anchor.diff:  [[ls-transport]]
   ==== Connecting with Transport protocol
   
  -By setting the "protocol" option to "transport", Logstash communicates with the Elasticsearch cluster through the same
  +When you set the `protocol` option to `transport`, Logstash communicates with the Elasticsearch cluster through the same
   protocol nodes use between each other. This avoids JSON un/marshalling and is therefore more efficient.
   
   In order to unlock this option, it's necessary to install an additional plugin in Logstash using the following command:
  
positive.code: [[ls-http]]
  ==== Connecting with HTTP/HTTPS
  
  All three input, filter and output plugins support HTTP Basic Authentication as well as SSL/TLS.
  The sections below demonstrate the output plugin's configuration parameters, but input and filter are the same.
  
  [float]
  [[ls-http-auth]]
  ===== Basic Authentication
  
  To connect to an instance of Elasticsearch with Shield, set up the username and password credentials with the following 
  configuration parameters:
  
  [source, shell]
  --------------------------------------------------
  
negative.code: --------------------------------------------------
  
  [float]
  [[ls-http-auth-pki]]
  ===== PKI Authentication
  
  Elasticsearch Output version 1.0.1 onwards supports the use of X.509 client-certificate to authenticate Logstash requests. To enable this you need to set up the following configuration parameters:
  
  [source, shell]
  --------------------------------------------------
  input { ... }
  output {
    elasticsearch {
      protocol => "http"
      ...
      keystore => ... # string
      keystore_password => ... # string
    }
  }
  --------------------------------------------------
  
  [float]
  [[ls-http-ssl]]
  ===== SSL/TLS Configuration for HTTPS
  
  