mongodb/jstests/noPassthrough/initial_sync_wt_cache_full.js

/**
 * Fills WiredTiger cache during initial sync oplog replay.
 * @tags: [requires_replication, requires_wiredtiger]
 */
(function() {
'use strict';

const rst = new ReplSetTest({
    nodes: [
        {
            slowms: 30000,  // Don't log slow operations on primary.
        },
        {
            // Disallow elections on secondary.
            rsConfig: {
                priority: 0,
                votes: 0,
            },
            // Constrain the storage engine cache size to make it easier to fill it up with
            // unflushed modifications.
            wiredTigerCacheSizeGB: 1,
        },
    ]
});
const nodes = rst.startSet();
rst.initiate();

const primary = rst.getPrimary();
const mydb = primary.getDB('test');
const coll = mydb.getCollection('t');

const numDocs = 2;
const minDocSizeMB = 10;

for (let i = 0; i < numDocs; ++i) {
    assert.commandWorked(
        coll.save({_id: i, i: 0, x: 'x'.repeat(minDocSizeMB * 1024 * 1024)},
                  {writeConcern: {w: nodes.length, wtimeout: ReplSetTest.kDefaultTimeoutMS}}));
}
assert.eq(numDocs, coll.find().itcount());

const secondary = rst.restart(1, {
    startClean: true,
    setParameter: 'failpoint.initialSyncHangBeforeCopyingDatabases=' + tojson({mode: 'alwaysOn'})
});

const batchOpsLimit =
    assert.commandWorked(secondary.adminCommand({getParameter: 1, replBatchLimitOperations: 1}))
        .replBatchLimitOperations;
jsTestLog('Oplog application on secondary ' + secondary.host + ' is limited to ' + batchOpsLimit +
          ' operations per batch.');

const numUpdates = 400;
jsTestLog('Buffering ' + numUpdates + ' updates to ' + numDocs + ' documents on secondary.');
checkLog.contains(secondary,
                  'initial sync - initialSyncHangBeforeCopyingDatabases fail point enabled');
for (let i = 0; i < numDocs; ++i) {
    for (let j = 0; j < numUpdates; ++j) {
        assert.commandWorked(coll.update({_id: i}, {$inc: {i: 1}}));
    }
}

jsTestLog('Applying updates on secondary ' + secondary.host);
assert.commandWorked(secondary.adminCommand(
    {configureFailPoint: 'initialSyncHangBeforeCopyingDatabases', mode: 'off'}));
rst.awaitReplication();

rst.stopSet();
})();