# Logstash crashing "can't convert Fixnum into String"

**URL:** <https://discuss.elastic.co/t/logstash-crashing-cant-convert-fixnum-into-string/157129>\
**Category:** Logstash\
**Created:** [November 16, 2018, 7:59pm UTC](https://discuss.elastic.co/t/logstash-crashing-cant-convert-fixnum-into-string/157129 "2018-11-16T19:59:47Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![joseph4325](https://avatars.discourse-cdn.com/v4/letter/j/f19dbf/32.png) [@joseph4325](https://discuss.elastic.co/u/joseph4325)\
**Post date:** [November 16, 2018, 7:59pm UTC](https://discuss.elastic.co/t/logstash-crashing-cant-convert-fixnum-into-string/157129/1 "2018-11-16T19:59:47Z")

</div>

I put in a filter recently which seemed to be working fine at first, but it would crash logstash every couple of hours with the following message:

```
{
    "level": "FATAL",
    "logEvent": {
        "error": {
            "metaClass": {
                "metaClass": {
                    "metaClass": {
                        "backtrace": [
                            "org/jruby/RubyString.java:4462:in `include?'",
                            "(eval):274760:in `initialize'",
                            "org/jruby/RubyArray.java:1613:in `each'",
                            "(eval):274758:in `initialize'",
                            "org/jruby/RubyProc.java:281:in `call'",
                            "(eval):21975:in `filter_func'",
                            "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:398:in `filter_batch'",
                            "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:379:in `worker_loop'",
                            "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:342:in `start_workers'"
                        ],
                        "error": "can't convert Fixnum into String"
                    }
                }
            }
        },
        "message": "An unexpected error occurred!"
    },
    "loggerName": "logstash.runner",
    "thread": "LogStash::Runner",
    "timeMillis": 1542319501747
}

```

The filter that errors looks like this:

```
filter {
  if [type] == "elasticsearch-index-name" {
    grok {
      patterns_dir => '/etc/logstash/patterns/custom-pattern/'
      match => ["message", "%{CUSTOM_GROK}"]
    }
    if !("_grokparsefailure" in [tags]) {
      date {
        match => ["timestamp", "MMM dd HH:mm:ss", "MMM d HH:mm:ss"]
      }
      ruby {
        code => "event.set('elk_lag', event.get('elk_recv_timestamp')-event.get('@timestamp'))"
      }
    json {
          source => "data"
        }
    }
    mutate {
      add_field => { "rotation_period" => "{{ rotation_period }}" }
      add_field => { "tgt_index" => "elasticsearch-index-name" }
    }
  }

```

It stops breaking if i revert the filter to this:

```
filter {
  if [type] == "elasticsearch-index-name" {
    mutate {
      add_field => { "rotation_period" => "{{ rotation_period }}" }
      add_field => { "tgt_index" => "elasticsearch-index-name" }
    }
  }
}

```

If i feed a log file that would break it through the input plugin everything works fine. The only problem is when i start logstash in production with all the other filters things break.

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [December 14, 2018, 7:59pm UTC](https://discuss.elastic.co/t/logstash-crashing-cant-convert-fixnum-into-string/157129/2 "2018-12-14T19:59:49Z")

</div>

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