Re: IWS REST API performance questions

I agree with the "It depends...." answer but not entirely on board with
async processing. If everything can be done on-thread, not sure why add
complexity. So it depends on what you want the API to do.

Sure, move things to batch and respond OK to client if the submission was
successful. But if you are returning a response, then you should do it
on-thread.

Now as far as help from IBM regarding performance, Lab services can help,
for a fee. I am sure the community will help with specific questions.

Since IWS is based on Java, any performance aspects relating to Java
affects IWS. Also ensure you have latest Java 8 64 bit Java group PTF on
your system in addition to HTTP group.

But the main thing is memory. You should have enough memory. How much? I
am not an expert so I really cannot say. Nothing really tied to hardware
although newer hardware means better performance just due to natural
advancements hardware technology.



"WEB400" <web400-bounces@xxxxxxxxxxxxxxxxxx> wrote on 05/10/2021 10:55:58
AM:

From: <midrangel@xxxxxxxxxxxxxxxxx>
To: "'Web Enabling the IBM i \(AS/400 and iSeries\)'"
<web400@xxxxxxxxxxxxxxxxxx>
Date: 05/10/2021 10:55 AM
Subject: [EXTERNAL] Re: [WEB400] IWS REST API performance questions
Sent by: "WEB400" <web400-bounces@xxxxxxxxxxxxxxxxxx>

As you might guess the best answer to all your questions is: "It
depends".....

Generally we see memory footprint and proper use on shared pools to have

the

biggest effect on this type of transaction. Rarely CPU becomes a

bottleneck

if the transactions are complicated, so I suggest you make the REST API

do

as little as possible and push the bulk of the processing to asynch

batch

(data queue ??)

The thing we see most often in these situations are network bottlenecks.
DNS look ups take too long, firewall rules that cause things to bounce
around, too slow of an internet connection, poorly configured line
descriptions, etc..

--
Jim Oberholtzer
Agile Technology Architects

-----Original Message-----
From: WEB400 <web400-bounces@xxxxxxxxxxxxxxxxxx> On Behalf Of Kelly

Cookson

via WEB400
Sent: Monday, May 10, 2021 9:56 AM
To: web400@xxxxxxxxxxxxxxxxxx
Cc: Kelly Cookson <KCookson@xxxxxxxxxxxx>
Subject: [WEB400] IWS REST API performance questions

We may adopt IWS REST APIs in our shop. However, I have concerns about
performance. I am *not* concerned that IWS REST APIs cannot perform

well. I

have heard from more than one person that shops have achieved good
performance with IWS APIs at high volumes of requests. I assume it is
possible to get the kind of performance we want from IWS REST APIs.

The question is whether or not *our shop* will be able to achieve that

good

performance.

1. If achieving good performance with IWS REST APIs requires a

relatively

big IBM i or additional partitions for conceptual load balancing or
something else that might involve significant new investments in

hardware,

then I would like to know this. This would not necessarily be a
deal-breaker. But I would like to know what to expect in advance. (I

know

this is hard to answer without the specifics of our system. I am looking

for

a general description of what size/configuration of an IBMi system is

needed

to handle a high volume of REST API requests-defining high volume

however

you want-with good performance.)

2. I know the "Integrated Web Services Server Administration and

Programming

Guide" contains suggestions for performance tuning. However, most of the
suggestions involve things that are new to us. if we need help to

optimize

the various performance tuning options mentioned in the programming

guide,

where can we turn to for more detailed help? Can we get help from IBM,

for

example?