GMT Timezone to CST in logstash

Yes. I realized the issue about the date pattern. I changed it to yyyy-MM-dd HH:mm:ss Z But i still get the same dateparsefailure error.

But that pattern also doesn't match "2017-02-16 06:52:31.5999". I'd try yyyy-MM-dd HH:mm:ss,SSSS.

Is there anyway i can simply remove the millisecs or microsecs?

Sure, you can use the mutate filter's gsub option.

Re: the timezone, i am trying to set Central Standard Time. How would i set the timezone as you suggested so it won't assume to be in local time?

I think a list of available timezone name are available via a link in the docs. I suspect that timezone => "Etc/UTC" might work for you.