SERVER-26223 Slow down inserts in initial_sync_oplog_rollover.js

1 files changed, 16 insertions, 12 deletions

diff --git a/jstests/noPassthroughWithMongod/initial_sync_oplog_rollover.js b/jstests/noPassthroughWithMongod/initial_sync_oplog_rollover.js
index 6808370b6d5..55cc54418a9 100644
--- a/jstests/noPassthroughWithMongod/initial_sync_oplog_rollover.js
+++ b/jstests/noPassthroughWithMongod/initial_sync_oplog_rollover.js
@@ -1,8 +1,8 @@
 /**
  * This test tests that initial sync succeeds when the sync source's oplog rolls over before the
  * destination node reaches the oplog apply phase. It adds a new secondary to a replicaset and then
- * pauses the initial sync before it copies the databases but after the oplog buffer has begun
- * buffering oplog entries. The primary then fills up its oplog until it rolls over. At that point
+ * pauses the initial sync before it copies the databases but after it starts to fetch and buffer
+ * oplog entries. The primary then fills up its oplog until it rolls over. At that point
  * initial sync is resumed and we assert that it succeeds and that all of the inserted documents
  * are there.
  */
@@ -12,7 +12,7 @@
     // If the parameter is already set, don't run this test.
     var parameters = db.adminCommand({getCmdLineOpts: 1}).parsed.setParameter;
     if (parameters.use3dot2InitialSync || parameters.initialSyncOplogBuffer) {
-        jsTest.log("Skipping initial_sync_parameters.js because use3dot2InitialSync or " +
+        jsTest.log("Skipping initial_sync_oplog_rollover.js because use3dot2InitialSync or " +
                    "initialSyncOplogBuffer was already provided.");
         return;
     }
@@ -30,7 +30,12 @@
 
     var coll = primary.getDB('test').foo;
     assert.writeOK(coll.insert({a: 1}));
-    var firstOplogEntry = primary.getDB('local').oplog.rs.find().sort({ts: 1}).limit(1)[0];
+
+    function getFirstOplogEntry(conn) {
+        return conn.getDB('local').oplog.rs.find().sort({ts: 1}).limit(1)[0];
+    }
+
+    var firstOplogEntry = getFirstOplogEntry(primary);
 
     // Add a secondary node but make it hang before copying databases.
     var secondary = replSet.add(
@@ -55,21 +60,20 @@
     };
     checkLog(secondary, 'initial sync - initialSyncHangBeforeCopyingDatabases fail point enabled');
 
-    // Make documents around 100KB so that they overflow the oplog.
-    const largeStr = new Array(16 * 1024 * oplogSizeOnPrimary).join('aaaaaaaa');
-    for (var i = 0; i < 40; i++) {
-        assert.writeOK(coll.insert({a: 2, x: i, long_str: largeStr}));
+    // Keep inserting large documents until they roll over the oplog.
+    const largeStr = new Array(4 * 1024 * oplogSizeOnPrimary).join('aaaaaaaa');
+    var i = 0;
+    while (bsonWoCompare(getFirstOplogEntry(primary), firstOplogEntry) === 0) {
+        assert.writeOK(coll.insert({a: 2, x: i++, long_str: largeStr}));
+        sleep(100);
     }
 
-    // Assert that the oplog has rolled over on the primary.
-    assert.neq(primary.getDB('local').oplog.rs.find().sort({ts: 1}).limit(1)[0], firstOplogEntry);
-
     assert.commandWorked(secondary.getDB('admin').runCommand(
         {configureFailPoint: 'initialSyncHangBeforeCopyingDatabases', mode: 'off'}));
 
     replSet.awaitSecondaryNodes(200 * 1000);
 
-    assert.eq(40,
+    assert.eq(i,
               secondary.getDB('test').foo.count({a: 2}),
               'collection successfully synced to secondary');
 })();