Little brother I wrote a program, but access for a while, will be the Apache card to die, only the restart will be good

I wrote a program, but for a while, the Apache card will be dead, only the restart will be good.
I would like to ask, what is this cause of yo?
How can I debug it and find out the problem?

------Solution--------------------
At least this is required:
Set a global variable OK order
OK = 1;
.....
if (S <= 1.5 && times < 3 && OK) {
OK = 0;
$.getjson (Getdataurl,{start:start,end:end,id:typeid},function (e) {
Scrolldata = e;
...
Scrolldata= ";
OK = 1;
}

The implication is that when Ajax data is not returned, the next round of requests is not made

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