Jmeter keeps pausing now and than during the test

[umesh prajapati]

I am wondering how can I make jmeter stop pausing in between the test. This
is how my script looks like:

Number of threads:100
ramp up:0
loop: forever

CSV Data Set Config

schedular: 1 hr

    Http cookie manager
    Http request for login
             synchronizing timer:100
              constant timer:${__javaScript(${__threadNum()}*300)}
              Xpath assertion
              Response assertion
              Summary Report
    Http request for logout