# Accessing Metafield \_index in Logstash
**URL:** https://discuss.elastic.co/t/accessing-metafield-index-in-logstash/228113
**Category:** Logstash
**Created:** [April 15, 2020, 12:20pm UTC](https://discuss.elastic.co/t/accessing-metafield-index-in-logstash/228113 "2020-04-15T12:20:18Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@InfiniteLoops](https://discuss.elastic.co/u/InfiniteLoops)
#### Post date: [April 15, 2020, 12:20pm UTC](https://discuss.elastic.co/t/accessing-metafield-index-in-logstash/228113/1 "2020-04-15T12:20:18Z")
I am using this output for Elasticsearch
index =\> "%{[headers][key]}-data-%{+YYYY.MM}"
So it creates a index name with the date added. I am trying to reindex this data through a logstash filter. So I am using the previous index as an input to logstash and trying to output the data to the same name while appending a reindexed value.
index =\> "%{[\_index]}-reindexed"
It says this is a Meta field. Do I need to do something different to access it? I have also tried
index =\> "%{[@metadata][\_index]}-reindexed"
---
### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [April 15, 2020, 2:31pm UTC](https://discuss.elastic.co/t/accessing-metafield-index-in-logstash/228113/2 "2020-04-15T14:31:59Z")
If you are using an elasticsearch input and want to reference the name of the index from which data was fetched you need to set
```
docinfo => true
```
on the input. And yes, you would reference [@metadata][\_index].
---
### Author:  [@InfiniteLoops](https://discuss.elastic.co/u/InfiniteLoops)
#### Post date: [April 15, 2020, 3:43pm UTC](https://discuss.elastic.co/t/accessing-metafield-index-in-logstash/228113/3 "2020-04-15T15:43:18Z")
Thanks for the reply. I looked up the documentation on that after your post. I now have
```auto
input {
elasticsearch {
hosts => ["address"]
index => "index-name*"
docinfo => true
}
}
filter{
some logic
}
output {
elasticsearch {
hosts => ["address"]
index => "copy-of-production.%{[@metadata][_index]}"
}
stdout { codec => rubydebug {} }
}
```
I am just getting this as the index name for the output - "copy-of-production.%{[@metadata][\_index]}"
Is there something I am missing. Thanks
---
### Author:  [@InfiniteLoops](https://discuss.elastic.co/u/InfiniteLoops)
#### Post date: [April 15, 2020, 5:12pm UTC](https://discuss.elastic.co/t/accessing-metafield-index-in-logstash/228113/4 "2020-04-15T17:12:10Z")
Your advice worked this with a newer version of Logstash. Thanks again for the help.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [May 13, 2020, 5:12pm UTC](https://discuss.elastic.co/t/accessing-metafield-index-in-logstash/228113/5 "2020-05-13T17:12:12Z")
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