Yes, a 32 bit murmur3 hash is taken of the ID field. Each of your three shards is assigned a third of the 0-2^32 range. The document is then sent to the shard who's range contains the hash of the ID.
Maybe your IDs don't create an even distribution of hashes (look at your maxdocs for each shard) or perhaps your documents simply have different sizes, as Raja suggested. I'm not really sure that what you see below is something to be overly concerned about. Is it causing you issues? Upayavira On Fri, Jul 31, 2015, at 04:14 PM, Raja Pothuganti wrote: > As far as I know sharding is done on basis of unique key hash(by > default). > So most of the time, each shard will have almost equal number of > documents. But each of document my have different size which can show up > as different index size per shard. > Thanks > > On 7/31/15, 5:49 AM, "wilanjar ." <wilan...@gmail.com> wrote: > > >hi folks, > > > >I'm new joiner in this milis and have question about amount of index in > >sharding. > >i have 3 sharding on collection, but capacity index in each sharding not > >equally or near each other. > >this below is example : > > du -sh shard1_replica12/ > >*1.1G shard1_replica12/* > > du -sh shard2_replica12/ > >*1.5G shard2_replica12/* > >du -sh shard3_replica12/ > > > > > >*841M shard3_replica12/* > >Sharding2 bigger from the other, may be anyone can give enlightenment > >about > >it? > > > >Thanks >
