SERVER-43990 A command to confirm that all chunks have been moved to the right zone after the initial split

8 files changed, 137 insertions, 0 deletions

diff --git a/jstests/auth/lib/commands_lib.js b/jstests/auth/lib/commands_lib.js
index 408b1fdbea2..4f1f1d88899 100644
--- a/jstests/auth/lib/commands_lib.js
+++ b/jstests/auth/lib/commands_lib.js
@@ -5664,6 +5664,22 @@ var authCommandsLib = {
               },
           ]
         },
+        {
+          testname: "balancerCollectionStatus",
+          command: {shardCollection: "test.x"},
+          skipUnlessSharded: true,
+          testcases: [
+              {
+                runOnDb: adminDbName,
+                roles: Object.extend({enableSharding: 1}, roles_clusterManager),
+                privileges:
+                    [{resource: {db: "test", collection: "x"}, actions: ["enableSharding"]}],
+                expectFail: true
+              },
+              {runOnDb: firstDbName, roles: {}},
+              {runOnDb: secondDbName, roles: {}}
+          ]
+		},
     ],
 
     /************* SHARED TEST LOGIC ****************/
diff --git a/jstests/core/views/views_all_commands.js b/jstests/core/views/views_all_commands.js
index 20fc61b2fdd..9a7e4f778a8 100644
--- a/jstests/core/views/views_all_commands.js
+++ b/jstests/core/views/views_all_commands.js
@@ -75,6 +75,7 @@ let viewsCommandTests = {
     _cloneCollectionOptionsFromPrimaryShard: {skip: isAnInternalCommand},
     _configsvrAddShard: {skip: isAnInternalCommand},
     _configsvrAddShardToZone: {skip: isAnInternalCommand},
+    _configsvrBalancerCollectionStatus: {skip: isAnInternalCommand},
     _configsvrBalancerStart: {skip: isAnInternalCommand},
     _configsvrBalancerStatus: {skip: isAnInternalCommand},
     _configsvrBalancerStop: {skip: isAnInternalCommand},
@@ -128,6 +129,16 @@ let viewsCommandTests = {
     },
     authenticate: {skip: isUnrelated},
     availableQueryOptions: {skip: isAnInternalCommand},
+    balancerCollectionStatus: {
+        command: {balancerCollectionStatus: "test.view"},
+        setup: function(conn) {
+            assert.commandWorked(conn.adminCommand({enableSharding: "test"}));
+        },
+        skipStandalone: true,
+        expectFailure: true,
+        isAdminCommand: true,
+        expectedErrorCode: ErrorCodes.NamespaceNotSharded,
+    },
     balancerStart: {skip: isUnrelated},
     balancerStatus: {skip: isUnrelated},
     balancerStop: {skip: isUnrelated},
diff --git a/jstests/sharding/balancer_collection_status.js b/jstests/sharding/balancer_collection_status.js
new file mode 100644
index 00000000000..e1cbb8f48c0
--- /dev/null
+++ b/jstests/sharding/balancer_collection_status.js
@@ -0,0 +1,102 @@
+/**
+ * Test the balancerCollectionStatus command and its possible outputs
+ *
+ * Remove requires_fcv_44 tag if SERVER-43990 is backported or 4.4 becomes last-stable.
+ * @tags: [requires_fcv_44]
+ */
+
+(function() {
+'use strict';
+
+var st = new ShardingTest({mongos: 1, shards: 3});
+
+function runBalancer(rounds) {
+    st.startBalancer();
+    let numRounds = 0;
+
+    // Let the balancer run for caller specified number of rounds.
+    assert.soon(() => {
+        st.awaitBalancerRound();
+        st.printShardingStatus(true);
+        numRounds++;
+        return (numRounds === rounds);
+    }, 'Balancer failed to run for ' + rounds + ' rounds', 1000 * 60 * (3 * rounds));
+
+    st.stopBalancer();
+}
+
+// only fully quilified namespaces are allowed on the command
+assert.commandFailedWithCode(st.s0.adminCommand({balancerCollectionStatus: 'db'}),
+                             ErrorCodes.InvalidNamespace);
+
+// only sharded databases are allowed
+assert.commandFailedWithCode(st.s0.adminCommand({balancerCollectionStatus: 'db.col'}),
+                             ErrorCodes.NamespaceNotFound);
+
+// setup the collection for the test
+assert.commandWorked(st.s0.adminCommand({enableSharding: 'db'}));
+assert.commandWorked(st.s0.adminCommand({shardCollection: 'db.col', key: {key: 1}}));
+
+// only sharded collections are allowed
+assert.commandFailedWithCode(st.s0.adminCommand({balancerCollectionStatus: 'db.col2'}),
+                             ErrorCodes.NamespaceNotSharded);
+
+var result = assert.commandWorked(st.s0.adminCommand({balancerCollectionStatus: 'db.col'}));
+
+// new collections must be balanced
+assert.eq(result.status, 'balanced');
+
+// get shardIds
+var shards = st.s0.getDB('config').shards.find().toArray();
+
+// manually split and place the 3 chunks on the same shard
+assert.commandWorked(st.s0.adminCommand({split: 'db.col', middle: {key: 10}}));
+assert.commandWorked(st.s0.adminCommand({split: 'db.col', middle: {key: 20}}));
+assert.commandWorked(st.s0.adminCommand({moveChunk: 'db.col', find: {key: 0}, to: shards[0]._id}));
+assert.commandWorked(st.s0.adminCommand({moveChunk: 'db.col', find: {key: 10}, to: shards[0]._id}));
+assert.commandWorked(st.s0.adminCommand({moveChunk: 'db.col', find: {key: 20}, to: shards[0]._id}));
+
+// check the current status
+result = assert.commandWorked(st.s0.adminCommand({balancerCollectionStatus: 'db.col'}));
+
+// chunksImbalanced expected
+assert.eq(result.status, 'chunksImbalance');
+
+// run balancer with 3 rounds
+runBalancer(3);
+
+// the chunks must be balanced now
+result = assert.commandWorked(st.s0.adminCommand({balancerCollectionStatus: 'db.col'}));
+
+assert.eq(result.status, 'balanced');
+
+// manually move a chunk to a shard before creating zones (this will help
+// testing the zone violation)
+assert.commandWorked(st.s0.adminCommand({moveChunk: 'db.col', find: {key: 10}, to: shards[2]._id}));
+
+// create zones on first two shards only
+assert.commandWorked(st.s0.adminCommand({addShardToZone: shards[0]._id, zone: 'zone0'}));
+assert.commandWorked(st.s0.adminCommand(
+    {updateZoneKeyRange: 'db.col', min: {key: MinKey}, max: {key: 10}, zone: 'zone0'}));
+
+assert.commandWorked(st.s0.adminCommand({addShardToZone: shards[1]._id, zone: 'zone1'}));
+assert.commandWorked(st.s0.adminCommand(
+    {updateZoneKeyRange: 'db.col', min: {key: 10}, max: {key: 20}, zone: 'zone1'}));
+
+result = assert.commandWorked(st.s0.adminCommand({balancerCollectionStatus: 'db.col'}));
+
+// having a chunk on a different zone will cause a zone violation
+assert.eq(result.status, 'zoneViolation');
+
+// run balancer, we don't know exactly where the first run moved the chunks
+// so lets run 3 rounds just in case
+runBalancer(3);
+
+// the chunks must be balanced now
+result = assert.commandWorked(st.s0.adminCommand({balancerCollectionStatus: 'db.col'}));
+
+// final check: all chunks are balanced and in the correct zone
+assert.eq(result.status, 'balanced');
+
+st.stop();
+})();
\ No newline at end of file
diff --git a/jstests/sharding/database_versioning_all_commands.js b/jstests/sharding/database_versioning_all_commands.js
index 10754c7f8ef..5ce6d28e2a2 100644
--- a/jstests/sharding/database_versioning_all_commands.js
+++ b/jstests/sharding/database_versioning_all_commands.js
@@ -252,6 +252,7 @@ let testCases = {
     },
     authenticate: {skip: "does not forward command to primary shard"},
     availableQueryOptions: {skip: "executes locally on mongos (not sent to any remote node)"},
+    balancerCollectionStatus: {skip: "does not forward command to primary shard"},
     balancerStart: {skip: "not on a user database"},
     balancerStatus: {skip: "not on a user database"},
     balancerStop: {skip: "not on a user database"},
diff --git a/jstests/sharding/safe_secondary_reads_drop_recreate.js b/jstests/sharding/safe_secondary_reads_drop_recreate.js
index aa08f7a6732..b7455ba3de1 100644
--- a/jstests/sharding/safe_secondary_reads_drop_recreate.js
+++ b/jstests/sharding/safe_secondary_reads_drop_recreate.js
@@ -41,6 +41,7 @@ let testCases = {
     _shardsvrCloneCatalogData: {skip: "primary only"},
     _configsvrAddShard: {skip: "primary only"},
     _configsvrAddShardToZone: {skip: "primary only"},
+    _configsvrBalancerCollectionStatus: {skip: "primary only"},
     _configsvrBalancerStart: {skip: "primary only"},
     _configsvrBalancerStatus: {skip: "primary only"},
     _configsvrBalancerStop: {skip: "primary only"},
@@ -87,6 +88,7 @@ let testCases = {
     authSchemaUpgrade: {skip: "primary only"},
     authenticate: {skip: "does not return user data"},
     availableQueryOptions: {skip: "does not return user data"},
+    balancerCollectionStatus: {skip: "primary only"},
     balancerStart: {skip: "primary only"},
     balancerStatus: {skip: "primary only"},
     balancerStop: {skip: "primary only"},
diff --git a/jstests/sharding/safe_secondary_reads_single_migration_suspend_range_deletion.js b/jstests/sharding/safe_secondary_reads_single_migration_suspend_range_deletion.js
index aa47096339a..96f2efd2978 100644
--- a/jstests/sharding/safe_secondary_reads_single_migration_suspend_range_deletion.js
+++ b/jstests/sharding/safe_secondary_reads_single_migration_suspend_range_deletion.js
@@ -48,6 +48,7 @@ let testCases = {
     _shardsvrCloneCatalogData: {skip: "primary only"},
     _configsvrAddShard: {skip: "primary only"},
     _configsvrAddShardToZone: {skip: "primary only"},
+    _configsvrBalancerCollectionStatus: {skip: "primary only"},
     _configsvrBalancerStart: {skip: "primary only"},
     _configsvrBalancerStatus: {skip: "primary only"},
     _configsvrBalancerStop: {skip: "primary only"},
@@ -100,6 +101,7 @@ let testCases = {
     authSchemaUpgrade: {skip: "primary only"},
     authenticate: {skip: "does not return user data"},
     availableQueryOptions: {skip: "does not return user data"},
+    balancerCollectionStatus: {skip: "primary only"},
     balancerStart: {skip: "primary only"},
     balancerStatus: {skip: "primary only"},
     balancerStop: {skip: "primary only"},
diff --git a/jstests/sharding/safe_secondary_reads_single_migration_waitForDelete.js b/jstests/sharding/safe_secondary_reads_single_migration_waitForDelete.js
index efa99b0c6ad..d310da83d9e 100644
--- a/jstests/sharding/safe_secondary_reads_single_migration_waitForDelete.js
+++ b/jstests/sharding/safe_secondary_reads_single_migration_waitForDelete.js
@@ -41,6 +41,7 @@ let testCases = {
     _shardsvrCloneCatalogData: {skip: "primary only"},
     _configsvrAddShard: {skip: "primary only"},
     _configsvrAddShardToZone: {skip: "primary only"},
+    _configsvrBalancerCollectionStatus: {skip: "primary only"},
     _configsvrBalancerStart: {skip: "primary only"},
     _configsvrBalancerStatus: {skip: "primary only"},
     _configsvrBalancerStop: {skip: "primary only"},
@@ -88,6 +89,7 @@ let testCases = {
     authenticate: {skip: "does not return user data"},
     authSchemaUpgrade: {skip: "primary only"},
     availableQueryOptions: {skip: "does not return user data"},
+    balancerCollectionStatus: {skip: "primary only"},
     balancerStart: {skip: "primary only"},
     balancerStatus: {skip: "primary only"},
     balancerStop: {skip: "primary only"},
diff --git a/jstests/sharding/track_unsharded_collections_check_shard_version.js b/jstests/sharding/track_unsharded_collections_check_shard_version.js
index 3020d78a397..9ff6e225d6b 100644
--- a/jstests/sharding/track_unsharded_collections_check_shard_version.js
+++ b/jstests/sharding/track_unsharded_collections_check_shard_version.js
@@ -72,6 +72,7 @@ let testCases = {
     },
     authenticate: {skip: "does not forward command to primary shard"},
     availableQueryOptions: {skip: "executes locally on mongos (not sent to any remote node)"},
+    balancerCollectionStatus: {skip: "does not forward command to primary shard"},
     balancerStart: {skip: "not on a user database"},
     balancerStatus: {skip: "not on a user database"},
     balancerStop: {skip: "not on a user database"},