# Cross-cluster search not returning all hits from IDs query, sometimes
**URL:** https://discuss.elastic.co/t/cross-cluster-search-not-returning-all-hits-from-ids-query-sometimes/192323
**Category:** Elasticsearch
**Created:** [July 25, 2019, 9:08pm UTC](https://discuss.elastic.co/t/cross-cluster-search-not-returning-all-hits-from-ids-query-sometimes/192323 "2019-07-25T21:08:39Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@loren](https://discuss.elastic.co/u/loren)
#### Post date: [July 25, 2019, 9:08pm UTC](https://discuss.elastic.co/t/cross-cluster-search-not-returning-all-hits-from-ids-query-sometimes/192323/1 "2019-07-25T21:08:39Z")
Why do my cross-cluster IDs queries sometimes return all but 1 or 2 of the results?
I have a 7.2.0 cluster executing an IDs query across 3 remote clusters usually with 500-1000 IDs in each query. I set the size parameter to be the length of my ID array. I usually get back all of the IDs but sometimes I get back all but 1 or 2 of them. Repeating the query again gets me 100% of the results.
If I just hit the clusters directly instead of going through CCS, I get back 100% of the results all the time with size=len(my\_ids).
Thinking it might be a fencepost error, I tried len(my\_ids)+1 but no luck. I also tried setting `ccs_minimize_roundtrips=False` just as a wild guess.
Strange as that all is, I seem to have found a hacky workaround: if I double the size param (i.e., size=2\*len(my\_ids)), _I get back 100% of the results all the time_.
Can anyone suggest what might be happening there?
Possibly related to [IDs query returning incomplete results](https://discuss.elastic.co/t/ids-query-returning-incomplete-results/127934).
---
### Author:  [@javanna](https://discuss.elastic.co/u/javanna)
#### Post date: [August 2, 2019, 9:20am UTC](https://discuss.elastic.co/t/cross-cluster-search-not-returning-all-hits-from-ids-query-sometimes/192323/2 "2019-08-02T09:20:24Z")
Hi Loren,
could you post more details on how to reproduce this please? Some sample data, your query etc.?
Thanks
Luca
---
### Author:  [@loren](https://discuss.elastic.co/u/loren)
#### Post date: [August 2, 2019, 6:02pm UTC](https://discuss.elastic.co/t/cross-cluster-search-not-returning-all-hits-from-ids-query-sometimes/192323/3 "2019-08-02T18:02:13Z")
Thank you for responding Luca.
The query was very simple:
```auto
GET cluster1:my_index,cluster2:my_index,cluster3:my_index/_search
{
"size": 5678,
"_source": "pa*",
"query": {
"ids": {
"values": [
"id1",
"id2",
"id3",
"id4",
....
"id5678"
]
}
}
}
```
I wish I could replicate it for you. The 3 indices on the remote clusters are all multi-TB, and the error only happens 5-10% of the time for a group of IDs, and then never again for that group.
As I ended up needing to bring back more than 10000 results, I changed the search query to a scan/scroll. I have not observed the problem there.
I'm sorry I can't be more helpful in tracking this down. Perhaps someone else will run across this issue, too, and add their finding to this post.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [August 30, 2019, 6:02pm UTC](https://discuss.elastic.co/t/cross-cluster-search-not-returning-all-hits-from-ids-query-sometimes/192323/4 "2019-08-30T18:02:14Z")
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