Failed to flush outgoing items

I tried set up ELB stack in single Vagrant machine based on Ubuntu 14.04 amd64 box. Whole stack was functional (ES 1.5.2, LS 1.5.0-1_all, Kibana 4.0.2-linux-x64) until I install Watcher plugin. It seems that Logstash couldn't connect to ES:

{:timestamp=>"2015-06-09T12:13:42.021000+0000", :message=>"Got error to send bulk of actions to elasticsearch server at logger : blocked by: [SERVICE_UNAVAILABLE/1/state not recovered / initialized];[SERVICE_UNAVAILABLE/2/no master];", :level=>:error, :file=>"logstash/o
utputs/elasticsearch.rb", :line=>"464", :method=>"flush"}
{:timestamp=>"2015-06-09T12:13:42.022000+0000", :message=>"Failed to flush outgoing items", :outgoing_count=>2, :exception=>org.elasticsearch.cluster.block.ClusterBlockException: blocked by: [SERVICE_UNAVAILABLE/1/state not recovered / initialized];[SERVICE_UNAVAILABLE/
2/no master];, :backtrace=>["org.elasticsearch.cluster.block.ClusterBlocks.globalBlockedException(org/elasticsearch/cluster/block/", "org.elasticsearch.cluster.block.ClusterBlocks.globalBlockedRaiseException(org/elasticsearch/cluster/block/Cluster", "org.elasticsearch.action.bulk.TransportBulkAction.executeBulk(org/elasticsearch/action/bulk/", "org.elasticsearch.action.bulk.TransportBulkAction.access$000(org/elasticsearch/action/bulk/", "or
g.elasticsearch.action.bulk.TransportBulkAction$1.onFailure(org/elasticsearch/action/bulk/", "$ThreadedActionListener$", "java.ut
il.concurrent.ThreadPoolExecutor.runWorker(java/util/concurrent/", "java.util.concurrent.ThreadPoolExecutor$", ""], :level=>:warn, :fi
le=>"stud/buffer.rb", :line=>"231", :method=>"buffer_flush"}

When I removed Watcher plugin my ELB stack start working.

LS config:

input {
  file {
    path => "/var/log/syslog"
    type => "syslog"

  udp {
    port => 30001

  heartbeat {

output {
    elasticsearch {
        host => "logger"
        cluster => "logstash"

ES config: "logstash" "logger" logger

/etc/hosts:	localhost logger.vbox logger

Could you try switching "protocol => transport" and checking that it works?

Wow, it works! You are my hero.

(by the way, with this new config I see much more responsive logstash process; without protocol => transport I wasn't able to restart logstash with service logstash restart, I must kill it manually and then start it)

Thank you very much

I was having the same issue, even after I uninstalled the plugin.

Just to clarify, this what your logstash config should look like to be fixed:

elasticsearch {
    host => ""
    manage_template => false
    index => "..."
    cluster => "..."
    protocol => "transport"

Could you elaborate on what's going on? Why did the plugin mess it up?