Cannot reproduce duplicate posting messages

[CTXMedia]

Still happening on a regular basis and affecting sites independently of each other (and sometimes all together!). I use responsive Adsense on all the sites, but it is not enabled for members ... and guests (who do see the ads) cannot post - so not sure that is the issue, unless the adsense js interferes with posting/ajax in some other way? I also use Skimlinks, which is enabled for both members and guests - with Skimwords enabled for guests only.

I got an SQL spike tonight, but suspect this may simply be a symptom as I don't need to restart MySQL to fix the issue, I stop and restart Apache to get rid of it (until the next time):



This is happening on almost a weekly basis now, with one or more of my sites - but mainly the cycling and cooking forums; CycleChat gets upwards of 2,100+ posts per day and CookingBites gets just 80+ posts per day but both are similarly affected.

What is the technicaly process of creating a post in XF and returning the user to the screen with the post content displayed?

 

[CTXMedia]

Having made some changes to Apache at the weekend (disabling Keepalive and extending the Timeout value - on a blind assumption it might be mobile device connections causing a problem) and restarting MySQL, I got a report of double-posting on CycleChat again this morning.

Do any of you use the Featured Threads add-on on your sites?

 

[Paul B]

Yes.
Never seen any double posts on my site.

 

[CTXMedia]

Yes.
Never seen any double posts on my site.

well I know you use it ... but I just wondered if anyone who's seeing double posts uses it, and if so what other add-ons they use too? (in case there's a rare or unusual situation that could cause this to happen).

I'm also curious as to whether anyone uses responsive Adsense - not the @media manual sizing version of the code - but the default Google automatic sizing code (I've seen this referred to in another thread)?

Unfortunately I'm not in a position to be able to disable all add-ons and turn off ads for weeks on end at CycleChat to test, so am looking to see if there's any common ground between any of us who are experiencing the problem. It would be handy if it would manifest itself in a matter of minutes - I could disable/uninstall everything for a short time - but it can take days and sometimes weeks to appear so at what point after I've disabled something do I call it "fixed" and roll it out to the other sites? I might disable / change a few things on the Cooking site since this will have much less impact, but I'm flying blind and somewhat clutching at straws to discover the source of the problem.

It's frustrating, but equally I can't expect the XF developers to concern themselves with it because it's not a common issue (and is quite likely going to be an add-on or ad-code issue in the end anyway).

I'll do some more tweaking and report back whether I have any success in resolving it.

 

[CTXMedia]

Can I just clarify - if I disable an add-on in the ACP does it completely stop the add-on from working and having any impact on the site whatsoever? Does it remove all hooks from templates and stop any part of it being called (whether it is used/processed or not)? Or do I need to completely uninstall to be 100% sure it is not impacting on the site?

I'm hoping that disabling an add-on will be just as effective as completely removing it (without the associated hassle of reinstalling if I find it doesn't affect the double-posting).

 

[DeltaHF]

Can I just clarify - if I disable an add-on in the ACP does it completely stop the add-on from working and having any impact on the site whatsoever? Does it remove all hooks from templates and stop any part of it being called (whether it is used/processed or not)? Or do I need to completely uninstall to be 100% sure it is not impacting on the site?

I'm hoping that disabling an add-on will be just as effective as completely removing it (without the associated hassle of reinstalling if I find it doesn't affect the double-posting).

For most add-ons, it should completely disable it, yes.

I've also seen double-posting, but I'm not using the Featured Threads add-on, nor am I using the Google-provided responsive AdSense code (I'm using Google DFP, with custom JavaScript to determine which ad units to show).

 

[CTXMedia]

Thanks @DeltaHF

 

[CTXMedia]

Do any of you with double-posting issues have APC Opcode cache installed on your servers?

I noticed that whilst double posting was happening there seemed to be a series of seg faults logged by Apache: [notice] child pid 2806 exit signal Segmentation fault (11)

A couple of nights ago I caught the beginning of a double-posting episode whilst I was responding to a PM. In particular, it seemed to coincide with the nightly log rotation cron job (which also happened to reset APC's cache). I then looked back at when I last upgraded PHP on the server and began wondering if APC might be less compatible with the newer version of PHP I upgraded to and be a part of the problem itself (or even the source of it!)? A quick Google showed that Opcache was stable and compatible with my version of PHP so I installed it and so far haven't had any seg faults or seen a return of the double-posting.

It's very early days yet - historically we've gone for weeks before seeing double-posting reappear - but I thought I'd throw my thoughts out to see if it resonates with anyone and whether any of you have managed to resolve your double-posting or are still dealing with the effects?

Cheers,
Shaun

 

[Mike]

We've seen various issues with APC in PHP 5.4 (and presumably newer). It can trigger all sorts of strange behaviors, including errors that should be impossible, along with somewhat random PHP crashes. We haven't seen these issues with the built-in opcache.

 

[CTXMedia]

We've seen various issues with APC in PHP 5.4 (and presumably newer). It can trigger all sorts of strange behaviors, including errors that should be impossible, along with somewhat random PHP crashes. We haven't seen these issues with the built-in opcache.

Thanks Mike - that's reassuring to know. I moved from PHP 5.3 --> 5.4 but it hadn't occured to me that this might cause conflicts with APC, and I've spent ages and ages looking at XF, MySQL, add-ons, etc. until I recently came across a web page related to seg faults and PHP that discussed the idea of instability with APC and how it is being superseded with Zend Opcache as a more stable option.

I'm hoping it will resolve the double-posting as it's been driving me (and our members and mods) mad for a long time. I suppose I'll know within a few weeks. <fingers crossed>

 

[CTXMedia]

So far, so good. No seg faults, and no issues after the log rotation last night (I sat up and waited and checked Apache's error.log).

 

[radu81]

I've had this problem in the past and it was my fault, I did some template edits to add ads and there was a js conflict if I remember well. I use the UI.X theme from @Mike Creuzer and after the ticket I opened he was kind to solve this.

 

[Mr Lucky]

I've had this problem in the past and it was my fault, I did some template edits to add ads and there was a js conflict if I remember well. I use the UI.X theme from @Mike Creuzer and after the ticket I opened he was kind to solve this.

maybe that ties in with my findings that Responsive Adsense was causing this.

https://xenforo.com/community/threads/duplicate-posting-messages.70925/page-2#post-783498

 

[CTXMedia]

So far, so good. No seg faults, and no issues after the log rotation last night (I sat up and waited and checked Apache's error.log).

Still no seg faults and no double-posting ... I'm beginning to think this is solved ...

 

[CTXMedia]

No seg faults for a week and no double-posting or other related issues. I'm calling this one as solved [for our server] and somewhat kicking myself for not thinking to look at APC sooner than I did.

 

[radu81]

glad you solved this the reason were the ads you addes?

 

[CTXMedia]

glad you solved this the reason were the ads you addes?

No, in my case I was using APC 3.1.13 Opcode cache with PHP 5.3 and everything worked fine; but then I upgraded the server to PHP 5.4 and didn't realise that APC didn't work very well with PHP 5.4 so kept looking at all manner of other things as the cause of the double-posting, including some XF add-ons that seemed to make things worse when they were installed and enable.

It was only by chance that I had a double-posting episode at precisely the time that the server does the Apache log rotation, which I know also flushed the APC cache, which sent me looking in the error logs where I found lots of seg faults that seemed to coincide with previous episodes that I'd been logging the rough time/date details of.

Researching the seg fault 11's online lead me to discover other people had similar strange issues on their servers with the PHP 5.4 / APC combination, which seemed to go away when they removed APC (most of them in favour of Zend Opcache). I made the switch on my own server and that has resolved the problem.

Cheers,
Shaun

 

[Mr Lucky]

Just happened to me here:

https://xenforo.com/community/threads/subdomain-or-subforum.114870/

 

[imno007]

Personally, I've only ever experienced double posting when there were memory issues on the server, long post times causing members to click the post button multiple times in an effort to hurry it along.

 

[rafass]

That happen to me sometimes, internet connection issues. [in my case]