Monday, July 25, 2011

Revit Server update

What a slacker! 2 months with no post, like I fell off a cliff. Well, I’ve been a bit busy especially trying to take care of some stuff I’ve been procrastinating on for a loooong time and it’s going to take a bit longer than anticipated. But enough excuses.

Our maverick Revit Server setup has been working quite good. Unfortunately we cannot get support since we’re not running on the required Windows Server 2008 / SP1 OS, but so far it seems to have been working perfectly fine. We did encounter some hitches that we were not quite sure what was causing them.

We’ve come to realize that our bandwidth was just not enough. Or at least that is the current indicator, especially based on some tests. Here’s what our setup looks like:

Central office: Bonded T1 with 3Mbps up and 3Mbps down

Remote office: DSL with up to 768Kbps up and up to 6Mbps down

Clearly the bottle-----neck is the remote office upload speed. The 768Kbps is not an absolute number (just like your 401(k)!). In our case we had some “traffic shaping” at the routers which allocated a certain percentage to VoIP and some other things, which meant that we barely had 200 to 300Kpbs for Revit Server uploads from the remote office to the central office. Here’s the conversion for reference (all this talk of bits and bytes is confusing for every-day users like myself):

1 Byte = 8 bits; 1 KB = 1,024 Bytes (8,192 bits)

Data transfer: 1 Kbps = 1,000 bits/sec

Data Storage: 1KB/s = 1,024 Bytes/sec (8,192 bits/sec)

So with our connection, the remote office was uploading to the central server at a familiar rate of 24.4 to 36.6 KB/s, which is probably too low (reminds me of dial-up downloads!). One of the issues we were having was with creating central files at the remote location: they kept failing, citing a “network failure”. However if we created them at the central office and then opened them at the remote location, everything ran just fine after the main copying was complete. Assuming we were getting 1Mbps, the upload from Central to Local server was happening at a familiar 122KB/s, which is a lot more acceptable. So it’s clear that you need to pay particular attention to your upload bandwidth. We temporarily disabled traffic shaping and were getting about 650Mbps (79.35KB/s) consistently from remote to central office. In theory this number could go up to 768Mbps (93.75KB/s) but it is unlikely you can get that throughput consistently, apart from the fact that you will also have other network traffic that will reduce this number. We have now finally been able to create moderately sized central files at the remote location. Increasing bandwidth will probably cure the failures but we have to assess what the cost implications are at this point. It is also noteworthy that round-trip ping times from each location are around 85ms. This seems to be a consistent baseline in our case but we have also seen it fluctuate pretty high. I think these fluctuations could also account for the network failures.

Autodesk has just released 3 documents which you really need to read before deploying Revit Server. They will help tremendously in planning your hardware costs and bandwidth requirements. You can download them from HERE.



Robert said...

You said three documents? But the link only takes me to one PDF? Where is this released on I searched Autodesk, Wikihelp and Subscription.

Dave Baldacchino said...

Hi Robert, sorry somehow I had the wrong link. I corrected it now (on wikihelp).

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