I have WCF function for accept data as an array from ajax request.
When array size is below 2500 then ajax hit my service method but when data is approx 5000. It is showing Bad request.
My wcf method is
public string PostDataInServer(declarationmis[] arrdeclaratiomis, loanee[] arrloaneemis)
Most probably you're exceeding the default maximum message size. You can change that in your bindings:
<binding name="BindingName" maxReceivedMessageSize="1048576" />
, the message size there being in byte (1 MB in my example). Note that this may leave you more vulnerable to malicious attacks (distributed denial of service, to be specific).