作为MongoDB的新手我试图让MapReduce调用进行。 不幸的是我得到以下错误:Mongo Map减少错误
mongos> db.events.mapReduce(m,r,"errors");
Fri Apr 12 11:39:15.637 JavaScript execution failed: map reduce failed:{
"ok" : 0,
"errmsg" : "MR parallel processing failed: { errmsg: \"exception: reduce -> multiple not supported yet\", code: 10075, ok: 0.0 }"
} at src/mongo/shell/collection.js:L970
mongos>
我使用蒙戈2.4.0
我的活动集合看起来是这样的:
{ "sid" : "1UADM45MCGRTW ", "time" : ISODate("2013-04-08T11:33:13.229Z"), "class" : "S", "service" : "service1" }
{ "sid" : "1UADM45MCGRTW ", "time" : ISODate("2013-04-08T11:33:13.229Z"), "class" : "I", "service" : "service1" }
{ "sid" : "1UADM45MCGRTW ", "time" : ISODate("2013-04-08T11:33:13.236Z"), "class" : "E", "text" : "error message" }
{ "sid" : "1UADM45MCGRTW ", "time" : ISODate("2013-04-08T11:33:13.239Z"), "class" : "F", "service" : "service1" }
{ "sid" : "1UDO3H7YUOK08 ", "time" : ISODate("2013-04-08T11:33:08.095Z"), "class" : "S", "service" : "service2" }
{ "sid" : "1UDO3H7YUOK08 ", "time" : ISODate("2013-04-08T11:33:08.095Z"), "class" : "I", "service" : "service2" }
{ "sid" : "1UDO3H7YUOK08 ", "time" : ISODate("2013-04-08T11:33:08.173Z"), "class" : "E", "text" : "another error message" }
{ "sid" : "1UDO3H7YUOK08 ", "time" : ISODate("2013-04-08T11:33:08.188Z"), "class" : "F", "service" : "service2" }
{ "sid" : "1UDO3JVXIS2UZ ", "time" : ISODate("2013-04-08T11:28:39.480Z"), "class" : "I", "service" : "service1" }
{ ""sid" : "1UDO3JVXIS2UZ ", "time" : ISODate("2013-04-08T11:28:39.480Z"), "class" : "S", "service" : "service1" }
{ "sid" : "1UDO3JVXIS2UZ ", "time" : ISODate("2013-04-08T11:28:40.853Z"), "class" : "F", "service" : "service1" }
{ "sid" : "1UDO3JVXIS2UZ ", "time" : ISODate("2013-04-08T11:28:40.852Z"), "class" : "I", "service" : "service1" }
我的目的是让所有的 “E”条目并将它们与“F”条目的相应“sid”的“服务”字段组合。所以这应该是非常简单的,但我无法得到它(因为上述错误)。
地图/减少I使用的是功能:
var m = function() {
if (this.class == "E") {
value = { time: this.time, error: this.text };
emit(this.sid, value);
} else if (this.class == "F") {
value = { service: this.service };
emit(this.sid, value);
}
}
var r = function(key,values) {
return values;
}
db.events.mapReduce(m,r,"errors");
非常有帮助 - 谢谢 – pitseeker