PayPal iPN intermittant failure HTTP error 500

[d0ugparker]

We recently moved to a new ISP. Almost all transactions
are being processed to completion, but a few (less than
5%) are receiving IPN error 500, an HTTP error of a general
nature with no further information available.

I've requested our ISP to look at the Apache logs for those
dates and times to see if there is any information in the
logs that might help, but haven't heard back yet.

Searching for threads on the issue turn up 1.3.8-era problems
from 2008 and 2009, so they're not current.

Is there anything I can be doing to track down this anomaly?

Thanks.

Dr Doug

[mc12345678]

We recently moved to a new ISP. Almost all transactions
are being processed to completion, but a few (less than
5%) are receiving IPN error 500, an HTTP error of a general
nature with no further information available.

I've requested our ISP to look at the Apache logs for those
dates and times to see if there is any information in the
logs that might help, but haven't heard back yet.

Searching for threads on the issue turn up 1.3.8-era problems
from 2008 and 2009, so they're not current.

Is there anything I can be doing to track down this anomaly?

Thanks.

Dr Doug

Is there a reason the less problematic paypal express isn't used, or is this occurring with it?

[d0ugparker]

I don't understand the interplay between ZC and
PP, its communications protocol, or its required
settings. I don't even know if IPN is something
that I need to have enabled or not for our site
to work properly. I really don't know how best
to go forward on this.

If PayPal's Instant Payment Notification (IPN)
isn't needed for generic ZC / PP processing, then
I can easily shut it off and be done with it, but
I'm afraid of shutting down the IPN feature and
having the site dead in the water.

I'm lost.

[d0ugparker]

I just found this link, and I'm reviewing it:

Why am I getting 500 INTERNAL SERVER ERROR messages?


It's on ZenCart support. I know we're using IIS, so that's
already a not so good indicator.

[mc12345678]

Regarding paypal and paypal's ipn, take a look at the following as well:

About setting up a portion of the IPN information:
http://www.zen-cart.com/content.php?...-automatically

Which leads to the below link if selected at the top.

For paypal setup instructions:
Documents in the installation package and,
http://www.zen-cart.com/wiki/index.php/PayPal
As well as the instructions provided in the admin panel when modules, payments, and the applicable/desired payPal option is selected.

[d0ugparker]

For a generic, vanilla ZenCart installation, with
no special, customized features programmed in
on our ZenCart side (just the ordinary, out-of-
the-box install that's done from the start),

1) do I even need to have IPNs activated, or
2) are the IPNs the method by which basic
purchase confirmations are communicated back
and forth between ZenCart and PayPal?

PayPal allows a setting to disable IPNs if I don't
want them. Again, I'm not clear on the purpose
of the IPNs. Were I to disable IPNs, would I
effectively shut down our online shopping
service? :-\

*sigh*