7 files changed, 25 insertions, 8 deletions

diff --git a/jstests/hooks/run_validate_collections_background.js b/jstests/hooks/run_validate_collections_background.js
index 89c8f2fcc21..9e0ca571d9b 100644
--- a/jstests/hooks/run_validate_collections_background.js
+++ b/jstests/hooks/run_validate_collections_background.js
@@ -90,6 +90,7 @@ const validateCollectionsBackgroundThread = function validateCollectionsBackgrou
                 return z.name;
             });
 
+    conn.adminCommand({configureFailPoint: "crashOnMultikeyValidateFailure", mode: "alwaysOn"});
     for (let dbName of dbNames) {
         let db = conn.getDB(dbName);
 
@@ -115,6 +116,7 @@ const validateCollectionsBackgroundThread = function validateCollectionsBackgrou
             }
         }
     }
+    conn.adminCommand({configureFailPoint: "crashOnMultikeyValidateFailure", mode: "off"});
 
     // If any commands failed, format and return an error.
     if (failedValidateResults.length) {
diff --git a/src/mongo/db/catalog/collection_validation.cpp b/src/mongo/db/catalog/collection_validation.cpp
index 76e04d45bd6..bdf944ce6ed 100644
--- a/src/mongo/db/catalog/collection_validation.cpp
+++ b/src/mongo/db/catalog/collection_validation.cpp
@@ -174,10 +174,9 @@ void _validateIndexes(OperationContext* opCtx,
             }
         }
 
-        if (curIndexResults.valid) {
-            keysPerIndex->appendNumber(descriptor->indexName(),
-                                       static_cast<long long>(numTraversedKeys));
-        } else {
+        keysPerIndex->appendNumber(descriptor->indexName(),
+                                   static_cast<long long>(numTraversedKeys));
+        if (!curIndexResults.valid) {
             results->valid = false;
         }
     }
@@ -261,6 +260,8 @@ void _reportValidationResults(OperationContext* opCtx,
                               BSONObjBuilder* output) {
     std::unique_ptr<BSONObjBuilder> indexDetails;
 
+    results->readTimestamp = validateState->getValidateTimestamp();
+
     if (validateState->isFullIndexValidation()) {
         invariant(opCtx->lockState()->isCollectionLockedForMode(validateState->nss(), MODE_X));
         indexDetails = std::make_unique<BSONObjBuilder>();
diff --git a/src/mongo/db/catalog/validate_adaptor.cpp b/src/mongo/db/catalog/validate_adaptor.cpp
index fad690d0834..e8cc65d9d5c 100644
--- a/src/mongo/db/catalog/validate_adaptor.cpp
+++ b/src/mongo/db/catalog/validate_adaptor.cpp
@@ -49,11 +49,14 @@
 #include "mongo/db/storage/record_store.h"
 #include "mongo/logv2/log.h"
 #include "mongo/rpc/object_check.h"
+#include "mongo/util/fail_point.h"
 
 namespace mongo {
 
 namespace {
 
+MONGO_FAIL_POINT_DEFINE(crashOnMultikeyValidateFailure);
+
 const long long kInterruptIntervalNumRecords = 4096;
 const long long kInterruptIntervalNumBytes = 50 * 1024 * 1024;  // 50MB.
 
@@ -124,6 +127,9 @@ Status ValidateAdaptor::validateRecord(OperationContext* opCtx,
             ValidateResults& curRecordResults = (*_indexNsResultsMap)[descriptor->indexName()];
             curRecordResults.errors.push_back(msg);
             curRecordResults.valid = false;
+            if (crashOnMultikeyValidateFailure.shouldFail()) {
+                invariant(false, msg);
+            }
         }
 
         if (descriptor->isMultikey()) {
diff --git a/src/mongo/db/catalog/validate_state.cpp b/src/mongo/db/catalog/validate_state.cpp
index 7eead34d9a5..c2e4d16b73e 100644
--- a/src/mongo/db/catalog/validate_state.cpp
+++ b/src/mongo/db/catalog/validate_state.cpp
@@ -180,6 +180,7 @@ void ValidateState::initializeCursors(OperationContext* opCtx) {
         opCtx, _collection->getRecordStore(), &_dataThrottle);
     _seekRecordStoreCursor = std::make_unique<SeekableRecordThrottleCursor>(
         opCtx, _collection->getRecordStore(), &_dataThrottle);
+    _validateTs = opCtx->recoveryUnit()->getPointInTimeReadTimestamp();
 
     const IndexCatalog* indexCatalog = _collection->getIndexCatalog();
     // The index iterator for ready indexes is timestamp-aware and will only return indexes that
diff --git a/src/mongo/db/catalog/validate_state.h b/src/mongo/db/catalog/validate_state.h
index 258fa6ca4c7..da58dc0b51f 100644
--- a/src/mongo/db/catalog/validate_state.h
+++ b/src/mongo/db/catalog/validate_state.h
@@ -146,6 +146,10 @@ public:
         return _extraLoggingForTest;
     }
 
+    boost::optional<Timestamp> getValidateTimestamp() {
+        return _validateTs;
+    }
+
 private:
     ValidateState() = delete;
 
@@ -213,6 +217,8 @@ private:
 
     // Can be set by unit tests to obtain better insight into what validate sees/does.
     bool _extraLoggingForTest;
+
+    boost::optional<Timestamp> _validateTs = boost::none;
 };
 
 }  // namespace CollectionValidation
diff --git a/src/mongo/db/commands/validate.cpp b/src/mongo/db/commands/validate.cpp
index 11c0b2515ad..c60c32076cc 100644
--- a/src/mongo/db/commands/validate.cpp
+++ b/src/mongo/db/commands/validate.cpp
@@ -183,6 +183,9 @@ public:
         }
 
         result.appendBool("valid", validateResults.valid);
+        if (validateResults.readTimestamp) {
+            result.append("readTimestamp", validateResults.readTimestamp.get());
+        }
         result.append("warnings", validateResults.warnings);
         result.append("errors", validateResults.errors);
         result.append("extraIndexEntries", validateResults.extraIndexEntries);
diff --git a/src/mongo/db/storage/record_store.h b/src/mongo/db/storage/record_store.h
index 1b1e17d7aee..5ccf804a584 100644
--- a/src/mongo/db/storage/record_store.h
+++ b/src/mongo/db/storage/record_store.h
@@ -569,10 +569,8 @@ protected:
 };
 
 struct ValidateResults {
-    ValidateResults() {
-        valid = true;
-    }
-    bool valid;
+    bool valid = true;
+    boost::optional<Timestamp> readTimestamp = boost::none;
     std::vector<std::string> errors;
     std::vector<std::string> warnings;
     std::vector<BSONObj> extraIndexEntries;