javascript - How to write nodejs service, running all time -

i new nodejs (and js), can explain me (or give link) how write simple service o nodejs, wich run permanently?

i want write service, wich send request every second foreign api @ store results db.

so, maybe nodejs have simple module run js method (methods) on , on again?

or, have write while loop , there?

setinterval() use run every second in node.js. call callback every nn milliseconds pass value of nn.

var interval = setinterval(function() {     // execute request here }, 1000); 

if want run forever, need handle situation remote server contacting off-line or having issues , not responsive normal (for example, may take more second troublesome request timeout or fail). might safer repeatedly use settimeout() schedule next request 1 second after 1 finishes processing.

function runrequest() {     issuerequest(..., function(err, data) {         // process request results here          // schedule next request         settimeout(runrequest, 1000);     }) }  // start repeated requests runrequest(); 

in code block issuerequest() placeholder whatever networking operation doing (i use request() module , use request.get().

because request processing asynchronous, not recursion , not cause stack buildup.

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fyi, node.js process active incoming server or active timer or in-process networking operation not exit (it keep running) long have timer running or network request running, node.js process keep running.