Stop filterworker and outputworker from crashing

[xebab]

When an exception is thrown during event processing, logstash may stop accepting data or crash altogether (cf. LOGSTASH-1353, LOGSTASH-1440 or LOGSTASH-1872).

I have commited two changes that make logstash continue working after encountering an exception. To test the patches, you can use the following configs.

For the filterworker case:

input {
  generator {
    lines => [
      "A%C3O",
      "foobar"
    ]
    count => 1
  }
}
filter {
  urldecode { }
  kv { }
}
output {
  stdout { }
}

For the outputworker case:

input {
  generator {
    lines => [
      "A%C3O",
      "foobar"
    ]
    count => 1
  }
}
filter {
  urldecode { }
}
output {
  stdout { codec => json {} }
}

Please consider including these patches in the next release. Thanks.

[elasticsearch-release]

Can one of the admins verify this patch?

[thomdixon]

This seems to work quite well for us. Would be nice to see it merged. @xebab can you do their whole CLA thing?

[xebab]

Thanks @thomdixon for pointing out this CLA issue to me. I was not aware of that. I have just signed the stuff so I hope this can get merged now.

[purbon]

@xebab The code looks good, but can you also add some test in the pipeline_spec (https://github.com/elasticsearch/logstash/blob/master/spec/core/pipeline_spec.rb) that test this functionality?

To test that you can use mocks from rspec as described https://relishapp.com/rspec/rspec-mocks/docs

[purbon]

test this please

[elasticsearch-release]

Test FAILed.
Refer to this link for build results (access rights to CI server needed):
http://build-eu-00.elasticsearch.org//job/Logstash_PR/546/
Test FAILed.

[purbon]

@xebab I was trying to test this PR and found there is no Rakefile, do you know why ? could you update the PR to be in sync with master?

[elasticsearch-release]

Jenkins standing by to test this. If you aren't a maintainer, you can ignore this comment. Someone with commit access, please review this and clear it for Jenkins to run; then say 'jenkins, test it'.

[elasticsearch-release]

Jenkins standing by to test this. If you aren't a maintainer, you can ignore this comment. Someone with commit access, please review this and clear it for Jenkins to run; then say 'jenkins, test it'.

[suyograo]

Closing this issue since the code has deviated quite a bit and we will not be able to add this feature now.