Files
mongo/jstests/sharding/query/cursor/cursor1.js
Steve McClure 1ffbc6c2e9 SERVER-109432: Autofix JS var usage to favor let (#40637)
GitOrigin-RevId: 9674b7db36a0f3f650d39c1e3fb2ad6ff2141cfb
2025-08-28 19:21:01 +00:00

84 lines
2.6 KiB
JavaScript

// cursor1.js
// checks that cursors survive a chunk's move
import {ShardingTest} from "jstests/libs/shardingtest.js";
import {findChunksUtil} from "jstests/sharding/libs/find_chunks_util.js";
let s = new ShardingTest({name: "sharding_cursor1", shards: 2});
s.config.settings.find().forEach(printjson);
// create a sharded 'test.foo', for the moment with just one chunk
s.adminCommand({enablesharding: "test", primaryShard: s.shard1.shardName});
s.adminCommand({shardcollection: "test.foo", key: {_id: 1}});
const db = s.getDB("test");
let primary = s.getPrimaryShard("test").getDB("test");
let secondary = s.getOther(primary).getDB("test");
let numObjs = 30;
let bulk = db.foo.initializeUnorderedBulkOp();
for (let i = 0; i < numObjs; i++) {
bulk.insert({_id: i});
}
assert.commandWorked(bulk.execute());
assert.eq(
1,
findChunksUtil.countChunksForNs(s.config, "test.foo"),
"test requires collection to have one chunk initially",
);
// Cursor timeout only occurs outside of sessions. Otherwise we rely on the session timeout
// mechanism to kill cursors.
TestData.disableImplicitSessions = true;
// we'll split the collection in two and move the second chunk while three cursors are open
// cursor1 still has more data in the first chunk, the one that didn't move
// cursor2 buffered the last obj of the first chunk
// cursor3 buffered data that was moved on the second chunk
let cursor1 = db.foo.find().batchSize(3);
assert.eq(3, cursor1.objsLeftInBatch());
let cursor2 = db.foo.find().batchSize(5);
assert.eq(5, cursor2.objsLeftInBatch());
let cursor3 = db.foo.find().batchSize(7);
assert.eq(7, cursor3.objsLeftInBatch());
s.adminCommand({split: "test.foo", middle: {_id: 5}});
s.adminCommand({movechunk: "test.foo", find: {_id: 5}, to: secondary.getMongo().name});
assert.eq(2, findChunksUtil.countChunksForNs(s.config, "test.foo"));
// the cursors should not have been affected
assert.eq(numObjs, cursor1.itcount(), "c1");
assert.eq(numObjs, cursor2.itcount(), "c2");
assert.eq(numObjs, cursor3.itcount(), "c3");
// Test that a cursor with a 1 second timeout eventually times out.
let cur = db.foo.find().batchSize(2);
assert(cur.next(), "T1");
assert(cur.next(), "T2");
assert.commandWorked(
s.admin.runCommand({
setParameter: 1,
cursorTimeoutMillis: 1000, // 1 second.
}),
);
assert.soon(
function () {
try {
cur.next();
cur.next();
print("cursor still alive");
return false;
} catch (e) {
return true;
}
},
"cursor failed to time out",
/*timeout*/ 30000,
/*interval*/ 5000,
);
TestData.disableImplicitSessions = false;
s.stop();