Import wiredtiger: bf1d78126c2ff448b868f199aef22b6c528dd45d from branch mongodb-4.4

ref: 4eb9f719ee..bf1d78126c
for: 4.4.0-rc9

WT-6353       Print out failing values and value history of prealloc
WT-6375       Test to verify RTS fixes the inconsistent checkpoint data
WT-6379       Split Evergreen stress test job into multiple shorter running jobs
WT-6381       RTS to remove hs record that is appended to the update chain
WT-6382       Use history store btree when searching

9 files changed, 473 insertions, 176 deletions

diff --git a/src/third_party/wiredtiger/import.data b/src/third_party/wiredtiger/import.data
index 049419a81f9..942a0437e0e 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": "4eb9f719eed3e24a9e49a6fa60d8d56eadb8b189"
+    "commit": "bf1d78126c2ff448b868f199aef22b6c528dd45d"
 }
diff --git a/src/third_party/wiredtiger/src/btree/bt_cursor.c b/src/third_party/wiredtiger/src/btree/bt_cursor.c
index 69fd38f3b4b..66f525ff862 100644
--- a/src/third_party/wiredtiger/src/btree/bt_cursor.c
+++ b/src/third_party/wiredtiger/src/btree/bt_cursor.c
@@ -1822,6 +1822,7 @@ __wt_btcur_init(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt)
     memset(cbt, 0, sizeof(WT_CURSOR_BTREE));
 
     cbt->iface.session = &session->iface;
+    cbt->dhandle = session->dhandle;
 }
 
 /*
diff --git a/src/third_party/wiredtiger/src/btree/col_srch.c b/src/third_party/wiredtiger/src/btree/col_srch.c
index e98cf094421..88a7b48ba88 100644
--- a/src/third_party/wiredtiger/src/btree/col_srch.c
+++ b/src/third_party/wiredtiger/src/btree/col_srch.c
@@ -78,6 +78,12 @@ __wt_col_search(
     btree = S2BT(session);
     current = NULL;
 
+    /*
+     * Assert the session and cursor have the right relationship (not search specific, but search is
+     * a convenient place to check given any operation on a cursor will likely search a page).
+     */
+    WT_ASSERT(session, session->dhandle == cbt->dhandle);
+
     __cursor_pos_clear(cbt);
 
     /*
diff --git a/src/third_party/wiredtiger/src/btree/row_srch.c b/src/third_party/wiredtiger/src/btree/row_srch.c
index 917705f6f9c..05516281d59 100644
--- a/src/third_party/wiredtiger/src/btree/row_srch.c
+++ b/src/third_party/wiredtiger/src/btree/row_srch.c
@@ -230,6 +230,12 @@ __wt_row_search(WT_CURSOR_BTREE *cbt, WT_ITEM *srch_key, bool insert, WT_REF *le
     item = cbt->tmp;
     current = NULL;
 
+    /*
+     * Assert the session and cursor have the right relationship (not search specific, but search is
+     * a convenient place to check given any operation on a cursor will likely search a page).
+     */
+    WT_ASSERT(session, session->dhandle == cbt->dhandle);
+
     __cursor_pos_clear(cbt);
 
     /*
diff --git a/src/third_party/wiredtiger/src/history/hs.c b/src/third_party/wiredtiger/src/history/hs.c
index 398b871ea57..b55e1a77171 100644
--- a/src/third_party/wiredtiger/src/history/hs.c
+++ b/src/third_party/wiredtiger/src/history/hs.c
@@ -279,6 +279,20 @@ __wt_hs_cursor_close(WT_SESSION_IMPL *session, uint32_t session_flags, bool is_o
 }
 
 /*
+ * __hs_row_search --
+ *     Search the history store for a given key and position the cursor on it.
+ */
+static int
+__hs_row_search(WT_CURSOR_BTREE *hs_cbt, WT_ITEM *srch_key, bool insert)
+{
+    WT_DECL_RET;
+
+    WT_WITH_BTREE(CUR2S(hs_cbt), CUR2BT(hs_cbt),
+      ret = __wt_row_search(hs_cbt, srch_key, insert, NULL, false, NULL));
+    return (ret);
+}
+
+/*
  * __wt_hs_modify --
  *     Make an update to the history store.
  *
@@ -406,7 +420,7 @@ __hs_insert_record_with_btree_int(WT_SESSION_IMPL *session, WT_CURSOR *cursor, W
      * Search the page and insert the updates. We expect there will be no existing data: assert that
      * we don't find a matching key.
      */
-    WT_WITH_PAGE_INDEX(session, ret = __wt_row_search(cbt, &cursor->key, true, NULL, false, NULL));
+    WT_WITH_PAGE_INDEX(session, ret = __hs_row_search(cbt, &cursor->key, true));
     WT_ERR(ret);
     WT_ERR(__wt_hs_modify(cbt, hs_upd));
 
@@ -1354,7 +1368,7 @@ __verify_history_store_id(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt, uint32
         WT_ERR(__wt_compare(session, NULL, &hs_key, prev_hs_key, &cmp));
         if (cmp == 0)
             continue;
-        WT_WITH_PAGE_INDEX(session, ret = __wt_row_search(cbt, &hs_key, false, NULL, false, NULL));
+        WT_WITH_PAGE_INDEX(session, ret = __hs_row_search(cbt, &hs_key, false));
         WT_ERR(ret);
 
         found = cbt->compare == 0;
diff --git a/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c b/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c
index d9f6afe3477..48dc34a2cf7 100644
--- a/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c
+++ b/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c
@@ -247,10 +247,11 @@ __rollback_row_ondisk_fixup_key(WT_SESSION_IMPL *session, WT_PAGE *page, WT_ROW
 
         /*
          * Stop processing when we find the newer version value of this key is stable according to
-         * the current version stop timestamp. Also it confirms that history store doesn't contains
-         * any newer version than the current version for the key.
+         * the current version stop timestamp when it is not appending the selected update to the
+         * update chain. Also it confirms that history store doesn't contains any newer version than
+         * the current version for the key.
          */
-        if (hs_stop_ts <= rollback_timestamp) {
+        if (!replace && hs_stop_ts <= rollback_timestamp) {
             __wt_verbose(session, WT_VERB_RTS,
               "history store update valid with stop timestamp: %s and stable timestamp: %s",
               __wt_timestamp_to_string(hs_stop_ts, ts_string[0]),
diff --git a/src/third_party/wiredtiger/test/evergreen.yml b/src/third_party/wiredtiger/test/evergreen.yml
index 4cc34b03a89..07f3d98502c 100755
--- a/src/third_party/wiredtiger/test/evergreen.yml
+++ b/src/third_party/wiredtiger/test/evergreen.yml
@@ -308,6 +308,88 @@ functions:
           done
         done
 
+#########################################################################################
+# VARIABLES
+#
+# The following stress tests are configured to run for six hours via the "-t 360"
+# argument to format.sh: format-stress-test, format-stress-sanitizer-test, and
+# race-condition-stress-sanitizer-test. The smoke and recovery tests run in a loop,
+# with the number of runs adjusted to provide aproximately six hours of testing.
+#########################################################################################
+variables:
+
+  - &format-stress-test
+    exec_timeout_secs: 25200
+    commands:
+      - func: "get project"
+      - func: "compile wiredtiger with builtins"
+      - func: "format test script"
+        vars:
+          format_test_script_args: -e "SEGFAULT_SIGNALS=all" -b "catchsegv ./t" -t 360
+
+  - &format-stress-sanitizer-test
+    exec_timeout_secs: 25200
+    commands:
+      - func: "get project"
+      - func: "compile wiredtiger address sanitizer"
+      - func: "format test script"
+        vars:
+          format_test_script_args: -t 360
+          test_env_vars:
+            ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0"
+            ASAN_SYMBOLIZER_PATH=/opt/mongodbtoolchain/v3/bin/llvm-symbolizer
+
+  - &format-stress-smoke-test
+    exec_timeout_secs: 25200
+    commands:
+      - func: "get project"
+      - func: "compile wiredtiger with builtins"
+      - func: "format test script"
+        vars:
+          format_test_script_args: -e "SEGFAULT_SIGNALS=all" -b "catchsegv ./t" -S
+          times: 30
+
+  - &format-stress-sanitizer-smoke-test
+    exec_timeout_secs: 25200
+    commands:
+      - func: "get project"
+      - func: "compile wiredtiger address sanitizer"
+      - func: "format test script"
+        vars:
+          test_env_vars:
+            ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0"
+            ASAN_SYMBOLIZER_PATH=/opt/mongodbtoolchain/v3/bin/llvm-symbolizer
+          format_test_script_args: -S
+          times: 20
+
+  - &race-condition-stress-sanitizer-test
+    exec_timeout_secs: 25200
+    commands:
+      - func: "get project"
+      - func: "compile wiredtiger"
+        vars:
+          configure_env_vars:
+            CC="/opt/mongodbtoolchain/v3/bin/clang -fsanitize=address"
+            PATH=/opt/mongodbtoolchain/v3/bin:$PATH CFLAGS="-ggdb -fPIC -fno-omit-frame-pointer"
+          posix_configure_flags: --enable-diagnostic --with-builtins=lz4,snappy,zlib
+      - func: "format test script"
+        vars:
+          format_test_script_args: -R -t 360
+          test_env_vars:
+            ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0"
+            ASAN_SYMBOLIZER_PATH=/opt/mongodbtoolchain/v3/bin/llvm-symbolizer
+
+  - &recovery-stress-test
+    exec_timeout_secs: 25200
+    commands:
+      - func: "get project"
+      - func: "compile wiredtiger"
+        vars:
+          posix_configure_flags: --enable-strict --enable-diagnostic --with-builtins=lz4,snappy,zlib
+      - func: "recovery stress test script"
+        vars:
+          times: 40
+
 pre:
   - func: "cleanup"
 post:
@@ -1981,8 +2063,6 @@ tasks:
   - name: time-shift-sensitivity-test
     depends_on:
     - name: compile
-      vars:
-        posix_configure_flags: --enable-strict
     commands:
       - func: "fetch artifacts"
         vars:
@@ -1996,140 +2076,6 @@ tasks:
 
             ./time_shift_test.sh /usr/local/lib/faketime/libfaketimeMT.so.1 0-1 2>&1
 
-  - name: format-stress-sanitizer-test
-    #set a 25 hours (25*60*60 = 90000 seconds) timeout
-    exec_timeout_secs: 90000
-    commands:
-      - func: "get project"
-      - func: "compile wiredtiger address sanitizer"
-      - func: "format test script"
-        vars:
-          test_env_vars: ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0" ASAN_SYMBOLIZER_PATH=/opt/mongodbtoolchain/v3/bin/llvm-symbolizer
-          # run for 24 hours ( 24 * 60 = 1440 minutes), skip known errors, don't stop at failed tests, use default config
-          format_test_script_args: -E -t 1440
-
-  - name: format-stress-sanitizer-lsm-test
-    commands:
-      - func: "get project"
-      - func: "compile wiredtiger address sanitizer"
-      - func: "format test script"
-        vars:
-          test_env_vars: ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0" ASAN_SYMBOLIZER_PATH=/opt/mongodbtoolchain/v3/bin/llvm-symbolizer
-          # Run for 30 mins, and explicitly set data_source to LSM with a large cache
-          format_test_script_args: -t 30 data_source=lsm cache_minimum=5000
-
-  - name: format-stress-sanitizer-smoke-test
-    #set a 7 hours timeout
-    exec_timeout_secs: 25200
-    commands:
-      - func: "get project"
-      - func: "compile wiredtiger address sanitizer"
-      - func: "format test script"
-        # to emulate the original Jenkins job's test coverage, we are running the smoke test 16 times
-        # run smoke tests, skip known errors, don't stop at failed tests, use default config
-        vars:
-          test_env_vars: ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0" ASAN_SYMBOLIZER_PATH=/opt/mongodbtoolchain/v3/bin/llvm-symbolizer
-          format_test_script_args: -E -S
-          times: 16
-
-  - name: race-condition-stress-sanitizer-test
-    # set an evergreen timeout of 25 hours
-    exec_timeout_secs: 90000
-    commands:
-      - func: "get project"
-      - func: "compile wiredtiger"
-        vars:
-          configure_env_vars: CC="/opt/mongodbtoolchain/v3/bin/clang -fsanitize=address" PATH=/opt/mongodbtoolchain/v3/bin:$PATH CFLAGS="-ggdb -fPIC -fno-omit-frame-pointer"
-          posix_configure_flags: --enable-diagnostic --with-builtins=lz4,snappy,zlib
-      - func: "format test script"
-        vars:
-          # set a format.sh timeout of 24 hours, skip known errors, don't stop at failed tests, use default config
-          format_test_script_args: -E -R -t 1440
-          test_env_vars: ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0" ASAN_SYMBOLIZER_PATH=/opt/mongodbtoolchain/v3/bin/llvm-symbolizer
-
-  - name: recovery-stress-test
-    #set a 25 hours timeout
-    exec_timeout_secs: 90000
-    commands:
-      - func: "get project"
-      - func: "compile wiredtiger"
-        vars:
-          posix_configure_flags: --enable-strict --enable-diagnostic --with-builtins=lz4,snappy,zlib
-      - func: "recovery stress test script"
-        vars:
-          # Repeat this script enough times to make this task run for 24 hours
-          # At the time of writing this script, one call to underlying scripts takes about ~15 mins to finish in worst case.
-          # We are giving an extra ~20% room for vairance in execution time.
-          times: 80
-
-  - name: split-stress-test
-    commands:
-      - func: "get project"
-      - func: "compile wiredtiger"
-        vars:
-          configure_env_vars: CXX=/opt/mongodbtoolchain/v3/bin/g++ PATH=/opt/mongodbtoolchain/v3/bin:$PATH CFLAGS="-ggdb -fPIC"
-      - command: shell.exec
-        params:
-          working_dir: "wiredtiger/bench/workgen/runner"
-          script: |
-            set -o errexit
-            set -o verbose
-            for i in {1..10}; do ${python_binary|python} split_stress.py; done
-
-  - name: format-stress-test
-    # Set 25 hours timeout
-    exec_timeout_secs: 90000
-    commands:
-      - func: "get project"
-      - func: "compile wiredtiger with builtins"
-      - func: "format test script"
-        vars:
-          #run for 24 hours ( 24 * 60 = 1440 minutes), use default config
-          format_test_script_args: -e "SEGFAULT_SIGNALS=all" -b "catchsegv ./t" -t 1440
-
-  - name: format-stress-smoke-test
-    # Set 7 hours timeout
-    exec_timeout_secs: 25200
-    commands:
-      - func: "get project"
-      - func: "compile wiredtiger with builtins"
-      - func: "format test script"
-        vars:
-          # to emulate the original Jenkins job's test coverage, we are running the smoke test 16 times
-          # run smoke tests, use default config (-S)
-          format_test_script_args: -e "SEGFAULT_SIGNALS=all" -b "catchsegv ./t" -S
-          times: 16
-
-  - name: checkpoint-stress-test
-    commands:
-      - command: timeout.update
-        params:
-          # set 24 hour timeout for the task and command
-          exec_timeout_secs: 86400
-          timeout_secs: 86400
-      - func: "get project"
-      - func: "compile wiredtiger with builtins"
-      - func: "checkpoint stress test"
-        vars:
-          # No of times to run the loop
-          times: 1
-          # No of processes to run in the background
-          no_of_procs: 8
-
-  # The task name is ppc-zseries because this task will be used in both buildVariants
-  - name: format-stress-ppc-zseries-test
-    # Set 2.5 hours timeout (60 * 60 * 2.5)
-    exec_timeout_secs: 9000
-    commands:
-      - func: "get project"
-      - func: "compile wiredtiger with builtins"
-      - func: "format test script"
-        vars:
-          # Make sure we dump core on failure
-          format_test_setting: ulimit -c unlimited
-          #run for 2 hours ( 2 * 60 = 120 minutes), use default config
-          format_test_script_args: -e "SEGFAULT_SIGNALS=all" -b "catchsegv ./t" -t 120
-
   - name: format-wtperf-test
     commands:
       - func: "get project"
@@ -2177,41 +2123,175 @@ tasks:
               exit 1
             fi
 
+  - name: format-stress-sanitizer-lsm-test
+    # Temporarily disabled (WT-6255)
+    # tags: ["stress-test-1"]
+    commands:
+      - func: "get project"
+      - func: "compile wiredtiger address sanitizer"
+      - func: "format test script"
+        vars:
+          test_env_vars:
+            ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0"
+            ASAN_SYMBOLIZER_PATH=/opt/mongodbtoolchain/v3/bin/llvm-symbolizer
+          # Run for 30 mins, and explicitly set data_source to LSM with a large cache
+          format_test_script_args: -t 30 data_source=lsm cache_minimum=5000
+
+  - name: checkpoint-stress-test
+    tags: ["stress-test-1"]
+    exec_timeout_secs: 86400
+    commands:
+      - command: timeout.update
+        params:
+          timeout_secs: 86400
+      - func: "get project"
+      - func: "compile wiredtiger with builtins"
+      - func: "checkpoint stress test"
+        vars:
+          times: 1       # No of times to run the loop
+          no_of_procs: 8 # No of processes to run in the background
+
+  - name: split-stress-test
+    tags: ["stress-test-1", "stress-test-zseries-1"]
+    commands:
+      - func: "get project"
+      - func: "compile wiredtiger"
+        vars:
+          configure_env_vars:
+            CXX=/opt/mongodbtoolchain/v3/bin/g++
+            PATH=/opt/mongodbtoolchain/v3/bin:$PATH CFLAGS="-ggdb -fPIC"
+      - command: shell.exec
+        params:
+          working_dir: "wiredtiger/bench/workgen/runner"
+          script: |
+            set -o errexit
+            set -o verbose
+            for i in {1..10}; do ${python_binary|python} split_stress.py; done
+
+  # The task name is ppc-zseries because this task will be used in both buildVariants
+  - name: format-stress-ppc-zseries-test
+    tags: ["stress-test-ppc-1", "stress-test-zseries-1"]
+    # Set 2.5 hours timeout (60 * 60 * 2.5)
+    exec_timeout_secs: 9000
+    commands:
+      - func: "get project"
+      - func: "compile wiredtiger with builtins"
+      - func: "format test script"
+        vars:
+          # Make sure we dump core on failure
+          format_test_setting: ulimit -c unlimited
+          #run for 2 hours ( 2 * 60 = 120 minutes), use default config
+          format_test_script_args: -e "SEGFAULT_SIGNALS=all" -b "catchsegv ./t" -t 120
+
+  # Replace this test with format-stress-sanitizer-test after BUILD-10248 fix.
   - name: format-stress-sanitizer-ppc-test
+    tags: ["stress-test-ppc-1"]
     # Set 2.5 hours timeout (60 * 60 * 2.5)
     exec_timeout_secs: 9000
     commands:
       - func: "get project"
       - func: "compile wiredtiger"
         vars:
-          # CC is set to the system default "clang" binary here as a workaround. Change it back to mongodbtoolchain "clang" binary after BUILD-10248 fix.
-          configure_env_vars: CCAS=/opt/mongodbtoolchain/v3/bin/gcc CC=/usr/bin/clang CXX=/opt/mongodbtoolchain/v3/bin/clang++ PATH=/opt/mongodbtoolchain/v3/bin:$PATH CFLAGS="-ggdb -fPIC -fsanitize=address -fno-omit-frame-pointer -I/opt/mongodbtoolchain/v3/lib/gcc/ppc64le-mongodb-linux/8.2.0/include"
+          # CC is set to the system default "clang" binary here as a workaround. Change it back
+          # to mongodbtoolchain "clang" binary after BUILD-10248 fix.
+          configure_env_vars:
+            CCAS=/opt/mongodbtoolchain/v3/bin/gcc CC=/usr/bin/clang
+            CXX=/opt/mongodbtoolchain/v3/bin/clang++ PATH=/opt/mongodbtoolchain/v3/bin:$PATH
+            CFLAGS="-ggdb -fPIC -fsanitize=address -fno-omit-frame-pointer
+            -I/opt/mongodbtoolchain/v3/lib/gcc/ppc64le-mongodb-linux/8.2.0/include"
           posix_configure_flags: --enable-diagnostic --with-builtins=lz4,snappy,zlib
       - func: "format test script"
         vars:
-          test_env_vars: ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0" ASAN_SYMBOLIZER_PATH=/usr/lib/llvm-6.0/bin/llvm-symbolizer
-          # run for 2 hours ( 2 * 60 = 120 minutes), don't stop at failed tests, use default config
+          test_env_vars:
+            ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0"
+            ASAN_SYMBOLIZER_PATH=/usr/lib/llvm-6.0/bin/llvm-symbolizer
+          # Run for 2 hours (2 * 60 = 120 minutes), don't stop at failed tests, use default config
           format_test_script_args: -t 120
 
+  # Replace this test with format-stress-sanitizer-smoke-test after BUILD-10248 fix.
   - name: format-stress-sanitizer-smoke-ppc-test
+    tags: ["stress-test-ppc-1"]
     # Set 7 hours timeout (60 * 60 * 7)
     exec_timeout_secs: 25200
     commands:
       - func: "get project"
       - func: "compile wiredtiger"
         vars:
-          # CC is set to the system default "clang" binary here as a workaround. Change it back to mongodbtoolchain "clang" binary after BUILD-10248 fix.
-          configure_env_vars: CCAS=/opt/mongodbtoolchain/v3/bin/gcc CC=/usr/bin/clang CXX=/opt/mongodbtoolchain/v3/bin/clang++ PATH=/opt/mongodbtoolchain/v3/bin:$PATH CFLAGS="-ggdb -fPIC -fsanitize=address -fno-omit-frame-pointer -I/opt/mongodbtoolchain/v3/lib/gcc/ppc64le-mongodb-linux/8.2.0/include"
+          # CC is set to the system default "clang" binary here as a workaround. Change it back
+          # to mongodbtoolchain "clang" binary after BUILD-10248 fix.
+          configure_env_vars:
+            CCAS=/opt/mongodbtoolchain/v3/bin/gcc CC=/usr/bin/clang
+            CXX=/opt/mongodbtoolchain/v3/bin/clang++ PATH=/opt/mongodbtoolchain/v3/bin:$PATH
+            CFLAGS="-ggdb -fPIC -fsanitize=address -fno-omit-frame-pointer
+            -I/opt/mongodbtoolchain/v3/lib/gcc/ppc64le-mongodb-linux/8.2.0/include"
           posix_configure_flags: --enable-diagnostic --with-builtins=lz4,snappy,zlib
       - func: "format test script"
-        # to emulate the original Jenkins job's test coverage, we are running the smoke test 16 times
-        # run smoke tests, don't stop at failed tests, use default config
+        # To emulate the original Jenkins job's test coverage, we are running the smoke test 16 times
+        # Run smoke tests, don't stop at failed tests, use default config
         vars:
-          test_env_vars: ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0" ASAN_SYMBOLIZER_PATH=/usr/lib/llvm-6.0/bin/llvm-symbolizer
+          test_env_vars:
+            ASAN_OPTIONS="detect_leaks=1:abort_on_error=1:disable_coredump=0"
+            ASAN_SYMBOLIZER_PATH=/usr/lib/llvm-6.0/bin/llvm-symbolizer
           format_test_script_args: -S
           times: 16
 
+  - <<: *format-stress-test
+    name: format-stress-test-1
+    tags: ["stress-test-1"]
+  - <<: *format-stress-test
+    name: format-stress-test-2
+    tags: ["stress-test-2"]
+  - <<: *format-stress-test
+    name: format-stress-test-3
+    tags: ["stress-test-3"]
+  - <<: *format-stress-test
+    name: format-stress-test-4
+    tags: ["stress-test-4"]
+  - <<: *format-stress-sanitizer-test
+    name: format-stress-sanitizer-test-1
+    tags: ["stress-test-1"]
+  - <<: *format-stress-sanitizer-test
+    name: format-stress-sanitizer-test-2
+    tags: ["stress-test-2"]
+  - <<: *format-stress-sanitizer-test
+    name: format-stress-sanitizer-test-3
+    tags: ["stress-test-3"]
+  - <<: *format-stress-sanitizer-test
+    name: format-stress-sanitizer-test-4
+    tags: ["stress-test-4"]
+  - <<: *format-stress-smoke-test
+    name: format-stress-smoke-test-1
+    tags: ["stress-test-1", "stress-test-ppc-1", "stress-test-zseries-1"]
+  - <<: *format-stress-smoke-test
+    name: format-stress-smoke-test-2
+    tags: ["stress-test-2", "stress-test-ppc-2", "stress-test-zseries-2"]
+  - <<: *format-stress-sanitizer-smoke-test
+    name: format-stress-sanitizer-smoke-test-1
+    tags: ["stress-test-1"]
+  - <<: *format-stress-sanitizer-smoke-test
+    name: format-stress-sanitizer-smoke-test-2
+    tags: ["stress-test-2"]
+  - <<: *race-condition-stress-sanitizer-test
+    name: race-condition-stress-sanitizer-test-1
+    tags: ["stress-test-1"]
+  - <<: *race-condition-stress-sanitizer-test
+    name: race-condition-stress-sanitizer-test-2
+    tags: ["stress-test-2"]
+  - <<: *race-condition-stress-sanitizer-test
+    name: race-condition-stress-sanitizer-test-3
+    tags: ["stress-test-3"]
+  - <<: *race-condition-stress-sanitizer-test
+    name: race-condition-stress-sanitizer-test-4
+    tags: ["stress-test-4"]
+  - <<: *recovery-stress-test
+    name: recovery-stress-test-1
+    tags: ["stress-test-1", "stress-test-zseries-1"]
+  - <<: *recovery-stress-test
+    name: recovery-stress-test-2
+    tags: ["stress-test-2", "stress-test-zseries-2"]
+
 buildvariants:
+
 - name: ubuntu1804
   display_name: "! Ubuntu 18.04"
   run_on:
@@ -2275,21 +2355,19 @@ buildvariants:
   run_on:
   - ubuntu1804-test
   expansions:
-    test_env_vars: LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libeatmydata.so PATH=/opt/mongodbtoolchain/v3/bin:$PATH LD_LIBRARY_PATH=$(pwd)/.libs top_srcdir=$(pwd)/.. top_builddir=$(pwd)
     smp_command: -j $(grep -c ^processor /proc/cpuinfo)
-    posix_configure_flags: --enable-silent-rules --enable-diagnostic --enable-python --enable-zlib --enable-snappy --enable-strict --enable-static --prefix=$(pwd)/LOCAL_INSTALL
     make_command: PATH=/opt/mongodbtoolchain/v3/bin:$PATH make
+    test_env_vars:
+      LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libeatmydata.so LD_LIBRARY_PATH=$(pwd)/.libs
+      PATH=/opt/mongodbtoolchain/v3/bin:$PATH top_srcdir=$(pwd)/.. top_builddir=$(pwd)
+    posix_configure_flags:
+      --enable-silent-rules --enable-diagnostic --enable-python --enable-zlib --enable-snappy
+      --enable-strict --enable-static --prefix=$(pwd)/LOCAL_INSTALL
   tasks:
-    - name: recovery-stress-test
-    - name: format-stress-sanitizer-test
-    - name: format-stress-sanitizer-smoke-test
-    # Temporarily disabled (WT-6255)
-    # - name: format-stress-sanitizer-lsm-test
-    - name: split-stress-test
-    - name: format-stress-test
-    - name: format-stress-smoke-test
-    - name: race-condition-stress-sanitizer-test
-    - name: checkpoint-stress-test
+    - name: ".stress-test-1"
+    - name: ".stress-test-2"
+    - name: ".stress-test-3"
+    - name: ".stress-test-4"
 
 - name: package
   display_name: "~ Package"
@@ -2433,18 +2511,19 @@ buildvariants:
   - ubuntu1804-power8-test
   expansions:
     smp_command: -j $(grep -c ^processor /proc/cpuinfo)
-    posix_configure_flags: --enable-silent-rules --enable-diagnostic --enable-python --enable-zlib --enable-snappy --enable-strict --enable-static --prefix=$(pwd)/LOCAL_INSTALL
     make_command: PATH=/opt/mongodbtoolchain/v3/bin:$PATH make
-    test_env_vars: PATH=/opt/mongodbtoolchain/v3/bin:$PATH LD_LIBRARY_PATH=$(pwd)/.libs top_srcdir=$(pwd)/.. top_builddir=$(pwd)
+    test_env_vars:
+      PATH=/opt/mongodbtoolchain/v3/bin:$PATH LD_LIBRARY_PATH=$(pwd)/.libs
+      top_srcdir=$(pwd)/.. top_builddir=$(pwd)
+    posix_configure_flags:
+      --enable-silent-rules --enable-diagnostic --enable-python --enable-zlib --enable-snappy
+      --enable-strict --enable-static --prefix=$(pwd)/LOCAL_INSTALL
   tasks:
   - name: compile
   - name: unit-test
-  - name: format-stress-ppc-zseries-test
-  - name: format-stress-smoke-test
   - name: format-wtperf-test
-  # Replace the below two tests with format-stress-sanitizer-ppc-test and format-stress-sanitizer-smoke-test after BUILD-10248 fix.
-  - name: format-stress-sanitizer-ppc-test
-  - name: format-stress-sanitizer-smoke-ppc-test
+  - name: ".stress-test-ppc-1"
+  - name: ".stress-test-ppc-2"
 
 - name: ubuntu1804-zseries
   display_name: "~ Ubuntu 18.04 zSeries"
@@ -2452,13 +2531,15 @@ buildvariants:
   - ubuntu1804-zseries-test
   expansions:
     smp_command: -j $(grep -c ^processor /proc/cpuinfo)
-    posix_configure_flags: --enable-silent-rules --enable-diagnostic --enable-python --enable-zlib --enable-snappy --enable-strict --enable-static --prefix=$(pwd)/LOCAL_INSTALL
     make_command: PATH=/opt/mongodbtoolchain/v3/bin:$PATH make
-    test_env_vars: PATH=/opt/mongodbtoolchain/v3/bin:$PATH LD_LIBRARY_PATH=$(pwd)/.libs:$(pwd)/lang/python top_srcdir=$(pwd)/.. top_builddir=$(pwd)
+    test_env_vars:
+      PATH=/opt/mongodbtoolchain/v3/bin:$PATH LD_LIBRARY_PATH=$(pwd)/.libs:$(pwd)/lang/python
+      top_srcdir=$(pwd)/.. top_builddir=$(pwd)
+    posix_configure_flags:
+      --enable-silent-rules --enable-diagnostic --enable-python --enable-zlib --enable-snappy
+      --enable-strict --enable-static --prefix=$(pwd)/LOCAL_INSTALL
   tasks:
   - name: compile
   - name: unit-test
-  - name: recovery-stress-test
-  - name: split-stress-test
-  - name: format-stress-ppc-zseries-test
-  - name: format-stress-smoke-test
+  - name: ".stress-test-zseries-1"
+  - name: ".stress-test-zseries-2"
diff --git a/src/third_party/wiredtiger/test/suite/test_bug019.py b/src/third_party/wiredtiger/test/suite/test_bug019.py
index a11581fbc0f..0cfcc2b13cb 100644
--- a/src/third_party/wiredtiger/test/suite/test_bug019.py
+++ b/src/third_party/wiredtiger/test/suite/test_bug019.py
@@ -57,6 +57,8 @@ class test_bug019(wttest.WiredTigerTestCase):
             if i % 500 == 0:
                 prealloc = self.get_prealloc_stat()
                 if prealloc > self.max_prealloc:
+                    self.pr("Updating max_prealloc from " + str(self.max_prealloc))
+                    self.pr("    to new prealloc " + str(prealloc))
                     self.max_prealloc = prealloc
         c.close()
 
@@ -78,6 +80,9 @@ class test_bug019(wttest.WiredTigerTestCase):
         start_prealloc = self.get_prealloc_stat()
         self.populate(self.entries)
         self.session.checkpoint()
+        if self.max_prealloc <= start_prealloc:
+            self.pr("FAILURE: max_prealloc " + str(self.max_prealloc))
+            self.pr("FAILURE: start_prealloc " + str(start_prealloc))
         self.assertTrue(self.max_prealloc > start_prealloc)
 
         # Loop, making sure pre-allocation is working and the range is moving.
diff --git a/src/third_party/wiredtiger/test/suite/test_rollback_to_stable10.py b/src/third_party/wiredtiger/test/suite/test_rollback_to_stable10.py
new file mode 100755
index 00000000000..e79c55203bf
--- /dev/null
+++ b/src/third_party/wiredtiger/test/suite/test_rollback_to_stable10.py
@@ -0,0 +1,183 @@
+#!/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 fnmatch, os, shutil, threading, time
+from helper import copy_wiredtiger_home
+from test_rollback_to_stable01 import test_rollback_to_stable_base
+from wiredtiger import stat
+from wtdataset import SimpleDataSet
+from wtscenario import make_scenarios
+from wtthread import checkpoint_thread, op_thread
+
+def timestamp_str(t):
+    return '%x' % t
+
+# test_rollback_to_stable10.py
+# Test the rollback to stable operation performs sweeping history store.
+class test_rollback_to_stable10(test_rollback_to_stable_base):
+    session_config = 'isolation=snapshot'
+
+    prepare_values = [
+        ('no_prepare', dict(prepare=False)),
+        ('prepare', dict(prepare=True))
+    ]
+
+    scenarios = make_scenarios(prepare_values)
+
+    def conn_config(self):
+        config = 'cache_size=5MB,statistics=(all),statistics_log=(json,on_close,wait=1),log=(enabled=true),timing_stress_for_test=[history_store_checkpoint_delay]'
+        return config
+
+    def simulate_crash_restart(self, olddir, newdir):
+        ''' Simulate a crash from olddir and restart in newdir. '''
+        # with the connection still open, copy files to new directory
+        shutil.rmtree(newdir, ignore_errors=True)
+        os.mkdir(newdir)
+        for fname in os.listdir(olddir):
+            fullname = os.path.join(olddir, fname)
+            # Skip lock file on Windows since it is locked
+            if os.path.isfile(fullname) and \
+                "WiredTiger.lock" not in fullname and \
+                "Tmplog" not in fullname and \
+                "Preplog" not in fullname:
+                shutil.copy(fullname, newdir)
+        #
+        # close the original connection and open to new directory
+        # NOTE:  This really cannot test the difference between the
+        # write-no-sync (off) version of log_flush and the sync
+        # version since we're not crashing the system itself.
+        #
+        self.close_conn()
+        self.conn = self.setUpConnectionOpen(newdir)
+        self.session = self.setUpSessionOpen(self.conn)
+
+    def test_rollback_to_stable(self):
+        nrows = 1000
+
+        # Create a table without logging.
+        uri_1 = "table:rollback_to_stable10_1"
+        ds_1 = SimpleDataSet(
+            self, uri_1, 0, key_format="i", value_format="S", config='log=(enabled=false)')
+        ds_1.populate()
+
+        # Create another table without logging.
+        uri_2 = "table:rollback_to_stable10_2"
+        ds_2 = SimpleDataSet(
+            self, uri_2, 0, key_format="i", value_format="S", config='log=(enabled=false)')
+        ds_2.populate()
+
+        # Pin oldest and stable to timestamp 10.
+        self.conn.set_timestamp('oldest_timestamp=' + timestamp_str(10) +
+            ',stable_timestamp=' + timestamp_str(10))
+
+        value_a = "aaaaa" * 100
+        value_b = "bbbbb" * 100
+        value_c = "ccccc" * 100
+        value_d = "ddddd" * 100
+        value_e = "eeeee" * 100
+        value_f = "fffff" * 100
+
+        # Perform several updates.
+        self.large_updates(uri_1, value_d, ds_1, nrows, 20)
+        self.large_updates(uri_1, value_c, ds_1, nrows, 30)
+        self.large_updates(uri_1, value_b, ds_1, nrows, 40)
+        self.large_updates(uri_1, value_a, ds_1, nrows, 50)
+
+        self.large_updates(uri_2, value_d, ds_2, nrows, 20)
+        self.large_updates(uri_2, value_c, ds_2, nrows, 30)
+        self.large_updates(uri_2, value_b, ds_2, nrows, 40)
+        self.large_updates(uri_2, value_a, ds_2, nrows, 50)
+
+        # Verify data is visible and correct.
+        self.check(value_d, uri_1, nrows, 20)
+        self.check(value_c, uri_1, nrows, 30)
+        self.check(value_b, uri_1, nrows, 40)
+        self.check(value_a, uri_1, nrows, 50)
+
+        self.check(value_d, uri_2, nrows, 20)
+        self.check(value_c, uri_2, nrows, 30)
+        self.check(value_b, uri_2, nrows, 40)
+        self.check(value_a, uri_2, nrows, 50)
+
+        # Pin stable to timestamp 60 if prepare otherwise 50.
+        if self.prepare:
+            self.conn.set_timestamp('stable_timestamp=' + timestamp_str(60))
+        else:
+            self.conn.set_timestamp('stable_timestamp=' + timestamp_str(50))
+
+        # Create a checkpoint thread
+        done = threading.Event()
+        ckpt = checkpoint_thread(self.conn, done)
+        ckpt.start()
+
+        # Perform several updates in parallel with checkpoint.
+        self.large_updates(uri_1, value_e, ds_1, nrows, 70)
+        self.large_updates(uri_2, value_e, ds_2, nrows, 70)
+        self.large_updates(uri_1, value_f, ds_1, nrows, 80)
+        self.large_updates(uri_2, value_f, ds_2, nrows, 80)
+
+        done.set()
+        ckpt.join()
+
+        # Simulate a server crash and restart.
+        self.simulate_crash_restart(".", "RESTART")
+
+        # Check that the correct data is seen at and after the stable timestamp.
+        self.check(value_a, uri_1, nrows, 50)
+        self.check(value_a, uri_1, nrows, 80)
+        self.check(value_b, uri_1, nrows, 40)
+        self.check(value_c, uri_1, nrows, 30)
+        self.check(value_d, uri_1, nrows, 20)
+
+        # Check that the correct data is seen at and after the stable timestamp.
+        self.check(value_a, uri_2, nrows, 50)
+        self.check(value_a, uri_2, nrows, 80)
+        self.check(value_b, uri_2, nrows, 40)
+        self.check(value_c, uri_2, nrows, 30)
+        self.check(value_d, uri_2, nrows, 20)
+
+        stat_cursor = self.session.open_cursor('statistics:', None, None)
+        calls = stat_cursor[stat.conn.txn_rts][2]
+        hs_removed = stat_cursor[stat.conn.txn_rts_hs_removed][2]
+        hs_sweep = stat_cursor[stat.conn.txn_rts_sweep_hs_keys][2]
+        keys_removed = stat_cursor[stat.conn.txn_rts_keys_removed][2]
+        keys_restored = stat_cursor[stat.conn.txn_rts_keys_restored][2]
+        pages_visited = stat_cursor[stat.conn.txn_rts_pages_visited][2]
+        upd_aborted = stat_cursor[stat.conn.txn_rts_upd_aborted][2]
+        stat_cursor.close()
+
+        self.assertEqual(calls, 0)
+        self.assertEqual(keys_removed, 0)
+        self.assertEqual(keys_restored, 0)
+        self.assertGreaterEqual(upd_aborted, 0)
+        self.assertGreater(pages_visited, 0)
+        self.assertGreaterEqual(hs_removed, 0)
+        self.assertGreater(hs_sweep, 0)
+
+if __name__ == '__main__':
+    wttest.run()