by emilepetrone on 7/31/14, 10:50 PM with 71 comments
by thenduks on 8/1/14, 2:05 AM
When my users are redirected back to my site (thanks page, or similar), I check if their transaction is completed, if not, I kick off an every-five-seconds check while asking the user to hold on while we talk with paypal. I will eventually fail after some number of checks of course, but this means PayPal can stop sending IPNs and everything will just keep going along just fine.
If the user might not end up back on your site for some reason, run a cronjob that tries to verify transactions created in the past day/hour/whatever.
An issue like this doesn't have to, and really shouldn't, cripple your business.
by contingencies on 7/31/14, 11:53 PM
Firstly, the degree of marketing bullshit that you have to push through just to get to the truth of the APIs is staggering.
Secondly, they perform backflips to avoid telling the truth about their integration options, which is to say that they're all fundamentally insecure for real time digital goods and services unless you implement IPN plus polling plus duplicate detection / additional round-trip validation calls, ie. you can't trust an IPN notification. The degree of complexity (order state tracking, IPN state tracking and duplicate detection, retry support, running your own IPN-receiving server) and latency requested here of client businesses is immense.
Thirdly, their idea of international support is pathetic. It seems that they've basically duplicated their entire business process to other countries, translated it, and then assumed that everyone in that country requires only one human language in all of their interactions: documentation, support, emails, etc.
Finally, as is widely known throughout the industry they have a shocking reputation for the arbitrary suspension and seizure of accounts and assets, with little to no recourse for those affected.
I am not surprised that Stripe has taken off. Unfortunately, that's still lipstick on a pig: fundamentally, the settlement, risk, transparency and government interaction model of credit card networks means they are unsuitable for an increasingly large volume of business around the world.
by erikcw on 7/31/14, 11:15 PM
It took us a fair amount of time to figure out that this was the cause of our issue -- the PayPal UI didn't indicate any problems and PayPal business customer support was unable to see the source of the problem either.
by driverdan on 8/1/14, 3:36 AM
by jay-saint on 8/1/14, 2:31 PM
I received a lot of "hmmm that's weird" and "well i've never seen the API do that" comments from the integration support specialist at PayPal."
What is happening for us is that Paypal is simultaneously sending a authorization and then a second later a capture. the results are weird some transactions process and other get a duplicate invoice it error.
by myddryn on 8/1/14, 12:09 AM
It is a more complex integration, but our product has been much more stable since we made the transition to Express Checkout.
This does not however prevent other problems with IPN delivery on refunds and other post order activity. Paypal's IPN infrastructure is pretty weak in general, very poorly documented and completely untestable.
by emilepetrone on 7/31/14, 11:02 PM
by csomar on 8/1/14, 4:40 AM
There are many reasons why an IPN will fail. Like having your firewall settings messed up, network issues on your or PayPal's side, PayPal actually sending an IPN but your infrastructure not making use of its information...
by WatchDog on 8/1/14, 12:12 AM
by pbreit on 8/1/14, 2:48 AM
IPN hasn't gotten much love in years but still pretty cool that it was (one of) the original webhooks back in 2001 and has worked decently for the past 13 years. In fact, an integration from 2001 should continue to work OK.
by d_runs_far on 8/1/14, 1:41 PM
by abritishguy on 8/1/14, 9:24 AM
b) IPN is clearly going to be flakey, there are several reasons why IPNs might not be delivered and they are not all paypal issues. In the paypal docs it says that if your webhook doesn't return 200 to some IPNs then it will stop sending them. For my new stuff I don't use paypal at all (stripe is just too good) but when I did I had a cron job running every 5 minutes that checked every transaction that had been created but no IPN had come through for. Over the cause of a couple of years I caught several transactions where the IPN had been lost.
by kawsper on 7/31/14, 11:15 PM
> Disbursements through US Bank Accounts or Debit Cards
Is it only related to US bank accounts and debit cards? Or is it an IPN issue affecting all card?
by Xorlev on 8/1/14, 12:46 AM
by mgkimsal on 8/1/14, 12:18 AM
by emilepetrone on 7/31/14, 11:21 PM
by kevin_thibedeau on 8/1/14, 3:05 PM