GWT RequestFactory Performance

Question

I have a question regarding the performance of RequestFactory and GWT. I have a Domain Entity with 8 fields that returns around 1000 EntityProxies. The time between the request fires and it responds is around 20 seconds. I do the same but returning 10 EntityProxies and the time is 17 seconds, almost the same.

Is this because I'm working in development mode, or when I release the code to the web the time will be the same?

Is there any way to improve the performance? , I'm only reading data so perhaps something that only read and doesn't writes may be the solution?

I read this post with something similar to my problem:

GWT Requestfactory performance suggestions

Thanks a lot.

PD: I read somewhere that one solution could be to create an xml in the server, send it to the client and recreate the object there, I don't want to do this because it would really change the design of my app.

Answer 1

Thank you all for the help, I realize now that perhaps using Request Factory to retrieve thousands of records was a mistake.

I initially used a Locator to override isLive() and Find() methods according to this post: gwt-requestfactory-performance-suggestions

The response time was reduced to about 13 seconds, but it is still too high.

But I solved it easily. Instead of returning 1000+ Entities , I created a new database table which each field has all the same field records (1000+) concatenated by a separator (each db field has a length of about 10000 ) and I only have one record in the table with around 8 fields.

Something like this:

 Field1           |           Field2          |           Field3         

Field1val;Field1val;Field1val;....... | Field2val;Field2val;Field2val;...... | Field3val;Field3val;Field3val;......

I return that One record through RequestFactory to my client and it reduced the speed a lot!, around 1 second. I parse this large String in the client and the duration of that is about 500ms. So instead of wasting around 20 seconds now it takes around 1-2 seconds to accomplish the same.

By the way I am only displaying information, it is not necessary to Insert, Delete or Update records so this solution works for me.

Thought I could share this solution.

Answer 2

Performance Profiling and Fixing issues in GWT is tricky. Avoid all profiling in GWT Hosted mode. They do not mean anything useful.

You should profile only in WEB mode.

GWT RequestFactory by design is slower than GWT RPC and GWT JSON etc. This is a trade off w.r.t GWT RF ability to calculate delta and send only small amount information to server on save.

You should recheck you application design to avoid loading 1000's of proxies. RF is mean for "Form" like applications. The only reason you might need 1000's of proxies is for a Grid display. You probably can use paginated async grid in that scenario.

Answer 3

You should profile your app in order to find out how much time is spent on following steps:

1. Entities retrieved from the database (server): This can be improved using second level cache and optimized queries
2. Entities serialized to JSON (server): There is a overhead here because RequestFactory and AutoBean respectively rely on reflections. You can try to only transmit the Entities that you are also going to display on the client. Another optimization which greatly reduces latency is to override the isLive method of your EntitiyLocator and to return true
3. HTTP request from server to client to tranmit the data (wire): You can think about using gzip compression to reduce the amount of data that has to be transferred (important if you send a lof of objects over the wire).
4. De-serialization on the client (client): This should be quite fast. There was a benchmark that showed that AutoBean serialization was one of the fastest ways to serialize JSON. Again this will benefit from not sending the whole object graph over the wire.

One way to improve performance is to use caching. You can use HTML5 localstorage to cache data on the client. This applies specifically to data that doesn't change often.