Import wiredtiger: 3901b43d1e0f034c46999ccfdbdd0914791859e0 from branch mongodb-4.4r4.4.0-rc8

ref: cc2458c2c2..3901b43d1e
for: 4.4.0-rc8

WT-5769       Search history store can potentially walk the whole history store tree
WT-6328       Update test_compact02 to handle being halted by eviction pressure
WT-6355       test/format can configure keys that are too short
WT-6364       Fix double counting sizes of existing updates on the update chain for the history store

4 files changed, 119 insertions, 23 deletions

diff --git a/src/third_party/wiredtiger/test/format/config.h b/src/third_party/wiredtiger/test/format/config.h
index 80d2ab99cd4..d0023be05d2 100644
--- a/src/third_party/wiredtiger/test/format/config.h
+++ b/src/third_party/wiredtiger/test/format/config.h
@@ -103,7 +103,12 @@ static CONFIG c[] = {
 
   {"btree.key_max", "maximum size of keys", 0x0, 20, 128, MEGABYTE(10), &g.c_key_max, NULL},
 
-  {"btree.key_min", "minimum size of keys", 0x0, 10, 32, 256, &g.c_key_min, NULL},
+  /*
+   * A minimum key size of 11 is necessary. Row-store keys have a leading 10-digit number and the
+   * 11 guarantees we never see a key that we can't convert to a numeric value without formatting
+   * it first because there's a trailing non-digit character in every key.
+   */
+  {"btree.key_min", "minimum size of keys", 0x0, 11, 32, 256, &g.c_key_min, NULL},
 
   {"btree.leaf_page_max", "maximum size of Btree leaf nodes", 0x0, 9, 17, 27, &g.c_leaf_page_max,
     NULL},
diff --git a/src/third_party/wiredtiger/test/suite/test_compact02.py b/src/third_party/wiredtiger/test/suite/test_compact02.py
index c15fb5bc78b..e466aa81a95 100644
--- a/src/third_party/wiredtiger/test/suite/test_compact02.py
+++ b/src/third_party/wiredtiger/test/suite/test_compact02.py
@@ -149,11 +149,11 @@ class test_compact02(wttest.WiredTigerTestCase):
         # Compact can collide with eviction, if that happens we retry. Wait for
         # a long time, the check for EBUSY means we're not retrying on any real
         # errors.
-        for i in range(1, 60):
+        for i in range(1, 80):
             if not self.raisesBusy(
               lambda: self.session.compact(self.uri, None)):
                 break
-            time.sleep(5)
+            time.sleep(6)
 
         # 6. Get stats on compacted table.
         sz = self.getSize()
diff --git a/src/third_party/wiredtiger/test/suite/test_hs11.py b/src/third_party/wiredtiger/test/suite/test_hs11.py
index f7d31c6796f..efc9d02401c 100644
--- a/src/third_party/wiredtiger/test/suite/test_hs11.py
+++ b/src/third_party/wiredtiger/test/suite/test_hs11.py
@@ -32,12 +32,13 @@ def timestamp_str(t):
     return '%x' % t
 
 # test_hs11.py
-# Ensure that mixed mode updates clear the history store records.
+# Ensure that when we delete a key due to a tombstone being globally visible, we delete its
+# associated history store content.
 class test_hs11(wttest.WiredTigerTestCase):
     conn_config = 'cache_size=50MB'
     session_config = 'isolation=snapshot'
 
-    def run_test(self, update_type):
+    def test_key_deletion_clears_hs(self):
         uri = 'table:test_hs11'
         create_params = 'key_format=S,value_format=S'
         self.session.create(uri, create_params)
@@ -57,16 +58,14 @@ class test_hs11(wttest.WiredTigerTestCase):
         # Reconcile and flush versions 1-3 to the history store.
         self.session.checkpoint()
 
-        # Apply a mixed mode update.
+        # Apply a non-timestamped tombstone. When the pages get evicted, the keys will get deleted
+        # since the tombstone is globally visible.
         for i in range(1, 10000):
             if i % 2 == 0:
-                if update_type == 'deletion':
-                    cursor.set_key(str(i))
-                    cursor.remove()
-                else:
-                    cursor[str(i)] = value2
+                cursor.set_key(str(i))
+                cursor.remove()
 
-        # Now apply an update at timestamp 10.
+        # Now apply an update at timestamp 10 to recreate each key.
         for i in range(1, 10000):
             self.session.begin_transaction()
             cursor[str(i)] = value2
@@ -77,17 +76,8 @@ class test_hs11(wttest.WiredTigerTestCase):
             self.session.begin_transaction('read_timestamp=' + timestamp_str(ts))
             for i in range(1, 10000):
                 if i % 2 == 0:
-                    if update_type == 'deletion':
-                        cursor.set_key(str(i))
-                        self.assertEqual(cursor.search(), wiredtiger.WT_NOTFOUND)
-                    else:
-                        self.assertEqual(cursor[str(i)], value2)
+                    cursor.set_key(str(i))
+                    self.assertEqual(cursor.search(), wiredtiger.WT_NOTFOUND)
                 else:
                     self.assertEqual(cursor[str(i)], value1)
             self.session.rollback_transaction()
-
-    def test_key_deletion_clears_hs(self):
-        self.run_test('deletion')
-
-    def test_key_update_clears_hs(self):
-        self.run_test('update')
diff --git a/src/third_party/wiredtiger/test/suite/test_hs14.py b/src/third_party/wiredtiger/test/suite/test_hs14.py
new file mode 100644
index 00000000000..ebd5f471f2b
--- /dev/null
+++ b/src/third_party/wiredtiger/test/suite/test_hs14.py
@@ -0,0 +1,101 @@
+#!/usr/bin/env python
+#
+# Public Domain 2014-2020 MongoDB, Inc.
+# Public Domain 2008-2014 WiredTiger, Inc.
+#
+# This is free and unencumbered software released into the public domain.
+#
+# Anyone is free to copy, modify, publish, use, compile, sell, or
+# distribute this software, either in source code form or as a compiled
+# binary, for any purpose, commercial or non-commercial, and by any
+# means.
+#
+# In jurisdictions that recognize copyright laws, the author or authors
+# of this software dedicate any and all copyright interest in the
+# software to the public domain. We make this dedication for the benefit
+# of the public at large and to the detriment of our heirs and
+# successors. We intend this dedication to be an overt act of
+# relinquishment in perpetuity of all present and future rights to this
+# software under copyright law.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+
+import time, wiredtiger, wttest
+
+def timestamp_str(t):
+    return '%x' % t
+
+# test_hs14.py
+# Ensure that point in time reads with few visible history store records don't
+# damage performance.
+class test_hs14(wttest.WiredTigerTestCase):
+    conn_config = 'cache_size=50MB'
+    session_config = 'isolation=snapshot'
+
+    def test_hs14(self):
+        uri = 'table:test_hs14'
+        self.session.create(uri, 'key_format=S,value_format=S')
+        self.conn.set_timestamp('oldest_timestamp=' + timestamp_str(1))
+        cursor = self.session.open_cursor(uri)
+
+        value1 = 'a' * 500
+        value2 = 'b' * 500
+        value3 = 'c' * 500
+        value4 = 'd' * 500
+        value5 = 'e' * 500
+
+        for i in range(1, 10000):
+            self.session.begin_transaction()
+            cursor[str(i)] = value1
+            self.session.commit_transaction('commit_timestamp=' + timestamp_str(2))
+            self.session.begin_transaction()
+            cursor[str(i)] = value2
+            self.session.commit_transaction('commit_timestamp=' + timestamp_str(2))
+            self.session.begin_transaction()
+            cursor[str(i)] = value3
+            self.session.commit_transaction('commit_timestamp=' + timestamp_str(3))
+            self.session.begin_transaction()
+            cursor[str(i)] = value4
+            self.session.commit_transaction('commit_timestamp=' + timestamp_str(4))
+
+        start = time.time()
+        self.session.begin_transaction('read_timestamp=' + timestamp_str(3))
+        for i in range(1, 10000):
+            self.assertEqual(cursor[str(i)], value3)
+        self.session.rollback_transaction()
+        end = time.time()
+
+        # The time spent when all history store keys are visible to us.
+        visible_hs_latency = (end - start)
+
+        for i in range(1, 10000):
+            self.session.begin_transaction()
+            cursor.set_key(str(i))
+            cursor.remove()
+            self.session.commit_transaction('commit_timestamp=' + timestamp_str(5))
+            self.session.begin_transaction()
+            cursor[str(i)] = value5
+            self.session.commit_transaction('commit_timestamp=' + timestamp_str(10))
+
+        start = time.time()
+        self.session.begin_transaction('read_timestamp=' + timestamp_str(9))
+        for i in range(1, 10000):
+            cursor.set_key(str(i))
+            self.assertEqual(cursor.search(), wiredtiger.WT_NOTFOUND)
+        self.session.rollback_transaction()
+        end = time.time()
+
+        # The time spent when all history store keys are invisible to us.
+        invisible_hs_latency = (end - start)
+
+        self.assertLess(invisible_hs_latency, (visible_hs_latency * 10),
+                        "Reader took an order of magnitude longer for when all "
+                        "history store records were invisible, visible={}, invisible={}".format(
+                            visible_hs_latency, invisible_hs_latency
+                        ))