# Logstash Cache
**URL:** https://discuss.elastic.co/t/logstash-cache/241202
**Category:** Logstash
**Created:** [July 14, 2020, 10:14pm UTC](https://discuss.elastic.co/t/logstash-cache/241202 "2020-07-14T22:14:21Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@csgeek](https://discuss.elastic.co/u/csgeek)
#### Post date: [July 14, 2020, 10:14pm UTC](https://discuss.elastic.co/t/logstash-cache/241202/1 "2020-07-14T22:14:21Z")
I'm working on an event filter written in ruby that needs to do a lookup.
I have the data stored in a JSON file that i'm loading locally and I'd like to know if there is any concept of a shared cache that I can leverage to avoid reading a file each time, parsing it in order to do a single lookup each time.
Ideally I would rather avoid adding a redis or memcache layer, though I suppose that is an option.
Any suggestions?
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### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [July 14, 2020, 10:18pm UTC](https://discuss.elastic.co/t/logstash-cache/241202/2 "2020-07-14T22:18:20Z")
That sounds like you are re-implementing the translate filter. If translate is not a match for your use case you can still harvest the dictionary loading and reloading [code from it](https://github.com/logstash-plugins/logstash-filter-translate/tree/master/lib/logstash/filters).
Or else just load the file into an @instance variable in the init section of the filter.
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### Author:  [@csgeek](https://discuss.elastic.co/u/csgeek)
#### Post date: [July 14, 2020, 10:21pm UTC](https://discuss.elastic.co/t/logstash-cache/241202/3 "2020-07-14T22:21:49Z")
I was actually thinking about that a second after posting it. I can just remove the code from the ruby filter and let translate take care of it.
Sorry about that, but thank you for the help.
I think the translate works a bit different since it's an actual plugin that a ruby filter that executes some arbitrary code. Still good reference to look at.
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### Author:  [@csgeek](https://discuss.elastic.co/u/csgeek)
#### Post date: [July 14, 2020, 10:28pm UTC](https://discuss.elastic.co/t/logstash-cache/241202/4 "2020-07-14T22:28:18Z")
> [@Badger](#):
>
> Or else just load the file into an @instance variable in the init section of the filter.
if I load the data in a @instance will it not be re-loaded again for each event? is that a one time operation?
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### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [July 14, 2020, 10:34pm UTC](https://discuss.elastic.co/t/logstash-cache/241202/5 "2020-07-14T22:34:58Z")
The code in the init option of a ruby filter is one and done when the pipeline starts. The code in the code option is per-event.
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [August 11, 2020, 10:35pm UTC](https://discuss.elastic.co/t/logstash-cache/241202/6 "2020-08-11T22:35:12Z")
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