I am currently developing my iOS application which includes some feature uploading images in one time along with its album name.

I came up with a solution to use encoding base64 image in order to send nested json format instead of using multipart form data method.

My question is on my localhost, it seems like my application is capable to send many pictures in one time, let say 15 pictures. However, when it comes to sending through my web server (Amazon EC2 free tier), it seems like my application is capable to send up to 4 pictures at a time, if there are more than 4 pictures, nothing would appear.

I have tried to debug on networking part, it turns out that status 200 is returned with no images sent. My question is that does the problem occur due to server stuff or something ??

Updated

I think I've found some important insight. I will classify into two scenarios. What I have found on simulator debugging is that

i) I use a simulator to connect with my server. When I send only one picture, the size of it is around 252 bytes. Sending two pictures, they are 450 bytes. The weird thing is that sending more than 3 pictures, its size is calculated to be only 208 bytes. This is very weird, it is supposed to be higher when a number of pictures increases.

However, I remember that things work perfectly fine on my localhost; thus I try to debug on a simulator that connects with localhost to figure it out more.

ii) I use a simulator to connect with localhost. When I send one picture, it has 252 bytes. Sending 2 pictures, it is around 450 bytes and sending 4 pictures, it is around 1152 bytes. We can see that data's size here is growing when the number of pictures is increasing. The scenario ii) does make sense.

Anyway, I still have no idea what causes this problem; I believe this should involve with server stuff for sure. Please help !!