Logstash change port

Logstash is running on 9600 by default and I want to run another logstash on same system
Is there opion to change default port for logstash
I don't want to use beats for this.
beacuse I want to run two logstash with different conf files
and
If have change configuration in conf file I want to get data from already present files.
Logstash is taking those files but elastic isn't. Can anyone help me??

You can with multiple Logstash Inputs... eg

Also with multiple protocols

input 
{
    tcp 
    {
        id => "main_tcp"
        port => "5043"
        codec => json
    }

    udp
    {
        id => "main_udp"
        port => 12201
        codec => "json"
    }
}

Logstash will bind to what you specify in the *.conf files

I found the solution
by editing logstash.yml file at config dir

http.host: "0.0.0.0"
#
# Bind port for the metrics REST endpoint, this option also accept a range
# (9600-9700) and logstash will pick up the first available ports.
#
http.port: 9650

but now already existing files are not indexing

That is for a different endpoint, the ports for ingesting data are controlled via the inputs modules, where 5044 is default. You are looking at the Logstash Configuration instead of the pipeline configuration

input {
	file{
		path => "/logs/archived/*.log"
		codec => multiline{
			pattern => "^[0-9]{4}-[0-9]{2}-[0-9]{2}"
			negate => true
			what => "previous"
	}
  }
}
filter{
	grok {
		match => {"message" => "%{TIMESTAMP_ISO8601:time_stamp}\s%{WORD:log_level}\s%{JAVACLASS:class}\s(\[%{DATA:thread}\])\s+(?<msg>(.|\r|\n)*)"}
	}
	mutate{
		gsub => ["time_stamp", " ", "T"]
	}
	mutate{
		gsub => ["time_stamp", ",", "."]
	}
	mutate{
		replace => {"time_stamp" => "%{time_stamp}Z"}
	}
}
output{
	stdout{
		codec => rubydebug
	}
	elasticsearch {
		hosts => ["http://0.0.0:9200"]
		index => "index-log"
  }
}

I am taking files from this path and if I made changes in config file I want to index already present files again

If you are using logstash to ingest a file, why do you need to change the logstash port number (5044)?

I want to use two config files and two logstash running so thats why

You can use multiple pipelines and each pipeline listens on a different port up specify on the Logstash Input Module

This is a much better, and the recommended approach @mangeshs.