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AZhappyjack

macrumors G3
Jul 3, 2011
9,630
22,760
Happy Jack, AZ
Just encountered my first one of these errors while replying to the MR thread about Tapbots... the error popped up while I was typing my response - long before I was ready to post the comment.

Screen Shot 2018-08-15 at 1.00.46 PM.png
 
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D.T.

macrumors G4
Sep 15, 2011
11,050
12,460
Vilano Beach, FL
Just encountered my first one of these errors while replying to the MR thread about Tapbots... the error popped up while I was typing my response - long before I was ready to post the comment.

View attachment 776160

Just a general FYI :)

The reason you see server related error (like the 503) when you're simply typing a post (i.e., doing something that seems passive), there are services called in the background from your browser without any kind of page refresh - for example, auto-save/draft-save - and they return the error from the server side.

The occasional 503 error sounds like some kind of concurrency / resource availability issue[?]
 

Scepticalscribe

macrumors Haswell
Original poster
Jul 29, 2008
64,043
46,495
In a coffee shop.
Just a general FYI :)

The reason you see server related error (like the 503) when you're simply typing a post (i.e., doing something that seems passive), there are services called in the background from your browser without any kind of page refresh - for example, auto-save/draft-save - and they return the error from the server side.

The occasional 503 error sounds like some kind of concurrency / resource availability issue[?]

Is this a resource availability issue on MR or on our own individual computers?
 

D.T.

macrumors G4
Sep 15, 2011
11,050
12,460
Vilano Beach, FL
Is this a resource availability issue on MR or on our own individual computers?

It's on the MR / server side - basically you're requesting a legitimate resource (vs. something like a 404 where it's not found), but for some reason (that's where the debugging gets fun ...) it can't respond - assuming the resource isn't broken (like faulty code), it's often that the number of requests the server can handle has been filled (both directly and deferment to a queue), so it's the human equivalent of "I'm busy, Don't bother me right now" :D
 

Scepticalscribe

macrumors Haswell
Original poster
Jul 29, 2008
64,043
46,495
In a coffee shop.
It's on the MR / server side - basically you're requesting a legitimate resource (vs. something like a 404 where it's not found), but for some reason (that's where the debugging gets fun ...) it can't respond - assuming the resource isn't broken (like faulty code), it's often that the number of requests the server can handle has been filled (both directly and deferment to a queue), so it's the human equivalent of "I'm busy, Don't bother me right now" :D

Fair enough.

Interesting to know; what surprised me was that I was doing what you described as 'something passive' - i.e. just writing a post - or, about to reply to one - when this message flashed up, leaving me somewhat puzzled.
 

D.T.

macrumors G4
Sep 15, 2011
11,050
12,460
Vilano Beach, FL
Fair enough.

Interesting to know; what surprised me was that I was doing what you described as 'something passive' - i.e. just writing a post - or, about to reply to one - when this message flashed up, leaving me somewhat puzzled.

Right, that's what I was explaining in my previous post, though I realize it's getting into the weeds a bit. Let me expand on it a little.

You have the SERVER, in the simplest terms, a "computer" sitting on the internet, running code in a web server, waiting to get a request from a CLIENT, that being, for example, your browser (Safari, Chrome, etc.)

When you click a link, a different topic area, the SERVER responds with the new content (of course there's databases, code, caches, and whatnot involved on the server side). That's a super simple request > response, that's obvious to the user (since you're seeing the new URL requests, seeing the new content).

Browsers can also run code, right in the browser without the need for any server processing, this allows for client side things to occur, formatting text, animation, popping up dialogs, events "in" the browser so to speak, checking the values in a form before it's sent to the server.

So that takes us to the scenario I was describing - you're sitting on a page, the server request has completed, you've got a form, basically a text box where you're entering a message/post. Now in the browser, there is also some code running (see above), this is where it gets pretty neat with modern web technology:

The browser code reads the text you've input (on a repeating timer event), and sends that over to the server - the page doesn't refresh, because you're not requesting a different URL, in the background this little browser side "application" is doing it. It doesn't get back a whole page (like when you click a link), just a very simple response message that's says, "OK, got that text and saved it", or, as we've seen, "I wasn't able to process your request due to <some error code>".

This is pretty much the architecture of most modern web sites/applications, lots of asynchronous background operations that do not require a page refresh, so that the user experience is way more like a desktop application. These little client applications can even partially update the content in the browser without having to update the entire page and request the entire page again from the server (so you can see how this design also reduces the amount of server traffic).

Hope that's helpful and informative without being too technical. :)
 

Scepticalscribe

macrumors Haswell
Original poster
Jul 29, 2008
64,043
46,495
In a coffee shop.
It is helpful, @D.T. - not that I fully understand it - and I would like to report that this thing (503) made yet another visitation a few minutes ago.....

Nevertheless, I think I am supposed to comprehend that this is not an especially egregious or serious issue.

Do mods wish to have us keep reporting it, or just grit your teeth in baffled bewilderment when it makes a fresh appearance and wait for that to pass.....
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
18,395
2,832
It's helpful if you can keep reporting them. I know it's a pain, and sorry about that. I know we've fixed a few issues that should lessen the frequency, but there are still some pesky ones we haven't tracked down. Thanks.
 

Clix Pix

macrumors Core
Just got a 503 error....... I had started writing a post but hadn't finished it before I was interrupted and had to step away from the computer for a few minutes. Came back to the machine to continue where I'd left off and to finally send the message; voila, a 503 error message popped up! Don't know if this makes a difference or not, someone interrupting themselves or being interrupted by circumstances and not finishing what they're writing at the time they are composing a post, then returning to complete it and send it off, but just thought I'd toss this into the mix.

Weather conditions could also apply here, as we've had flaky weather all day together with stormy conditions and then things seemingly settling down only to have the emergence of more rain, thunder and lightning...... That said, it was not storming at the time I was composing my post and then interrupted and returning to the post. Location: Mid-Atlantic states, Washington, DC regional area.

First time I've gotten the 503 error message, even though I had been reading and responding to posts without any problem up until that point.
 
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Scepticalscribe

macrumors Haswell
Original poster
Jul 29, 2008
64,043
46,495
In a coffee shop.
I got a 503 while composing a post last night, but, before, while I was still writing, that is, before I had managed to press "post reply".

Moreover, I've noticed that the forums are very slow and laggy today and for the past few days, as well.
 

sman789

Customer Support
Staff member
Dec 25, 2007
2,581
2,208
Richmond, VA
I got a 503 while composing a post last night, but, before, while I was still writing, that is, before I had managed to press "post reply".

Moreover, I've noticed that the forums are very slow and laggy today and for the past few days, as well.
I've just experienced this error (I haven't seen a 503/403/401 in at least a year) and in the same manner as you. I am using a VPN though, I wonder if that has anything to do with it.
 
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D.T.

macrumors G4
Sep 15, 2011
11,050
12,460
Vilano Beach, FL
So I see the MR forums is on Host Duplex, which indicates _managed_ XenForo services, at what level are they involved in this issue? Is the MR staff having to debug this? Seems like their service language is: we host/manage/resolve any client issues.

Just curious (please tell me to get bent if it's none of my business :D)
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
18,395
2,832
@HDSam, who has been involved in this thread, is our main contact at Host Duplex and yes, he's been the primary one debugging things. The issues are very spotty, and as you can imagine, we generate a LOT of logs to sift through. We've fixed a few issues that were causing some of the 503s, but it's clear we've still got some more to track down.
 

Scepticalscribe

macrumors Haswell
Original poster
Jul 29, 2008
64,043
46,495
In a coffee shop.
@HDSam, who has been involved in this thread, is our main contact at Host Duplex and yes, he's been the primary one debugging things. The issues are very spotty, and as you can imagine, we generate a LOT of logs to sift through. We've fixed a few issues that were causing some of the 503s, but it's clear we've still got some more to track down.

So, er, do you wish for us to continue to report these - er - things?

Or, do you think you have them under control and that reports are superfluous to your needs?

If it is under control, I'd hate to think I (or other posters) were clogging up the systems with unnecessary reports; however, if you need notifications that some issues still require attention, then, obviously, I would be more than glad to furnish you with such reports as they arise.
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
18,395
2,832
It's helpful if you can continue to report them if you have a chance...probably just a quick note to say you ran into one is sufficient, and we can follow up if we need more info.
 
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Scepticalscribe

macrumors Haswell
Original poster
Jul 29, 2008
64,043
46,495
In a coffee shop.
Another 503 Error made an appearance in the football thread a short while ago when I was attempting to reply to a post, before I had managed to write a single, solitary syllable.
[doublepost=1535486905][/doublepost]Another 503 Error made an appearance in the football thread a short while ago when I was attempting to reply to a post, before I had managed to write a single, solitary syllable.
[doublepost=1535486940][/doublepost]And I'll leave that double post where it is as an illustration of what can happen: The system has been stalling, and hanging and slow this evening, and is prone to stalling and freezing (and has been giving rise to double posts) especially when alerts come in.
 
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