/rippled-example.cfg

@@ -1051,10 +1051,11 @@
 #                           The online delete process checks periodically
 #                           that rippled is still in sync with the network,
 #                           and that the validated ledger is less than
-#                           'age_threshold_seconds' old. If not, then continue
+#                           'age_threshold_seconds' old, and that all
+#                           recent ledgers are available. If not, then continue
 #                           sleeping for this number of seconds and
 #                           checking until healthy.
-#                           Default is 5.
+#                           Default is 1.
 #
 #   Notes:
 #       The 'node_db' entry configures the primary, persistent storage.

src/test/app/LedgerMaster_test.cpp

@@ -2,6 +2,7 @@
 #include <test/jtx/Env.h>
 
 #include <xrpld/app/ledger/LedgerMaster.h>
+#include <xrpld/app/misc/SHAMapStore.h>
 
 namespace ripple {
 namespace test {
@@ -100,6 +101,89 @@ class LedgerMaster_test : public beast::unit_test::suite
         }
     }
 
+    void
+    testCompleteLedgerRange(FeatureBitset features)
+    {
+        // Note that this test is intentionally very similar to
+        // SHAMapStore_test::testLedgerGaps, but has a different
+        // focus.
+
+        testcase("Complete Ledger operations");
+
+        using namespace test::jtx;
+
+        auto const deleteInterval = 8;
+
+        Env env{*this, envconfig([](auto cfg) {
+                    return online_delete(std::move(cfg), deleteInterval);
+                })};
+
+        auto const alice = Account("alice");
+        env.fund(XRP(1000), alice);
+        env.close();
+
+        auto& lm = env.app().getLedgerMaster();
+        LedgerIndex minSeq = 2;
+        LedgerIndex maxSeq = env.closed()->info().seq;
+        auto& store = env.app().getSHAMapStore();
+        store.rendezvous();
+        LedgerIndex lastRotated = store.getLastRotated();
+        BEAST_EXPECTS(maxSeq == 3, to_string(maxSeq));
+        BEAST_EXPECTS(
+            lm.getCompleteLedgers() == "2-3", lm.getCompleteLedgers());
+        BEAST_EXPECTS(lastRotated == 3, to_string(lastRotated));
+        BEAST_EXPECT(lm.missingFromCompleteLedgerRange(minSeq, maxSeq) == 0);
+        BEAST_EXPECT(
+            lm.missingFromCompleteLedgerRange(minSeq + 1, maxSeq - 1) == 0);
+        BEAST_EXPECT(
+            lm.missingFromCompleteLedgerRange(minSeq - 1, maxSeq + 1) == 2);
+        BEAST_EXPECT(
+            lm.missingFromCompleteLedgerRange(minSeq - 2, maxSeq - 2) == 2);
+        BEAST_EXPECT(
+            lm.missingFromCompleteLedgerRange(minSeq + 2, maxSeq + 2) == 2);
+
+        // Close enough ledgers to rotate a few times
+        for (int i = 0; i < 24; ++i)
+        {
+            for (int t = 0; t < 3; ++t)
+            {
+                env(noop(alice));
+            }
+            env.close();
+            store.rendezvous();
+
+            ++maxSeq;
+
+            if (maxSeq == lastRotated + deleteInterval)
+            {
+                minSeq = lastRotated;
+                lastRotated = store.getLastRotated();
+                BEAST_EXPECT(lastRotated = maxSeq + 2);
+            }
+            BEAST_EXPECTS(
+                env.closed()->info().seq == maxSeq,
+                to_string(env.closed()->info().seq));
+            BEAST_EXPECTS(
+                store.getLastRotated() == lastRotated,
+                to_string(store.getLastRotated()));
+            std::stringstream expectedRange;
+            expectedRange << minSeq << "-" << maxSeq;
+            BEAST_EXPECTS(
+                lm.getCompleteLedgers() == expectedRange.str(),
+                lm.getCompleteLedgers());
+            BEAST_EXPECT(
+                lm.missingFromCompleteLedgerRange(minSeq, maxSeq) == 0);
+            BEAST_EXPECT(
+                lm.missingFromCompleteLedgerRange(minSeq + 1, maxSeq - 1) == 0);
+            BEAST_EXPECT(
+                lm.missingFromCompleteLedgerRange(minSeq - 1, maxSeq + 1) == 2);
+            BEAST_EXPECT(
+                lm.missingFromCompleteLedgerRange(minSeq - 2, maxSeq - 2) == 2);
+            BEAST_EXPECT(
+                lm.missingFromCompleteLedgerRange(minSeq + 2, maxSeq + 2) == 2);
+        }
+    }
+
 public:
     void
     run() override
@@ -113,6 +197,7 @@ public:
     testWithFeats(FeatureBitset features)
     {
         testTxnIdFromIndex(features);
+        testCompleteLedgerRange(features);
     }
 };
 

src/test/app/SHAMapStore_test.cpp

@@ -1,6 +1,7 @@
 #include <test/jtx.h>
 #include <test/jtx/envconfig.h>
 
+#include <xrpld/app/ledger/LedgerMaster.h>
 #include <xrpld/app/main/Application.h>
 #include <xrpld/app/main/NodeStoreScheduler.h>
 #include <xrpld/app/misc/SHAMapStore.h>
@@ -10,6 +11,8 @@
 #include <xrpl/nodestore/detail/DatabaseRotatingImp.h>
 #include <xrpl/protocol/jss.h>
 
+#include <thread>
+
 namespace ripple {
 namespace test {
 
@@ -20,10 +23,8 @@ class SHAMapStore_test : public beast::unit_test::suite
     static auto
     onlineDelete(std::unique_ptr<Config> cfg)
     {
-        cfg->LEDGER_HISTORY = deleteInterval;
-        auto& section = cfg->section(ConfigSection::nodeDatabase());
-        section.set("online_delete", std::to_string(deleteInterval));
-        return cfg;
+        using namespace jtx;
+        return online_delete(std::move(cfg), deleteInterval);
     }
 
     static auto
@@ -226,9 +227,10 @@ public:
 
         store.rendezvous();
 
-        BEAST_EXPECT(store.getLastRotated() == deleteInterval + 3);
+        BEAST_EXPECT(env.closed()->info().seq == deleteInterval + 3);
         lastRotated = store.getLastRotated();
-        BEAST_EXPECT(lastRotated == 11);
+        BEAST_EXPECT(lastRotated == deleteInterval + 5);
+        BEAST_EXPECT(lastRotated == 13);
 
         // That took care of the fake hashes
         ledgerCheck(env, deleteInterval + 1, 3);
@@ -236,9 +238,11 @@ public:
         accountTransactionCheck(env, 2 * deleteInterval);
 
         // The last iteration of this loop should trigger a rotate
-        for (auto i = lastRotated - 1; i < lastRotated + deleteInterval - 1;
+        for (auto i = lastRotated - 3; i < lastRotated + deleteInterval - 1;
              ++i)
         {
+            BEAST_EXPECT(store.getLastRotated() == lastRotated);
+
             env.close();
 
             ledgerTmp = env.rpc("ledger", "current");
@@ -256,7 +260,8 @@ public:
 
         store.rendezvous();
 
-        BEAST_EXPECT(store.getLastRotated() == deleteInterval + lastRotated);
+        BEAST_EXPECT(
+            store.getLastRotated() == deleteInterval + lastRotated + 2);
 
         ledgerCheck(env, deleteInterval + 1, lastRotated);
         transactionCheck(env, 0);
@@ -397,8 +402,8 @@ public:
 
         ledgerCheck(env, ledgerSeq - lastRotated, lastRotated);
 
-        BEAST_EXPECT(store.getLastRotated() == ledgerSeq - 1);
-        lastRotated = ledgerSeq - 1;
+        lastRotated = store.getLastRotated();
+        BEAST_EXPECT(lastRotated == ledgerSeq + 1);
 
         for (; ledgerSeq < lastRotated + deleteInterval; ++ledgerSeq)
         {
@@ -425,10 +430,10 @@ public:
 
         store.rendezvous();
 
-        ledgerCheck(env, ledgerSeq - firstBatch, firstBatch);
+        ledgerCheck(env, ledgerSeq - firstBatch - 2, firstBatch + 2);
 
-        BEAST_EXPECT(store.getLastRotated() == ledgerSeq - 1);
-        lastRotated = ledgerSeq - 1;
+        lastRotated = store.getLastRotated();
+        BEAST_EXPECT(lastRotated == ledgerSeq + 1);
 
         // This does not kick off a cleanup
         canDelete = env.rpc("can_delete", "always");
@@ -464,13 +469,13 @@ public:
 
         ledgerCheck(env, ledgerSeq - lastRotated, lastRotated);
 
-        BEAST_EXPECT(store.getLastRotated() == ledgerSeq - 1);
-        lastRotated = ledgerSeq - 1;
+        lastRotated = store.getLastRotated();
+        BEAST_EXPECT(lastRotated == ledgerSeq + 1);
 
         // This does not kick off a cleanup
         canDelete = env.rpc("can_delete", "now");
         BEAST_EXPECT(!RPC::contains_error(canDelete[jss::result]));
-        BEAST_EXPECT(canDelete[jss::result][jss::can_delete] == ledgerSeq - 1);
+        BEAST_EXPECT(canDelete[jss::result][jss::can_delete] == lastRotated);
 
         for (; ledgerSeq < lastRotated + deleteInterval; ++ledgerSeq)
         {
@@ -499,8 +504,8 @@ public:
 
         ledgerCheck(env, ledgerSeq - lastRotated, lastRotated);
 
-        BEAST_EXPECT(store.getLastRotated() == ledgerSeq - 1);
-        lastRotated = ledgerSeq - 1;
+        lastRotated = store.getLastRotated();
+        BEAST_EXPECT(lastRotated == ledgerSeq + 1);
     }
 
     std::unique_ptr<NodeStore::Backend>
@@ -626,6 +631,212 @@ public:
         BEAST_EXPECT(dbr->getName() == "3");
     }
 
+    void
+    testLedgerGaps()
+    {
+        // Note that this test is intentionally very similar to
+        // LedgerMaster_test::testCompleteLedgerRange, but has a different
+        // focus.
+
+        testcase("Wait for ledger gaps to fill in");
+
+        using namespace test::jtx;
+
+        Env env{*this, envconfig(onlineDelete)};
+
+        auto& ns = env.app().getNodeStore();
+        std::map<LedgerIndex, uint256> hashes;
+        auto storeHash = [&]() {
+            hashes.emplace(
+                env.current()->info().seq, env.current()->info().hash);
+
+            auto const& root =
+                ns.fetchNodeObject(hashes[env.current()->info().seq]);
+            BEAST_EXPECT(root);
+        };
+
+        auto failureMessage = [&](char const* label,
+                                  auto expected,
+                                  auto actual) {
+            std::stringstream ss;
+            ss << label << ": Expected: " << expected << ", Got: " << actual;
+            return ss.str();
+        };
+
+        auto const alice = Account("alice");
+        env.fund(XRP(1000), alice);
+        env.close();
+        storeHash();
+
+        auto& lm = env.app().getLedgerMaster();
+        LedgerIndex minSeq = 2;
+        LedgerIndex maxSeq = env.closed()->info().seq;
+        auto& store = env.app().getSHAMapStore();
+        store.rendezvous();
+        LedgerIndex lastRotated = store.getLastRotated();
+        BEAST_EXPECTS(maxSeq == 3, to_string(maxSeq));
+        BEAST_EXPECTS(
+            lm.getCompleteLedgers() == "2-3", lm.getCompleteLedgers());
+        BEAST_EXPECTS(lastRotated == 3, to_string(lastRotated));
+        BEAST_EXPECT(lm.missingFromCompleteLedgerRange(minSeq, maxSeq) == 0);
+        BEAST_EXPECT(
+            lm.missingFromCompleteLedgerRange(minSeq + 1, maxSeq - 1) == 0);
+        BEAST_EXPECT(
+            lm.missingFromCompleteLedgerRange(minSeq - 1, maxSeq + 1) == 2);
+        BEAST_EXPECT(
+            lm.missingFromCompleteLedgerRange(minSeq - 2, maxSeq - 2) == 2);
+        BEAST_EXPECT(
+            lm.missingFromCompleteLedgerRange(minSeq + 2, maxSeq + 2) == 2);
+
+        // Close enough ledgers to rotate a few times
+        while (maxSeq < 28)
+        {
+            for (int t = 0; t < 3; ++t)
+            {
+                env(noop(alice));
+            }
+            env.close();
+            storeHash();
+            store.rendezvous();
+
+            ++maxSeq;
+
+            if (maxSeq + 1 == lastRotated + deleteInterval)
+            {
+                using namespace std::chrono_literals;
+
+                // The next ledger will trigger a rotation. Delete the
+                // current ledger from LedgerMaster.
+                std::this_thread::sleep_for(100ms);
+                LedgerIndex const deleteSeq = maxSeq;
+                while (!lm.haveLedger(deleteSeq))
+                {
+                    std::this_thread::sleep_for(100ms);
+                }
+                lm.clearLedger(deleteSeq);
+
+                auto expectedRange =
+                    [](auto minSeq, auto deleteSeq, auto maxSeq) {
+                        std::stringstream expectedRange;
+                        expectedRange << minSeq << "-" << (deleteSeq - 1);
+                        if (deleteSeq + 1 == maxSeq)
+                            expectedRange << "," << maxSeq;
+                        else if (deleteSeq < maxSeq)
+                            expectedRange << "," << (deleteSeq + 1) << "-"
+                                          << maxSeq;
+                        return expectedRange.str();
+                    };
+                BEAST_EXPECTS(
+                    lm.getCompleteLedgers() ==
+                        expectedRange(minSeq, deleteSeq, maxSeq),
+                    failureMessage(
+                        "Complete ledgers",
+                        expectedRange(minSeq, deleteSeq, maxSeq),
+                        lm.getCompleteLedgers()));
+                BEAST_EXPECT(
+                    lm.missingFromCompleteLedgerRange(minSeq, maxSeq) == 1);
+
+                // Close another ledger, which will trigger a rotation, but the
+                // rotation will be stuck until the missing ledger is filled in.
+                env.close();
+                storeHash();
+                // DO NOT CALL rendezvous()! You'll end up with a deadlock.
+                ++maxSeq;
+
+                // Nothing has changed
+                BEAST_EXPECTS(
+                    store.getLastRotated() == lastRotated,
+                    failureMessage(
+                        "lastRotated", lastRotated, store.getLastRotated()));
+                BEAST_EXPECTS(
+                    lm.getCompleteLedgers() ==
+                        expectedRange(minSeq, deleteSeq, maxSeq),
+                    failureMessage(
+                        "Complete ledgers",
+                        expectedRange(minSeq, deleteSeq, maxSeq),
+                        lm.getCompleteLedgers()));
+
+                // Close 5 more ledgers, waiting one second in between to
+                // simulate the ledger making progress while online delete waits
+                // for the missing ledger to be filled in.
+                // This ensures the healthWait check has time to run and
+                // detect the gap.
+                for (int l = 0; l < 5; ++l)
+                {
+                    env.close();
+                    storeHash();
+                    // DO NOT CALL rendezvous()! You'll end up with a deadlock.
+                    ++maxSeq;
+                    // Nothing has changed
+                    BEAST_EXPECTS(
+                        store.getLastRotated() == lastRotated,
+                        failureMessage(
+                            "lastRotated",
+                            lastRotated,
+                            store.getLastRotated()));
+                    BEAST_EXPECTS(
+                        lm.getCompleteLedgers() ==
+                            expectedRange(minSeq, deleteSeq, maxSeq),
+                        failureMessage(
+                            "Complete Ledgers",
+                            expectedRange(minSeq, deleteSeq, maxSeq),
+                            lm.getCompleteLedgers()));
+                    std::this_thread::sleep_for(1s);
+                }
+
+                // Put the missing ledger back in LedgerMaster
+                lm.setLedgerRangePresent(deleteSeq, deleteSeq);
+
+                // Wait for the rotation to finish
+                store.rendezvous();
+
+                minSeq = lastRotated;
+                lastRotated = maxSeq + 2;
+
+                // Bypass caching and try to load the ledger roots from the node
+                // store
+                for (auto const& [seq, hash] : hashes)
+                {
+                    auto const nodeObject = ns.fetchNodeObject(hash);
+                    std::stringstream ss;
+                    ss << "minSeq: " << minSeq << ", maxSeq: " << maxSeq
+                       << ", search: " << seq << ". Should "
+                       << (seq < minSeq ? "NOT " : "") << "be found";
+                    if (seq < minSeq)
+                        BEAST_EXPECTS(!nodeObject, ss.str());
+                    else
+                        BEAST_EXPECTS(nodeObject, ss.str());
+                }
+            }
+            BEAST_EXPECT(maxSeq != lastRotated + deleteInterval);
+            BEAST_EXPECTS(
+                env.closed()->info().seq == maxSeq,
+                failureMessage("maxSeq", maxSeq, env.closed()->info().seq));
+            BEAST_EXPECTS(
+                store.getLastRotated() == lastRotated,
+                failureMessage(
+                    "lastRotated", lastRotated, store.getLastRotated()));
+            std::stringstream expectedRange;
+            expectedRange << minSeq << "-" << maxSeq;
+            BEAST_EXPECTS(
+                lm.getCompleteLedgers() == expectedRange.str(),
+                failureMessage(
+                    "CompleteLedgers",
+                    expectedRange.str(),
+                    lm.getCompleteLedgers()));
+            BEAST_EXPECT(
+                lm.missingFromCompleteLedgerRange(minSeq, maxSeq) == 0);
+            BEAST_EXPECT(
+                lm.missingFromCompleteLedgerRange(minSeq + 1, maxSeq - 1) == 0);
+            BEAST_EXPECT(
+                lm.missingFromCompleteLedgerRange(minSeq - 1, maxSeq + 1) == 2);
+            BEAST_EXPECT(
+                lm.missingFromCompleteLedgerRange(minSeq - 2, maxSeq - 2) == 2);
+            BEAST_EXPECT(
+                lm.missingFromCompleteLedgerRange(minSeq + 2, maxSeq + 2) == 2);
+        }
+    }
+
     void
     run() override
     {
@@ -633,6 +844,7 @@ public:
         testAutomatic();
         testCanDelete();
         testRotate();
+        testLedgerGaps();
     }
 };
 

src/test/jtx/envconfig.h

@@ -58,6 +58,17 @@ envconfig(F&& modfunc, Args&&... args)
     return modfunc(envconfig(), std::forward<Args>(args)...);
 }
 
+/// @brief adjust config to enable online_delete
+///
+/// @param cfg config instance to be modified
+///
+/// @param deleteInterval how many new ledgers should be available before
+/// rotating. Defaults to 8, because the standalone minimum is 8.
+///
+/// @return unique_ptr to Config instance
+std::unique_ptr<Config>
+online_delete(std::unique_ptr<Config> cfg, std::uint32_t deleteInterval = 8);
+
 /// @brief adjust config so no admin ports are enabled
 ///
 /// this is intended for use with envconfig, as in

src/test/jtx/impl/envconfig.cpp

@@ -53,6 +53,15 @@ setupConfigForUnitTests(Config& cfg)
 
 namespace jtx {
 
+std::unique_ptr<Config>
+online_delete(std::unique_ptr<Config> cfg, std::uint32_t deleteInterval)
+{
+    cfg->LEDGER_HISTORY = deleteInterval;
+    auto& section = cfg->section(ConfigSection::nodeDatabase());
+    section.set("online_delete", std::to_string(deleteInterval));
+    return cfg;
+}
+
 std::unique_ptr<Config>
 no_admin(std::unique_ptr<Config> cfg)
 {

src/xrpld/app/ledger/LedgerMaster.h

@@ -108,7 +108,10 @@ public:
     failedSave(std::uint32_t seq, uint256 const& hash);
 
     std::string
-    getCompleteLedgers();
+    getCompleteLedgers() const;
+
+    std::size_t
+    missingFromCompleteLedgerRange(LedgerIndex first, LedgerIndex last) const;
 
     /** Apply held transactions to the open ledger
         This is normally called as we close the ledger.
@@ -325,7 +328,7 @@ private:
     // A set of transactions to replay during the next close
     std::unique_ptr<LedgerReplay> replayData;
 
-    std::recursive_mutex mCompleteLock;
+    std::recursive_mutex mutable mCompleteLock;
     RangeSet<std::uint32_t> mCompleteLedgers;
 
     // Publish thread is running.

src/xrpld/app/ledger/detail/LedgerMaster.cpp

@@ -1571,12 +1571,36 @@ LedgerMaster::getPublishedLedger()
 }
 
 std::string
-LedgerMaster::getCompleteLedgers()
+LedgerMaster::getCompleteLedgers() const
 {
     std::lock_guard sl(mCompleteLock);
     return to_string(mCompleteLedgers);
 }
 
+std::size_t
+LedgerMaster::missingFromCompleteLedgerRange(
+    LedgerIndex first,
+    LedgerIndex last) const
+{
+    // Make a copy of the range to avoid holding the lock
+    auto const range = [&] {
+        std::lock_guard sl(mCompleteLock);
+        return mCompleteLedgers;
+    }();
+
+    std::size_t missing = 0;
+
+    for (LedgerIndex idx = first; idx <= last; ++idx)
+    {
+        if (!boost::icl::contains(range, idx))
+        {
+            ++missing;
+        }
+    }
+
+    return missing;
+}
+
 std::optional<NetClock::time_point>
 LedgerMaster::getCloseTimeBySeq(LedgerIndex ledgerIndex)
 {

src/xrpld/app/misc/SHAMapStoreImp.cpp

@@ -289,6 +289,18 @@ SHAMapStoreImp::run()
             validatedSeq >= lastRotated + deleteInterval_ &&
             canDelete_ >= lastRotated - 1 && healthWait() == keepGoing;
 
+        JLOG(journal_.debug())
+            << "run: Setting lastGoodValidatedLedger_ to " << validatedSeq;
+
+        {
+            // Note that this is set after the healthWait() check, so that we
+            // don't start the rotation until the validated ledger is fully
+            // processed. It is not guaranteed to be done at this point. It also
+            // allows the testLedgerGaps unit test to work.
+            std::unique_lock<std::mutex> lock(mutex_);
+            lastGoodValidatedLedger_ = validatedSeq;
+        }
+
         // will delete up to (not including) lastRotated
         if (readyToRotate)
         {
@@ -297,7 +309,9 @@ SHAMapStoreImp::run()
                 << lastRotated << " deleteInterval " << deleteInterval_
                 << " canDelete_ " << canDelete_ << " state "
                 << app_.getOPs().strOperatingMode(false) << " age "
-                << ledgerMaster_->getValidatedLedgerAge().count() << 's';
+                << ledgerMaster_->getValidatedLedgerAge().count()
+                << "s. Complete ledgers: "
+                << ledgerMaster_->getCompleteLedgers();
 
             clearPrior(lastRotated);
             if (healthWait() == stopping)
@@ -345,7 +359,13 @@ SHAMapStoreImp::run()
             if (healthWait() == stopping)
                 return;
 
-            lastRotated = validatedSeq;
+            // The rotation process takes time, and more ledgers - possibly many
+            // more - may have been written to the now-archive database before
+            // the writable database was created. Update the validatedSeq to the
+            // current validated ledger sequence plus a buffer to ensure that
+            // all modified nodes for that ledger forward are all written to the
+            // new writable database.
+            lastRotated = ledgerMaster_->getValidLedgerIndex() + 2;
 
             dbRotating_->rotate(
                 std::move(newBackend),
@@ -360,7 +380,10 @@ SHAMapStoreImp::run()
                     clearCaches(validatedSeq);
                 });
 
-            JLOG(journal_.warn()) << "finished rotation " << validatedSeq;
+            JLOG(journal_.warn())
+                << "finished rotation. validatedSeq: " << validatedSeq
+                << ", lastRotated: " << lastRotated << ". Complete ledgers: "
+                << ledgerMaster_->getCompleteLedgers();
         }
     }
 }
@@ -615,22 +638,47 @@ SHAMapStoreImp::clearPrior(LedgerIndex lastRotated)
 SHAMapStoreImp::HealthResult
 SHAMapStoreImp::healthWait()
 {
+    auto index = ledgerMaster_->getValidLedgerIndex();
     auto age = ledgerMaster_->getValidatedLedgerAge();
     OperatingMode mode = netOPs_->getOperatingMode();
     std::unique_lock lock(mutex_);
-    while (!stop_ && (mode != OperatingMode::FULL || age > ageThreshold_))
+
+    auto numMissing = ledgerMaster_->missingFromCompleteLedgerRange(
+        lastGoodValidatedLedger_, index);
+    while (
+        !stop_ &&
+        (mode != OperatingMode::FULL || age > ageThreshold_ || numMissing > 0))
     {
+        // this value shouldn't change, so grab it while we have the
+        // lock
+        auto const lastGood = lastGoodValidatedLedger_;
+
         lock.unlock();
-        JLOG(journal_.warn()) << "Waiting " << recoveryWaitTime_.count()
-                              << "s for node to stabilize. state: "
-                              << app_.getOPs().strOperatingMode(mode, false)
-                              << ". age " << age.count() << 's';
+
+        auto const stream = mode != OperatingMode::FULL || age > ageThreshold_
+            ? journal_.warn()
+            : journal_.info();
+        JLOG(stream) << "Waiting " << recoveryWaitTime_.count()
+                     << "s for node to stabilize. state: "
+                     << app_.getOPs().strOperatingMode(mode, false) << ". age "
+                     << age.count() << "s. Missing ledgers: " << numMissing
+                     << ". Expect: " << lastGood << "-" << index
+                     << ". Complete ledgers: "
+                     << ledgerMaster_->getCompleteLedgers();
         std::this_thread::sleep_for(recoveryWaitTime_);
+        index = ledgerMaster_->getValidLedgerIndex();
         age = ledgerMaster_->getValidatedLedgerAge();
         mode = netOPs_->getOperatingMode();
+        numMissing =
+            ledgerMaster_->missingFromCompleteLedgerRange(lastGood, index);
+
         lock.lock();
     }
 
+    JLOG(journal_.debug()) << "healthWait: Setting lastGoodValidatedLedger_ to "
+                           << index;
+    lastGoodValidatedLedger_ = index;
+
     return stop_ ? stopping : keepGoing;
 }
 

src/xrpld/app/misc/SHAMapStoreImp.h

@@ -71,6 +71,11 @@ private:
     std::thread thread_;
     bool stop_ = false;
     bool healthy_ = true;
+    // Used to prevent ledger gaps from forming during online deletion. Keeps
+    // track of the last validated ledger that was processed without gaps. There
+    // are no guarantees about gaps while online delete is not running. For
+    // that, use advisory_delete and check for gaps externally.
+    LedgerIndex lastGoodValidatedLedger_ = 0;
     mutable std::condition_variable cond_;
     mutable std::condition_variable rendezvous_;
     mutable std::mutex mutex_;
@@ -84,11 +89,11 @@ private:
     std::uint32_t deleteBatch_ = 100;
     std::chrono::milliseconds backOff_{100};
     std::chrono::seconds ageThreshold_{60};
-    /// If  the node is out of sync during an online_delete healthWait()
-    /// call, sleep the thread for this time, and continue checking until
-    /// recovery.
+    /// If  the node is out of sync, or any recent ledgers are not
+    /// available during an online_delete healthWait() call, sleep
+    /// the thread for this time, and continue checking until recovery.
     /// See also: "recovery_wait_seconds" in rippled-example.cfg
-    std::chrono::seconds recoveryWaitTime_{5};
+    std::chrono::seconds recoveryWaitTime_{1};
 
     // these do not exist upon SHAMapStore creation, but do exist
     // as of run() or before
@@ -212,6 +217,8 @@ private:
     enum HealthResult { stopping, keepGoing };
     [[nodiscard]] HealthResult
     healthWait();
+    bool
+    hasCompleteRange(LedgerIndex first, LedgerIndex last);
 
 public:
     void