MongoDB Shard distribution issue I am facing an issue in the shard distribution.

MongoDB Version: 3.0.15

I have a collection that is sharded. I have two shards.

Output of db.getCollection('event').stats()

{
 "sharded" : true,
 "capped" : false,
 "ns" : "coll.event",
 "count" : 386631514,
  size" : NumberLong(4178195857267),
 "storageSize" : 293516279808.0,
 "totalIndexSize" : 391203631104.0,
 "shards" : {
    **"shard0000" :** {
    "ns" : "coll.event",
    "count" : 182463940,
    "size" : NumberLong(2187685928765),
    "avgObjSize" : 11989,
    "storageSize" : 148825059328.0,
    "capped" : false,            
    },
**"shard0001"** : {
    "ns" : "coll.event",
    "count" : 204167574,
    "size" : NumberLong(1990509928502),
    "avgObjSize" : 9749,
    "storageSize" : 144691220480.0,
    "capped" : false,
    }
},
"ok" : 1.0
}


Output of Shard Distribution

db.getCollection('event').getShardDistribution()

Shard shard0000 at localhost:27010


Even though there are two shards, the shard distribution shows only one. Now only one of the sharded folder is getting full.

Why is it so?
What do I have to do to make the shard distribution common?
As per MongoDB documentation here which prints the data distribution statistics for a sharded collection. You must call the getShardDistribution() method on a sharded collection, as in the following example:

db.myShardedCollection.getShardDistribution()


In the following example, the collection has two shards. The output displays both the individual shard distribution information as well the total shard distribution:

Shard &lt;shard-a&gt; at &lt;host-a&gt;
 data : &lt;size-a&gt; docs : &lt;count-a&gt; chunks : &lt;number of chunks-a&gt;
 estimated data per chunk : &lt;size-a&gt;/&lt;number of chunks-a&gt;
 estimated docs per chunk : &lt;count-a&gt;/&lt;number of chunks-a&gt;

Shard &lt;shard-b&gt; at &lt;host-b&gt;
 data : &lt;size-b&gt; docs : &lt;count-b&gt; chunks : &lt;number of chunks-b&gt;
 estimated data per chunk : &lt;size-b&gt;/&lt;number of chunks-b&gt;
 estimated docs per chunk : &lt;count-b&gt;/&lt;number of chunks-b&gt;

Totals
 data : &lt;stats.size&gt; docs : &lt;stats.count&gt; chunks : &lt;calc total chunks&gt;
 Shard &lt;shard-a&gt; contains  &lt;estDataPercent-a&gt;% data, &lt;estDocPercent-a&gt;% docs in cluster, avg obj size on shard : stats.shards[ &lt;shard-a&gt; ].avgObjSize
 Shard &lt;shard-b&gt; contains  &lt;estDataPercent-b&gt;% data, &lt;estDocPercent-b&gt;% docs in cluster, avg obj size on shard : stats.shards[ &lt;shard-b&gt; ].avgObjSize


For your further ref here, here