Re: Socket Speed Question - RPG vs PC

[Charles Wilt <charles.wilt@xxxxxxxxx>]

Do you by chance have an old device configuration with a smaller frame size
set?

If you cannot configure the device to support your frame size, you must
decrease your maximum frame size to a size that the device can support. You
can change one or more of the following maximum frame size fields (location
of the field in parentheses):
- SSAP maximum frame parameter (line description)
- Maximum frame size (line descriptions for token ring, Gigabit and 10
Gigabit Ethernet networks)
- Maximum frame size (controller description)

1GB and 10GB ethernet should default to 8992...

I think some of the older/slower adapters can be configure to 8992 even
though they default to 1492
https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_72/rzajy/rzajymaximumethernetframesize.htm

Charles



On Sun, Oct 4, 2020 at 9:23 AM Brad Stone <bvstone@xxxxxxxxx> wrote:

> I am playing around with some sockets and I am finding that the speed at
> which RPG sockets receive data is much slower than, say, a PC downloading
> with a browser.
>
> On a PC a 5mb file downloads in 3-5 seconds.
>
> On the IBM i using GETURI or HTTPAPI the same file downloading takes around
> 20 seconds which is a huge difference.
>
> These test are HTTP (not SSL).  SSL I understand will slow things down more
> as well, but the time difference seems to be fairly consistent.
>
> In running debugs it seems that the servers I have tested "limit" the
> amount of data on each read() from the socket to 1448 bytes (at least in
> this case).  This seems to be the possible bottleneck.   The receiver
> variable I'm using is 1mb.
>
> I sort of understand it's up to the server to decide how much to send at
> once... I am just curious if any of you that have a deeper understanding of
> the OS and how these things work can explain this.
>
> Is it simply that RPG is a "slower" language than C, etc?
>
> Of course I'm scanning Stack Overflow for answers, but I haven't found
> anything that explains this, which is why I assume it's just RPG's fault.
> :)
>
> Bradley V. Stone
> www.bvstools.com
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