
That WoW server blade - facorreia
http://augustl.com/blog/2014/that_wow_server_blade/
======
ChuckMcM
Wow, the memories and the pain. Its weird because I spent enough time in
Azeroth that I think of it as a 'place' and as a place with fond memories that
I cannot go back to as Blizzard has moved on, its oddly painful for me. It was
the only game where the social aspects were as fun, or sometimes more fun,
than the game play.

That said, I worked at NetApp when WoW first released and their architecture
at the time was these blade servers talking to oracle database instances that
were using EMC SAN boxes for storage. We tried to convince them they would
have less down time if they converted to Oracle over NFS as Oracle had done in
their big data center in Texas.

As an engineer it started me thinking about the whole 'world as a database
transaction' sort of model of things. How that got built, where did latency
matter, where did it not? What could you un-do and what had to be at-most-
once. And then the scale of that with respect to localizing transactions when
actors (characters) were within scoping distance of database changes. Quite
the interesting challenge.

Oh and the 'weird custom board' on that blade is a compact flash to IDE
adapter. The blades booted from compact flash.

EDIT: Hmm, not CF adapter, going back and looking again I think that was the
NVRAM card which allowed them to recover transaactions after a server crash.

~~~
moogleii
Moved on how? I haven't really played except for the original beta, so I
haven't been following WoW news much.

~~~
crusso
Regarding the social aspects, they've made the game so accessible to casual
players that they've eliminated the need to form strong social bonds for 99%
of the content that people play.

You can level pretty quickly just by soloing, so you don't need to find a
buddy to help. With the Dungeon and Raid Finders, you don't even need to join
a guild or have a set of regular friends for tackling harder content.

With the battleground queues, you don't need friends to participate in PVP.

Unless you want to attempt the harder versions of the same Raid content or try
to compete more rigorously at PVP, all of the classic reasons to meet and keep
friends in WoW are gone.

~~~
moogleii
Very interesting. There's "raging" debate over in some Destiny threads (which
shares some MMO traits) regarding the lack of matchmaking for certain raids
(the designers require you to form up your own band of friends, because it's
intended to be a difficult challenge that a random lot could probably not take
on) and whether or not things should be accessible to all or tailored for a
more dedicated few. I saw several comparisons to how WoW had watered the
experience down, and now I know more. Thanks!

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Daneel_
I've worked extensively with HP equipment. I've just sent August an email with
a _ton_ of extra detail about this blade.

The 'weird custom card' mentioned in ChuckMcM's comment is actually a
SmartArray 6i raid controller. The black slot is to put a small stick of ram
into to act as cache.

Happy to answer any and all questions about the server :)

Out of interest, there are two CPUs in this server, and they're both an AMD
Opteron 275 (2.2 GHz, dual core). The 512MB Hynix ram sticks would have come
from the factory, while the 2GB micron sticks would have been an upgrade.

~~~
ChikkaChiChi
Thank you for reaching out and helping to complete the story of this box.

Maybe someone from Blizz can even tell them what the server's role was...

~~~
Daneel_
Posting the email I sent:

I saw your blog post about your WoW blade, via Hacker News, and couldn't help
but want to contribute.

I have worked as a sysadmin and hardware specialist for the past 5-6 years,
with a lot of experience with HP equipment - I was wondering if you'd like me
to help provide better descriptions of any of the parts of your blade? Extra
detail like the fact that Hynix ram came in the machine from the factory, but
the micron ram was added as an upgrade. Your machine probably only ever had
those 6 sticks in it, as the next generation of servers used newer DDR2 and
wasn't compatible (hence no reason to remove ram from this blade). That blade
is what is called a 'half-height blade and it would have sat vertically in a
Blade Enclosure, ie, the HPBL25p text would be horizontal. Blade enclosures
usually hold up to 16 half-height blades, or 8 full height blades, but yours
is a p-class blade, so it would have been in an enclosure for half-height
blades only (8 blades max). The network ports and all other connections are on
the blade enclosure. If you'd like a full spec sheet on your blade and the
enclosure, you can look at this PDF from HP:
[http://h10010.www1.hp.com/wwpc/images/ap/BL25p_v7.pdf](http://h10010.www1.hp.com/wwpc/images/ap/BL25p_v7.pdf)

Regarding your concerns about the CPUs and heatsink paste, etc: The CPUs will
actually be attached to the heatsinks and you should simply be able to lift
them out as a unit. This is done so that if a CPU were to fail in the blade
you can replace the CPU in just a few minutes. The detail of which CPU you
have is more than likely attached to the underside of the heatsink as well,
next to the processor, but you can actually tell which one you have from the
model number (that sticker that says 392439-B21). It's an HP ProLiant BL25p
275 2.2GHz-1MB Dual Core 2P 2GB Blade Server. This means your CPUs are AMD
Opteron 275s, and you have two of them. The '5' in BL25p also indicates an AMD
CPU. Intel servers end in a zero.

I can also tell you what most of the bits of hardware on the motherboard do
too, if you like.. I'm happy to annotate photos. The large green card towards
the rear of the server with the little silver heatsink and the empty black
slot is the hard drive controller. In this server the model would be a
SmartArray 6i. The slot is for a small stick of RAM (128MB for this model)
that the controller would have used for cache - it probably never had any
installed though.

As general information: the little 'add in cards' are called daughter-boards,
and are actually completely normal in servers, especially of this size,
partially due to space constraints. The main reason for daughter boards though
is so you can quickly and easily replace a failed component. Servers are
generally designed to be easily and quickly serviceable. I've personally
replaced a server motherboard in under 10 minutes (from power off to power
back on again). It's generally all tool-less and extremely modular.

The clear magnetised lid on these server is definitely not standard - Blizzard
must have added this when they decided to memorialise the server. The standard
lid would be metal and held on with a quick-release lever mechanism.. I really
like the magnetised approach though :)

I can keep going on, but yeah, let me know if you'd like any information or
more insight into the server. Glad to see that it's in the hands of someone
who obviously cares about the equipment though :) it's nice that they made
them into a collectible rather than just selling them to a used equipment
vendor.

------
mahouse
I would really like to know the software architecture of a WoW realm. (Beyond
the basics of... one blade for each continent).

OS, tools, programming languages, how did the different parts of the software
(such as, again, continents) communicate between themselves... For example, I
was told once dungeons and raids were/are scripted in Lua.

~~~
valarauca1
>Beyond the basics of... one blade for each continent).

On launch there was 2 continents, but 4 server blades per _server_.

Scripted events take place in Lua. But most raids until I believe Cataclysm
weren't scripted so much as it was just mob abilities + cool downs.

Note: Not a wow server architect just played _way_ to much WoW

~~~
mahouse
These things I know. WoW server reimplementations are pretty monolithic and
that causes a lot of problems on heavy loads. I know of a private server
that's working on having some "load balancing" to avoid that.

What I mean by this is that currently the only way to have lots of players
playing at once in the same realm is to buy very expensive hardware. That plus
the amount of DoS attacks you receive if you are popular means that having a
private WoW server online is anything but cheap.

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kevinoconnor7
Oh man, my first year of college I was in a freshman seminar and idly bid on
one of these with a fairly low offer (~$200). Twenty minutes later I was the
proud owner of a WoW server.

My lack of foresight has led to it being stuck, still in the original shipping
box, in my parent's basement.

~~~
thehermit
I envy you greatly. When these were put on sale a freak snowstorm happened to
hit the northeast and me and everyone else around had no power for close to a
week. I was after one of the more populated servers (Kil'jaeden) and my phones
battery just didn't last long enough to get that final bid in. I still regret
not just putting in a higher bid earlier that day.

~~~
kevinoconnor7
I just found my winning bid e-mail: I got Quel'Thalas for $212.50 on
2011-10-24. I remember that freak Halloween snow storm.. somehow it managed to
avoid hitting me the capital region.

I'll probably sell the server at some point but I have no idea what a fair
price for it is. Perhaps I'll sell it using a double-blind auction.

------
dsl
[http://webcache.googleusercontent.com/search?q=cache:wWPD9Dl...](http://webcache.googleusercontent.com/search?q=cache:wWPD9DlVIJAJ:augustl.com/blog/2014/that_wow_server_blade/+&cd=1&hl=en&ct=clnk&gl=us)

~~~
augustl
Out of curiosity, do you remember how long my blog was down? Linode reports
100% uptime and no monitoring show traces of congestion.

------
jokoon
I still wonder about how many players those servers could hold, and what about
other MMO games networking architecture ? For examples I know that in guild
wars, once you get out of town, you don't see other players. In wow they also
merged many zones so they are "cross realm".

How does EVE online work by the way ?

I'm fascinated by this stuff. I wish there was an unique realm MMO game like
wow.

I guess EVEO is unique level.

I'd love to see a game using more p2p architectures to enable small parties to
offload servers.

~~~
chillacy
Patrick Wyatt (worked at blizzard on WC, starcraft, battle.net, then on guild
wars) blogged a bit about the design of some of these games:
[http://www.codeofhonor.com/blog/scaling-guild-wars-for-
massi...](http://www.codeofhonor.com/blog/scaling-guild-wars-for-massive-
concurrency)

Worth a read

~~~
scrollaway
Less tech-oriented and more design-oriented, Alexander Brazie has blogged a
lot about various design decisions he and his team made at the time in WoW.

[https://alexanderbrazie.blogspot.co.uk](https://alexanderbrazie.blogspot.co.uk)

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guard-of-terra
What's the definition of a blade? I thought it was a diskless server but this
one used to have a hard drive.

~~~
incision
_> 'What's the definition of a blade?'_

I'm not sure there's any hard and fast definition.

Generally, a blade is going to share power at least, likely network uplinks as
well. Diskless configurations are common, with some sort of shared storage
being used, but local disk is finding its way back into blades via SSD.

------
oconnor0
4 blades to run an entire realm? That's more impressive than I thought.

~~~
stavrus
That was probably the case back in vanilla (pre-expansion) WoW. With the
introduction of cross-realm battlegrounds in 1.12 - a month before the first
expansion - followed by the activation of arenas in the first expansion, they
most likely considerably expanded their server capacity to accommodate for the
increased load. I remember seeing news articles back in the day just a few
months before Burning Crusade's launch that Blizzard had bought a massive
amount of servers, but the only thing I can find now is this blog post:
[http://www.rahulsood.com/2006/02/blizzard-going-crazy-for-
op...](http://www.rahulsood.com/2006/02/blizzard-going-crazy-for-opteron.html)

However, it's important to note that around this time Blizzard was heavily
improving their Battle.NET service and launched a download service where you
could register your CD keys from their previous games such as Starcraft and
Warcraft III and download a fully working ISO that did not require the
physical CD to run. The server purchases may have gone towards that instead.

Would love it if Blizzard wasn't so secretive about everything, especially
their tech. CCP, makers of Eve Online, have been very forthcoming in talking
about their entire stack in their developer blogs and videos - from
infrastructure and hardware, to how they profile their code and the software
design choices they make.

~~~
crazypyro
The market for private WoW servers in the past has been a major concern for
Blizzard and I'd imagine has been a large motivator in their decision to
closely guard their infrastructure design.

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ymeshesha
Does anyone know when exactly they changed their specs?

