Is there a limit to the number of Ajax requests that can be launched on Apache

Is there a limit to the number of simultaneous Ajax requests than can be launched toward an Apache server? For example, consider the following function to update div elements on a page (prototype JS):

function trigger_content_update(cell) {
    //asynchronous : false is required for this to work properly
    $$('.update').each(function(update_item){  
        new Ajax.Request('/neighbouring?.state=update_template&dummy='+(new Date()).getTime(),{
            asynchronous: false,
            parameters: {divid: update_item.id, source: cell},
            onComplete: function(response) {
                var elm = response.getHeader('Element');
                if ($(elm) !== null) { $(elm).update(response.responseText) }
            }
        });
});

}

On my HTML page, there are 8 div elements that are marked with the "update" CSS selector, thus launching 8 ajax requests. The code works fine with the asynch开发者_如何学JAVAronous property set to false, but as soon as i set asynchronous:true i can observe (in Firebug) most Ajax requests returning a 500 status (internal server error).

Once this occurs, it is required to restart apache to recover.

I'd check the server side code that's handling the requests.

As far as Apache is concerned, your Ajax request is just a POST - the same as if you'd submitted a form. 8 simultaneous requests should easily be handled by Apache, so it suggests that the server side code that Apache is running is locking up - perhaps it's trying to write to a data file and finding it locked?

I just wrote a test case where I sent out 10,000 simultanuous Ajax calls to a service. Works fine on Apache Tomcat. All service came back with a proper answer.

It sounds like your service is having some internal synchronization issues.