小编Mar*_*ark的帖子

我试图在一个集群上使用带有mapReduce的MongoDB 2.4.3(也尝试过2.4.4),每个3个副本有2个分片.我有一个问题,mapReduce作业的结果没有减少到输出集合.我尝试了增量贴图减少.我也试过"合并"而不是减少,但这也没有用.

map reduce命令在mongos上运行:( coll不分片)

db.coll.mapReduce(map, reduce, {out: {reduce: "events", "sharded": true}})

产生以下输出:

{
    "result" : "events",
    "counts" : {
        "input" : NumberLong(2),
        "emit" : NumberLong(2),
        "reduce" : NumberLong(0),
        "output" : NumberLong(28304112)
    },
    "timeMillis" : 418,
    "timing" : {
        "shardProcessing" : 11,
        "postProcessing" : 407
    },
    "shardCounts" : {
        "stats2/192.168.…:27017,192.168.…" : {
            "input" : 2,
            "emit" : 2,
            "reduce" : 0,
            "output" : 2
        }
    },
    "postProcessCounts" : {
        "stats1/192.168.…:27017,…" : {
            "input" : NumberLong(0),
            "reduce" : NumberLong(0), …