# How to determine when dissect fails and branch to try a different dissect clause?

**URL:** <https://discuss.elastic.co/t/how-to-determine-when-dissect-fails-and-branch-to-try-a-different-dissect-clause/159824>\
**Category:** Logstash\
**Created:** [December 7, 2018, 12:16am UTC](https://discuss.elastic.co/t/how-to-determine-when-dissect-fails-and-branch-to-try-a-different-dissect-clause/159824 "2018-12-07T00:16:48Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![RussellBateman](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/russellbateman/32/34928_2.png) [@RussellBateman](https://discuss.elastic.co/u/RussellBateman)\
**Post date:** [December 13, 2018, 3:58pm UTC](https://discuss.elastic.co/t/how-to-determine-when-dissect-fails-and-branch-to-try-a-different-dissect-clause/159824/5 "2018-12-13T15:58:32Z")

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Thanks, Nachiket. The pipelining set up by sebp/elk was what I was respecting as you see by my post and I somewhat naively followed his lead by integrating my numeric filename prefixes in just as he had done. This seems to work fine. What doesn't work is the nesting of additional `dissect` paragraphs and error-handling. I wrote a new post on this: [Use of keyword 'else' causes error "Couldn't find any filter plugin named 'else'."](https://discuss.elastic.co/t/use-of-keyword-else-causes-error-couldnt-find-any-filter-plugin-named-else/159988).

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