Import wiredtiger: 805fe0276c367cb70321af3e1f473c881d0adc87 from branch mongodb-5.0

ref: 5f201b99d9..805fe0276c
for: 4.9.0

WT-6693       Add compatibility testing for imported objects
WT-6824       Fix OSX python test errors related to UTF encoding
WT-6836       Handle the last key in the shadow table being removed by rollback to stable in timestamp abort
WT-6867       Documentation: create model subpages for architecture guide
WT-6870       Rename history store statistic to better describe its use case.
WT-6872       Replace the yield instructions with an ISB
WT-6875       Remove legacy import invocation

30 files changed, 665 insertions, 259 deletions

diff --git a/src/third_party/wiredtiger/dist/docs.py b/src/third_party/wiredtiger/dist/docs.py
new file mode 100644
index 00000000000..1b26c8090d3
--- /dev/null
+++ b/src/third_party/wiredtiger/dist/docs.py
@@ -0,0 +1,45 @@
+# Read and verify the documentation data to make sure path names are valid.
+
+import os, sys
+import docs_data
+
+def check_sort(got, msg, keyfunc=None):
+    if keyfunc:
+        expect = sorted(got, key=keyfunc)
+    else:
+        expect = sorted(got)
+    if got != expect:
+        print(msg)
+        print('  got: ' + str(got))
+        print('  expect: ' + str(expect))
+
+# An include filename will be sorted first.
+def inc_first(f):
+    if '/include/' in f:
+        return '_' + f
+    else:
+        return f
+
+top_dir = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
+
+pages = docs_data.arch_doc_pages
+all_names = [ page.doxygen_name for page in pages]
+check_sort(all_names, 'arch_doc_pages must be sorted by name.')
+
+for page in pages:
+    name = page.doxygen_name
+    check_sort(page.data_structures, name + ': data structures must be sorted.')
+    for partial in page.files:
+        fullpath = os.path.join(top_dir, partial)
+        if not os.path.exists(fullpath):
+            print(name + ': ' + partial + ': does not exist')
+        elif os.path.isdir(fullpath):
+            if fullpath[-1:] != '/':
+                print(name + ': ' + partial + ': is a directory, must end in /')
+        else:
+            if fullpath[-1:] == '/':
+                print(name + ': ' + partial + ': not a directory, cannot end in /')
+    check_sort(page.files,
+      name + ': sources must be sorted, with include files first.', inc_first)
+
+sys.exit(0)
diff --git a/src/third_party/wiredtiger/dist/docs_data.py b/src/third_party/wiredtiger/dist/docs_data.py
new file mode 100644
index 00000000000..47ae7c3c51a
--- /dev/null
+++ b/src/third_party/wiredtiger/dist/docs_data.py
@@ -0,0 +1,26 @@
+# Create entries used by our doxygen filter to expand the arch_page
+# macros in the documentation.
+
+class ArchDocPage:
+    def __init__(self, doxygen_name, data_structures, files):
+        self.doxygen_name = doxygen_name
+        self.data_structures = data_structures
+        self.files = files
+
+##########################################
+# List of all architecture subsections
+##########################################
+arch_doc_pages = [
+    ArchDocPage('arch-dhandle',
+        ['WT_BTREE', 'WT_DHANDLE'],
+        ['src/include/btree.h', 'src/include/dhandle.h',
+         'src/conn/conn_dhandle.c', 'src/session/session_dhandle.c']),
+    ArchDocPage('arch-schema',
+        ['WT_COLGROUP', 'WT_INDEX', 'WT_LSM_TREE', 'WT_TABLE'],
+        ['src/include/intpack_inline.h', 'src/include/packing_inline.h',
+         'src/include/schema.h',
+         'src/lsm/', 'src/packing/', 'src/schema/']),
+    ArchDocPage('arch-transaction',
+        ['WT_TXN', 'WT_TXN_GLOBAL', 'WT_TXN_OP', 'WT_TXN_SHARED'],
+        ['src/include/txn.h', 'src/include/txn_inline.h', 'src/txn/']),
+]
diff --git a/src/third_party/wiredtiger/dist/s_docs b/src/third_party/wiredtiger/dist/s_docs
index 2bb134d0244..37686c3187b 100755
--- a/src/third_party/wiredtiger/dist/s_docs
+++ b/src/third_party/wiredtiger/dist/s_docs
@@ -124,6 +124,18 @@ valid_build()
 	done
 }
 
+check_docs_data()
+{
+	python docs.py > $t
+	test -s $t && {
+		echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+		echo 'Documentation data errors in docs_data.py'
+		sed -e 's/^/	/' < $t
+		echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+		e=1
+	}
+}
+
 build()
 {
 	# Build from scratch on demand.
@@ -153,7 +165,7 @@ EOF
 	# Any cmapx files that are generated by plantuml need to be referred to
 	CMAPX=`find ../src/docs/ -type f -name "*.cmapx" 2>/dev/null`
 	if [ "$CMAPX" != '' ]; then
-		cd ../docs
+		(cd ../docs
 		for f in $CMAPX; do
 			b=`echo $f | sed -e 's:.*/::' -e 's/.cmapx$//'`
 			for html in `grep -l $b.png *.html`; do
@@ -165,6 +177,7 @@ EOF
 				mv $html.NEW $html
 			done
 		done
+		)
 	fi
 
 	# Fixup the man pages generated by Doxygen. We want the command line
@@ -225,6 +238,9 @@ wtperf_config
 spellchk
 structurechk
 
+# Check the docs data input file.
+check_docs_data
+
 # Build the documentation.
 build $clean
 
diff --git a/src/third_party/wiredtiger/dist/s_string.ok b/src/third_party/wiredtiger/dist/s_string.ok
index 58090bf42be..0e4185705d9 100644
--- a/src/third_party/wiredtiger/dist/s_string.ok
+++ b/src/third_party/wiredtiger/dist/s_string.ok
@@ -349,6 +349,7 @@ RocksDB
 SIMD
 SLIST
 SLVG
+SMT
 SOURCE's
 SPINLOCK
 SQL
@@ -894,6 +895,8 @@ io
 ip
 isalnum
 isalpha
+isascii
+isb
 iscntrl
 isdigit
 isgraph
diff --git a/src/third_party/wiredtiger/dist/stat_data.py b/src/third_party/wiredtiger/dist/stat_data.py
index 2c0b5195465..807516d8eeb 100644
--- a/src/third_party/wiredtiger/dist/stat_data.py
+++ b/src/third_party/wiredtiger/dist/stat_data.py
@@ -284,8 +284,8 @@ connection_stats = [
     CacheStat('cache_hs_insert', 'history store table insert calls'),
     CacheStat('cache_hs_insert_restart', 'history store table insert calls that returned restart'),
     CacheStat('cache_hs_key_truncate', 'history store table truncation to remove an update'),
-    CacheStat('cache_hs_key_truncate_mix_ts', 'history store table truncation to remove range of updates due to mixed timestamps'),
     CacheStat('cache_hs_key_truncate_onpage_removal', 'history store table truncation to remove range of updates due to key being removed from the data page during reconciliation'),
+    CacheStat('cache_hs_key_truncate_non_ts', 'history store table truncation to remove range of updates due to non timestamped update on data page'),
     CacheStat('cache_hs_key_truncate_rts', 'history store table truncation by rollback to stable to remove an update'),
     CacheStat('cache_hs_key_truncate_rts_unstable', 'history store table truncation by rollback to stable to remove an unstable update'),
     CacheStat('cache_hs_ondisk', 'history store table on-disk size', 'no_clear,no_scale,size'),
@@ -769,8 +769,8 @@ dsrc_stats = [
     CacheStat('cache_hs_insert', 'history store table insert calls'),
     CacheStat('cache_hs_insert_restart', 'history store table insert calls that returned restart'),
     CacheStat('cache_hs_key_truncate', 'history store table truncation to remove an update'),
-    CacheStat('cache_hs_key_truncate_mix_ts', 'history store table truncation to remove range of updates due to mixed timestamps'),
     CacheStat('cache_hs_key_truncate_onpage_removal', 'history store table truncation to remove range of updates due to key being removed from the data page during reconciliation'),
+    CacheStat('cache_hs_key_truncate_non_ts', 'history store table truncation to remove range of updates due to non timestamped update on data page'),
     CacheStat('cache_hs_key_truncate_rts', 'history store table truncation by rollback to stable to remove an update'),
     CacheStat('cache_hs_key_truncate_rts_unstable', 'history store table truncation by rollback to stable to remove an unstable update'),
     CacheStat('cache_hs_order_fixup_insert', 'history store table out-of-order updates that were fixed up during insertion'),
diff --git a/src/third_party/wiredtiger/examples/c/ex_all.c b/src/third_party/wiredtiger/examples/c/ex_all.c
index a6c6c5f8c43..e63ca868d64 100644
--- a/src/third_party/wiredtiger/examples/c/ex_all.c
+++ b/src/third_party/wiredtiger/examples/c/ex_all.c
@@ -686,12 +686,6 @@ session_ops(WT_SESSION *session)
         error_check(session->compact(session, "table:mytable", NULL));
         /*! [Compact a table] */
 
-#ifdef MIGHT_NOT_RUN
-        /*! [Import a file] */
-        error_check(session->import(session, "file:import", NULL));
-/*! [Import a file] */
-#endif
-
         error_check(
           session->create(session, "table:old", "key_format=r,value_format=S,cache_resident=true"));
         /*! [Rename a table] */
diff --git a/src/third_party/wiredtiger/import.data b/src/third_party/wiredtiger/import.data
index 283f696cc64..12b52ce60eb 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-5.0",
-    "commit": "5f201b99d99f813e6b553a37e9c5d7f1cab1e136"
+    "commit": "805fe0276c367cb70321af3e1f473c881d0adc87"
 }
diff --git a/src/third_party/wiredtiger/src/cursor/cur_json.c b/src/third_party/wiredtiger/src/cursor/cur_json.c
index 89e5ecba4d3..ef24017b02d 100644
--- a/src/third_party/wiredtiger/src/cursor/cur_json.c
+++ b/src/third_party/wiredtiger/src/cursor/cur_json.c
@@ -315,7 +315,8 @@ __wt_json_unpack_char(u_char ch, u_char *buf, size_t bufsz, bool force_unicode)
     u_char abbrev;
 
     if (!force_unicode) {
-        if (__wt_isprint(ch) && ch != '\\' && ch != '"') {
+        /* We treat all non-ASCII characters as non-printable. */
+        if (__wt_isascii(ch) && __wt_isprint(ch) && ch != '\\' && ch != '"') {
             if (bufsz >= 1)
                 *buf = ch;
             return (1);
diff --git a/src/third_party/wiredtiger/src/docs/Doxyfile b/src/third_party/wiredtiger/src/docs/Doxyfile
index 378b1fd5f50..3653e6cd242 100644
--- a/src/third_party/wiredtiger/src/docs/Doxyfile
+++ b/src/third_party/wiredtiger/src/docs/Doxyfile
@@ -206,6 +206,8 @@ TAB_SIZE               = 8
 # You can put \n's in the value part of an alias to insert newlines.
 
 ALIASES                = \
+                         arch_page_table{2}="<div class="arch_head"><table><tr><th rowspan=2 style=\"width:10%;\">@htmlonly <div><a href=\"arch-index.html\"><img class=\"arch_thumbnail\" src=\"wt_diagram.png\" style=\"background-image: url(wt_diagram.png)\"></a></div>@endhtmlonly</th><th style=\"width:44%\">Data Structures</th><th style=\"width:45%\">Source Location</th></tr><tr><td><code>\1</code></td><td><code>\2</code></td></tr></table></div>" \
+                         arch_page_top{2}="@page \1 \2 (Architecture Guide)"  \
                          config{3}="  @row{<tt>\1</tt>,\2,\3}" \
                          configempty{2}="@param config configuration string, see @ref config_strings.  No values currently permitted." \
                          configend="  </table>" \
diff --git a/src/third_party/wiredtiger/src/docs/arch-dhandle.dox b/src/third_party/wiredtiger/src/docs/arch-dhandle.dox
new file mode 100644
index 00000000000..d88c82f9675
--- /dev/null
+++ b/src/third_party/wiredtiger/src/docs/arch-dhandle.dox
@@ -0,0 +1,17 @@
+/*! @arch_page arch-dhandle Data Handles and Btrees
+
+An internal structure called a Data Handle (dhandle) is used to represent and
+access Btrees and other data sources in WiredTiger. A dhandle gets created
+when a table is accessed for the first time. It is kept in a global list
+and is shared across the sessions.  When a dhandle is not needed anymore
+and has been idle for a while, it is closed and destroyed, releasing all the
+resources associated with it.
+
+A Btree is one kind of dhandle. It embodies both the on-disk and in-memory
+representations of the Btree.
+
+@subpage arch-dhandle-lifecycle
+
+This section describes how dhandles are created, and how and when they are destroyed.
+
+*/
diff --git a/src/third_party/wiredtiger/src/docs/arch-index.dox b/src/third_party/wiredtiger/src/docs/arch-index.dox
index f5430ccb7e7..7be364d330e 100644
--- a/src/third_party/wiredtiger/src/docs/arch-index.dox
+++ b/src/third_party/wiredtiger/src/docs/arch-index.dox
@@ -5,6 +5,7 @@ use the API interface to direct WiredTiger's operations (see @ref basic_api).
 Here is an overview of the software components in WiredTiger and how they are organized.
 An arrow indicates the "from" component uses "to" component.
 
+<div class="arch_diagram">
 @plantuml_start{wt_diagram.png}
 @startuml{wt_diagram.png}
 
@@ -41,11 +42,11 @@ rectangle "**WiredTiger Engine**
     rectangle "                                        C API                                        " as c_api
     file "____" as SPACE_api2
   }
-  rectangle "[[#component-schema Schema]]" as schema
+  rectangle "[[arch-schema.html Schema]]" as schema
   rectangle "Cursor" as cursor
-  rectangle "Transactions" as txn
+  rectangle "[[arch-transaction.html Transactions]]" as txn
   rectangle "Metadata" as meta
-  rectangle "[[#component-dhandle dhandle/\n Btree]]" as btree
+  rectangle "[[arch-dhandle.html  dhandle/\n Btree]]" as btree
   rectangle " Row\n storage" as row
   rectangle " Column\n storage" as column
   rectangle "History\n Store" as history
@@ -116,27 +117,25 @@ wt_file -[hidden]right-> log_file
 
 @enduml
 @plantuml_end
+</div>
 
 We go into some detail for some of the internal components.
 
-@subpage arch-glossary
+@subpage arch-dhandle
 
-WiredTiger assigns specific meanings to certain words. Here we decode them.
+An internal structure called a Data Handle (dhandle) is used to represent and
+access Btrees and other data sources in WiredTiger.
 
-\anchor component-schema
 @subpage arch-schema
 
-Most applications begin to make use of WiredTiger by creating a table (or other
-data object) to store their data in. Create is one of several schema operations
-available in WiredTiger.
+A schema defines the format of the application data in WiredTiger.
+
+@subpage arch-transaction
 
-\anchor component-dhandle
-@subpage arch-dhandle-lifecycle
+Transactions provide a powerful abstraction for multiple threads to operate on data concurrently.
 
-An internal structure called Data Handle (dhandle) is used to represent and
-access a table in WiredTiger. A dhandle gets created when a table is accessed
-for the first time. It is kept in a global list and is shared across the
-sessions.  When a dhandle is not needed anymore and has been idle for a while,
-it is closed and destroyed, releasing all the resources associated with it.
+@subpage arch-glossary
+
+WiredTiger assigns specific meanings to certain words. Here we decode them.
 
 */
diff --git a/src/third_party/wiredtiger/src/docs/arch-schema-ops.dox b/src/third_party/wiredtiger/src/docs/arch-schema-ops.dox
new file mode 100644
index 00000000000..8428208c6d9
--- /dev/null
+++ b/src/third_party/wiredtiger/src/docs/arch-schema-ops.dox
@@ -0,0 +1,206 @@
+/*! @page arch-schema-ops Schema Operations
+
+A @ref arch-schema defines the format of the application data in WiredTiger.
+This section details the internals of various schema operations.
+
+Schema operations cause an update to the metadata and are performed under a
+schema lock to avoid concurrent operations on the same object. The following
+sequence of steps define a generic schema operation:
+
+@plantuml_start{schema_generic.png}
+@startuml{schema_generic.png}
+:A schema operation;
+partition with-schema-lock {
+    :perform operation on underlying data-object;
+    :update metadata-file;
+    :checkpoint and sync metadata;
+}
+stop
+@enduml
+@plantuml_end
+
+@section schema_create Schema Create
+
+The create schema operation is responsible for creating the underlying data
+object on the filesystem with the right parameters and then creating an entry
+for this new object into the metadata. The sequence of operations involved in a
+create for various schema types are as follows:
+
+@plantuml_start{schema_create.png}
+@startuml{schema_create.png}
+:WT_SESSION->create(.,name,.)
+(__session_create());
+
+partition session-API-call {
+    :API session init with NULL dhandle;
+    :exit if PANIC flag set;
+    :exit if invalid configuration;
+}
+
+:validate "name" and if passed "type" config parameter;
+note right
+    "name" parameter is called as "uri" internally.
+    "type" is usually not passed and generally
+    implied from the uri.
+end note
+
+partition with-schema-lock {
+    partition with-table-lock {
+        :turn on meta tracking;
+        :check uri}
+
+        split
+            :uri matches "file:"
+            ("file" is the underlying
+             type for all the objects);
+        split again
+            :uri matches "colgroup:";
+            :__create_colgroup();
+        split again
+            :uri matches "table:";
+            :__create_table();
+        split again
+            :uri matches "lsm:";
+            :__wt_lsm_tree_create();
+        split again
+            :uri matches "index:";
+            :__create_index();
+        split again
+            :matches a named data-source;
+            :__create_data_source();
+        end split
+
+        partition __create_file() {
+            :exit if file exists;
+            :validate allocation size;
+            :block manager creates the file:
+             1.create file using __wt_open()
+             2.write an initial descriptor to file
+             3.fsync and close the file handle;
+            if (metadata-file?) then (yes)
+            else (no)
+                :update metadata with file
+                 configuration and version;
+            endif
+            :check if file setup correctly by
+             getting btree handle with
+             WT_DHANDLE_EXCLUSIVE set;
+            if (metatracking on?) then (yes)
+                :track locked handle*;
+            else (no)
+                :release btree -
+                 sync and close;
+            endif
+        }
+
+        partition turn-off-meta-tracking {
+            if (errors?) then (yes)
+                :unroll operations;
+            else (no)
+                if (logging?) then (yes)
+                    :sync log;
+                else (no)
+                endif
+                :checkpoint and sync;
+            endif
+            :apply post-commit ops:
+             release tracked (handle) btree* -
+             sync and close;
+            note right
+                if meta tracking is on, this btree
+                was being tracked as locked. As part
+                of tuning off meta tracking, we sync
+                and close this btree
+            end note
+        }
+    }
+}
+
+:API-end;
+
+stop
+@enduml
+@plantuml_end
+
+@section schema_rename Schema Rename
+
+The rename schema operation is responsible for renaming the underlying data
+object on the filesystem and updating the metadata accordingly. The sequence of
+operations involved in a rename for various schema types are as follows:
+
+@plantuml_start{schema_rename.png}
+@startuml{schema_rename.png}
+:WT_SESSION->rename(old-uri, new-uri, .)
+(__session_rename());
+:session-API-call;
+
+partition with-checkpoint-lock {
+    partition with-schema-lock {
+        partition with-table-write-lock {
+            :validate new uri-type to match the old type;
+            :turn on meta tracking;
+            :check uri}
+
+            split
+                :uri matches "file:"
+                ("file" is the underlying
+                 type for all the objects);
+            split again
+                :uri matches "lsm:";
+                :__wt_lsm_tree_rename();
+            split again
+                :matches a named data-source;
+                :WT_DATA_SOURCE::rename();
+            split again
+                :uri matches "table:";
+                partition __rename_table() {
+                    :rename colgroups and indices represented by the table:
+                     1. extract names from the uri
+                     2. create new uri with existing types and configuration
+                     3. recursive call the rename operation on individual
+                        colgroup and index with the old and the new uri
+                     4. remove old entry for colgroups and indices from
+                        the metadata table and add the new ones;
+                    :close and remove table handle from the session;
+                    :remove old table entry from the metadata table
+                     and add a new one;
+                }
+            end split
+
+            partition __rename_file() {
+                :fail if backup cursor open and schema operations will conflict;
+                :close btree handles in the file;
+                :fail if file with the old name doesn't exist or with the new
+                 name exists;
+                :remove old file entries and add new in the metadata;
+                :rename the underlying file;
+                if (meta-tracking?) then (yes)
+                    :track filesystem op;
+                else (no)
+                endif
+            }
+
+            :bump schema generation number to ignore stale data;
+
+            partition turn-off-meta-tracking {
+                if (errors?) then (yes)
+                    :unroll operations;
+                else (no)
+                    if (logging?) then (yes)
+                        :sync log;
+                    else (no)
+                    endif
+                    :checkpoint and sync;
+                endif
+            }
+        }
+    }
+}
+
+:API-end;
+
+stop
+@enduml
+@plantuml_end
+
+*/
diff --git a/src/third_party/wiredtiger/src/docs/arch-schema.dox b/src/third_party/wiredtiger/src/docs/arch-schema.dox
index f6ead3ac824..6494da597a2 100644
--- a/src/third_party/wiredtiger/src/docs/arch-schema.dox
+++ b/src/third_party/wiredtiger/src/docs/arch-schema.dox
@@ -1,208 +1,11 @@
-/*! @page arch-schema Schema Operations
+/*! @arch_page arch-schema Schema
 
 A schema defines the format of the application data in WiredTiger. WiredTiger
 supports various types of schemas (See @ref schema for more
-information), operated upon through a WT_SESSION reference. This section details
-the internals of these various schema operations.
+information), operated upon through a WT_SESSION reference.
 
-Schema operations cause an update to the metadata and are performed under a
-schema lock to avoid concurrent operations on the same object. The following
-sequence of steps define a generic schema operation:
+@subpage arch-schema-ops
 
-@plantuml_start{schema_generic.png}
-@startuml{schema_generic.png}
-:A schema operation;
-partition with-schema-lock {
-    :perform operation on underlying data-object;
-    :update metadata-file;
-    :checkpoint and sync metadata;
-}
-stop
-@enduml
-@plantuml_end
-
-@section schema_create Schema Create
-
-The create schema operation is responsible for creating the underlying data
-object on the filesystem with the right parameters and then creating an entry
-for this new object into the metadata. The sequence of operations involved in a
-create for various schema types are as follows:
-
-@plantuml_start{schema_create.png}
-@startuml{schema_create.png}
-:WT_SESSION->create(.,name,.)
-(__session_create());
-
-partition session-API-call {
-    :API session init with NULL dhandle;
-    :exit if PANIC flag set;
-    :exit if invalid configuration;
-}
-
-:validate "name" and if passed "type" config parameter;
-note right
-    "name" parameter is called as "uri" internally.
-    "type" is usually not passed and generally
-    implied from the uri.
-end note
-
-partition with-schema-lock {
-    partition with-table-lock {
-        :turn on meta tracking;
-        :check uri}
-
-        split
-            :uri matches "file:"
-            ("file" is the underlying
-             type for all the objects);
-        split again
-            :uri matches "colgroup:";
-            :__create_colgroup();
-        split again
-            :uri matches "table:";
-            :__create_table();
-        split again
-            :uri matches "lsm:";
-            :__wt_lsm_tree_create();
-        split again
-            :uri matches "index:";
-            :__create_index();
-        split again
-            :matches a named data-source;
-            :__create_data_source();
-        end split
-
-        partition __create_file() {
-            :exit if file exists;
-            :validate allocation size;
-            :block manager creates the file:
-             1.create file using __wt_open()
-             2.write an initial descriptor to file
-             3.fsync and close the file handle;
-            if (metadata-file?) then (yes)
-            else (no)
-                :update metadata with file
-                 configuration and version;
-            endif
-            :check if file setup correctly by
-             getting btree handle with
-             WT_DHANDLE_EXCLUSIVE set;
-            if (metatracking on?) then (yes)
-                :track locked handle*;
-            else (no)
-                :release btree -
-                 sync and close;
-            endif
-        }
-
-        partition turn-off-meta-tracking {
-            if (errors?) then (yes)
-                :unroll operations;
-            else (no)
-                if (logging?) then (yes)
-                    :sync log;
-                else (no)
-                endif
-                :checkpoint and sync;
-            endif
-            :apply post-commit ops:
-             release tracked (handle) btree* -
-             sync and close;
-            note right
-                if meta tracking is on, this btree
-                was being tracked as locked. As part
-                of tuning off meta tracking, we sync
-                and close this btree
-            end note
-        }
-    }
-}
-
-:API-end;
-
-stop
-@enduml
-@plantuml_end
-
-@section schema_rename Schema Rename
-
-The rename schema operation is responsible for renaming the underlying data
-object on the filesystem and updating the metadata accordingly. The sequence of
-operations involved in a rename for various schema types are as follows:
-
-@plantuml_start{schema_rename.png}
-@startuml{schema_rename.png}
-:WT_SESSION->rename(old-uri, new-uri, .)
-(__session_rename());
-:session-API-call;
-
-partition with-checkpoint-lock {
-    partition with-schema-lock {
-        partition with-table-write-lock {
-            :validate new uri-type to match the old type;
-            :turn on meta tracking;
-            :check uri}
-
-            split
-                :uri matches "file:"
-                ("file" is the underlying
-                 type for all the objects);
-            split again
-                :uri matches "lsm:";
-                :__wt_lsm_tree_rename();
-            split again
-                :matches a named data-source;
-                :WT_DATA_SOURCE::rename();
-            split again
-                :uri matches "table:";
-                partition __rename_table() {
-                    :rename colgroups and indices represented by the table:
-                     1. extract names from the uri
-                     2. create new uri with existing types and configuration
-                     3. recursive call the rename operation on individual
-                        colgroup and index with the old and the new uri
-                     4. remove old entry for colgroups and indices from
-                        the metadata table and add the new ones;
-                    :close and remove table handle from the session;
-                    :remove old table entry from the metadata table
-                     and add a new one;
-                }
-            end split
-
-            partition __rename_file() {
-                :fail if backup cursor open and schema operations will conflict;
-                :close btree handles in the file;
-                :fail if file with the old name doesn't exist or with the new
-                 name exists;
-                :remove old file entries and add new in the metadata;
-                :rename the underlying file;
-                if (meta-tracking?) then (yes)
-                    :track filesystem op;
-                else (no)
-                endif
-            }
-
-            :bump schema generation number to ignore stale data;
-
-            partition turn-off-meta-tracking {
-                if (errors?) then (yes)
-                    :unroll operations;
-                else (no)
-                    if (logging?) then (yes)
-                        :sync log;
-                    else (no)
-                    endif
-                    :checkpoint and sync;
-                endif
-            }
-        }
-    }
-}
-
-:API-end;
-
-stop
-@enduml
-@plantuml_end
+This section details the internals of various API operations that operate on schemas, such as WT_SESSION::create and WT_SESSION::rename.
 
 */
diff --git a/src/third_party/wiredtiger/src/docs/arch-transaction.dox b/src/third_party/wiredtiger/src/docs/arch-transaction.dox
new file mode 100644
index 00000000000..bc3c4e59722
--- /dev/null
+++ b/src/third_party/wiredtiger/src/docs/arch-transaction.dox
@@ -0,0 +1,8 @@
+/*! @arch_page arch-transaction Transactions
+
+Transactions provide a powerful abstraction for multiple threads to operate on data concurrently.
+A caller of WiredTiger uses @ref transactions within the API to start and stop transactions within
+a session (thread of control).
+
+Internally, the current transaction state is represented by the WT_TXN structure.
+*/
diff --git a/src/third_party/wiredtiger/src/docs/images/plantuml_gen_img/wt_diagram.cmapx b/src/third_party/wiredtiger/src/docs/images/plantuml_gen_img/wt_diagram.cmapx
index 411d3905b8e..2f29589a7a7 100644
--- a/src/third_party/wiredtiger/src/docs/images/plantuml_gen_img/wt_diagram.cmapx
+++ b/src/third_party/wiredtiger/src/docs/images/plantuml_gen_img/wt_diagram.cmapx
@@ -1,4 +1,5 @@
 <map id="wt_diagram_map" name="wt_diagram_map">
-<area shape="rect" id="id1" href="#component-schema" title="#component-schema" alt="" coords="98,224,151,241"/>
-<area shape="rect" id="id2" href="#component-dhandle" title="#component-dhandle" alt="" coords="181,320,244,353"/>
+<area shape="rect" id="id1" href="arch-schema.html" title="arch-schema.html" alt="" coords="98,224,151,241"/>
+<area shape="rect" id="id2" href="arch-transaction.html" title="arch-transaction.html" alt="" coords="341,329,429,345"/>
+<area shape="rect" id="id3" href="arch-dhandle.html" title="arch-dhandle.html" alt="" coords="181,320,244,353"/>
 </map>
diff --git a/src/third_party/wiredtiger/src/docs/images/plantuml_gen_img/wt_diagram.png b/src/third_party/wiredtiger/src/docs/images/plantuml_gen_img/wt_diagram.png
index 57480c2156f..0dcf1f285ed 100644
--- a/src/third_party/wiredtiger/src/docs/images/plantuml_gen_img/wt_diagram.png
+++ b/src/third_party/wiredtiger/src/docs/images/plantuml_gen_img/wt_diagram.png
diff --git a/src/third_party/wiredtiger/src/docs/style/wiredtiger.css b/src/third_party/wiredtiger/src/docs/style/wiredtiger.css
index 984e525f42f..9757f79b7d8 100644
--- a/src/third_party/wiredtiger/src/docs/style/wiredtiger.css
+++ b/src/third_party/wiredtiger/src/docs/style/wiredtiger.css
@@ -26,6 +26,50 @@ img {
 	height: auto;
 }
 
+div.arch_diagram {
+    display: block;
+    background: #FFFFFF;
+    background: radial-gradient(#FFDDAA,#FFFFFF);
+}
+
+/* match just one image */
+img[src="wt_diagram.png"] {
+    display: block;
+    margin-left: auto;
+    margin-right: auto;
+}
+
+.arch_head table {
+    background-color: #FFDDAA;
+    border-color: #624D32;
+    /*border: solid 1px;*/
+    border-spacing: 5px;
+}
+
+.arch_head td {
+    border-color: #FFFFFF;
+    /*border: solid 1px;*/
+    vertical-align: top;
+    text-align: left;
+}
+
+.arch_head th {
+    border-color: #624D32;
+    vertical-align: top;
+    text-align: left;
+}
+
+.arch_thumbnail {
+    padding: 0px 0px 0px 0px;
+    border: 3px solid #fff;
+    outline: 1px solid #000;
+    margin: 3px;
+    width: 70px;
+    height: 70px;
+    display: block;
+    text-align: center;
+}
+
 .tablist {
 	width: 800px;
 }
diff --git a/src/third_party/wiredtiger/src/docs/tools/doxfilter.py b/src/third_party/wiredtiger/src/docs/tools/doxfilter.py
index efe5c3ca80a..42f47426578 100755
--- a/src/third_party/wiredtiger/src/docs/tools/doxfilter.py
+++ b/src/third_party/wiredtiger/src/docs/tools/doxfilter.py
@@ -32,7 +32,19 @@
 # (i.e., from "/*!" to "/**"), because the latter are configured to not
 # search for brief descriptions at the beginning of pages.
 
-import re, sys
+import os, re, sys
+
+# We want to import the docs_data.py page from the dist directory.
+# First get our (src/doc/tools) directory.
+doc_tools_dir = os.path.dirname(os.path.realpath(__file__))
+top_dir = os.path.dirname(os.path.dirname(os.path.dirname(doc_tools_dir)))
+dist_dir = os.path.join(top_dir, 'dist')
+sys.path.insert(1, dist_dir)
+import docs_data
+
+arch_doc_lookup = {}
+for page in docs_data.arch_doc_pages:
+    arch_doc_lookup[page.doxygen_name] = page
 
 progname = 'doxfilter.py'
 linenum = 0
@@ -42,8 +54,40 @@ def err(arg):
     sys.stderr.write(filename + ':' + str(linenum) + ': ERROR: ' + arg + '\n')
     sys.exit(1)
 
+# Convert @arch_page to @arch_page_expanded, adding in information
+# from docs_data.py.
+def process_arch(source):
+    result = ''
+    mpage_content = []
+    arch_page_pat = re.compile(r'^(.*)@arch_page  *([^ ]*)  *(.*)')
+    for line in source.split('\n'):
+        m = re.search(arch_page_pat, line)
+        if line.count('@arch_page') > 0 and not m:
+            err('@arch_page incorrect syntax, need identifier and title')
+        if m:
+            groups = m.groups()
+            prefix = groups[0]
+            doxy_name = groups[1]
+            title = groups[2]
+
+            page_info = arch_doc_lookup[doxy_name]
+            data_structures_str = '<code>' + '<br>'.join(page_info.data_structures) + '</code>'
+            files_str = '<code>' + '<br>'.join(page_info.files) + '</code>'
+            result += prefix + '@arch_page_top{' + \
+                doxy_name + ',' + \
+                title + '}\n'
+            result += '@arch_page_table{' + \
+                data_structures_str + ',' + \
+                files_str + '}\n'
+        else:
+            result += line + '\n'
+    return result
+
 def process(source):
-    return source.replace(r'/*!', r'/**')
+    source = source.replace(r'/*!', r'/**')
+    if '@arch_page' in source:
+        source = process_arch(source)
+    return source
 
 if __name__ == '__main__':
     for f in sys.argv[1:]:
diff --git a/src/third_party/wiredtiger/src/history/hs_rec.c b/src/third_party/wiredtiger/src/history/hs_rec.c
index c70ffa63251..39c6104ac9c 100644
--- a/src/third_party/wiredtiger/src/history/hs_rec.c
+++ b/src/third_party/wiredtiger/src/history/hs_rec.c
@@ -535,14 +535,14 @@ __wt_hs_insert_updates(WT_SESSION_IMPL *session, WT_PAGE *page, WT_MULTI *multi)
           !F_ISSET(first_non_ts_upd, WT_UPDATE_CLEARED_HS)) {
             /* We can only delete history store entries that have timestamps. */
             WT_ERR(__wt_hs_delete_key_from_ts(session, btree->id, key, 1, true));
-            WT_STAT_CONN_INCR(session, cache_hs_key_truncate_mix_ts);
-            WT_STAT_DATA_INCR(session, cache_hs_key_truncate_mix_ts);
+            WT_STAT_CONN_INCR(session, cache_hs_key_truncate_non_ts);
+            WT_STAT_DATA_INCR(session, cache_hs_key_truncate_non_ts);
             F_SET(first_non_ts_upd, WT_UPDATE_CLEARED_HS);
         } else if (first_non_ts_upd != NULL && !F_ISSET(first_non_ts_upd, WT_UPDATE_CLEARED_HS) &&
           (list->ins == NULL || ts_updates_in_hs)) {
             WT_ERR(__wt_hs_delete_key_from_ts(session, btree->id, key, 1, true));
-            WT_STAT_CONN_INCR(session, cache_hs_key_truncate_mix_ts);
-            WT_STAT_DATA_INCR(session, cache_hs_key_truncate_mix_ts);
+            WT_STAT_CONN_INCR(session, cache_hs_key_truncate_non_ts);
+            WT_STAT_DATA_INCR(session, cache_hs_key_truncate_non_ts);
             F_SET(first_non_ts_upd, WT_UPDATE_CLEARED_HS);
         }
 
diff --git a/src/third_party/wiredtiger/src/include/ctype_inline.h b/src/third_party/wiredtiger/src/include/ctype_inline.h
index e751eedc090..0daf748f3b2 100644
--- a/src/third_party/wiredtiger/src/include/ctype_inline.h
+++ b/src/third_party/wiredtiger/src/include/ctype_inline.h
@@ -29,6 +29,16 @@ __wt_isalpha(u_char c)
 }
 
 /*
+ * __wt_isascii --
+ *     Wrap the ctype function without sign extension.
+ */
+static inline bool
+__wt_isascii(u_char c)
+{
+    return (isascii(c) != 0);
+}
+
+/*
  * __wt_isdigit --
  *     Wrap the ctype function without sign extension.
  */
diff --git a/src/third_party/wiredtiger/src/include/extern.h b/src/third_party/wiredtiger/src/include/extern.h
index 10d5a737718..0a6f3d79a9b 100644
--- a/src/third_party/wiredtiger/src/include/extern.h
+++ b/src/third_party/wiredtiger/src/include/extern.h
@@ -1811,6 +1811,7 @@ static inline bool __wt_eviction_updates_needed(WT_SESSION_IMPL *session, double
   WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 static inline bool __wt_isalnum(u_char c) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 static inline bool __wt_isalpha(u_char c) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
+static inline bool __wt_isascii(u_char c) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 static inline bool __wt_isdigit(u_char c) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 static inline bool __wt_isprint(u_char c) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
 static inline bool __wt_isspace(u_char c) WT_GCC_FUNC_DECL_ATTRIBUTE((warn_unused_result));
diff --git a/src/third_party/wiredtiger/src/include/gcc.h b/src/third_party/wiredtiger/src/include/gcc.h
index 85ba3214d3e..b620f614b07 100644
--- a/src/third_party/wiredtiger/src/include/gcc.h
+++ b/src/third_party/wiredtiger/src/include/gcc.h
@@ -217,7 +217,14 @@ WT_ATOMIC_FUNC(size, size_t, size_t *vp, size_t v)
     } while (0)
 
 #elif defined(__aarch64__)
-#define WT_PAUSE() __asm__ volatile("yield" ::: "memory")
+/*
+ * Use an isb instruction here to be closer to the original x86 pause instruction. The yield
+ * instruction that was previously here is a nop that is intended to provide a hint that a
+ * thread in a SMT system could yield. This is different from the x86 pause instruction
+ * which delays execution by O(100) cycles. The isb will typically delay execution by about
+ * 50 cycles so it's a reasonable alternative.
+ */
+#define WT_PAUSE() __asm__ volatile("isb" ::: "memory")
 
 /*
  * dmb are chosen here because they are sufficient to guarantee the ordering described above. We
diff --git a/src/third_party/wiredtiger/src/include/stat.h b/src/third_party/wiredtiger/src/include/stat.h
index 234350bbdc3..200d63759a1 100644
--- a/src/third_party/wiredtiger/src/include/stat.h
+++ b/src/third_party/wiredtiger/src/include/stat.h
@@ -401,7 +401,7 @@ struct __wt_connection_stats {
     int64_t cache_hs_key_truncate_rts;
     int64_t cache_hs_key_truncate;
     int64_t cache_hs_key_truncate_onpage_removal;
-    int64_t cache_hs_key_truncate_mix_ts;
+    int64_t cache_hs_key_truncate_non_ts;
     int64_t cache_hs_write_squash;
     int64_t cache_inmem_splittable;
     int64_t cache_inmem_split;
@@ -848,7 +848,7 @@ struct __wt_dsrc_stats {
     int64_t cache_hs_key_truncate_rts;
     int64_t cache_hs_key_truncate;
     int64_t cache_hs_key_truncate_onpage_removal;
-    int64_t cache_hs_key_truncate_mix_ts;
+    int64_t cache_hs_key_truncate_non_ts;
     int64_t cache_hs_write_squash;
     int64_t cache_inmem_splittable;
     int64_t cache_inmem_split;
diff --git a/src/third_party/wiredtiger/src/include/wiredtiger.in b/src/third_party/wiredtiger/src/include/wiredtiger.in
index e17e90439a0..846bc11d603 100644
--- a/src/third_party/wiredtiger/src/include/wiredtiger.in
+++ b/src/third_party/wiredtiger/src/include/wiredtiger.in
@@ -4932,9 +4932,9 @@ extern int wiredtiger_extension_terminate(WT_CONNECTION *connection);
 #define	WT_STAT_CONN_CACHE_HS_KEY_TRUNCATE_ONPAGE_REMOVAL	1105
 /*!
  * cache: history store table truncation to remove range of updates due
- * to mixed timestamps
+ * to non timestamped update on data page
  */
-#define	WT_STAT_CONN_CACHE_HS_KEY_TRUNCATE_MIX_TS	1106
+#define	WT_STAT_CONN_CACHE_HS_KEY_TRUNCATE_NON_TS	1106
 /*! cache: history store table writes requiring squashed modifies */
 #define	WT_STAT_CONN_CACHE_HS_WRITE_SQUASH		1107
 /*! cache: in-memory page passed criteria to be split */
@@ -6008,9 +6008,9 @@ extern int wiredtiger_extension_terminate(WT_CONNECTION *connection);
 #define	WT_STAT_DSRC_CACHE_HS_KEY_TRUNCATE_ONPAGE_REMOVAL	2074
 /*!
  * cache: history store table truncation to remove range of updates due
- * to mixed timestamps
+ * to non timestamped update on data page
  */
-#define	WT_STAT_DSRC_CACHE_HS_KEY_TRUNCATE_MIX_TS	2075
+#define	WT_STAT_DSRC_CACHE_HS_KEY_TRUNCATE_NON_TS	2075
 /*! cache: history store table writes requiring squashed modifies */
 #define	WT_STAT_DSRC_CACHE_HS_WRITE_SQUASH		2076
 /*! cache: in-memory page passed criteria to be split */
diff --git a/src/third_party/wiredtiger/src/support/stat.c b/src/third_party/wiredtiger/src/support/stat.c
index 98292870d31..5700b72fd44 100644
--- a/src/third_party/wiredtiger/src/support/stat.c
+++ b/src/third_party/wiredtiger/src/support/stat.c
@@ -79,7 +79,8 @@ static const char *const __stats_dsrc_desc[] = {
   "cache: history store table truncation to remove an update",
   "cache: history store table truncation to remove range of updates due to key being removed from "
   "the data page during reconciliation",
-  "cache: history store table truncation to remove range of updates due to mixed timestamps",
+  "cache: history store table truncation to remove range of updates due to non timestamped update "
+  "on data page",
   "cache: history store table writes requiring squashed modifies",
   "cache: in-memory page passed criteria to be split",
   "cache: in-memory page splits",
@@ -326,7 +327,7 @@ __wt_stat_dsrc_clear_single(WT_DSRC_STATS *stats)
     stats->cache_hs_key_truncate_rts = 0;
     stats->cache_hs_key_truncate = 0;
     stats->cache_hs_key_truncate_onpage_removal = 0;
-    stats->cache_hs_key_truncate_mix_ts = 0;
+    stats->cache_hs_key_truncate_non_ts = 0;
     stats->cache_hs_write_squash = 0;
     stats->cache_inmem_splittable = 0;
     stats->cache_inmem_split = 0;
@@ -557,7 +558,7 @@ __wt_stat_dsrc_aggregate_single(WT_DSRC_STATS *from, WT_DSRC_STATS *to)
     to->cache_hs_key_truncate_rts += from->cache_hs_key_truncate_rts;
     to->cache_hs_key_truncate += from->cache_hs_key_truncate;
     to->cache_hs_key_truncate_onpage_removal += from->cache_hs_key_truncate_onpage_removal;
-    to->cache_hs_key_truncate_mix_ts += from->cache_hs_key_truncate_mix_ts;
+    to->cache_hs_key_truncate_non_ts += from->cache_hs_key_truncate_non_ts;
     to->cache_hs_write_squash += from->cache_hs_write_squash;
     to->cache_inmem_splittable += from->cache_inmem_splittable;
     to->cache_inmem_split += from->cache_inmem_split;
@@ -787,7 +788,7 @@ __wt_stat_dsrc_aggregate(WT_DSRC_STATS **from, WT_DSRC_STATS *to)
     to->cache_hs_key_truncate += WT_STAT_READ(from, cache_hs_key_truncate);
     to->cache_hs_key_truncate_onpage_removal +=
       WT_STAT_READ(from, cache_hs_key_truncate_onpage_removal);
-    to->cache_hs_key_truncate_mix_ts += WT_STAT_READ(from, cache_hs_key_truncate_mix_ts);
+    to->cache_hs_key_truncate_non_ts += WT_STAT_READ(from, cache_hs_key_truncate_non_ts);
     to->cache_hs_write_squash += WT_STAT_READ(from, cache_hs_write_squash);
     to->cache_inmem_splittable += WT_STAT_READ(from, cache_inmem_splittable);
     to->cache_inmem_split += WT_STAT_READ(from, cache_inmem_split);
@@ -1040,7 +1041,8 @@ static const char *const __stats_connection_desc[] = {
   "cache: history store table truncation to remove an update",
   "cache: history store table truncation to remove range of updates due to key being removed from "
   "the data page during reconciliation",
-  "cache: history store table truncation to remove range of updates due to mixed timestamps",
+  "cache: history store table truncation to remove range of updates due to non timestamped update "
+  "on data page",
   "cache: history store table writes requiring squashed modifies",
   "cache: in-memory page passed criteria to be split",
   "cache: in-memory page splits",
@@ -1556,7 +1558,7 @@ __wt_stat_connection_clear_single(WT_CONNECTION_STATS *stats)
     stats->cache_hs_key_truncate_rts = 0;
     stats->cache_hs_key_truncate = 0;
     stats->cache_hs_key_truncate_onpage_removal = 0;
-    stats->cache_hs_key_truncate_mix_ts = 0;
+    stats->cache_hs_key_truncate_non_ts = 0;
     stats->cache_hs_write_squash = 0;
     stats->cache_inmem_splittable = 0;
     stats->cache_inmem_split = 0;
@@ -2053,7 +2055,7 @@ __wt_stat_connection_aggregate(WT_CONNECTION_STATS **from, WT_CONNECTION_STATS *
     to->cache_hs_key_truncate += WT_STAT_READ(from, cache_hs_key_truncate);
     to->cache_hs_key_truncate_onpage_removal +=
       WT_STAT_READ(from, cache_hs_key_truncate_onpage_removal);
-    to->cache_hs_key_truncate_mix_ts += WT_STAT_READ(from, cache_hs_key_truncate_mix_ts);
+    to->cache_hs_key_truncate_non_ts += WT_STAT_READ(from, cache_hs_key_truncate_non_ts);
     to->cache_hs_write_squash += WT_STAT_READ(from, cache_hs_write_squash);
     to->cache_inmem_splittable += WT_STAT_READ(from, cache_inmem_splittable);
     to->cache_inmem_split += WT_STAT_READ(from, cache_inmem_split);
diff --git a/src/third_party/wiredtiger/test/csuite/timestamp_abort/main.c b/src/third_party/wiredtiger/test/csuite/timestamp_abort/main.c
index 0179adddf46..7c4c97cb974 100644
--- a/src/third_party/wiredtiger/test/csuite/timestamp_abort/main.c
+++ b/src/third_party/wiredtiger/test/csuite/timestamp_abort/main.c
@@ -826,7 +826,8 @@ main(int argc, char *argv[])
             cur_shadow->set_key(cur_shadow, kname);
             /*
              * The collection table should always only have the data as of the checkpoint. The
-             * shadow table should always have the exact same data (or not) as the collection table.
+             * shadow table should always have the exact same data (or not) as the collection table,
+             * except for the last key that may be committed after the stable timestamp.
              */
             if ((ret = cur_coll->search(cur_coll)) != 0) {
                 if (ret != WT_NOTFOUND)
@@ -850,7 +851,12 @@ main(int argc, char *argv[])
             } else if ((ret = cur_shadow->search(cur_shadow)) != 0) {
                 if (ret != WT_NOTFOUND)
                     testutil_die(ret, "shadow search");
-                else {
+                /*
+                 * We respectively insert the record to the collection table at timestamp t and to
+                 * the shadow table at t + 1. If the checkpoint finishes at timestamp t, the last
+                 * shadow table record will be removed by rollback to stable after restart.
+                 */
+                if (durable_fp <= stable_val) {
                     printf("%s: SHADOW no record with key %" PRIu64 "\n", fname, key);
                     absent_shadow++;
                 }
diff --git a/src/third_party/wiredtiger/test/evergreen.yml b/src/third_party/wiredtiger/test/evergreen.yml
index 8a627e7fac5..cf65f3efb1d 100755
--- a/src/third_party/wiredtiger/test/evergreen.yml
+++ b/src/third_party/wiredtiger/test/evergreen.yml
@@ -1658,6 +1658,17 @@ tasks:
             set -o verbose
             test/evergreen/compatibility_test_for_releases.sh -w
 
+  - name: import-compatibility-test
+    commands:
+      - func: "get project"
+      - command: shell.exec
+        params:
+          working_dir: "wiredtiger"
+          script: |
+            set -o errexit
+            set -o verbose
+            test/evergreen/import_compatibility_test.sh
+
   - name: generate-datafile-little-endian
     depends_on:
       - name: compile
@@ -2541,6 +2552,7 @@ buildvariants:
   - ubuntu1804-test
   tasks:
     - name: compatibility-test-for-newer-releases
+    - name: import-compatibility-test
 
 - name: windows-64
   display_name: "! Windows 64-bit"
diff --git a/src/third_party/wiredtiger/test/evergreen/import_compatibility_test.sh b/src/third_party/wiredtiger/test/evergreen/import_compatibility_test.sh
new file mode 100755
index 00000000000..6f0ba25ee09
--- /dev/null
+++ b/src/third_party/wiredtiger/test/evergreen/import_compatibility_test.sh
@@ -0,0 +1,151 @@
+#!/usr/bin/env bash
+#
+# Test importing of files created in previous versions of WiredTiger.
+# Test that we can downgrade a database after importing a file.
+
+set -e
+
+# build_branch --
+#     1: branch
+build_branch()
+{
+    echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+    echo "Building branch: \"$1\""
+    echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+
+    # Clone if it doesn't already exist.
+    if [ ! -d "$1" ]; then
+        git clone --quiet https://github.com/wiredtiger/wiredtiger.git "$1"
+    fi
+    cd "$1"
+
+    git checkout --quiet "$1"
+
+    config=""
+    config+="--enable-snappy "
+    (sh build_posix/reconf &&
+         ./configure $config && make -j $(grep -c ^processor /proc/cpuinfo)) > /dev/null
+    cd ..
+}
+
+# create_file --
+#     1: branch
+#     2: file
+create_file()
+{
+    echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+    echo "Branch \"$1\" creating and populating \"$2\""
+    echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+
+    wt_cmd="$1/wt"
+    test_dir="$1/WT_TEST/"
+    uri="file:$2"
+
+    # Make the home directory.
+    mkdir -p $test_dir
+
+    # Create the file and populate with a few key/values.
+    $wt_cmd -h $test_dir create -c "key_format=S,value_format=S" $uri
+    $wt_cmd -h $test_dir write $uri abc 123 def 456 hij 789
+}
+
+# import_file --
+#     1: dest branch
+#     2: source branch
+#     3: file
+import_file()
+{
+    echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+    echo "Importing file \"$3\" from \"$1\" to \"$2\""
+    echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+
+    wt_cmd="$1/wt"
+    test_dir="$1/WT_TEST/"
+    mkdir -p $test_dir
+
+    # Move the file across to the destination branch's home directory.
+    import_file="$2/WT_TEST/$3"
+    cp $import_file $test_dir
+
+    # Run import via the wt tool.
+    uri="file:$3"
+    $wt_cmd -h $test_dir create -c "import=(enabled,repair=true)" $uri
+}
+
+# verify_file --
+#     1: branch
+#     2: file
+verify_file()
+{
+    echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+    echo "Branch \"$1\" verifying \"$2\""
+    echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+
+    wt_cmd="$1/wt"
+    test_dir="$1/WT_TEST/"
+    uri="file:$2"
+
+    $wt_cmd -h $test_dir verify $uri
+}
+
+# cleanup_branch --
+#     1: branch
+cleanup_branch()
+{
+    test_dir="$1/WT_TEST/"
+    if [ -d $test_dir ]; then
+        rm -rf $test_dir
+    fi
+}
+
+# import_compatibility_test --
+#     1: newer branch
+#     2: older branch
+import_compatibility_test()
+{
+    echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+    echo "Testing import compatibility between \"$1\" and \"$2\""
+    echo "=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-="
+
+    # Remove any leftover data files.
+    cleanup_branch $1
+    cleanup_branch $2
+
+    # Create a file in the older branch.
+    create_file $2 test_import
+
+    # Now import it into the newer branch and verify.
+    import_file $1 $2 test_import
+    verify_file $1 test_import
+
+    # Now downgrade by running wt from the older branch and dumping the table contents.
+    #
+    # Before trying this, we must remove the base configuration. The wt tool produces this file
+    # however MongoDB will not so we should emulate this.
+    rm $1/WT_TEST/WiredTiger.basecfg
+    $2/wt -h $1/WT_TEST/ dump file:test_import
+}
+
+# Release branches.
+#
+# Go all the way back to mongodb-4.2 since that's the first release where we don't support live
+# import.
+release_branches=(develop mongodb-5.0 mongodb-4.4 mongodb-4.2)
+
+# Build each of the release branches.
+for b in ${release_branches[@]}; do
+    build_branch $b
+done
+
+for i in ${!release_branches[@]}; do
+    newer=${release_branches[$i]}
+
+    # MongoDB v4.2 doesn't support live import so it should only ever be used as the "older" branch
+    # that we're importing from.
+    if [ $newer = mongodb-4.2 ]; then
+        continue
+    fi
+
+    older=${release_branches[$i+1]}
+    import_compatibility_test $newer $older
+done
diff --git a/src/third_party/wiredtiger/test/suite/test_jsondump02.py b/src/third_party/wiredtiger/test/suite/test_jsondump02.py
index 9ae8dead18c..080b698d7a2 100755
--- a/src/third_party/wiredtiger/test/suite/test_jsondump02.py
+++ b/src/third_party/wiredtiger/test/suite/test_jsondump02.py
@@ -92,9 +92,6 @@ class test_jsondump02(wttest.WiredTigerTestCase, suite_subprocess):
         Create JSON cursors and test them directly, also test
         dump/load commands.
         """
-        import platform
-        if platform.system() == 'Darwin':
-            self.skipTest('JSON cursor test for OSX not yet working on Python3')
         extra_params = ',allocation_size=512,' +\
             'internal_page_max=16384,leaf_page_max=131072'
         self.session.create(self.table_uri1,
diff --git a/src/third_party/wiredtiger/test/suite/test_util01.py b/src/third_party/wiredtiger/test/suite/test_util01.py
index 9dae07f3ca6..3eb457ceb1f 100755
--- a/src/third_party/wiredtiger/test/suite/test_util01.py
+++ b/src/third_party/wiredtiger/test/suite/test_util01.py
@@ -133,7 +133,21 @@ class test_util01(wttest.WiredTigerTestCase, suite_subprocess):
 
     def dump_kv_to_line(self, b):
         # The output from dump is a 'u' format.
-        return b.strip(b'\x00').decode() + '\n'
+        # Printable chars appear 'as is', unprintable chars
+        # appear as \hh where hh are hex digits.
+        # We can't decode the entire byte array, some Unicode decoders
+        # will complain as the set of bytes don't represent UTF-8 encoded
+        # characters.
+
+        # Create byte representation of printable ascii chars
+        printable_chars = bytes(string.printable, 'ascii')
+        result = ''
+        for byte in b.strip(b'\x00'):
+            if byte in printable_chars:
+                result += bytearray([byte]).decode()
+            else:
+                result += "\\{:02x}".format(byte)
+        return result + '\n'
 
     def write_entries(self, cursor, expectout, hexoutput, commit_timestamp, write_expected):
         if commit_timestamp is not None:
@@ -217,9 +231,6 @@ class test_util01(wttest.WiredTigerTestCase, suite_subprocess):
         self.dump(False, True, None, None)
 
     def test_dump_api(self):
-        import platform
-        if platform.system() == 'Darwin':
-            self.skipTest('dump API test for OSX not yet working on Python3')
         self.dump(True, False, None, None)
 
     def test_dump_api_hex(self):