perfSONAR User Q&A and Other Discussion

["Jeff W. Boote" <>]

Chris Welti wrote:
> SWITCH is currently using the python release.
> I'm a bit reluctant to change to the java version as it seems to have a HUGE 
> overhead. Also the performance of the python version seems better,
> according to reports on this list.

Well, I'm not sure which list you are talking about. Looking back, it looks like 
the problems were reported on the user list, but the resolution was only 
reported on the developers list. (Not good PR! :) ) A good portion of the 
performance problems were fixed for the 1.0 production release by removing some 
debugging code. From Vedrin's message to the list referring to the RC2 version 
that corrected these issues:

| We noticed that Java RRD MA performance in processing SetupDataRequests has
| significantly improved, compared to RC1 (and Python RRD MA):
|
| 1 MetadataKeyRequest for 160 interfaces (Java)  ~  10 sec
| 160 SetupDataREquests for 1 interface (Java)    ~  40 sec (!!!)
|
| 1 MetadataKeyRequest for 160 interfaces (Python)  ~  2.5 sec
| 160 SetupDataREquests for 1 interface (Python)    ~  106 sec
|
| Java RRD MA now clearly outperforms Python RRD MA for SetupDataRequest
| processing and completes the task 2.5 times faster on average (same client,
| same server, same data). However, the low MetadaKeyRequest processing
| performance of Java RRD MA still remains an open issue.

SetupDataRequests are the messages that actually fetch data. This is the request 
that is duplicated - the MetadataKeyRequest is for the initial metadata and does 
not need to be repeated very often by the client. So, I would expect the Java 
performance to be superior for most uses of the RRD MA. (This is not an 
exhaustive benchmark, so ymmv of course. But, this is the data we have.)

> As I understand, there needs to be plenty of installation works (Java, 
> Apache, Tomcat/Axis, eXist) even before the perfSONAR java installation.
> Is there a installation guide for this stuff?

If the README is inadequate, we would appreciate any feedback you have. (Perhaps 
we need to do something to let people know to look in the README?)

> On the www.perfsonar.net I can only find a guide for perfSONAR package
> itself, but not the the pre-Install requirements :)
> Keep in mind, I'm only a Network Engineer, not a Developer or Sys Admin :)
> So until there is a real easy way to install it, or I get enough time on my 
> hands to figure it out myself, the SWITCH RRD and ping MA will remain based 
> on the python version.

Then you are exactly the audience we need to support. We would benefit greatly 
from any effort you are willing to put toward this. (Especially if we can create 
some documentation to address each road block you hit - as you hit it.)

jeff