mongoimport unable to import $numberLong

A collection with NumberLong type data as follows :

> db.hc_whois.findOne();
       "_id" : NumberLong(3000001),
       "startIpInLong" : NumberLong(1543503872),
       "endIpInLong" : NumberLong(1544552447),
       "name" : "ap-net-1",
       //...
 }   

Export it with mongoexport :

$ mongoexport -d mydb -c hc_whois -o whois.json

{ 
  "_id" : { "$numberLong" : "3000001" }, 
  "startIpInLong" : { "$numberLong" : "1543503872" }, 
  "endIpInLong" : { "$numberLong" : "1544552447" 

1. Problem

Copy the exported data whois.json to another server, and import it with mongoexport.

$ mongoimport -d mydb -c hc_whois --file whois.json

The imported data look weird, an extra $numberLong is inserted, and the long value is unable to search anymore.

> db.hc_whois.findOne();
        "_id" : {
                "$numberLong" : "3000001"
        },
        "startIpInLong" : {
                "$numberLong" : "1543503872"
        },
        "endIpInLong" : {
                "$numberLong" : "1544552447"
        },
        "name" : "ap-net-1",
		//...

Why mongoimport didn’t convert the $numberLong into long value?

2. Solution

After a quick check, find out that server1 is using MongoDB v2.6.4 to export the data, and try to import the data into a server2, where MongoDB v2.4.3 is installed.

To fix it, make sure both server1 and server2 are using the same MongoDB version, look like the exported $numberLong value is supported in version 2.6.x only.

1. Refer to this guide to upgrade MongoDB to 2.6, it’s simple, just stop the MongoDB process and replace the $mongo\bin folder with the latest.

2. After server2 is upgraded to MongoDB 2.6, try importing it again.

$ mongoimport -d mydb -c hc_whois --file whois.json

> db.hc_whois.findOne();
        "_id" : 3000001,
        "startIpInLong" : 1543503872,
        "endIpInLong" : 1544552447,
        "name" : "ap-net-1"
		//...

Done.