Elasticsearch output plugin is using deprecated _retry_on_conflict

[jguay]

Elasticsearch deprecated logs contain the following entry for every bulk sent by logstash to ES 6.x

[2018-02-05T11:04:55,636][WARN ][o.e.d.c.ParseField ] Deprecated field [_retry_on_conflict] used, expected [retry_on_conflict] instead

• Environment : Stack 6.1.3 - logstash-output-elasticsearch (9.0.2)
• Steps to Reproduce:

Add this conf and wait 10 seconds to start getting deprecated log entries

input {
  heartbeat {
    interval => 5
    message  => 'Hello from Logstash 💓'
  }
}

output {
  elasticsearch {
    action => 'update'
    document_id => '1'
    doc_as_upsert => true
  }
}

Background : If output is to ES 5.X then there will be no issue since "_retry_on_conflict" is the right setting. However when writing to ES 6.x this causes a lot of deprecated logs entries so better would be to use the new v6 setting

Workaround in case disk space issue is sparse would be to add a regex rule in log4j2.properties, this example is for standard docker ES

appender.console.filter.regex.type = RegexFilter
appender.console.filter.regex.onMatch = DENY
appender.console.filter.regex.regex = .*Deprecated field \[_retry_on_conflict\]  
used, expected \[retry_on_conflict\] instead$
appender.console.filter.regex.onMisMatch = ACCEPT

[ghost]

I've noticed the exact same behavior, is there any updates regarding this besides Jguay's workaround?

[jsvd]

closing as duplicate of logstash-plugins/logstash-output-elasticsearch#710