Import wiredtiger: 404b4a70af14e7d3aecf7f206380884af5d06786 from branch mongodb-4.4r4.4.0-rc5

ref: 18dfb9e58e..404b4a70af
for: 4.4.0-rc5

WT-6093       Fix and reenable test_random_abort in recovery-stress-test
WT-6097       Let the Python test suite runner allocate tests to buckets for evergreen
WT-6128       Reduce the data size in test_checkpoint04 so it completes quickly
WT-6131       Add a test to verify checkpointing truncation in durable history
WT-6137       Fix calculation of bits versus bytes for incremental bitmap
WT-6138       Turn off non-timestamp testing in schema_abort
WT-6141       Disable checkpoint deletion during backup
WT-6142       Fix the assert with no more than one aborted update in chain
WT-6144       Avoid configures verify_metadata in test/format when running on historic builds
WT-6152       Fix accessing checkpoint durable timestamp including older version
WT-6156       Enable format to select "backup.incremental=log"

19 files changed, 241 insertions, 86 deletions

diff --git a/src/third_party/wiredtiger/import.data b/src/third_party/wiredtiger/import.data
index 4fcc4a17180..a08ef7d90d9 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-4.4",
-    "commit": "18dfb9e58e39927696affcd8e362364e23e1aa59"
+    "commit": "404b4a70af14e7d3aecf7f206380884af5d06786"
 }
diff --git a/src/third_party/wiredtiger/src/block/block_ckpt.c b/src/third_party/wiredtiger/src/block/block_ckpt.c
index 292917be5d6..7480ddfca2b 100644
--- a/src/third_party/wiredtiger/src/block/block_ckpt.c
+++ b/src/third_party/wiredtiger/src/block/block_ckpt.c
@@ -661,14 +661,20 @@ static int
 __ckpt_add_blkmod_entry(
   WT_SESSION_IMPL *session, WT_BLOCK_MODS *blk_mod, wt_off_t offset, wt_off_t len)
 {
-    uint64_t end, start;
-    uint32_t end_buf_bytes, end_rdup_bytes;
+    uint64_t end_bit, start_bit;
+    uint32_t end_buf_bytes, end_rdup_bits, end_rdup_bytes;
 
     WT_ASSERT(session, blk_mod->granularity != 0);
-    start = (uint64_t)offset / blk_mod->granularity;
-    end = (uint64_t)(offset + len) / blk_mod->granularity;
-    WT_ASSERT(session, end < UINT32_MAX);
-    end_rdup_bytes = WT_MAX(__wt_rduppo2((uint32_t)end, 8), WT_BLOCK_MODS_LIST_MIN);
+    /*
+     * Figure out how the starting and ending bits based on the granularity and our offset and
+     * length.
+     */
+    start_bit = (uint64_t)offset / blk_mod->granularity;
+    end_bit = (uint64_t)(offset + len - 1) / blk_mod->granularity;
+    WT_ASSERT(session, end_bit < UINT32_MAX);
+    /* We want to grow the bitmap by 64 bits, or 8 bytes at a time. */
+    end_rdup_bits = WT_MAX(__wt_rduppo2((uint32_t)end_bit, 64), WT_BLOCK_MODS_LIST_MIN);
+    end_rdup_bytes = end_rdup_bits >> 3;
     end_buf_bytes = (uint32_t)blk_mod->nbits >> 3;
     /*
      * We are doing a lot of shifting. Make sure that the number of bytes we end up with is a
@@ -687,11 +693,10 @@ __ckpt_add_blkmod_entry(
             memset(
               (uint8_t *)blk_mod->bitstring.mem + end_buf_bytes, 0, end_rdup_bytes - end_buf_bytes);
         }
-        blk_mod->nbits = end_rdup_bytes << 3;
+        blk_mod->nbits = end_rdup_bits;
     }
-
     /* Set all the bits needed to record this offset/length pair. */
-    __bit_nset(blk_mod->bitstring.mem, start, end);
+    __bit_nset(blk_mod->bitstring.mem, start_bit, end_bit);
     return (0);
 }
 
diff --git a/src/third_party/wiredtiger/src/btree/bt_sync.c b/src/third_party/wiredtiger/src/btree/bt_sync.c
index fd36f6b24f9..100aeed5105 100644
--- a/src/third_party/wiredtiger/src/btree/bt_sync.c
+++ b/src/third_party/wiredtiger/src/btree/bt_sync.c
@@ -373,9 +373,9 @@ __wt_sync_file(WT_SESSION_IMPL *session, WT_CACHE_OP syncop)
     /*
      * Skip all deleted pages. For a page to be marked deleted, it must have been evicted from cache
      * and marked clean. Checkpoint should never instantiate deleted pages: if a truncate is not
-     * visible to the checkpoint, the on-disk version is correct. If the truncate is visible, we
-     * skip over the child page when writing its parent. We check whether a truncate is visible in
-     * the checkpoint as part of reconciling internal pages (specifically in __rec_child_modify).
+     * visible to the checkpoint, the on-disk version is correct. If the truncate is visible to
+     * checkpoint, we write a proxy cell to its parent. We check whether a truncate is visible in
+     * the checkpoint as part of reconciling internal pages (specifically in __rec_child_deleted).
      */
     LF_SET(WT_READ_DELETED_SKIP);
 
diff --git a/src/third_party/wiredtiger/src/include/meta.h b/src/third_party/wiredtiger/src/include/meta.h
index f9160c6b28c..0b0d436f146 100644
--- a/src/third_party/wiredtiger/src/include/meta.h
+++ b/src/third_party/wiredtiger/src/include/meta.h
@@ -85,7 +85,7 @@ struct __wt_blkincr {
 /*
  * At the default granularity, this is enough for blocks in a 2G file.
  */
-#define WT_BLOCK_MODS_LIST_MIN 16 /* Initial bytes for bitmap. */
+#define WT_BLOCK_MODS_LIST_MIN 128 /* Initial bits for bitmap. */
 struct __wt_block_mods {
     const char *id_str;
 
diff --git a/src/third_party/wiredtiger/src/meta/meta_ckpt.c b/src/third_party/wiredtiger/src/meta/meta_ckpt.c
index 21acec991c6..9742d16a9ef 100644
--- a/src/third_party/wiredtiger/src/meta/meta_ckpt.c
+++ b/src/third_party/wiredtiger/src/meta/meta_ckpt.c
@@ -598,6 +598,16 @@ __ckpt_load(WT_SESSION_IMPL *session, WT_CONFIG_ITEM *k, WT_CONFIG_ITEM *v, WT_C
     WT_RET_NOTFOUND_OK(ret);
     if (ret != WT_NOTFOUND && a.len != 0)
         ckpt->ta.newest_start_durable_ts = (uint64_t)a.val;
+    else {
+        /*
+         * Backward compatibility changes, as the parameter name is different in older versions of
+         * WT, make sure that we read older format in case if we didn't find the newer format name.
+         */
+        ret = __wt_config_subgets(session, v, "start_durable_ts", &a);
+        WT_RET_NOTFOUND_OK(ret);
+        if (ret != WT_NOTFOUND && a.len != 0)
+            ckpt->ta.newest_start_durable_ts = (uint64_t)a.val;
+    }
 
     ret = __wt_config_subgets(session, v, "newest_stop_ts", &a);
     WT_RET_NOTFOUND_OK(ret);
@@ -613,6 +623,16 @@ __ckpt_load(WT_SESSION_IMPL *session, WT_CONFIG_ITEM *k, WT_CONFIG_ITEM *v, WT_C
     WT_RET_NOTFOUND_OK(ret);
     if (ret != WT_NOTFOUND && a.len != 0)
         ckpt->ta.newest_stop_durable_ts = (uint64_t)a.val;
+    else {
+        /*
+         * Backward compatibility changes, as the parameter name is different in older versions of
+         * WT, make sure that we read older format in case if we didn't find the newer format name.
+         */
+        ret = __wt_config_subgets(session, v, "stop_durable_ts", &a);
+        WT_RET_NOTFOUND_OK(ret);
+        if (ret != WT_NOTFOUND && a.len != 0)
+            ckpt->ta.newest_stop_durable_ts = (uint64_t)a.val;
+    }
 
     ret = __wt_config_subgets(session, v, "prepare", &a);
     WT_RET_NOTFOUND_OK(ret);
diff --git a/src/third_party/wiredtiger/src/reconcile/rec_visibility.c b/src/third_party/wiredtiger/src/reconcile/rec_visibility.c
index aa44301a21d..93991af5983 100644
--- a/src/third_party/wiredtiger/src/reconcile/rec_visibility.c
+++ b/src/third_party/wiredtiger/src/reconcile/rec_visibility.c
@@ -378,7 +378,7 @@ __wt_rec_upd_select(WT_SESSION_IMPL *session, WT_RECONCILE *r, WT_INSERT *ins, v
             tombstone = upd;
 
             /* Find the update this tombstone applies to. */
-            if (!__wt_txn_visible_all(session, upd->txnid, upd->start_ts)) {
+            if (!__wt_txn_upd_visible_all(session, upd)) {
                 while (upd->next != NULL && upd->next->txnid == WT_TXN_ABORTED)
                     upd = upd->next;
                 WT_ASSERT(session, upd->next == NULL || upd->next->txnid != WT_TXN_ABORTED);
@@ -387,12 +387,12 @@ __wt_rec_upd_select(WT_SESSION_IMPL *session, WT_RECONCILE *r, WT_INSERT *ins, v
                 upd_select->upd = upd = upd->next;
             }
         }
-        if (upd != NULL) {
+        if (upd != NULL)
             /* The beginning of the validity window is the selected update's time pair. */
             __wt_time_window_set_start(select_tw, upd);
-        } else if (select_tw->stop_ts != WT_TS_NONE || select_tw->stop_txn != WT_TXN_NONE) {
+        else if (select_tw->stop_ts != WT_TS_NONE || select_tw->stop_txn != WT_TXN_NONE) {
             /* If we only have a tombstone in the update list, we must have an ondisk value. */
-            WT_ASSERT(session, vpack != NULL && tombstone != NULL);
+            WT_ASSERT(session, vpack != NULL && tombstone != NULL && last_upd->next == NULL);
             /*
              * It's possible to have a tombstone as the only update in the update list. If we
              * reconciled before with only a single update and then read the page back into cache,
@@ -404,12 +404,22 @@ __wt_rec_upd_select(WT_SESSION_IMPL *session, WT_RECONCILE *r, WT_INSERT *ins, v
              * window ends when this tombstone started.
              */
             WT_ERR(__rec_append_orig_value(session, page, tombstone, vpack));
-            WT_ASSERT(session, last_upd->next != NULL &&
-                last_upd->next->txnid == vpack->tw.start_txn &&
-                last_upd->next->start_ts == vpack->tw.start_ts &&
-                last_upd->next->type == WT_UPDATE_STANDARD && last_upd->next->next == NULL);
-            upd_select->upd = last_upd->next;
-            __wt_time_window_set_start(select_tw, last_upd->next);
+
+            /*
+             * We may have updated the global transaction concurrently and the tombstone is now
+             * globally visible. In this case, the on page value is not appended. Check that.
+             */
+            if (last_upd->next != NULL) {
+                WT_ASSERT(session, last_upd->next->txnid == vpack->tw.start_txn &&
+                    last_upd->next->start_ts == vpack->tw.start_ts &&
+                    last_upd->next->type == WT_UPDATE_STANDARD && last_upd->next->next == NULL);
+                upd_select->upd = last_upd->next;
+                __wt_time_window_set_start(select_tw, last_upd->next);
+            } else {
+                WT_ASSERT(
+                  session, __wt_txn_upd_visible_all(session, tombstone) && upd_select->upd == NULL);
+                upd_select->upd = tombstone;
+            }
         }
     }
 
diff --git a/src/third_party/wiredtiger/src/txn/txn.c b/src/third_party/wiredtiger/src/txn/txn.c
index 0fdf022bd51..bcde2932ab2 100644
--- a/src/third_party/wiredtiger/src/txn/txn.c
+++ b/src/third_party/wiredtiger/src/txn/txn.c
@@ -718,8 +718,7 @@ __txn_fixup_prepared_update(WT_SESSION_IMPL *session, WT_TXN_OP *op, WT_CURSOR *
             upd->next = cbt->ins->upd;
         else if (cbt->ref->page->modify != NULL && cbt->ref->page->modify->mod_row_update != NULL)
             upd->next = cbt->ref->page->modify->mod_row_update[cbt->slot];
-        WT_ASSERT(session,
-          upd->next != NULL && upd->next->next == NULL && upd->next->txnid == WT_TXN_ABORTED);
+        WT_ASSERT(session, upd->next != NULL && upd->next->txnid == WT_TXN_ABORTED);
 
         /* Append a tombstone if the stop timestamp exists. */
         if (hs_stop_ts != WT_TS_MAX) {
diff --git a/src/third_party/wiredtiger/src/txn/txn_ckpt.c b/src/third_party/wiredtiger/src/txn/txn_ckpt.c
index 577281a2a47..2297f957e5f 100644
--- a/src/third_party/wiredtiger/src/txn/txn_ckpt.c
+++ b/src/third_party/wiredtiger/src/txn/txn_ckpt.c
@@ -1259,12 +1259,19 @@ __checkpoint_lock_dirty_tree_int(WT_SESSION_IMPL *session, bool is_checkpoint, b
             continue;
         is_wt_ckpt = WT_PREFIX_MATCH(ckpt->name, WT_CHECKPOINT);
 
+/*
+ * If there is a hot backup, don't delete any WiredTiger checkpoint that could possibly have been
+ * created before the backup started. Fail if trying to delete any other named checkpoint.
+ */
+#ifdef DISABLED_CODE
+        if (conn->hot_backup_start != 0 && ckpt->sec <= conn->hot_backup_start) {
+#else
         /*
-         * If there is a hot backup, don't delete any WiredTiger checkpoint that could possibly have
-         * been created before the backup started. Fail if trying to delete any other named
-         * checkpoint.
+         * N.B. Despite the comment above, dropping checkpoints during backup can corrupt the
+         * backup. For now we retain all WiredTiger checkpoints.
          */
-        if (conn->hot_backup_start != 0 && ckpt->sec <= conn->hot_backup_start) {
+        if (conn->hot_backup_start != 0) {
+#endif
             if (is_wt_ckpt) {
                 F_CLR(ckpt, WT_CKPT_DELETE);
                 continue;
diff --git a/src/third_party/wiredtiger/test/csuite/random_abort/smoke.sh b/src/third_party/wiredtiger/test/csuite/random_abort/smoke.sh
index aea7fedf4b9..713b000b4f1 100755
--- a/src/third_party/wiredtiger/test/csuite/random_abort/smoke.sh
+++ b/src/third_party/wiredtiger/test/csuite/random_abort/smoke.sh
@@ -9,10 +9,6 @@ set -e
 top_builddir=${top_builddir:-../../build_posix}
 top_srcdir=${top_srcdir:-../..}
 
-#FIXME-WT-6093: reenable calls to test_random_abort
-echo "Warning: test_random_abort temporarily disabled"
-exit 0
-
 $TEST_WRAPPER $top_builddir/test/csuite/test_random_abort -t 10 -T 5
 $TEST_WRAPPER $top_builddir/test/csuite/test_random_abort -m -t 10 -T 5
 $TEST_WRAPPER $top_builddir/test/csuite/test_random_abort -C -t 10 -T 5
diff --git a/src/third_party/wiredtiger/test/csuite/schema_abort/smoke.sh b/src/third_party/wiredtiger/test/csuite/schema_abort/smoke.sh
index 2e52b6f438c..78effe1acab 100755
--- a/src/third_party/wiredtiger/test/csuite/schema_abort/smoke.sh
+++ b/src/third_party/wiredtiger/test/csuite/schema_abort/smoke.sh
@@ -13,5 +13,6 @@ $TEST_WRAPPER $top_builddir/test/csuite/test_schema_abort -t 10 -T 5
 $TEST_WRAPPER $top_builddir/test/csuite/test_schema_abort -m -t 10 -T 5
 $TEST_WRAPPER $top_builddir/test/csuite/test_schema_abort -C -t 10 -T 5
 $TEST_WRAPPER $top_builddir/test/csuite/test_schema_abort -C -m -t 10 -T 5
-$TEST_WRAPPER $top_builddir/test/csuite/test_schema_abort -m -t 10 -T 5 -z
+# FIXME: In WT-6116 the test is failing if timestamps are turned off.
+#$TEST_WRAPPER $top_builddir/test/csuite/test_schema_abort -m -t 10 -T 5 -z
 $TEST_WRAPPER $top_builddir/test/csuite/test_schema_abort -m -t 10 -T 5 -x
diff --git a/src/third_party/wiredtiger/test/evergreen.yml b/src/third_party/wiredtiger/test/evergreen.yml
index 62b5c205035..1e306fe4b2e 100755
--- a/src/third_party/wiredtiger/test/evergreen.yml
+++ b/src/third_party/wiredtiger/test/evergreen.yml
@@ -198,9 +198,7 @@ functions:
       script: |
         set -o errexit
         set -o verbose
-        #FIXME-WT-6093: reenable all calls to test_random_abort
-        echo "Warning: test_random_abort temporarily disabled"
-        ##${test_env_vars|} ./test_random_abort ${random_abort_args|} 2>&1
+        ${test_env_vars|} ./test_random_abort ${random_abort_args|} 2>&1
   "timestamp abort test":
     command: shell.exec
     params:
@@ -228,20 +226,19 @@ functions:
         for i in $(seq ${times|1}); do
           # Run the various combinations of args.  Let time and threads be random.
           # Run current version with write-no-sync txns.
-          echo "Warning: test_random_abort temporarily disabled"
-          ##${test_env_vars|} ./test_random_abort 2>&1
+          ${test_env_vars|} ./test_random_abort 2>&1
           ${test_env_vars|} ./test_timestamp_abort 2>&1
 
           # Current version with memory-based txns (MongoDB usage).
-          ##${test_env_vars|} ./test_random_abort -m 2>&1
+          ${test_env_vars|} ./test_random_abort -m 2>&1
           ${test_env_vars|} ./test_timestamp_abort -m 2>&1
 
           # V1 log compatibility mode with write-no-sync txns.
-          ##${test_env_vars|} ./test_random_abort -C 2>&1
+          ${test_env_vars|} ./test_random_abort -C 2>&1
           ${test_env_vars|} ./test_timestamp_abort -C 2>&1
 
           # V1 log compatibility mode with memory-based txns.
-          ##${test_env_vars|} ./test_random_abort -C -m 2>&1
+          ${test_env_vars|} ./test_random_abort -C -m 2>&1
           ${test_env_vars|} ./test_timestamp_abort -C -m 2>&1
 
           ${test_env_vars|} ./test_truncated_log ${truncated_log_args|} 2>&1
@@ -1249,12 +1246,8 @@ tasks:
           dependent_task: compile-linux-no-ftruncate
       - func: "unit test"
 
-  # Break out Python unit tests into multiple buckets/tasks based on test name and runtime
-  # The test/suite/run.py script can work out test names by casting each command argument
-  # with "test_" prefix and "*.py" postfix.
-  #
-  # One example:
-  # "test/suite/run.py [ab]" will be translated to testing "test_a*.py" and "test_b*.py"
+  # Break out Python unit tests into multiple buckets/tasks.  We have a fixed number of buckets,
+  # and we use the -b option of the test/suite/run.py script to split up the tests.
 
   - name: unit-test-bucket00
     tags: ["pull_request", "unit_test"]
@@ -1269,7 +1262,7 @@ tasks:
             set -o errexit
             set -o verbose
 
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py [ab] ${unit_test_args|-v 2} ${smp_command|} 2>&1
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 0/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
 
   - name: unit-test-bucket01
     tags: ["pull_request", "unit_test"]
@@ -1284,8 +1277,7 @@ tasks:
             set -o errexit
             set -o verbose
 
-            # Reserve this bucket only for compat tests, which take a long time to run
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py compat ${unit_test_args|-v 2} ${smp_command|} 2>&1
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 1/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
 
   - name: unit-test-bucket02
     tags: ["pull_request", "unit_test"]
@@ -1300,9 +1292,7 @@ tasks:
             set -o errexit
             set -o verbose
 
-            # Non-compat tests in the 'c' family
-            non_compat_tests=$(ls ../test/suite/test_c*.py | xargs -n1 basename | grep -v compat)
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py $non_compat_tests ${unit_test_args|-v 2} ${smp_command|} 2>&1
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 2/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
 
   - name: unit-test-bucket03
     tags: ["pull_request", "unit_test"]
@@ -1317,7 +1307,8 @@ tasks:
             set -o errexit
             set -o verbose
 
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py [defg] ${unit_test_args|-v 2} ${smp_command|} 2>&1
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 3/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
+
   - name: unit-test-bucket04
     tags: ["pull_request", "unit_test"]
     depends_on:
@@ -1331,9 +1322,7 @@ tasks:
             set -o errexit
             set -o verbose
 
-            # Reserve this bucket only for history store tests, which take a long time to run
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py hs ${unit_test_args|-v 2} ${smp_command|} 2>&1
-
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 4/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
 
   - name: unit-test-bucket05
     tags: ["pull_request", "unit_test"]
@@ -1348,10 +1337,7 @@ tasks:
             set -o errexit
             set -o verbose
 
-            # Non-history store tests in the 'h' family
-            non_ts_tests=$(ls ../test/suite/test_h*.py | xargs -n1 basename | grep -v _hs)
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py $non_ts_tests ${unit_test_args|-v 2} ${smp_command|} 2>&1
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py [ijk] ${unit_test_args|-v 2} ${smp_command|} 2>&1
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 5/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
 
   - name: unit-test-bucket06
     tags: ["pull_request", "unit_test"]
@@ -1366,7 +1352,7 @@ tasks:
             set -o errexit
             set -o verbose
 
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py [lmnopq] ${unit_test_args|-v 2} ${smp_command|} 2>&1
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 6/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
 
   - name: unit-test-bucket07
     tags: ["pull_request", "unit_test"]
@@ -1381,7 +1367,7 @@ tasks:
             set -o errexit
             set -o verbose
 
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py [rs] ${unit_test_args|-v 2} ${smp_command|} 2>&1
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 7/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
 
   - name: unit-test-bucket08
     tags: ["pull_request", "unit_test"]
@@ -1396,8 +1382,7 @@ tasks:
             set -o errexit
             set -o verbose
 
-            # Reserve this bucket only for timestamp tests, which take a long time to run
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py timestamp ${unit_test_args|-v 2} ${smp_command|} 2>&1
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 8/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
 
   - name: unit-test-bucket09
     tags: ["pull_request", "unit_test"]
@@ -1412,9 +1397,7 @@ tasks:
             set -o errexit
             set -o verbose
 
-            # Non-timestamp tests in the 't' family
-            non_ts_tests=$(ls ../test/suite/test_t*.py | xargs -n1 basename | grep -v timestamp)
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py $non_ts_tests ${unit_test_args|-v 2} ${smp_command|} 2>&1
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 9/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
 
   - name: unit-test-bucket10
     tags: ["pull_request", "unit_test"]
@@ -1429,7 +1412,7 @@ tasks:
             set -o errexit
             set -o verbose
 
-            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py [uvwxyz] ${unit_test_args|-v 2} ${smp_command|} 2>&1
+            ${test_env_vars|} ${python_binary|python} ../test/suite/run.py -b 10/11 ${unit_test_args|-v 2} ${smp_command|} 2>&1
 
   # End of Python unit test tasks
 
diff --git a/src/third_party/wiredtiger/test/format/config.c b/src/third_party/wiredtiger/test/format/config.c
index 54a09229ce4..eb86c0860e7 100644
--- a/src/third_party/wiredtiger/test/format/config.c
+++ b/src/third_party/wiredtiger/test/format/config.c
@@ -264,8 +264,13 @@ static void
 config_backup_incr(void)
 {
     /* Incremental backup requires backup. */
-    if (g.c_backups == 0)
+    if (g.c_backups == 0) {
+        if (!config_is_perm("backup.incremental"))
+            config_single("backup.incremental=off", false);
+        if (g.c_backup_incr_flag != INCREMENTAL_OFF)
+            testutil_die(EINVAL, "backup.incremental requires backups be configured");
         return;
+    }
 
     /*
      * Incremental backup using log files is incompatible with logging archival. Testing log file
@@ -298,6 +303,7 @@ config_backup_incr(void)
             if (g.c_logging_archive)
                 config_single("logging.archive=0", false);
             config_single("backup.incremental=log", false);
+            break;
         }
     /* FALLTHROUGH */
     case 7: /* 40% block based incremental */
diff --git a/src/third_party/wiredtiger/test/format/wts.c b/src/third_party/wiredtiger/test/format/wts.c
index ea72c4c7f0f..66a319a9982 100644
--- a/src/third_party/wiredtiger/test/format/wts.c
+++ b/src/third_party/wiredtiger/test/format/wts.c
@@ -281,8 +281,10 @@ wts_open(const char *home, bool set_api, WT_CONNECTION **connp)
         CONFIG_APPEND(p, ",split_8");
     CONFIG_APPEND(p, "]");
 
+#if WIREDTIGER_VERSION_MAJOR >= 10
     if (g.c_verify)
         CONFIG_APPEND(p, ",verify_metadata=true");
+#endif
 
     /* Extensions. */
     CONFIG_APPEND(p,
diff --git a/src/third_party/wiredtiger/test/suite/run.py b/src/third_party/wiredtiger/test/suite/run.py
index 5fb4e0728a5..5cf39777fca 100755
--- a/src/third_party/wiredtiger/test/suite/run.py
+++ b/src/third_party/wiredtiger/test/suite/run.py
@@ -105,6 +105,8 @@ def usage():
 \n\
 Options:\n\
             --asan               run with an ASAN enabled shared library\n\
+  -b K/N  | --batch K/N          run batch K of N, 0 <= K < N. The tests\n\
+                                 are split into N batches and the Kth is run.\n\
   -C file | --configcreate file  create a config file for controlling tests\n\
   -c file | --config file        use a config file for controlling tests\n\
   -D dir  | --dir dir            use dir rather than WT_TEST.\n\
@@ -301,6 +303,7 @@ if __name__ == '__main__':
     asan = False
     parallel = 0
     random_sample = 0
+    batchtotal = batchnum = 0
     configfile = None
     configwrite = False
     dirarg = None
@@ -318,6 +321,24 @@ if __name__ == '__main__':
             if option == '-asan':
                 asan = True
                 continue
+            if option == '-batch' or option == 'b':
+                if batchtotal != 0 or len(args) == 0:
+                    usage()
+                    sys.exit(2)
+                # Batch expects an argument that has int slash int.
+                # For example "-b 4/12"
+                try:
+                    left, right = args.pop(0).split('/')
+                    batchnum = int(left)
+                    batchtotal = int(right)
+                except:
+                    print('batch argument should be nnn/nnn')
+                    usage()
+                    sys.exit(2)
+                if batchtotal <= 0 or batchnum < 0 or batchnum >= batchtotal:
+                    usage()
+                    sys.exit(2)
+                continue
             if option == '-dir' or option == 'D':
                 if dirarg != None or len(args) == 0:
                     usage()
@@ -511,12 +532,34 @@ if __name__ == '__main__':
     if debug:
         import pdb
         pdb.set_trace()
+    if batchtotal != 0:
+        # For test batching, we want to split up all the tests evenly, and
+        # spread out the tests, so each batch contains tests of all kinds. We'd
+        # like to prioritize the lowest scenario numbers first, so if there's a
+        # failure, we won't have to do all X thousand of some test's scenarios
+        # before we see a failure in the next test.  To that end, we define a
+        # sort function that sorts by scenario first, and test name second.
+        hugetests = set()
+        def get_sort_keys(test):
+            s = 0
+            name = test.simpleName()
+            if hasattr(test, 'scenario_number'):
+                s = test.scenario_number
+                if s > 1000:
+                    hugetests.add(name)    # warn for too many scenarios
+            return (s, test.simpleName())  # sort by scenerio number first
+        all_tests = sorted(tests, key = get_sort_keys)
+        if not longtest:
+            for name in hugetests:
+                print("WARNING: huge test " + name + " has > 1000 scenarios.\n" +
+                      "That is only appropriate when using the --long option.\n" +
+                      "The number of scenerios for the test should be pruned")
+
+        # At this point we have an ordered list of all the tests.
+        # Break it into just our batch.
+        tests = unittest.TestSuite(all_tests[batchnum::batchtotal])
     if dryRun:
-        # We have to de-dupe here as some scenarios overlap in the same suite
-        dryOutput = set()
-        for test in tests:
-            dryOutput.add(test.shortDesc())
-        for line in dryOutput:
+        for line in tests:
             print(line)
     else:
         result = wttest.runsuite(tests, parallel)
diff --git a/src/third_party/wiredtiger/test/suite/test_backup01.py b/src/third_party/wiredtiger/test/suite/test_backup01.py
index a39da2e3d18..2494945dba2 100644
--- a/src/third_party/wiredtiger/test/suite/test_backup01.py
+++ b/src/third_party/wiredtiger/test/suite/test_backup01.py
@@ -192,12 +192,15 @@ class test_backup(wttest.WiredTigerTestCase, suite_subprocess):
         # Confirm that a named checkpoint created after a backup cursor can be dropped.
         # Need to pause a couple seconds; checkpoints that are assigned the same timestamp as
         # the backup will be pinned, even if they occur after the backup starts.
+
         time.sleep(2)
-        self.session.checkpoint("name=four")
-        self.session.checkpoint("drop=(four)")
-        self.assertRaises(wiredtiger.WiredTigerError,
-            lambda: self.session.open_cursor(
-            self.objs[0][0], None, "checkpoint=four"))
+        # N.B. This test is temporarily disabled because deleting checkpoints during backup
+        # can corrupt the backup.
+        #self.session.checkpoint("name=four")
+        #self.session.checkpoint("drop=(four)")
+        #self.assertRaises(wiredtiger.WiredTigerError,
+        #    lambda: self.session.open_cursor(
+        #    self.objs[0][0], None, "checkpoint=four"))
 
         # Confirm that after closing the backup cursor the original named checkpoint can
         # be deleted.
diff --git a/src/third_party/wiredtiger/test/suite/test_checkpoint04.py b/src/third_party/wiredtiger/test/suite/test_checkpoint04.py
index 5ba0612c680..eb6f0313d61 100644..100755
--- a/src/third_party/wiredtiger/test/suite/test_checkpoint04.py
+++ b/src/third_party/wiredtiger/test/suite/test_checkpoint04.py
@@ -66,8 +66,8 @@ class test_checkpoint04(wttest.WiredTigerTestCase):
         return val
 
     def test_checkpoint_stats(self):
-        nrows = 1000
-        ntables = 50
+        nrows = 100
+        ntables = 5
 
         self.conn.set_timestamp('oldest_timestamp=' + timestamp_str(10) +
             ',stable_timestamp=' + timestamp_str(10))
diff --git a/src/third_party/wiredtiger/test/suite/test_checkpoint05.py b/src/third_party/wiredtiger/test/suite/test_checkpoint05.py
index 58af3003a60..041f1e53718 100644
--- a/src/third_party/wiredtiger/test/suite/test_checkpoint05.py
+++ b/src/third_party/wiredtiger/test/suite/test_checkpoint05.py
@@ -76,7 +76,10 @@ class test_checkpoint05(wttest.WiredTigerTestCase):
         # is generous.  But if WT isn't deleting checkpoints there would
         # be about 30x more checkpoints here.
         final_count = self.count_checkpoints()
-        self.assertTrue (final_count < initial_count * 3)
+
+        # N.B. This test is temporarily disabled because deleting checkpoints during backup
+        # can corrupt the backup.
+        # self.assertTrue (final_count < initial_count * 3)
 
         self.session.close()
 
diff --git a/src/third_party/wiredtiger/test/suite/test_checkpoint06.py b/src/third_party/wiredtiger/test/suite/test_checkpoint06.py
new file mode 100644
index 00000000000..2ec5f0e472c
--- /dev/null
+++ b/src/third_party/wiredtiger/test/suite/test_checkpoint06.py
@@ -0,0 +1,77 @@
+#!/usr/bin/env python
+#
+# Public Domain 2014-2020 MongoDB, Inc.
+# Public Domain 2008-2014 WiredTiger, Inc.
+#
+# This is free and unencumbered software released into the public domain.
+#
+# Anyone is free to copy, modify, publish, use, compile, sell, or
+# distribute this software, either in source code form or as a compiled
+# binary, for any purpose, commercial or non-commercial, and by any
+# means.
+#
+# In jurisdictions that recognize copyright laws, the author or authors
+# of this software dedicate any and all copyright interest in the
+# software to the public domain. We make this dedication for the benefit
+# of the public at large and to the detriment of our heirs and
+# successors. We intend this dedication to be an overt act of
+# relinquishment in perpetuity of all present and future rights to this
+# software under copyright law.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+
+import time
+import wiredtiger, wttest
+
+def timestamp_str(t):
+    return '%x' % t
+
+# test_checkpoint06.py
+# Verify that we rollback the truncation that is committed after stable
+# timestamp in the checkpoint.
+class test_checkpoint06(wttest.WiredTigerTestCase):
+    conn_config = 'create,cache_size=50MB'
+    session_config = 'isolation=snapshot'
+
+    def test_rollback_truncation_in_checkpoint(self):
+        self.uri = 'table:ckpt06'
+        self.session.create(self.uri, 'key_format=i,value_format=S')
+
+        value = "abcdefghijklmnopqrstuvwxyz" * 3
+        self.conn.set_timestamp('oldest_timestamp=' + timestamp_str(1))
+        cursor = self.session.open_cursor(self.uri)
+        self.session.begin_transaction()
+        # Setup: Insert some data
+        for i in range(10000):
+            cursor[i] = value
+        self.session.commit_transaction('commit_timestamp=' + timestamp_str(2))
+        self.conn.set_timestamp('stable_timestamp=' + timestamp_str(2))
+
+        # Flush everything to disk
+        self.reopen_conn()
+
+        # Truncate large portion of the data in the table
+        self.session.begin_transaction()
+        start = self.session.open_cursor(self.uri)
+        start.set_key(5)
+        end = self.session.open_cursor(self.uri)
+        end.set_key(9995)
+        self.session.truncate(None, start, None, None)
+        self.session.commit_transaction('commit_timestamp=' + timestamp_str(3))
+
+        # Do a checkpoint
+        self.session.checkpoint()
+
+        # rollback to stable
+        self.reopen_conn()
+
+        # Verify the truncation is rolled back.
+        cursor = self.session.open_cursor(self.uri)
+        for i in range(1000):
+            self.assertEqual(cursor[i], value)
diff --git a/src/third_party/wiredtiger/test/suite/test_hs12.py b/src/third_party/wiredtiger/test/suite/test_hs12.py
index 7403126fd5e..ed332dc3349 100644
--- a/src/third_party/wiredtiger/test/suite/test_hs12.py
+++ b/src/third_party/wiredtiger/test/suite/test_hs12.py
@@ -102,4 +102,4 @@ class test_hs12(wttest.WiredTigerTestCase):
         self.assertEquals(cursor2.get_value(), 'AB' + value1)
 
 if __name__ == '__main__':
-    wttest.run()
\ No newline at end of file
+    wttest.run()