MongoDB 基准测试插入

Question

I am trying to benchmark MongoDB with the JS harness. I am trying to do inserts. The example given in mongo website .

However, I am trying an insert operation, which works totally fine, but gives out wrong queries/sec.

ops = [{op: "insert", ns: "benchmark.bench", safe: false, doc: {"a": 1}}]

The above works fine. Then, I have run the following in mongo shell:

for ( x = 1; x<=128; x*=2){
    res = benchRun( { parallel : x ,
                      seconds : 5 ,
                      ops : ops
                    } )
    print( "threads: " + x + "\t queries/sec: " + res.query )
}

It gives out:

threads: 1   queries/sec: 0
threads: 2   queries/sec: 0
threads: 4   queries/sec: 0
threads: 8   queries/sec: 0
threads: 16  queries/sec: 0
threads: 32  queries/sec: 1.4
threads: 64  queries/sec: 0
threads: 128     queries/sec: 0

I dont understand why the queries/sec is 0 and not a single doc has been inserted. Is this right was testing performance for inserts?

Answer 1

Answering because I just encountered a similar problem.

Try replacing your print statement with printjson(res) . You will see that res has the following fields:

{
    "note" : "values per second",
    "errCount" : NumberLong(0),
    "trapped" : "error: not implemented",
    "insertLatencyAverageMicros" : 8.173300153139357,
    "totalOps" : NumberLong(130600),
    "totalOps/s" : 25366.173139864142,
    "findOne" : 0,
    "insert" : 25366.173139864142,
    "delete" : 0,
    "update" : 0,
    "query" : 0,
    "command" : 0
}

As you can see, the query count is 0, hence when you print res.query it gives 0. To get the number of insert operations per second you would want to print res.insert . I believe res.query corresponds to the "find" operation.