RabbitMQ output not sending any event

[Flavio_Campana]

Hi,
we are trying to ship some IIS log to Elasticsearch using logstash, with a RabbitMQ instance to act as a buffer, something like (IIS Server [IIS W3C logs] -> [logstash]) -> [RabbitMQ] -> [Logstash] -> [ElasticSearch] (maybe it would be better to use FileBeat on iis server and a separate, centralized logstash if we have more server, but right now we have only one).
The thing is, while logstash do connect to RabbitMQ, and i can see it in RabbitMQ management ui, it doesn't send any event at all.

The config is:

## We have IIS configured to use a single log file for all sites
#   because logstash can't handle parsing files in different
#   directories if they have the same name.
#
input {  
  file {
    type => "iis-w3c"
    path => "D:/LogFiles/W3SVC*/*.log"
  }

}

filter {  
  ## Ignore the comments that IIS will add to the start of the W3C logs
  #
  if [message] =~ "^#" {
    drop {}
  }

  grok {
    ## Very helpful site for building these statements:
    #   http://grokdebug.herokuapp.com/
    #
    # This is configured to parse out every field of IIS's W3C format when
    #   every field is included in the logs
    #
    match => ["message", "%{TIMESTAMP_ISO8601:log_timestamp} %{WORD:serviceName} \<%{WORD:serverName}\> %{IP:serverIP} %{WORD:method} %{URIPATH:uriStem} %{NOTSPACE:uriQuery} %{NUMBER:port} %{NOTSPACE:username} %{IPORHOST:clientIP} %{NOTSPACE:protocolVersion} %{NOTSPACE:userAgent} %{NOTSPACE:cookie} %{NOTSPACE:referer} %{NOTSPACE:requestHost} %{NUMBER:response} %{NUMBER:subresponse} %{NUMBER:win32response} %{NUMBER:bytesSent} %{NUMBER:bytesReceived} %{NUMBER:timetaken}"]
  }

  ## Set the Event Timesteamp from the log
  #
  date {
    match => [ "log_timestamp", "YYYY-MM-dd HH:mm:ss" ]
      timezone => "Etc/UTC"
  }

  ## If the log record has a value for 'bytesSent', then add a new field
  #   to the event that converts it to kilobytes
  #
  if [bytesSent] {
    ruby {
	  code => "event.set('kilobytesSent',event.get('bytesSent').to_i / 1024.0)"
    }
  }


  ## Do the same conversion for the bytes received value
  #
  if [bytesReceived] {
    ruby {
      code => "event.set('kilobytesReceived',event.get('bytesReceived').to_i / 1024.0)"
    }
  }

  ## Perform some mutations on the records to prep them for Elastic
  #
  mutate {
    ## Convert some fields from strings to integers
    #
    convert => ["bytesSent", "integer"]
    convert => ["bytesReceived", "integer"]
    convert => ["timetaken", "integer"]

    ## Create a new field for the reverse DNS lookup below
    #
    add_field => { "clientHostname" => "%{clientIP}" }

    ## Finally remove the original log_timestamp field since the event will
    #   have the proper date on it
    #
    remove_field => [ "log_timestamp"]
  }


  ## Do a reverse lookup on the client IP to get their hostname.
  #
  dns {
    ## Now that we've copied the clientIP into a new field we can
    #   simply replace it here using a reverse lookup
    #
    action => "replace"
    reverse => ["clientHostname"]
  }

  ## Parse out the user agent
  #
    useragent {
        source=> "useragent"
        prefix=> "browser"
    }

}

## We're only going to output these records to Elasticsearch so configure
#   that.
#
output {  
  #elasticsearch {
    #hosts => ["elastichost"]
    #
    ## Log records into month-based indexes
    #
    #index => "%{type}-%{+YYYY.MM}"
  #}
 rabbitmq {
	exchange => "exchange.iis.w3c"
	key => "common"
	exchange_type => "direct"
	durable => true
	host => "rabbithost" 
	user => "user"
	password => "pass"
	port => 5672
  }
  
  ## stdout included just for testing
  #
  #stdout {codec => rubydebug}
}

Inside logstash log files there is no error, but there is no line related to the output plugin after the connection event:

[2017-09-22T16:51:07,459][DEBUG][logstash.outputs.rabbitmq] Connecting to RabbitMQ. Settings: {:vhost=>"/", :hosts=>["rabbithost"], :port=>5672, :user=>"user", :automatic_recovery=>true, :pass=>"pass", :timeout=>0, :heartbeat=>0}
[2017-09-22T16:51:07,587][INFO ][logstash.outputs.rabbitmq] Connected to RabbitMQ at 
[2017-09-22T16:51:07,587][DEBUG][logstash.outputs.rabbitmq] Declaring an exchange {:name=>"exchange.icinga.main", :type=>"direct", :durable=>true}
[2017-09-22T16:51:07,680][DEBUG][logstash.outputs.rabbitmq] Exchange declared

Previously we sent events directly to elasticsearch and we had no problem, so the input and filter parts should be fine.

Any idea?