mongo/jstests/sharding/move_primary_basic.js

import {FixtureHelpers} from "jstests/libs/fixture_helpers.js";
import {ShardingTest} from "jstests/libs/shardingtest.js";

function collectionExists(shard, dbName, collName) {
    return Array.contains(shard.getDB(dbName).getCollectionNames(), collName);
}

let st = new ShardingTest({mongos: 1, shards: 2});

let mongos = st.s0;
let shard0 = st.shard0;
let shard1 = st.shard1;
let config = st.config;

const dbName = "test_db";
const coll1Name = "test_coll_1";
const coll2Name = "test_coll_2";
const coll3Name = "test_coll_3";
const coll4Name = "test_coll_4";
const coll1NS = dbName + "." + coll1Name;
const coll2NS = dbName + "." + coll2Name;
const coll3NS = dbName + "." + coll3Name;
const coll4NS = dbName + "." + coll4Name;

assert.commandWorked(mongos.adminCommand({enableSharding: dbName, primaryShard: shard0.shardName}));
assert.commandWorked(mongos.getCollection(coll1NS).insert({name: "Tom"}));
assert.commandWorked(mongos.getCollection(coll1NS).insert({name: "Dick"}));
assert.commandWorked(mongos.getCollection(coll2NS).insert({name: "Harry"}));

assert.commandWorked(mongos.getDB(dbName).runCommand({createUnsplittableCollection: coll3Name}));
assert.commandWorked(mongos.getCollection(coll3NS).insert({name: "Peter"}));

assert.commandWorked(
    mongos.getDB(dbName).runCommand({createUnsplittableCollection: coll4Name, dataShard: shard1.shardName}),
);
assert.commandWorked(mongos.getCollection(coll4NS).insert({name: "Jack"}));

assert.commandWorked(st.s.adminCommand({shardCollection: coll2NS, key: {_id: 1}}));

jsTest.log("Test preconditions");
{
    // Fail with internal databases.
    assert.commandFailed(mongos.adminCommand({movePrimary: "config", to: shard1.shardName}));
    assert.commandFailed(mongos.adminCommand({movePrimary: "admin", to: shard1.shardName}));
    assert.commandFailed(mongos.adminCommand({movePrimary: "local", to: shard1.shardName}));

    // Fail with invalid database names.
    assert.commandFailed(mongos.adminCommand({movePrimary: "", to: shard1.shardName}));
    assert.commandFailed(mongos.adminCommand({movePrimary: "a.b", to: shard1.shardName}));

    // Fail against a non-admin database.
    assert.commandFailedWithCode(
        mongos.getDB("test").runCommand({movePrimary: dbName, to: shard1.shardName}),
        ErrorCodes.Unauthorized,
    );

    // Fail if the destination shard is invalid or does not exist.
    assert.commandFailed(mongos.adminCommand({movePrimary: dbName}));
    assert.commandFailed(mongos.adminCommand({movePrimary: dbName, to: ""}));
    assert.commandFailed(mongos.adminCommand({movePrimary: dbName, to: "Unknown"}));

    // Succeed if the destination shard is already the primary for the given database.
    assert.commandWorked(mongos.adminCommand({movePrimary: dbName, to: shard0.shardName}));
}

jsTest.log("Test that orphaned documents on recipient causes the operation to fail");
{
    // Insert an orphaned document on shard1.
    assert.commandWorked(shard1.getCollection(coll1NS).insertOne({name: "Emma"}));

    // The documents are on both the shards.
    assert.eq(2, shard0.getCollection(coll1NS).find().itcount());
    assert.eq(1, shard1.getCollection(coll1NS).find().itcount());

    // If the collection is being cloned by the movePrimary operation, this will fail with
    // NamespaceExists. Otherwise, when the collection is being cloned, it will fail with
    // InvalidOptions due to the UUIDS not matching.
    let expectedErrorCode = ErrorCodes.NamespaceExists;
    assert.commandFailedWithCode(mongos.adminCommand({movePrimary: dbName, to: shard1.shardName}), expectedErrorCode);

    // The documents are on both the shards.
    assert.eq(2, shard0.getCollection(coll1NS).find().itcount());
    assert.eq(1, shard1.getCollection(coll1NS).find().itcount());

    // Remove the orphaned document on shard1 leaving an empty collection.
    assert.commandWorked(shard1.getCollection(coll1NS).remove({name: "Emma"}));
    assert.eq(0, shard1.getCollection(coll1NS).find().itcount());

    assert.commandFailedWithCode(mongos.adminCommand({movePrimary: dbName, to: shard1.shardName}), expectedErrorCode);

    // Drop the orphaned collection on shard1.
    shard1.getCollection(coll1NS).drop();
}

jsTest.log("Test that unsharded, untracked collections are moved");
{
    {
        // Unsharded (maybe tracked) collection (1)'s documents are on shard 0.
        assert.eq(2, shard0.getCollection(coll1NS).find().itcount());
        assert.eq(0, shard1.getCollection(coll1NS).find().itcount());
        // Sharded collection (2)'s documents are on shard 0.
        assert.eq(1, shard0.getCollection(coll2NS).find().itcount());
        assert.eq(0, shard1.getCollection(coll2NS).find().itcount());
        // Unsharded, tracked collection (3)'s documents are on shard 0.

        assert.eq(1, shard0.getCollection(coll3NS).find().itcount());
        assert.eq(0, shard1.getCollection(coll3NS).find().itcount());

        // Unsharded, tracked collection (4)'s documents are on shard 1.

        assert.eq(1, shard1.getCollection(coll4NS).find().itcount());
        assert.eq(0, shard0.getCollection(coll4NS).find().itcount());
    }

    assert.commandWorked(mongos.adminCommand({movePrimary: dbName, to: shard1.shardName}));

    {
        // Unsharded collection (1) may or may not be tracked. If it is tracked, it's documents will
        // still be on shard 0, otherwise, they will have moved to shard 1.
        if (FixtureHelpers.isTracked(mongos.getCollection(coll1NS))) {
            assert.eq(2, shard0.getCollection(coll1NS).find().itcount());
            assert.eq(0, shard1.getCollection(coll1NS).find().itcount());
        } else {
            assert.eq(0, shard0.getCollection(coll1NS).find().itcount());
            assert.eq(2, shard1.getCollection(coll1NS).find().itcount());
        }
        // Sharded collection (2)'s documents are on shard 0
        assert.eq(1, shard0.getCollection(coll2NS).find().itcount());
        assert.eq(0, shard1.getCollection(coll2NS).find().itcount());
        // Unsharded, tracked collection (3)'s documents are on shard 0

        assert.eq(1, shard0.getCollection(coll3NS).find().itcount());
        assert.eq(0, shard1.getCollection(coll3NS).find().itcount());

        // Unsharded, tracked collection (4)'s documents are on shard 1

        assert.eq(0, shard0.getCollection(coll4NS).find().itcount());
        assert.eq(1, shard1.getCollection(coll4NS).find().itcount());
    }

    assert.commandWorked(mongos.adminCommand({movePrimary: dbName, to: shard0.shardName}));

    {
        // Unsharded collection (1)'s documents are on shard 0.
        assert.eq(2, shard0.getCollection(coll1NS).find().itcount());
        assert.eq(0, shard1.getCollection(coll1NS).find().itcount());
        // Sharded collection (2)'s documents are on shard 0
        assert.eq(1, shard0.getCollection(coll2NS).find().itcount());
        assert.eq(0, shard1.getCollection(coll2NS).find().itcount());
        // Unsharded, tracked collection (3)'s documents are on shard 0

        assert.eq(1, shard0.getCollection(coll3NS).find().itcount());
        assert.eq(0, shard1.getCollection(coll3NS).find().itcount());

        // Unsharded, tracked collection (4)'s documents are on shard 1

        assert.eq(0, shard0.getCollection(coll4NS).find().itcount());
        assert.eq(1, shard1.getCollection(coll4NS).find().itcount());
    }
}

jsTest.log("Test that metadata has changed");
{
    //  The current primary shard is shard1.
    const previousMetadata = config.databases.findOne({_id: dbName});
    assert.eq(shard0.shardName, previousMetadata.primary);

    assert.commandWorked(mongos.adminCommand({movePrimary: dbName, to: shard1.shardName}));

    // The new primary shard is shard0.
    const nextMetadata = config.databases.findOne({_id: dbName});
    assert.eq(shard1.shardName, nextMetadata.primary);

    // UUID has not changed, but timestamp and lastMod have been bumped.
    assert.eq(previousMetadata.version.uuid, nextMetadata.version.uuid);
    assert.eq(-1, timestampCmp(previousMetadata.version.timestamp, nextMetadata.version.timestamp));
    assert.eq(previousMetadata.version.lastMod + 1, nextMetadata.version.lastMod);
}

st.stop();