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// Test that 'atClusterTime' triggers a noop write to advance the majority commit point if
// necessary.
// @tags: [requires_sharding]
(function() {
"use strict";
// Skip this test if running with --nojournal and WiredTiger.
if (jsTest.options().noJournal &&
(!jsTest.options().storageEngine || jsTest.options().storageEngine === "wiredTiger")) {
print("Skipping test because running WiredTiger without journaling isn't a valid" +
" replica set configuration");
return;
}
const conn = MongoRunner.runMongod();
assert.neq(null, conn, "mongod was unable to start up");
if (!assert.commandWorked(conn.getDB("test").serverStatus())
.storageEngine.supportsSnapshotReadConcern) {
MongoRunner.stopMongod(conn);
return;
}
MongoRunner.stopMongod(conn);
const st = new ShardingTest({shards: 2, rs: {nodes: 2}});
// Create database "test0" on shard 0.
const testDB0 = st.s.getDB("test0");
assert.commandWorked(testDB0.adminCommand({enableSharding: testDB0.getName()}));
st.ensurePrimaryShard(testDB0.getName(), st.shard0.shardName);
assert.commandWorked(testDB0.createCollection("coll0"));
// Create a database "test1" on shard 1.
const testDB1 = st.s.getDB("test1");
assert.commandWorked(testDB1.adminCommand({enableSharding: testDB1.getName()}));
st.ensurePrimaryShard(testDB1.getName(), st.shard1.shardName);
assert.commandWorked(testDB1.createCollection("coll1"));
// Perform a write on shard 0 and get its op time.
let res = assert.commandWorked(testDB0.runCommand({insert: "coll0", documents: [{_id: 0}]}));
assert(res.hasOwnProperty("operationTime"), tojson(res));
let clusterTime = res.operationTime;
// Propagate 'clusterTime' to shard 1. This ensures that its next write will be at time >=
// 'clusterTime'.
testDB1.coll1.find().itcount();
// Attempt a snapshot read at 'clusterTime' on shard 1. Test that it performs a noop write to
// advance its majority commit point. The snapshot read itself may fail if the noop write
// advances the node's majority commit point past 'clusterTime' and it releases that snapshot.
// Test reading from the primary.
const shard1Session =
st.rs1.getPrimary().getDB("test1").getMongo().startSession({causalConsistency: false});
res = shard1Session.getDatabase("test1").runCommand({
find: "coll1",
readConcern: {level: "snapshot", atClusterTime: clusterTime},
txnNumber: NumberLong(0)
});
if (res.ok === 0) {
assert.commandFailedWithCode(res, ErrorCodes.SnapshotTooOld);
}
const shard1PrimaryMajOpTime =
st.rs1.getReadConcernMajorityOpTimeOrThrow(st.rs1.getPrimary()).ts;
assert.gte(shard1PrimaryMajOpTime, clusterTime);
// Perform a write on shard 1 and get its op time.
res = assert.commandWorked(testDB1.runCommand({insert: "coll1", documents: [{_id: 0}]}));
assert(res.hasOwnProperty("operationTime"), tojson(res));
clusterTime = res.operationTime;
// Propagate 'clusterTime' to shard 0. This ensures that its next write will be at time >=
// 'clusterTime'.
testDB0.coll0.find().readPref('secondary').itcount();
// Attempt a snapshot read at 'clusterTime' on shard 0. Test that it performs a noop write to
// advance its majority commit point. The snapshot read itself may fail if the noop write
// advances the node's majority commit point past 'clusterTime' and it releases that snapshot.
// Test reading from the secondary.
const shard0Session =
st.rs0.getSecondary().getDB("test0").getMongo().startSession({causalConsistency: false});
res = shard0Session.getDatabase("test0").runCommand({
find: "coll0",
readConcern: {level: "snapshot", atClusterTime: clusterTime},
txnNumber: NumberLong(0)
});
if (res.ok === 0) {
assert.commandFailedWithCode(res, ErrorCodes.SnapshotTooOld);
}
const shard0SecondaryMajOpTime =
st.rs0.getReadConcernMajorityOpTimeOrThrow(st.rs0.getSecondary()).ts;
assert.gte(shard0SecondaryMajOpTime, clusterTime);
st.stop();
}());
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