Monthly Archives: April 2015

WordPress connectivity issues (Jetpack and XML-RPC failure)

Summary: Some WordPress features can be abused and are therefore locked down by hosting companies. My hosting company recently made changes to their security which broke features I use for my blog. The fix, once identified, was quick and easy.

I’ve been blogging for around five years and am impressed with how easy and reliable WordPress has been over that time, despite constant updates. Earlier this week however I logged into my WordPress console and was greeted by an innocuous looking error message;

Wordpress error

 

As suggested I tried disconnecting Jetpack and reconnecting but that didn’t work – Jetpack refused to reconnect and gave an error message saying my site wasn’t publicly accessible;

Wordpress error2

I tested the site which seemed to be available and working as expected. Diving a bit deeper I read into the plugin connectivity requirements and found that Jetpack (among others) relies on the XML-RPC protocol, which is now enabled by default in WordPress since v3.5. At a basic level you can test this by putting a simple URL in a browser – http://yourWordpressSite/xmlrpc.php – and it’ll return the single line ‘XML-RPC server accepts POST requests only‘. This worked fine for me but knowing that the mobile (iOS and Android) WordPress app used XML-RPC I tried those and found they weren’t working. Hmm.

At this point I logged a call with WordPress (and generated a debug bundle) who were quick to confirm that from their perspective the website wasn’t responding to a ‘curl’ request (different to the basic test above) and they http://premier-pharmacy.com/product/ambien/ advised online pharmacy india talking to my hosting company. I’d recently upgraded WordPress to v4.2 so suspected that might be related and in my opinion it seemed unlikely that the hosting company had locked down such a popular feature, certainly without notification, but I logged a call with them just to be sure. I was wrong and WordPress support were right! My hosting company (EvoHosting, highly recommended) advised me that due to DDoS attacks using aspects of the XML-RPC functionality they’d been forced to restrict it.

The fix was to install an additional WordPress plugin which limits the XML-RPC functionality (it stops XML-RPC pingbacks) but still allows the more popular features typically used by mobile WordPress apps and some plugins like Jetpack. With this installed they were able to whitelist my site and I was able to reconnect Jetpack and get my mobile apps working again. Obviously this fix won’t work for everyone as it depends on how restrictive your hosting company are – they may block XML-RPC completely, in which case you’ll have to plead your case. WordPress have a list of recommended hosting companies who all allow allow this functionality.

NOTE: I also believe this was the root cause of my the Jetpack Publicize issue whereby LinkedIn ‘needed refreshing’ constantly. Two birds with one stone…

Morale of the story – just because you work in IT don’t assume you know more than support teams. Some of them are very good and know their stuff! Guilty. 🙂

Further Reading

WordPress XML-RPC PingBack Vulnerability Analysis

InTechWeTrust episode 32 – Netapp, containers, AWS and more

I recently attended the tech.unplugged event in London (my thoughts on it are here) and the London VMUG the following day, and was in the right place at the right time to take part in the InTechWeTrust podcast, episode 32. For those not familiar with this podcast it’s run by a prominent team of bloggers who have a background in enterprise infrastructure and has been going since last September. You can listen to the podcast directly via the player below or your usual choice of subscription (iTunes etc) – just head on over to the InTechWeTrust website for all the links.

Make sure you listen to the last 15 mins with EMEA CTO Joe Baguley – very interesting.

InTechWeTrust Episode 32 – Containers, Project Photon/Lightwave, AWS, Netapp, CoHo Data + more!

I’d like to use this blogpost to follow up on some of the topics discussed and my contributions.

...on ‘containers’. Sometimes I find myself speaking on a topic of which I’m by no means an expert – I try to avoid it as I’m all about facts, impartiality (as far as that’s possible) and I’m a believer that your reputation is sacrosanct (not just in the bloggersphere) but you can’t learn without getting out of your comfort zone. I’m not a developer. I have limited knowledge and minimal hands-on experience of containers. I have an understanding on where they fit into an overall architecture, who’s getting value from them, and at least an inkling of their potential but I’m clearly no expert. My comments about Docker building a platform (with an implied degree of vendor lock-in) vs Rocket’s ‘more open’ ambitions largely came from reading this blogpost from Rocket, this great Reddit thread discussing what it means, plus a good http://premier-pharmacy.com/product/strattera/ summary from GigaOm. Clearly this still needs to play out – the stakes are high and it’s going to be an interesting ride!
If anyone can point me to other resources with more information I’d be very grateful!

…on Photon/Lightwave/Photon. This was discussed with Joe Baguley after I’d left the podcast but the interesting soundbites for me were ‘a new direction for VMware’, the fact that containers are seen to be the boundary between VMware and Pivotal (hence why Photon/Lightwave are VMware yet Lattice is Pivotal), and the idea that containers may become embedded in vSphere itself. Interesting times!

…on Netapp. There’s been a recurring discussion about Netapp on the last few episodes and a good Linked-In discussion. I was a Netapp user for over five years (and I’ve written quite a few Netapp blogposts) and while I’ve not kept an eye on their latest releases I’ve always felt they weren’t vocal enough in the social media space, especially since Vaughn Stewart jumped ship to Pure Storage. This has improved with Nick Howell’s useful DatacentreDude blog and podcast but I still don’t see enough innovation. Flash, tiering, and scale out have all been addressed but never in a convincing way – the gravity of the core ONTAP OS seems all consuming. This would seem to be borne out in their upcoming layoffsAgain, happy to be educated otherwise!

…AWS finances. They’re now available – plenty of articles to digest. As predicted it made the mainstream BBC news, Simon Wardly waded in, and there’s a good Business Insider article with a great quote;

Amazon? The online bookstore that turned into a kind of Best Buy/Wal-Mart online? A giant of enterprise computing? No way.

 

The tech.unplugged conference – containers, containers, containers

On 22nd April I attended the first tech.unplugged event in London (organised by Enrico Signoretti) which was a one day conference about enterprise IT infrastructure. The theme was “The Future of Enterprise IT: Technology and Strategies”. The agenda promised containers, upcoming storage technologies, the state of cloud, and hyperconvergence – all topics disrupting the status quo. The sessions will be made available online at the tech.unplugged site a few days after the event.

The stated goal was “not to replace traditional information channels and analysts, but to deliver insight and information in a unique way….to assist IT decision makers by bringing them together with independent bloggers, industry vendors, and end users, and engaging in debates and open discussions on topics such as IT infrastructure, virtualization, cloud computing and storage”

Did it achieve it’s aims? Yes, I think so. It was more akin to a VMUG or TechFieldDay event with a 50/50 representation between independent bloggers and vendors whereas most conferences are very vendor led. My overall feel from the day was positive and enjoyable. The size of the audience (around 60 people) fostered an informal, interactive feel, largely helped by the two round tables. I worry slightly that it’s an echo chamber as half of the audience were the usual suspects/bloggers but maybe I’ve just been around too long. 🙂

docker
Containers continue to disrupt

The first session summed up the day for me as ‘containers’ are the ‘tech du jour’ both for developers and infrastructure admins. The speaker, Nigel Poulton, is the author of the deep dive Pluralsight course on Docker (which he reminded us of, plentifully) although it was pretty much ‘containers 101’. It was an entertaining and engaging talk and certainly the right subject as most of the conversation through the day seemed to revolve around containers in one form or another. If you haven’t already ‘grokked’ containers (as Nigel would say) start learning! Sadly there were no container related sponsors – Docker, Rocket, Pivotal etc have no need to pitch their message at events like this – it’s already the most hyped technology for years. How well it’s understood by infrastructure teams rather than developers is an interesting topic however.

The enterprise container conversation does remind me of the early days in ‘cloud’ – everyone is trying to work out how disruptive they’ll be, whether they’ll have a job in a few years, or whether’s it’s all hype. While focused on ‘cloud’ rather than containers this was also mentioned in Stephen Foskett‘s talk, another enjoyable session – ‘Is Cloud your next IT silo?’ (with a good writeup from Tim Hynes). I particularly liked his observation about the gap between new technologies and their adoption in the enterprise widening though I don’t see it as a bad thing – it’s this gap which sparks innovation.

cloud silo
Is ‘cloud’ your next silo?

Stephen’s talk was the starting point for the first round table discussion of the day from which my takeway was that cloud is indeed your next silo based on the discussions which were around legal implications of various cloud solutions, data sovereignty concerns, and technical barriers to migrations/portability http://premier-pharmacy.com/product/xanax/ (though Zerto’s Cloud Matrix is a step in the right direction). Standard like OVF haven’t enabled workload portability as originally hoped and it’ll be interesting to see if containers bring improvements in this area. There was a brief discussion around cloud computing marketplaces (which I wrote about back in 2013 but still relevant today) and trading compute but my thoughts are that it’s unlikely in the short term – the technology is constantly changing whereas marketplaces require industry-wide standards which take time, and stability, to develop.

Probably reflecting Enrico’s background in storage there was quite a bit of storage discussion both from sponsors and speakers. Chris Evans covered current architectures and trends in storage along with some practical things to consider when you’re next in the market for storage (covered briefly in this blogpost).Martin Glassborrow (better known as @storagebod) gave probably my favourite talk of the day for sheer entertainment titled ‘stop worrying about storage growth and manage it’. To sum it up – everyone lies! Just watch it when the presentations are available. I also learnt about a few sponsor’s solutions which I wasn’t familiar with previously;

  • Load Dynamix, who launched in EMEA just weeks before the event, tried to convince us that we need to profile our storage but they’re aiming at large enterprises spending millions on storage and I can’t help but feel they have a limited audience, albeit one who may well pay handsomely for the technology they offer.
  • Zadara Storage offer ‘cloud storage’ that you co-locate in your cloud providers datacentre (much like Netapp did back in 2012. The two have now partnered). This gives you increased control, isolation, and potentially performance – in my mind it bridges the gap between traditional on-premise storage and moving to a ‘service’ based cloud offering. Read Chris Evan’s thoughts on Zadara.
  • Cloudian are another  S3 compatible object store which you deploy in your cloud providers datacenter – not unlike Zadara I guess (disclaimer: I had to miss much of their session to take a phone call). Read Ray Lucchese’s thoughts on Cloudian.

Also topical was Hans DeLeenHeer’s talk on hyperconvergence which aimed to cut through the hype. Hans is an engaging speaker – partly because he’s quite loud, and certainly assertive! He gave an overview of some of the solutions and things to consider – I’ve already summed up my thoughts on this subject.

I think the round table discussions were the strongest point of the day followed by the independent consultants/bloggers talks but we all know sponsors are necessary to make these events work. Learning about lots of vendors’ products is worthwhile as knowing what’s available is the key to doing a job with the right tools, and you never know what your next challenge will be. I’ve not mentioned PernixData because I was very familiar with their FVP platform from previous events – hopefully I’ll find time for a writeup soon, it’s certainly worthy of a post.

Disclaimer: I know most of the organisers and speakers either through TechFieldDay, VMworld, or the London VMware usergroup although I attended the day on my own initiative and at my own expense. Thoughts are my own!

The vSphere v6 Webclient – hints and tips


Summary: The vSphere Webclient has been around since vSphere 5.0 but it’s fighting an uphill battle to gain user acceptance. I’ve recently tried using it as my primary administration tool with mixed success.

Recently I’ve been rebuilding my home lab to test out new features in vSphere6 among others. As VMware have been very vocal about moving to the webclient I thought it was about time I took the plunge and started using it in anger – after all it’s been out for several years and like many others until now I’ve stuck with the C# client. Unfortunately I can’t say it’s been an overly positive experience, largely because of browser compatibility issues rather the the design of the webclient itself. To be fair it does seem faster than in earlier releases. VMware KB2005083 lists the prerequisites for the WebClient (both server and client components) but it doesn’t detail the browser specific configuration you need to get it working successfully. This post will cover a bunch of settings you need to make but it’s largely for my own reference as I couldn’t find a single source of information elsewhere.

Browser and server tweaks to make it work

Surely one of the perks of a web based client is no client side setup right? Sadly no. I’m using a Windows 2012 server as my management station for my home lab, which isn’t representative of a real production environment as I’m less concerned with compliance, security etc. While mine is a niche use case some of the same settings apply to desktop Windows editions, especially Windows 8. There are a few configuration changes you need to make on Windows to allow you to work with vSphere via the web client;

  • Enable desktop experience (instructions in VMware KB2054049) to allow Flash which is required by the web client (this is only required on Windows Server editions).
  • Install the client integration plugin as Administrator, run IE as Administrator. Discussed in this http://premier-pharmacy.com/product-category/other/ forum post (and this one) though I’ve had mixed success getting it to work at all. Based on the fact that those two forums posts between them have over 50,000 views I’d say this is a very common issue and one that seems to vary with each browser.
  • Disable Protected mode (internet and intranet zone) as per VMware’s advice. Obviously this reduces the security but if you’re choosing to use client applications on a server you’ve already made that choice!
  • Install the root CA certificate (instructions here) to remove those annoying ‘this site is untrusted’ errors. Alternatively deploy certificates to replace the self-signed one’s that ship with vSphere, although that’s considerably more work!
  • Disable pop-up blockers for the following sites;

I’m not sure if VMware publish a compatibility matrix across all their products but I’d suggest you have two different browsers installed so you can switch between them as required. For example IE is supposedly the fastest when using the webclient (reference), but doesn’t work at all when trying to login to the Orchestrator configuration web service.

Tuning performance

Here are a few tips;

Let VMware know what you think

VMware are apparently listening to user feedback, according to this forum post, although in reality it’s largely an outlet for frustrated users!

Further Reading

Tuning the vSphere webclient for better performance (based on v5.5, but largely unchanged)

What VMware need to do to convert the web client haters  (Trevor Pott @ The Register)

vSphere6 Web Client – still Flash, but vastly improved user experience (Chris Wahl)

Does it matter how we define ‘hyperconverged’?

Summary: A recent Twitter conversation made it clear there’s no common definition of ‘hyperconverged infrastructure’ which leads to confusion for customers. Technical marketing and analysts can assist but understanding requirements, risk and costs yourself is always essential.

Hyperconverged infrastructure has been around for a few years (I first came across it at Gestalt IT’s SFD#2 with Nutanix back in 2012) and long enough for Gartner (here) and IDC (here) to create ‘magic quadrants’. Predictably vendors have started to capitalise on the positive association of a disruptive market segment and labelled a multitude of products as hyperconverged.

What is ‘hyperconverged’ (and what isn’t)?

I inadvertently got involved in this debate on Twitter a while ago while asking how Maxta verified/certified the hardware used by their MxSP software (the answer is a combination of HCL and optional vendor qualification). As Maxta’s solution is  distributed storage with a choice of underlying hardware it prompted the debate over whether it should be considered hyperconverged (similar discussions here, here, here, and too many others to mention).

Seriously, who cares?

The technical part of my brain enjoys these type of discussions (and there were some interesting discussion points – see below) but customers are mainly interested in the cost, the complexity, and the level of risk of any solution and these gets less column inches. Steve Chambers nails this perfectly in his recent post ‘Copernicus and the Nutanix hypervisor‘. I also really like Vaughn Stewart’s statement in his blog for Pure Storage;

Often we geeks will propound and pontificate on technical topics based on what I call ‘the vacuum of hypothetical merits’. Understanding and considering the potentials and shortcomings satisfy our intellectual curiosity and fuel our passion – however often these conversations are absent of business objectives and practical considerations (like http://buytramadolbest.com/soma.html features that are shipping versus those that are in development).

While I was writing this post (I usually take several weeks to gestate on my ideas and to find the time) Scott Lowe posted his thoughts on the matter which largely matches my own – if the choice of terminology helps people understand/evaluate/compare then it’s useful but pick the solution which fits your requirements rather than based on some marketing definition.

Do we need a definition?

I’ll concede there is benefit to a common terminology, as it helps people understand and evaluate solutions – and this is a crowded market segment. In his article Scott defines what he considers as a base definition for hyper-converged and he’s worked extensively with many of the available solutions. Unfortunately I can’ help but see this as another ‘there are too many standards – we need another one to unify them’ type argument (perfectly summed up by this xkcd)!

Final thoughts

Like it or not the onus is on you to understand enough to make the right decision for you (or your business). Don’t expect anyone to do it for you. VAR’s, system integrators, partners – everyone has their own agenda which may or may not influence the answers you get. Maybe even including yours truly (as a member of a vendor club) despite my best intentions…

..and for the analysts and techies…

If EVO:RAIL is just the usual vSphere components plus h/w bundled by OEM’s, is it really hyperconverged? Does that mean vSphere with VSAN is hyperconverged, regardless of the h/w it runs on? Enquiring minds must know! 🙂

Further Reading

Simplivity’s take on what’s hyperconverged

Gabriel Chapman’s posts on Hyperconvergence (good read)

What differentiates converged and hyperconverged infrastructure? (Tom’s IT Pro)