Question

I am using a modified version of the TaskCloud example to try and read/write my own data.

While testing on a a deployed version, I’ve noticed that the round-trip response time is slow.

From my Android device, I have a 100ms ping response to appspot.com.
I have changed the AppEngine application to do nothing (The Google Dashboard shows insignificant Average Latency.

The problem is that the time it takes for HttpClient client .execute(post) is about 3 seconds.
(This is the time when an instance is already loaded)

Any suggestions would be greatly appreciated.

EDIT: I’ve watched the video of Google I/O showing the CloudTasks Android-AppEngine app, and you can see that refreshing the list (a single call to AppEngine) takes about 3 seconds as well. The guy is saying something about performance which I didn’t fully get (debuggers are running at both ends?)

The video: http://www.youtube.com/watch?v=M7SxNNC429U&feature=related
Time location: 0:46:45

I’ll keep investigating…
Thanks for your help so far.

EDIT 2: Back to this issue…

I’ve used shark packet sniffer to find out what is happening. Some of the time is spent negotiating a SSL connection for each server call. Using http (and ACSID) is faster than https (and SACSID).

new DefaultHttpClient() and new HttpPost() are used for each server call.

EDIT 3:

Looking at the sniffer logs again, there is an almost 2 seconds delay before the actual POST.

I have also found out that the issue exists with Android 2.2 (all versions) but is resolved with Android 2.3

EDIT 4: It’s been resolved. Please see my answer below.

Answer 1

After using the Shark sniffer, I was able to understand the exact issue and I’ve found the answer in this question.

I have used Liudvikas Bukys’s comment and solved the problem using the suggested line:

post.getParams().setBooleanParameter(CoreProtocolPNames.USE_EXPECT_CONTINUE, false);