# Extract base64 encoded field from JSON message and write the decoded field to a file

**URL:** <https://discuss.elastic.co/t/extract-base64-encoded-field-from-json-message-and-write-the-decoded-field-to-a-file/320398>\
**Category:** Logstash\
**Created:** [December 2, 2022, 10:07pm UTC](https://discuss.elastic.co/t/extract-base64-encoded-field-from-json-message-and-write-the-decoded-field-to-a-file/320398 "2022-12-02T22:07:53Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![Badger](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/badger/32/25190_2.png) [@Badger](https://discuss.elastic.co/u/Badger)\
**Post date:** [December 5, 2022, 10:03pm UTC](https://discuss.elastic.co/t/extract-base64-encoded-field-from-json-message-and-write-the-decoded-field-to-a-file/320398/4 "2022-12-05T22:03:13Z")

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See [this thread](https://discuss.elastic.co/t/heapdumponoutofmemoryerror/298786/2) for how to diagnose the memory leak.

I would guess the problem is the json codec on the input -- it is just reading more and more data and never finding the end of the first JSON object.

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_[View the full topic](https://discuss.elastic.co/t/extract-base64-encoded-field-from-json-message-and-write-the-decoded-field-to-a-file/320398)._