Do you have a massive number of records you need to dump into MongoDB in a hurry?  Try out the bulk insert capabilities of the C++ driver.  Depending on the documents I routinely get an insert rate of 50,000 records/sec, sometimes even up over 100,000/sec.

The trick is to use a vector of BSON objects and call insert once.  Here’s a simple example application.

#include "client/dbclient.h"
#include <iostream>
#include <vector>
#include <sys/time.h>

#define RECORDS 5000000

int main(int argc, char **argv) {
    std::vector<mongo::BSONObj> bulk_data;
    mongo::DBClientConnection mongo;

    struct timeval start;
    gettimeofday(&amp;start, NULL);

    for (int i=0; i<RECORDS; i++) {
        mongo::BSONObj record = BSON (
                "_id" << i <<
                "mystring" << "hello world" );

        if (i % 10000 == 0) {
            mongo.insert("insert_test.col1", bulk_data);

    struct timeval end;
    gettimeofday(&amp;end, NULL);
    int now = (end.tv_sec * 1000) + (int)(end.tv_usec/1000);
    int elapsed_time = now - ((start.tv_sec * 1000) +

    std::cout << "rate: " << RECORDS/(elapsed_time/1000) <<
        "/sec" << std::endl;

    return 0;

Here’s a sample run:

{nehresma@frodo:/tmp}$ time ./bulk
rate: 138888/sec

real    0m36.306s
user    0m0.380s
sys     0m1.904s

36 seconds to insert 5 million records. Not too shabby.