# Help! I can't filter out docs with bad ids in reindex
**URL:** https://discuss.elastic.co/t/help-i-cant-filter-out-docs-with-bad-ids-in-reindex/280968
**Category:** Elasticsearch
**Created:** [August 10, 2021, 10:21pm UTC](https://discuss.elastic.co/t/help-i-cant-filter-out-docs-with-bad-ids-in-reindex/280968 "2021-08-10T22:21:03Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@tasslehawf](https://discuss.elastic.co/u/tasslehawf)
#### Post date: [August 10, 2021, 10:21pm UTC](https://discuss.elastic.co/t/help-i-cant-filter-out-docs-with-bad-ids-in-reindex/280968/1 "2021-08-10T22:21:03Z")
Our index has a number of docs with bad ids. They were set by this script during a previous reindex:
```auto
def lowerCaseAuthor = ctx.author_string != null ? ctx.author_string.toLowerCase() : null;
def lowerCasePub = ctx.publication_fqdn != null ? ctx.publication_fqdn.toLowerCase() : null;
ctx._id = lowerCaseAuthor + lowerCasePub + ctx.collection_id
```
The problem is that some our author\_string fields are very long. More than 256 characters long making the id fields longer than the 256 character limit.
Now that I am trying to reindex again, I am getting frequent errors trying to reindex.
```auto
"error": { -
"type": "action_request_validation_exception",
"reason": "Validation Failed: 1: id is too long, must be no longer than 512 bytes but was: 529;"
}
```
I had thought that maybe I could filter out the bad docs in the reindex. I came up with the query which seems to work fine as a standalone query:
```auto
{
"query": {
"bool" : {
"filter": {
"script": {
"script":"doc['_id'].value.length() > 256"
}
}
}
}
}
```
To count the number of docs with ids that are too long. But when I apply this query script to my reindex:
```auto
{
"source": {
"index": "testing",
"query": {
"bool": {
"filter": {
"script": {
"script": "doc['_id'].value.length() < 256"
}
}
}
}
},
"dest": {
"index": "testing_v6"
}
}
```
I am back to square one. It runs a bit and then I get the same validation error as above:
```auto
"error": { -
"type": "action_request_validation_exception",
"reason": "Validation Failed: 1: id is too long, must be no longer than 512 bytes but was: 529;"
}
```
---
### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [August 10, 2021, 11:28pm UTC](https://discuss.elastic.co/t/help-i-cant-filter-out-docs-with-bad-ids-in-reindex/280968/2 "2021-08-10T23:28:40Z")
Please don't create multiple topics on the same thing - [Cannot reindex due to bad id field(s)](https://discuss.elastic.co/t/cannot-reindex-due-to-bad-id-field-s/280601)
Feel free to bump your original topic and add a bit more info to it though 🙂
---
### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [August 10, 2021, 11:28pm UTC](https://discuss.elastic.co/t/help-i-cant-filter-out-docs-with-bad-ids-in-reindex/280968/3 "2021-08-10T23:28:43Z")