小编Kum*_*ran的帖子

在MySQL中

select a,b,count(1) as cnt from list group by a, b having cnt > 2;

我必须使用mongodb中的条件来执行group by函数.但我得到以下错误.请分享您的意见.

在MongoDB中

> res = db.list.group({key:{a:true,b:true},
...                      reduce: function(obj,prev) {prev.count++;},
...                      initial: {count:0}}).limit(10);

Sat Jan  7 16:36:30 uncaught exception: group command failed: {
        "errmsg" : "exception: group() can't handle more than 20000 unique keys",
        "code" : 10043,
        "ok" : 0

一旦执行,我们需要在下一个文件上运行以下文件.

for (i in res) {if (res[i].count>2) printjson(res[i])};

此致,库马兰

我们使用node + mongodb为聊天模块实现了mongodb分片概念.

MongoDB Sharding Configuration
===============================
Shard1 = PRIMARY + SECONDARY + ARBITER
Shard2  = PRIMARY + SECONDARY + ARBITER
Config
Mongos

以下详情我们今天早上得到了它.但我们不知道如何解决这个问题.

请告诉我们如何解决此问题.

"errmsg":"回滚2错误findcommonpoint等待一段时间才重新尝试"

"errmsg":"错误RS102过于陈旧无法赶上"

data2:PRIMARY> rs.status()
{
    "set" : "data2",
    "date" : ISODate("2012-07-27T04:30:29Z"),
    "myState" : 1,
    "members" : [
        {
            "_id" : 0,
            "name" : "50.52.108.16:20001",
            "health" : 1,
            "state" : 9,
            "stateStr" : "ROLLBACK",
            "uptime" : 322,
            "optime" : {
                "t" : 1343361602000,
                "i" : 155
            },
            "optimeDate" : ISODate("2012-07-27T04:00:02Z"),
            "lastHeartbeat" : ISODate("2012-07-27T04:30:29Z"),
            **"errmsg" : "rollback …