SERVER-37853 Create sharded_core_txn with balancer suite

25 files changed, 615 insertions, 20 deletions

diff --git a/buildscripts/resmokeconfig/suites/multi_stmt_txn_jscore_passthrough_with_migration.yml b/buildscripts/resmokeconfig/suites/multi_stmt_txn_jscore_passthrough_with_migration.yml
new file mode 100644
index 00000000000..8d8a2457b99
--- /dev/null
+++ b/buildscripts/resmokeconfig/suites/multi_stmt_txn_jscore_passthrough_with_migration.yml
@@ -0,0 +1,450 @@
+test_kind: multi_stmt_txn_passthrough
+
+selector:
+  roots:
+  - jstests/core/**/*.js
+  exclude_files:
+  # These tests run in the jscore_txn passthrough suites.
+  - jstests/core/txns/**/*.js
+  
+  # The following tests fail because a certain command or functionality is not supported by
+  # mongos. This command or functionality is placed in a comment next to the failing test.
+  - jstests/core/apitest_db.js  # serverStatus output doesn't have storageEngine.
+  - jstests/core/apitest_db_profile_level.js  # profiling.
+  - jstests/core/apply_ops*.js  # applyOps, SERVER-1439.
+  - jstests/core/awaitdata_getmore_cmd.js  # capped collections.
+  - jstests/core/bypass_doc_validation.js  # sharded $out output not permitted
+  - jstests/core/capped*.js  # capped collections.
+  - jstests/core/check_shard_index.js  # checkShardingIndex.
+  - jstests/core/collection_truncate.js  # emptycapped.
+  - jstests/core/collmod_without_uuid.js # applyOps, SERVER-1439
+  - jstests/core/compact_keeps_indexes.js  # compact.
+  - jstests/core/currentop.js  # uses fsync.
+  - jstests/core/dbadmin.js  # "local" database.
+  - jstests/core/dbhash.js  # dbhash.
+  - jstests/core/dbhash2.js  # dbhash.
+  - jstests/core/diagdata.js # Command not supported in mongos
+  - jstests/core/do_txn*.js  # doTxn
+  - jstests/core/dropdb_race.js  # syncdelay.
+  - jstests/core/fsync.js  # uses fsync.
+  - jstests/core/geo_haystack*.js  # geoSearch.
+  - jstests/core/geo_s2cursorlimitskip.js  # profiling.
+  - jstests/core/geo_update_btree2.js  # notablescan.
+  - jstests/core/index_id_options.js  # "local" database.
+  - jstests/core/index9.js  # "local" database.
+  - jstests/core/max_time_ms.js  # sleep, SERVER-2212.
+  - jstests/core/mr_replaceIntoDB.js  # MapReduceResult, SERVER-20495.
+  - jstests/core/notablescan.js  # notablescan.
+  - jstests/core/profile*.js  # profiling.
+  - jstests/core/queryoptimizera.js  # "local" database. 
+  - jstests/core/rename*.js # renameCollection.
+  - jstests/core/stages*.js  # stageDebug.
+  - jstests/core/startup_log.js  # "local" database.
+  - jstests/core/tailable_cursor_invalidation.js # capped collections.
+  - jstests/core/tailable_getmore_batch_size.js # capped collections.
+  - jstests/core/tailable_skip_limit.js # capped collections.
+  - jstests/core/top.js  # top.
+  # The following tests fail because mongos behaves differently from mongod when testing certain
+  # functionality. The differences are in a comment next to the failing test.
+  - jstests/core/explain_missing_database.js  # Behavior with no db different on mongos, SERVER-18047.
+  - jstests/core/geo_2d_explain.js  # executionSuccess in different spot in explain().
+  - jstests/core/geo_s2explain.js  # inputStage in different spot in explain().
+  - jstests/core/geo_s2sparse.js  # keysPerIndex in different spot in validate().
+  - jstests/core/operation_latency_histogram.js  # Stats are counted differently on mongos, SERVER-24880.
+  # Test expects to run against a standalone, but shards in this passthrough are repl sets.
+  - jstests/core/read_after_optime.js
+  # The following tests fail because they count indexes. These counts do not take into account the
+  # additional hashed shard key indexes that are automatically added by this passthrough.
+  - jstests/core/apitest_dbcollection.js
+  - jstests/core/bad_index_plugin.js
+  - jstests/core/create_indexes.js
+  - jstests/core/list_indexes_non_existent_ns.js
+  - jstests/core/rename6.js
+  # The following tests fail because they expect no databases to be created. However a DB is created
+  # automatically when we shard a collection.
+  - jstests/core/dbcase.js
+  - jstests/core/dbcase2.js
+  - jstests/core/no_db_created.js
+  - jstests/core/ns_length.js
+  - jstests/core/views/*.js # Views tests aren't expected to work when collections are implicitly sharded.
+  - jstests/core/killop_drop_collection.js # Uses fsyncLock.
+  # These tests fail because sharded clusters do not clean up correctly after failed index builds.
+  # See SERVER-33207 as an example.
+  - jstests/core/geo_borders.js
+  # TODO: Remove after fixing SERVER-32555. executionStats.nReturned is incorrect for sharded
+  # queries with a limit or for distinct commands.
+  - jstests/core/distinct_index1.js
+  - jstests/core/explain1.js
+  - jstests/core/explain4.js
+  - jstests/core/sortk.js
+  # TODO: Remove after fixing SERVER-32563. The implementation of explain for the count command is
+  # incorrect on sharded collections.
+  - jstests/core/explain_count.js
+  # TODO: Remove after fixing SERVER-14324. mapReduce behaves unpredictably when the out collection
+  # is sharded on anything other than {_id: 1}.
+  - jstests/core/mr_undef.js
+  # TODO SERVER-32311: These tests use plan stage helpers which can't handle sharded explain output.
+  - jstests/core/expr_index_use.js
+  - jstests/core/index_multikey.js
+  - jstests/core/optimized_match_explain.js
+  - jstests/core/sort_array.js
+  # TODO: SERVER-16605 MapReduce into sharded collection with hashed index fails
+  - jstests/core/mr1.js
+  - jstests/core/mr3.js
+  - jstests/core/mr4.js
+  # Create index command arbitrarily picks one of the errors if there are multiple errors from the
+  # shards. In this suite, it is possible that one of the shards don't have the collection created
+  # so it can return cannot implicitly create collection.
+  - jstests/core/index_create_too_many.js
+  - jstests/core/index_create_with_nul_in_name.js
+
+  ##
+  ## Limitations with the way the runner file injects transactions.
+  ##
+  
+  # These tests expects some statements to error, which will cause txns to abort entirely.
+  - jstests/core/bulk_api_ordered.js
+  - jstests/core/bulk_api_unordered.js
+  - jstests/core/bulk_legacy_enforce_gle.js
+  - jstests/core/capped5.js
+  - jstests/core/commands_with_uuid.js
+  - jstests/core/explain_execution_error.js
+  - jstests/core/expr.js
+  - jstests/core/find9.js
+  - jstests/core/find_getmore_bsonsize.js
+  - jstests/core/find_getmore_cmd.js
+  - jstests/core/geo_allowedcomparisons.js
+  - jstests/core/geo_big_polygon2.js
+  - jstests/core/geonear_key.js
+  - jstests/core/in.js
+  - jstests/core/index8.js # No explicit check for failed command.
+  - jstests/core/index_decimal.js
+  - jstests/core/index_multiple_compatibility.js
+  - jstests/core/index_partial_write_ops.js
+  - jstests/core/indexa.js # No explicit check for failed command.
+  - jstests/core/indexes_multiple_commands.js
+  - jstests/core/js2.js
+  - jstests/core/json_schema/json_schema.js
+  - jstests/core/mr_bigobject.js
+  - jstests/core/not2.js
+  - jstests/core/notablescan.js
+  - jstests/core/null_query_semantics.js
+  - jstests/core/or1.js
+  - jstests/core/or2.js
+  - jstests/core/or3.js
+  - jstests/core/orj.js
+  - jstests/core/ref.js
+  - jstests/core/ref4.js
+  - jstests/core/regex_limit.js
+  - jstests/core/remove_undefined.js
+  - jstests/core/set7.js 
+  - jstests/core/sortb.js
+  - jstests/core/sortf.js
+  - jstests/core/sortg.js
+  - jstests/core/sortj.js
+  - jstests/core/tailable_skip_limit.js
+  - jstests/core/type_array.js
+  - jstests/core/uniqueness.js
+  - jstests/core/unset2.js
+  - jstests/core/update_addToSet.js
+  - jstests/core/update_arrayFilters.js
+  - jstests/core/update_find_and_modify_id.js
+  - jstests/core/update_modifier_pop.js
+  - jstests/core/updateh.js
+  - jstests/core/updatej.js
+
+  # SERVER-38096 Mongos opCounter doesn't increase when last op causes the transaction to implicitly abort
+  - jstests/core/opcounters_write_cmd.js
+
+  # SERVER-36311 Remove txn_override.js restriction of snapshot readConcern
+  - jstests/core/read_after_optime.js
+
+  # Consecutive writes totalling more than the size upper threshold will cause the txn to
+  # abort with a TransactionTooLarge error.
+  - jstests/core/batch_size.js
+  - jstests/core/single_batch.js
+  # For insert1.js, only Windows DEBUG builds are affected. We compute the in-memory size
+  # of the transaction, which uses the size of the oplog entry and is 8 bytes larger on
+  # Windows debug builds than other builds.
+  - jstests/core/insert1.js
+
+  # TODO: SERVER-38207 Cannot insert document with MaxKey shard key.
+  - jstests/core/type8.js
+
+  # TODO: SERVER-38326 mapReduce cleanup doesn't obey writeConcern, rendering
+  # txn_passthrough_cmd_massage.js ineffective for preventing 2 phase drops
+  # from contesting db/coll locks.
+  - jstests/core/function_string_representations.js
+  - jstests/core/geo_mapreduce2.js
+  - jstests/core/mr*.js
+  - jstests/core/or4.js
+  - jstests/core/temp_cleanup.js
+
+  # TODO: SERVER-38570 txn_override.js does not check writeError field.
+  - jstests/core/update_setOnInsert.js
+  
+  # TODO: SERVER-38588 Hybrid index builds races with prepare in replication.
+  - jstests/core/background_index_multikey.js
+
+  # TODO: SERVER-38686 createIndex should prioritize other errors over
+  # CannotImplicitlyCreateCollection
+  - jstests/core/fts_spanish.js
+  - jstests/core/geo_invalid_polygon.js
+  - jstests/core/geo_s2index.js
+  - jstests/core/wildcard_index_validindex.js
+
+  # TODO: SERVER-38215 delx.js touches 2 different collections, which makes it susceptible for
+  # migration to happen in between and cause the transaction to abort due to StaleConfigException
+  # because it is not the first op of the transaction.
+  - jstests/core/delx.js
+
+  # benchRun bypasses the txn_override.js so it doesn't run under the same transaction and can
+  # cause test to timeout because of the 3 hr transactions lifetime setting and moveChunk
+  # getting blocked trying to acquire collection X lock while doing chunk refresh.
+  - jstests/core/bench_test*.js
+
+  ##
+  ## Some aggregation stages don't support snapshot readconcern.
+  ##
+
+  # $explain (requires read concern local)
+  - jstests/core/agg_hint.js
+  - jstests/core/and.js
+  - jstests/core/collation.js
+  - jstests/core/explain_shell_helpers.js
+  - jstests/core/index_partial_read_ops.js
+  - jstests/core/optimized_match_explain.js
+  - jstests/core/sort_array.js
+  - jstests/core/views/views_collation.js
+  - jstests/core/wildcard_index_count.js
+
+  # $out
+  - jstests/core/bypass_doc_validation.js
+  - jstests/core/views/views_aggregation.js
+
+  # $listSessions
+  - jstests/core/list_all_local_sessions.js
+  - jstests/core/list_all_sessions.js
+  - jstests/core/list_local_sessions.js
+  - jstests/core/list_sessions.js
+
+  # $indexStats
+  - jstests/core/index_stats.js
+
+  # $collStats
+  - jstests/core/operation_latency_histogram.js
+  - jstests/core/views/views_coll_stats.js
+  - jstests/core/views/views_stats.js
+
+  ##
+  ## WriteErrors get converted to WriteCommandErrors if part of a txn.
+  ##
+
+  # The same error code, but with ok:0.
+  - jstests/core/json_schema/additional_items.js
+  - jstests/core/json_schema/additional_properties.js
+  - jstests/core/json_schema/bsontype.js
+  - jstests/core/json_schema/dependencies.js
+  - jstests/core/json_schema/items.js
+  - jstests/core/json_schema/logical_keywords.js
+  - jstests/core/json_schema/min_max_items.js
+  - jstests/core/json_schema/min_max_properties.js
+  - jstests/core/json_schema/pattern_properties.js
+  - jstests/core/json_schema/required.js
+  - jstests/core/json_schema/unique_items.js
+
+  - jstests/core/field_name_validation.js
+  - jstests/core/fts_array.js
+  - jstests/core/inc-SERVER-7446.js
+  - jstests/core/invalid_db_name.js
+  - jstests/core/push_sort.js
+
+  # Checks for "WriteErrors" explicitly from the response of db.runCommand()
+  - jstests/core/max_doc_size.js
+
+  # Calls res.getWriteError() or res.hasWriteError().
+  - jstests/core/bulk_api_ordered.js
+  - jstests/core/bulk_api_unordered.js
+  - jstests/core/bulk_legacy_enforce_gle.js
+  - jstests/core/cappeda.js
+  - jstests/core/doc_validation.js
+  - jstests/core/doc_validation_options.js
+  - jstests/core/geo_multinest0.js
+  - jstests/core/insert_illegal_doc.js
+  - jstests/core/ns_length.js
+  - jstests/core/push2.js
+  - jstests/core/remove6.js
+  - jstests/core/removeb.js
+  - jstests/core/rename4.js
+  - jstests/core/shell_writeconcern.js
+  - jstests/core/storefunc.js
+  - jstests/core/update_arrayFilters.js
+  - jstests/core/update_dbref.js
+  - jstests/core/updatel.js
+  - jstests/core/write_result.js
+
+  # Multiple writes in a txn, some of which fail because the collection doesn't exist.
+  # We create the collection and retry the last write, but previous writes would have
+  # still failed.
+  - jstests/core/dbref1.js
+  - jstests/core/dbref2.js
+  - jstests/core/ref3.js
+  - jstests/core/update3.js
+  - jstests/core/rename3.js
+
+  ##
+  ## Error: Unable to acquire lock within a max lock request timeout of '0ms' milliseconds
+  ##
+
+  # Collection drops done through applyOps are not converted to w:majority
+  - jstests/core/views/invalid_system_views.js
+
+  ##
+  ## Misc. reasons.
+  ##
+
+  # SERVER-34868 Cannot run a legacy query on a session.
+  - jstests/core/exhaust.js
+  - jstests/core/validate_cmd_ns.js
+
+  # SERVER-34772 Tailable Cursors are not allowed with snapshot readconcern.
+  - jstests/core/awaitdata_getmore_cmd.js
+  - jstests/core/getmore_cmd_maxtimems.js
+  - jstests/core/tailable_cursor_invalidation.js
+  - jstests/core/tailable_getmore_batch_size.js
+
+  # SERVER-34918 The "max" option of a capped collection can be exceeded until the next insert.
+  # The reason is that we don't update the count of a collection until a transaction commits,
+  # by which point it is too late to complain that "max" has been exceeded.
+  - jstests/core/capped_max1.js
+
+  # The "max" option of a capped collection can be temporarily exceeded before a
+  # txn is committed.
+  - jstests/core/bulk_insert_capped.js
+
+  # Wrong count for top info (WriteLock)
+  - jstests/core/top.js
+
+  # Expects collection to not have been created
+  - jstests/core/insert_id_undefined.js
+
+  # Creates sessions explicitly, resulting in txns being run through different sessions
+  # using a single txnNumber.
+  - jstests/core/json_schema/misc_validation.js
+  - jstests/core/views/views_all_commands.js
+
+  # Fails with implicit sessions because it will use multiple sessions on the same Mongo connection.
+  - jstests/core/dropdb.js
+
+  # Committing a transaction when the server is fsync locked fails.
+  - jstests/core/fsync.js
+
+  # Expects legacy errors ($err).
+  - jstests/core/constructors.js
+
+  # txn interrupted by command outside of txn before getMore runs.
+  - jstests/core/commands_namespace_parsing.js
+  - jstests/core/drop3.js
+  - jstests/core/ensure_sorted.js
+  - jstests/core/geo_s2cursorlimitskip.js
+  - jstests/core/getmore_invalidated_cursors.js
+  - jstests/core/getmore_invalidated_documents.js
+  - jstests/core/kill_cursors.js
+  - jstests/core/list_collections1.js
+  - jstests/core/list_indexes.js
+  - jstests/core/max_time_ms.js
+  - jstests/core/oro.js
+
+  # Expects certain number of operations in the system.profile collection.
+  - jstests/core/profile*.js
+
+  # Parallel Shell - we do not signal the override to end a txn when a parallel shell closes.
+  - jstests/core/awaitdata_getmore_cmd.js
+  - jstests/core/compact_keeps_indexes.js
+  - jstests/core/count10.js
+  - jstests/core/count_plan_summary.js
+  - jstests/core/coveredIndex3.js
+  - jstests/core/currentop.js
+  - jstests/core/distinct3.js
+  - jstests/core/find_and_modify_concurrent_update.js
+  - jstests/core/fsync.js
+  - jstests/core/geo_update_btree.js
+  - jstests/core/killop_drop_collection.js
+  - jstests/core/loadserverscripts.js
+  - jstests/core/mr_killop.js
+  - jstests/core/queryoptimizer3.js
+  - jstests/core/remove9.js
+  - jstests/core/removeb.js
+  - jstests/core/removec.js
+  - jstests/core/shellstartparallel.js
+  - jstests/core/updatef.js
+
+  # Command expects to see result from parallel operation.
+  # E.g. Suppose the following sequence of events: op1, join() op2 in parallel shell, op3.
+  # op3 will still be using the snapshot from op1, and not see op2 at all.
+  - jstests/core/cursora.js
+  - jstests/core/bench_test1.js
+
+  exclude_with_any_tags:
+  # "Cowardly refusing to override read concern of command: ..."
+  - assumes_read_concern_unchanged
+  # "writeConcern is not allowed within a multi-statement transaction"
+  - assumes_write_concern_unchanged
+  - assumes_against_mongod_not_mongos
+  # Tests tagged with the following will fail because they assume collections are not sharded.
+  - assumes_no_implicit_collection_creation_after_drop
+  - assumes_no_implicit_index_creation
+  - assumes_unsharded_collection
+  - cannot_create_unique_index_when_using_hashed_shard_key
+  - assumes_balancer_off
+  - requires_fastcount
+
+executor:
+  config:
+    shell_options:
+      eval: >-
+        var testingReplication = true;
+        load('jstests/libs/override_methods/implicitly_shard_accessed_collections.js');
+        ImplicitlyShardAccessCollSettings.setMode(ImplicitlyShardAccessCollSettings.Modes.kHashedMoveToSingleShard);
+        load('jstests/libs/override_methods/enable_sessions.js');
+        load('jstests/libs/override_methods/txn_passthrough_cmd_massage.js');
+        load('jstests/libs/txns/txn_override.js');
+      global_vars:
+        TestData:
+          sessionOptions:
+            # Tests in this suite only read from primaries and only one node is electable, so causal
+            # consistency is not required to read your own writes.   
+            causalConsistency: false
+      readMode: commands
+  hooks:
+  # The CheckReplDBHash hook waits until all operations have replicated to and have been applied
+  # on the secondaries, so we run the ValidateCollections hook after it to ensure we're
+  # validating the entire contents of the collection.
+  - class: CheckReplDBHash
+  - class: ValidateCollections
+  - class: DropShardedCollections
+  - class: CleanEveryN
+    n: 20
+  fixture:
+    class: ShardedClusterFixture
+    mongos_options:
+      set_parameters:
+        enableTestCommands: 1
+    mongod_options:
+      set_parameters:
+        logComponentVerbosity:
+          verbosity: 0
+          command: 2
+          replication:
+            election: 4
+            heartbeats: 2
+            initialSync: 2
+            rollback: 2
+          storage:
+            recovery: 2
+          transaction: 4
+        enableTestCommands: 1
+        numInitialSyncAttempts: 1
+        writePeriodicNoops: true
+    num_rs_nodes_per_shard: 2
+    num_shards: 2
diff --git a/buildscripts/resmokelib/testing/hooks/drop_sharded_collections.py b/buildscripts/resmokelib/testing/hooks/drop_sharded_collections.py
new file mode 100644
index 00000000000..90752571909
--- /dev/null
+++ b/buildscripts/resmokelib/testing/hooks/drop_sharded_collections.py
@@ -0,0 +1,22 @@
+"""Hook for cleaning up sharded collections created during tests."""
+
+from __future__ import absolute_import
+
+import os.path
+
+from . import jsfile
+
+
+class DropShardedCollections(jsfile.JSHook):
+    """Drops all sharded collections.
+
+    With the exception of internal collections like config.system.sessions.
+    """
+
+    def __init__(  # pylint: disable=super-init-not-called
+            self, hook_logger, fixture, shell_options=None):
+        """."""
+        description = "Drop all sharded collections"
+        js_filename = os.path.join("jstests", "hooks", "drop_sharded_collections.js")
+        jsfile.JSHook.__init__(  # pylint: disable=non-parent-init-called
+            self, hook_logger, fixture, js_filename, description, shell_options=shell_options)
diff --git a/etc/evergreen.yml b/etc/evergreen.yml
index 30ad3ddc457..b16ba792c16 100644
--- a/etc/evergreen.yml
+++ b/etc/evergreen.yml
@@ -6084,6 +6084,15 @@ tasks:
     vars:
       resmoke_args: --suites=multi_shard_local_read_write_multi_stmt_txn_jscore_passthrough --storageEngine=wiredTiger
 
+  name: multi_stmt_txn_jscore_passthrough_with_migration
+  depends_on:
+  - name: jsCore
+  commands:
+  - func: "do setup"
+  - func: "run tests"
+    vars:
+      resmoke_args: --suites=multi_stmt_txn_jscore_passthrough_with_migration --storageEngine=wiredTiger
+
 - <<: *task_template
   name: parallel
   depends_on:
@@ -8791,6 +8800,7 @@ buildvariants:
   - name: mongosTest
   - name: multi_shard_local_read_write_multi_stmt_txn_jscore_passthrough
   - name: multi_shard_multi_stmt_txn_jscore_passthrough
+  - name: multi_stmt_txn_jscore_passthrough_with_migration
   - name: noPassthrough
   - name: noPassthroughWithMongod
   - name: parallel
@@ -10472,6 +10482,8 @@ buildvariants:
   - name: logical_session_cache_sharding_1sec_refresh_jscore_passthrough
   - name: logical_session_cache_standalone_1sec_refresh_jscore_passthrough
   - name: mongosTest
+  - name: multi_shard_multi_stmt_txn_jscore_passthrough
+  - name: multi_stmt_txn_jscore_passthrough_with_migration
   - name: noPassthrough
   - name: noPassthroughWithMongod
   - name: rollback_fuzzer_gen
@@ -12124,6 +12136,9 @@ buildvariants:
   - name: multi_shard_multi_stmt_txn_jscore_passthrough
     distros:
     - rhel62-large
+  - name: multi_stmt_txn_jscore_passthrough_with_migration
+    distros:
+    - rhel62-large
   - name: multiversion_auth
   - name: multiversion
   - name: noPassthroughWithMongod
diff --git a/jstests/core/batch_size.js b/jstests/core/batch_size.js
index cdd60e77cd2..b280b8ceb77 100644
--- a/jstests/core/batch_size.js
+++ b/jstests/core/batch_size.js
@@ -1,4 +1,4 @@
-// @tags: [requires_getmore]
+// @tags: [requires_getmore, assumes_balancer_off]
 
 // Test subtleties of batchSize and limit.
 
diff --git a/jstests/core/distinct_compound_index.js b/jstests/core/distinct_compound_index.js
index 446313fee7f..2af57ffa3bb 100644
--- a/jstests/core/distinct_compound_index.js
+++ b/jstests/core/distinct_compound_index.js
@@ -1,3 +1,4 @@
+// @tags [assumes_balancer_off]
 (function() {
     "use strict";
 
diff --git a/jstests/core/explain5.js b/jstests/core/explain5.js
index 35841ac0789..03fcec4ddc6 100644
--- a/jstests/core/explain5.js
+++ b/jstests/core/explain5.js
@@ -1,4 +1,5 @@
 // Check explain results for a plan that uses an index to obtain the requested sort order.
+// @tags: [assumes_balancer_off]
 
 t = db.jstests_explain5;
 t.drop();
diff --git a/jstests/core/explain_execution_error.js b/jstests/core/explain_execution_error.js
index ff999f48bb9..a59a4b7930f 100644
--- a/jstests/core/explain_execution_error.js
+++ b/jstests/core/explain_execution_error.js
@@ -1,4 +1,4 @@
-// @tags: [requires_getmore]
+// @tags: [requires_getmore, assumes_balancer_off]
 
 // Test that even when the execution of a query fails, explain reports query
 // planner information.
diff --git a/jstests/core/getmore_invalidated_cursors.js b/jstests/core/getmore_invalidated_cursors.js
index 37f2a508013..788fb662cba 100644
--- a/jstests/core/getmore_invalidated_cursors.js
+++ b/jstests/core/getmore_invalidated_cursors.js
@@ -1,4 +1,5 @@
-// @tags: [requires_getmore, requires_non_retryable_commands, requires_collstats]
+// @tags: [requires_getmore, requires_non_retryable_commands, requires_collstats,
+//         assumes_balancer_off]
 
 // Tests that running a getMore on a cursor that has been invalidated by something like a collection
 // drop will return an appropriate error message.
diff --git a/jstests/core/index_check7.js b/jstests/core/index_check7.js
index fda248db467..d02725616a8 100644
--- a/jstests/core/index_check7.js
+++ b/jstests/core/index_check7.js
@@ -1,3 +1,4 @@
+// @tags: [assumes_balancer_off]
 
 t = db.index_check7;
 t.drop();
diff --git a/jstests/core/index_diag.js b/jstests/core/index_diag.js
index 3779d5f3c78..2064527ef72 100644
--- a/jstests/core/index_diag.js
+++ b/jstests/core/index_diag.js
@@ -1,3 +1,4 @@
+// @tags: [assumes_balancer_off]
 load("jstests/libs/fixture_helpers.js");
 
 t = db.index_diag;
diff --git a/jstests/core/min_max_bounds.js b/jstests/core/min_max_bounds.js
index 1e4a80efbf6..713dc75b844 100644
--- a/jstests/core/min_max_bounds.js
+++ b/jstests/core/min_max_bounds.js
@@ -1,5 +1,6 @@
 /**
  * This test ensures that queries using simple ranges handle bound inclusion properly.
+ * @tags: [assumes_balancer_off]
  */
 (function() {
     'use strict';
diff --git a/jstests/core/minmax.js b/jstests/core/minmax.js
index 72653b23811..43a321d9c80 100644
--- a/jstests/core/minmax.js
+++ b/jstests/core/minmax.js
@@ -1,4 +1,5 @@
 // Test min / max query parameters.
+// @tags: [assumes_balancer_off]
 (function() {
     "use strict";
 
diff --git a/jstests/core/orf.js b/jstests/core/orf.js
index 5d58e59c74f..66d943aa764 100644
--- a/jstests/core/orf.js
+++ b/jstests/core/orf.js
@@ -1,4 +1,5 @@
 // Test a query with 200 $or clauses
+// @tags: [assumes_balancer_off]
 
 t = db.jstests_orf;
 t.drop();
diff --git a/jstests/core/remove7.js b/jstests/core/remove7.js
index 226a4cfb150..2cda8945089 100644
--- a/jstests/core/remove7.js
+++ b/jstests/core/remove7.js
@@ -25,7 +25,7 @@ for (i = 0; i < 200; i++) {
         t.save({tags: getTags(100)});
     var q = {tags: {$in: getTags(10)}};
     var before = t.find(q).count();
-    var res = t.remove(q);
+    var res = assert.writeOK(t.remove(q));
     var after = t.find(q).count();
     assert.eq(0, after, "not zero after!");
     assert.writeOK(res);
diff --git a/jstests/core/wildcard_and_text_indexes.js b/jstests/core/wildcard_and_text_indexes.js
index 4fd7ad34ac1..a4b552e3220 100644
--- a/jstests/core/wildcard_and_text_indexes.js
+++ b/jstests/core/wildcard_and_text_indexes.js
@@ -1,5 +1,6 @@
 /**
  * Tests that a {$**: 1} index can coexist with a {$**: 'text'} index in the same collection.
+ * @tags: [assumes_balancer_off]
  */
 (function() {
     "use strict";
diff --git a/jstests/core/wildcard_index_basic_index_bounds.js b/jstests/core/wildcard_index_basic_index_bounds.js
index c5e1f87f7e1..e2ee7da8710 100644
--- a/jstests/core/wildcard_index_basic_index_bounds.js
+++ b/jstests/core/wildcard_index_basic_index_bounds.js
@@ -4,7 +4,7 @@
  * Does not support stepdowns because the test issues getMores, which the stepdown/kill_primary
  * passthroughs will reject.
  *
- * @tags: [does_not_support_stepdowns]
+ * @tags: [does_not_support_stepdowns, assumes_balancer_off]
  */
 (function() {
     "use strict";
diff --git a/jstests/core/wildcard_index_cached_plans.js b/jstests/core/wildcard_index_cached_plans.js
index d0c2a50abe9..96b8cfa4055 100644
--- a/jstests/core/wildcard_index_cached_plans.js
+++ b/jstests/core/wildcard_index_cached_plans.js
@@ -5,7 +5,7 @@
  * $planCacheStats aggregation source. Both operations must be routed to the primary, and the latter
  * only supports 'local' readConcern.
  * @tags: [assumes_read_preference_unchanged, assumes_read_concern_unchanged,
- * does_not_support_stepdowns]
+ *         does_not_support_stepdowns, assumes_balancer_off]
  */
 (function() {
     "use strict";
diff --git a/jstests/core/wildcard_index_multikey.js b/jstests/core/wildcard_index_multikey.js
index 93e9492d6de..d9704963720 100644
--- a/jstests/core/wildcard_index_multikey.js
+++ b/jstests/core/wildcard_index_multikey.js
@@ -1,5 +1,6 @@
 /**
  * Tests that queries using a multikey $** index, return correct results.
+ * @tags: [assumes_balancer_off]
  */
 (function() {
     "use strict";
diff --git a/jstests/core/wildcard_index_nonblocking_sort.js b/jstests/core/wildcard_index_nonblocking_sort.js
index fa400fb89e6..c21a0cacdb5 100644
--- a/jstests/core/wildcard_index_nonblocking_sort.js
+++ b/jstests/core/wildcard_index_nonblocking_sort.js
@@ -1,3 +1,4 @@
+// @tags: [assumes_balancer_off]
 (function() {
     "use strict";
 
diff --git a/jstests/hooks/drop_sharded_collections.js b/jstests/hooks/drop_sharded_collections.js
new file mode 100644
index 00000000000..5758e3027e5
--- /dev/null
+++ b/jstests/hooks/drop_sharded_collections.js
@@ -0,0 +1,33 @@
+/**
+ * Drops all sharded collections (except for collections used internally,
+ * like config.system.sessions).
+ */
+(function() {
+    "use strict";
+
+    load("jstests/libs/fixture_helpers.js");  // For isMongos.
+
+    assert.neq(typeof db, 'undefined', 'No `db` object, is the shell connected to a mongod?');
+    assert(FixtureHelpers.isMongos(db), "not connected to mongos");
+
+    let balSettingResult = assert.commandWorked(db.adminCommand({balancerStatus: 1}));
+    if (balSettingResult.mode !== 'off') {
+        assert.commandWorked(db.adminCommand({balancerStop: 1}));
+    }
+
+    db.getSiblingDB('config').collections.find().forEach(collEntry => {
+        if (collEntry._id !== 'config.system.sessions') {
+            let nsSplit = collEntry._id.split('.');
+            const dbName = nsSplit.shift();
+            const collName = nsSplit.join('.');
+
+            // Note: drop also cleans up tags and chunks associated with ns.
+            assert.commandWorked(db.getSiblingDB(dbName).runCommand({drop: collName}));
+        }
+    });
+
+    // Turn balancer back on if it was not off earlier.
+    if (balSettingResult.mode !== 'off') {
+        assert.commandWorked(db.adminCommand({balancerStart: 1}));
+    }
+})();
diff --git a/jstests/libs/override_methods/implicitly_shard_accessed_collections.js b/jstests/libs/override_methods/implicitly_shard_accessed_collections.js
index 93f3cbd3e15..a6cb5a6c2a0 100644
--- a/jstests/libs/override_methods/implicitly_shard_accessed_collections.js
+++ b/jstests/libs/override_methods/implicitly_shard_accessed_collections.js
@@ -9,6 +9,30 @@
  * dropped in a sharded cluster.
  */
 
+/**
+ * Settings for the converting implictily accessed collections to sharded collections.
+ */
+const ImplicitlyShardAccessCollSettings = (function() {
+    let mode = 0;  // Default to hashed shard key.
+
+    return {
+        Modes: {
+            kUseHashedSharding: 0,
+            kHashedMoveToSingleShard: 1,
+        },
+        setMode: function(newMode) {
+            if (newMode !== 0 && newMode !== 1) {
+                throw new Error("Cannot set mode to unknown mode: " + newMode);
+            }
+
+            mode = newMode;
+        },
+        getMode: function() {
+            return mode;
+        },
+    };
+})();
+
 (function() {
     'use strict';
 
@@ -31,6 +55,8 @@
         /\.system\./,
     ];
 
+    const kZoneName = 'moveToHereForMigrationPassthrough';
+
     function shardCollection(collection) {
         var db = collection.getDB();
         var dbName = db.getName();
@@ -51,18 +77,45 @@
 
         res = db.adminCommand(
             {shardCollection: fullName, key: {_id: 'hashed'}, collation: {locale: "simple"}});
-        if (res.ok === 0 && testMayRunDropInParallel) {
-            // We ignore ConflictingOperationInProgress error responses from the
-            // "shardCollection" command if it's possible the test was running a "drop" command
-            // concurrently. We could retry running the "shardCollection" command, but tests
-            // that are likely to trigger this case are also likely running the "drop" command
-            // in a loop. We therefore just let the test continue with the collection being
-            // unsharded.
-            assert.commandFailedWithCode(res, ErrorCodes.ConflictingOperationInProgress);
-            print("collection '" + fullName +
-                  "' failed to be sharded due to a concurrent drop operation");
-        } else {
-            assert.commandWorked(res, "sharding '" + fullName + "' with a hashed _id key failed");
+
+        let checkResult = function(res, opDescription) {
+            if (res.ok === 0 && testMayRunDropInParallel) {
+                // We ignore ConflictingOperationInProgress error responses from the
+                // "shardCollection" command if it's possible the test was running a "drop" command
+                // concurrently. We could retry running the "shardCollection" command, but tests
+                // that are likely to trigger this case are also likely running the "drop" command
+                // in a loop. We therefore just let the test continue with the collection being
+                // unsharded.
+                assert.commandFailedWithCode(res, ErrorCodes.ConflictingOperationInProgress);
+                jsTest.log("Ignoring failure while " + opDescription +
+                           " due to a concurrent drop operation: " + tojson(res));
+            } else {
+                assert.commandWorked(res, opDescription + " failed");
+            }
+        };
+
+        checkResult(res, 'shard ' + fullName);
+
+        // Set the entire chunk range to a single zone, so balancer will be forced to move the
+        // evenly distributed chunks to a shard (selected at random).
+        if (res.ok === 1 &&
+            ImplicitlyShardAccessCollSettings.getMode() ===
+                ImplicitlyShardAccessCollSettings.Modes.kHashedMoveToSingleShard) {
+            let shardName =
+                db.getSiblingDB('config').shards.aggregate([{$sample: {size: 1}}]).toArray()[0]._id;
+
+            checkResult(db.adminCommand({addShardToZone: shardName, zone: kZoneName}),
+                        'add ' + shardName + ' to zone ' + kZoneName);
+            checkResult(db.adminCommand({
+                updateZoneKeyRange: fullName,
+                min: {_id: MinKey},
+                max: {_id: MaxKey},
+                zone: kZoneName
+            }),
+                        'set zone for ' + fullName);
+
+            // Wake up the balancer.
+            checkResult(db.adminCommand({balancerStart: 1}), 'turn on balancer');
         }
     }
 
diff --git a/src/mongo/db/s/balancer/balancer.cpp b/src/mongo/db/s/balancer/balancer.cpp
index 86a80ee5032..5e1f2ed131d 100644
--- a/src/mongo/db/s/balancer/balancer.cpp
+++ b/src/mongo/db/s/balancer/balancer.cpp
@@ -661,4 +661,9 @@ void Balancer::_splitOrMarkJumbo(OperationContext* opCtx,
     }
 }
 
+void Balancer::notifyPersistedBalancerSettingsChanged() {
+    stdx::unique_lock<stdx::mutex> lock(_mutex);
+    _condVar.notify_all();
+}
+
 }  // namespace mongo
diff --git a/src/mongo/db/s/balancer/balancer.h b/src/mongo/db/s/balancer/balancer.h
index eb0b143b6bc..db11d7d0c64 100644
--- a/src/mongo/db/s/balancer/balancer.h
+++ b/src/mongo/db/s/balancer/balancer.h
@@ -144,6 +144,11 @@ public:
      */
     void report(OperationContext* opCtx, BSONObjBuilder* builder);
 
+    /**
+     * Informs the balancer that a setting that affects it changed.
+     */
+    void notifyPersistedBalancerSettingsChanged();
+
 private:
     /**
      * Possible runtime states of the balancer. The comments indicate the allowed next state.
diff --git a/src/mongo/db/s/config/configsvr_control_balancer_command.cpp b/src/mongo/db/s/config/configsvr_control_balancer_command.cpp
index 85e949d0d4e..b7bb313ece7 100644
--- a/src/mongo/db/s/config/configsvr_control_balancer_command.cpp
+++ b/src/mongo/db/s/config/configsvr_control_balancer_command.cpp
@@ -105,6 +105,7 @@ private:
     void _run(OperationContext* opCtx, BSONObjBuilder* result) override {
         uassertStatusOK(Grid::get(opCtx)->getBalancerConfiguration()->setBalancerMode(
             opCtx, BalancerSettingsType::kFull));
+        Balancer::get(opCtx)->notifyPersistedBalancerSettingsChanged();
     }
 };
 
@@ -121,6 +122,7 @@ private:
 
         uassertStatusOK(Grid::get(opCtx)->getBalancerConfiguration()->setBalancerMode(
             opCtx, BalancerSettingsType::kOff));
+        Balancer::get(opCtx)->notifyPersistedBalancerSettingsChanged();
         Balancer::get(opCtx)->joinCurrentRound(opCtx);
     }
 };
diff --git a/src/mongo/db/s/split_chunk.cpp b/src/mongo/db/s/split_chunk.cpp
index b1cb6c5a93e..ddb7d5a9f53 100644
--- a/src/mongo/db/s/split_chunk.cpp
+++ b/src/mongo/db/s/split_chunk.cpp
@@ -136,13 +136,12 @@ StatusWith<boost::optional<ChunkRange>> splitChunk(OperationContext* opCtx,
                                                    const std::string& shardName,
                                                    const OID& expectedCollectionEpoch) {
     //
-    // Lock the collection's metadata and get highest version for the current shard
     // TODO(SERVER-25086): Remove distLock acquisition from split chunk
     //
     const std::string whyMessage(
         str::stream() << "splitting chunk " << chunkRange.toString() << " in " << nss.toString());
     auto scopedDistLock = Grid::get(opCtx)->catalogClient()->getDistLockManager()->lock(
-        opCtx, nss.ns(), whyMessage, DistLockManager::kSingleLockAttemptTimeout);
+        opCtx, nss.ns(), whyMessage, DistLockManager::kDefaultLockTimeout);
     if (!scopedDistLock.isOK()) {
         return scopedDistLock.getStatus().withContext(
             str::stream() << "could not acquire collection lock for " << nss.toString()