Pipeline yaml file cannot run multiple conf

[sukesh_nagaraja (sukesh)]

  Error : 
   [2018-07-10T14:50:49,640][FATAL][logstash.runner          ] Logstash could not be started because    there is already another instance using the configured data directory.  If you wish to run multiple     instances, you must change the "path.data" setting.
   [2018-07-10T14:50:49,644][ERROR][org.logstash.Logstash    ] java.lang.IllegalStateException: org.jruby.exceptions.RaiseException: (SystemExit) exit

my pipeline is as below:

  - pipeline.id: hdfs
    path.config: "/etc/logstash/conf.d/pipeline_hdfs.cfg"
  - pipeline.id: elastic
    path.config: "/etc/logstash/conf.d/pipeline_elastic.cfg"
 - pipeline.id: file
   path.config: "/etc/logstash/conf.d/pipeline_file.cfg"


 if i use only one conf as below in a pipeline it works but not for multiples
 - pipeline.id: file
   path.config: "/etc/logstash/conf.d/pipeline_file.cfg"

 what would be the workaround for this? where can i mention path.data  for multiple configs , i am running pipeline, if am running only logstash conf then i can mention in command line but i want to run in pipeline?