Logstash config file no output

[Yuvaraja_kannan]

HI All,

I have a simple log file with the below data, I tried to grok, i used grok debugger and got the expected output, But when I tried the say with logstash config file I am not getting any output. Please advice if there are any issues with the config.
Log:
2017-12-28 17:01:43,712
config:
input {
file {
path => "C:\Users\yuvaraja.kannan\Documents\Process_project\sample_log.log"
start_position=>"beginning"
sincedb_path=>"/dev/null"
}
}

filter {
grok {
match=>{"message"=>"(?%{YEAR}-%{MONTHNUM}-%{MONTHDAY}) (?%{HOUR}:%{MINUTE}:%{SECOND})(?,%{POSINT})"}
}
}

output {
stdout {}
}

[magnusbaeck (Magnus Bäck)]

sincedb_path=>"/dev/null"

On Windows use "nul" instead of "/dev/null".

[Yuvaraja_kannan]

Thanks.