Import wiredtiger: 4a4a0259eca4e9b7cdebc4512145b7ca17c2e742 from branch mongodb-master

ref: d6bd5d1ffd..4a4a0259ec
for: 5.2.0

WT-8114       Revert allow setting the prepare timestamp smaller than or equal to the latest active read timestamp with roundup prepare config

6 files changed, 21 insertions, 40 deletions

diff --git a/src/third_party/wiredtiger/dist/api_data.py b/src/third_party/wiredtiger/dist/api_data.py
index 75d5a6dbe40..5eb4ceaebf1 100644
--- a/src/third_party/wiredtiger/dist/api_data.py
+++ b/src/third_party/wiredtiger/dist/api_data.py
@@ -1728,11 +1728,10 @@ methods = {
             applicable only for prepared transactions. Indicates if the prepare
             timestamp and the commit timestamp of this transaction can be
             rounded up. If the prepare timestamp is less than the oldest
-            timestamp, the prepare timestamp will be rounded to the oldest
+            timestamp, the prepare timestamp  will be rounded to the oldest
             timestamp. If the commit timestamp is less than the prepare
             timestamp, the commit timestamp will be rounded up to the prepare
-            timestamp. Allows setting the prepared timestamp smaller than or equal
-            to the latest active read timestamp''', type='boolean'),
+            timestamp''', type='boolean'),
         Config('read', 'false', r'''
             if the read timestamp is less than the oldest timestamp, the
             read timestamp will be rounded up to the oldest timestamp''',
diff --git a/src/third_party/wiredtiger/import.data b/src/third_party/wiredtiger/import.data
index 6a48130188b..eb5aac2219c 100644
--- a/src/third_party/wiredtiger/import.data
+++ b/src/third_party/wiredtiger/import.data
@@ -2,5 +2,5 @@
     "vendor": "wiredtiger",
     "github": "wiredtiger/wiredtiger.git",
     "branch": "mongodb-master",
-    "commit": "d6bd5d1ffd1f9fa4cb3be94f0d29d18544a07827"
+    "commit": "4a4a0259eca4e9b7cdebc4512145b7ca17c2e742"
 }
diff --git a/src/third_party/wiredtiger/src/docs/transactions.dox b/src/third_party/wiredtiger/src/docs/transactions.dox
index 3c1233b0400..c594b6b15c9 100644
--- a/src/third_party/wiredtiger/src/docs/transactions.dox
+++ b/src/third_party/wiredtiger/src/docs/transactions.dox
@@ -246,15 +246,6 @@ For example, for the timestamp values <code>prepare_timestamp=100,
     timestamp is rounded up to the new prepare timestamp as
     <code>commit_timestamp=200</code>.
 
-Configuring <code>roundup_timestamps=(prepared=true)</code> also allows setting
-the prepared timestamps smaller than or equal to the latest active read timestamps.
-Use this feature carefully as it may break repeated read. For example, consider a
-transaction with a read timestamp set to 30 and a key that has a value with
-timestamp 20. Before a prepared transaction (in another thread), reading the key
-returns the value. Now a prepared transaction elsewhere in the system sets a prepared
-timestamp at 30. The reader, trying to do a repeat read of the key, gets return a
-prepared conflict error instead of the value.
-
 Configuring <code>roundup_timestamps=(read=true)</code> causes the read
 timestamp to be rounded up to the oldest timestamp, if the read timestamp is
 greater than the oldest timestamp no change will be made.
diff --git a/src/third_party/wiredtiger/src/include/wiredtiger.in b/src/third_party/wiredtiger/src/include/wiredtiger.in
index 2bbebb4c5ce..576c10b53ae 100644
--- a/src/third_party/wiredtiger/src/include/wiredtiger.in
+++ b/src/third_party/wiredtiger/src/include/wiredtiger.in
@@ -1695,12 +1695,11 @@ struct __wt_session {
 	 * and the commit timestamp of this transaction can be rounded up.  If the prepare timestamp
 	 * is less than the oldest timestamp\, the prepare timestamp will be rounded to the oldest
 	 * timestamp.  If the commit timestamp is less than the prepare timestamp\, the commit
-	 * timestamp will be rounded up to the prepare timestamp.  Allows setting the prepared
-	 * timestamp smaller than or equal to the latest active read timestamp., a boolean flag;
-	 * default \c false.}
-	 * @config{&nbsp;&nbsp;&nbsp;&nbsp;read, if the read timestamp is less
-	 * than the oldest timestamp\, the read timestamp will be rounded up to the oldest
-	 * timestamp., a boolean flag; default \c false.}
+	 * timestamp will be rounded up to the prepare timestamp., a boolean flag; default \c
+	 * false.}
+	 * @config{&nbsp;&nbsp;&nbsp;&nbsp;read, if the read timestamp is less than the
+	 * oldest timestamp\, the read timestamp will be rounded up to the oldest timestamp., a
+	 * boolean flag; default \c false.}
 	 * @config{ ),,}
 	 * @config{sync, whether to sync log records when the transaction commits\, inherited from
 	 * ::wiredtiger_open \c transaction_sync., a boolean flag; default empty.}
diff --git a/src/third_party/wiredtiger/src/txn/txn_timestamp.c b/src/third_party/wiredtiger/src/txn/txn_timestamp.c
index c138f23fe57..784c2cacfed 100644
--- a/src/third_party/wiredtiger/src/txn/txn_timestamp.c
+++ b/src/third_party/wiredtiger/src/txn/txn_timestamp.c
@@ -715,19 +715,7 @@ __wt_txn_set_prepare_timestamp(WT_SESSION_IMPL *session, wt_timestamp_t prepare_
         WT_RET_MSG(session, EINVAL,
           "commit timestamp should not have been set before the prepare timestamp");
 
-        /*
-         * Allows setting the prepared timestamp smaller than or equal to the latest active read
-         * timestamp. This feature is necessary to find the largest key in the table even if that
-         * key has been deleted. Set this flag cautiously as it breaks repeated reads.
-         */
-#ifdef HAVE_DIAGNOSTIC
-    if (!F_ISSET(txn, WT_TXN_TS_ROUND_PREPARED))
-        WT_RET(__txn_assert_after_reads(session, "prepare", prepare_ts));
-    else
-        WT_RET(__wt_msg(session,
-          "Skip checking prepare timestamp %s against the latest active read timestamp.",
-          __wt_timestamp_to_string(prepare_ts, ts_string[0])));
-#endif
+    WT_RET(__txn_assert_after_reads(session, "prepare", prepare_ts));
 
     /*
      * Check whether the prepare timestamp is less than the oldest timestamp.
diff --git a/src/third_party/wiredtiger/test/suite/test_prepare06.py b/src/third_party/wiredtiger/test/suite/test_prepare06.py
index de9a7475817..b4e65f183b0 100644
--- a/src/third_party/wiredtiger/test/suite/test_prepare06.py
+++ b/src/third_party/wiredtiger/test/suite/test_prepare06.py
@@ -90,18 +90,24 @@ class test_prepare06(wttest.WiredTigerTestCase, suite_subprocess):
         s_reader = self.conn.open_session()
         s_reader.begin_transaction('read_timestamp=' + self.timestamp_str(40))
 
-        # It is legal to set the prepare timestamp earlier than an active
-        # read timestamp with roundup_timestamps settings. This is only
+        # It is illegal to set the prepare timestamp as earlier than an active
+        # read timestamp even with roundup_timestamps settings.  This is only
         # checked in diagnostic builds.
         if wiredtiger.diagnostic_build():
             self.session.begin_transaction('roundup_timestamps=(prepared=true)')
-            self.assertEqual(self.session.prepare_transaction('prepare_timestamp=' + self.timestamp_str(10)), 0)
+            self.assertRaisesWithMessage(wiredtiger.WiredTigerError,
+                lambda: self.session.prepare_transaction(
+                'prepare_timestamp=' + self.timestamp_str(10)),
+                "/must be greater than the latest active read timestamp/")
             self.session.rollback_transaction()
 
-            # It is legal to set the prepare timestamp the same as an active read
-            # timestamp with roundup_timestamps settings.
+            # It is illegal to set the prepare timestamp the same as an active read
+            # timestamp even with roundup_timestamps settings.
             self.session.begin_transaction('roundup_timestamps=(prepared=true)')
-            self.assertEqual(self.session.prepare_transaction('prepare_timestamp=' + self.timestamp_str(40)), 0)
+            self.assertRaisesWithMessage(wiredtiger.WiredTigerError,
+                lambda: self.session.prepare_transaction(
+                'prepare_timestamp=' + self.timestamp_str(40)),
+                "/must be greater than the latest active read timestamp/")
             self.session.rollback_transaction()
 
         '''
@@ -138,7 +144,5 @@ class test_prepare06(wttest.WiredTigerTestCase, suite_subprocess):
 
         s_reader.commit_transaction()
 
-        self.ignoreStdoutPatternIfExists("Skip checking prepare timestamp")
-
 if __name__ == '__main__':
     wttest.run()