[JCLOUDS-358] Improve blob request signing performance

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 1.6.3
• Fix Version/s: 1.7.0
• Component/s: jclouds-blobstore
• Assignee: Unassigned
• Reporter: Shri Javadekar
• Created: 24/Oct/13 18:25
• Updated: 19/Nov/13 01:39
• Resolved: 19/Nov/13 01:39

Description

I ran an application which calls into jclouds for signing blob put requests (against the aws-s3 blobstore) and analyzed its performance using YourKit. The analysis shows that each request for signing blobs takes about 13 ms (average of 160K requests). > 10 out of these 13 ms are spent in the RestAnnotationProcessor. Mainly in RestAnnotationProcessor.apply() and RestAnnotationProcessor.decorateRequest(). Looking at the code, it seems that processing of all the annotations is done for every request, which also means that there is the Java Reflections overhead for every request.

Are there options that we can explore to make this better; such as

i) caching the output of the RestAnnotationProcessor and only updating fields that change in every request
ii) not using java Reflections API

Note that I am using jclouds-1.6.3-SNAPSHOT which includes the fixes for bug 301.
https://issues.apache.org/jira/browse/JCLOUDS-301