Hi,
We have a solr index running in 4.5.0 that we are trying to upgrade to 4.7.2 and split the shard. The uniqueKey is a TrieLongField, and it's values are always negative : In prod (2 shards, 1 replica for each shard) Max : -9223372035490849922 Min : -9223372036854609508 In lab (1 shard, 1 replica): Negatives between ( -21339 to -9223372036854687955 ) and couple of documents with positive values. To test out if it will work, I executed following steps in lab on new instances containing solr/zk cluster 1. From the old cluster(C1), zip up the index while server is not running. We are not going to the source to re-index into new cluster(C2) as we don't own the data(yes. that's being addressed). 2. On the new cluster(C2), create a new collection. 2. Stop tomcat server in new cluster(C2). 3. Overwrite new cluster index(C2) with the original cluster's index(C1). 4. Start the server and optimize(C2). 5. Num of docs match with the original cluster and everything seems to work. Total documents: 4021887(C2 and C1). then 1. Split the shard in new cluster(C2). For 1.5 GB it takes around 6 minutes to complete. 2. Two shards are created, with hash range(0-7fffffff and 80000000-ffffffff). Original range was 80000000-ffffffff. Num docs for hash range "0-7fffffff" is 4021886, and for " 80000000-ffffffff" is "3680519" Apparently, both shards contain lot of duplicate documents. It's not properly sharded at all. I tried this twice with the same output. What might be the issue here? Any pointers really appreciated. Azazel