_reindex API issue

Elastic Stack Elasticsearch
1

When I try to _reindex an existing index to new index, I see drop in document volume. I’m trying to do it as the original is created with wrong mapping.

_count API on original results as below

{
"count": 3273105,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
}
}

_count API on new results as below
{
"count": 267199,
"_shards": {
"total": 2,
"successful": 2,
"failed": 0
}
}

I see a huge difference. The process didn’t throw any error as well. Any pointers!

2

Providing the reindex request you made would be helpful.

3

Hi Mark,

Below is the exact request made (using sense plugin)

POST /_reindex
{
"source": {
"index": "IdxOld"
},
"dest": {
"index": "IdxNew"
}
}

I passed the parameter wait_for_complete=true to request.
Few other information:
Source Index has 5 shards/1 Replica in settings and went with default mapping (all analyzed strings).
Target has a valid mapping, which it is intended for. It has 2 shards/1 Replica in settings.
No errors were thrown

4

From here I can't tell what happened those kinds of reindex requests work
fine for me.