Limiting access to drives.

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blackgoth
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Limiting access to drives.

Post by blackgoth » 2006-04-22 08:20

Okay, I might have missed this one in the search, sorry if i did.

Would it be possible to limit the ammount of connections per harddrive? on our local network there is dchub and if 3 or more clients connect to 1 drive to download the speed drops to <400KB/s(server is 1000Mbit linked and capable of transferring at 60MB/s+) and wont speed up untill the downloads are completed.
Hope to hear soon.

Blackgoth

GargoyleMT
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Post by GargoyleMT » 2006-04-23 11:26

So if you're already uploading one file from that drive, and a second user requests a second one (either as their first file that connection, or after downloading a file on another drive), what happens?

I think you want to return an error to that user. But in that case, I think it makes more sense to limit your upload slots instead of limiting the number of files open for a particular drive. Plus, your configuration is unique enough that I haven't heard of it before -- this feature would be just for you.

blackgoth
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Post by blackgoth » 2006-04-24 02:56

GargoyleMT wrote:So if you're already uploading one file from that drive, and a second user requests a second one (either as their first file that connection, or after downloading a file on another drive), what happens?

If 2 users or more start downloading from 1 disk the speed drops, if it was just a bit it would be fine, but mostly to <800KB/s witch isnt fine.
GargoyleMT wrote:I think you want to return an error to that user. But in that case, I think it makes more sense to limit your upload slots instead of limiting the number of files open for a particular drive. Plus, your configuration is unique enough that I haven't heard of it before -- this feature would be just for you.

I want something like the limited upload slots, but then for the drives. Even if i limit it to 10 upload slots sometimes they all need files on that drive. And its not just me, there are thousands more, mostly used on LAN party's.

GargoyleMT
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Post by GargoyleMT » 2006-04-24 18:30

blackgoth wrote:And its not just me, there are thousands more

Well, that's why the official feature tracker has a voting feature, to gauge relative popularity of features.

(You're the only one I rememember asking since I got involved in 2002.)

Quindor
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I might have to disagree

Post by Quindor » 2006-04-26 17:23

I might have to disagree that this feature is one of the least wanted one's. I often go to a lanparty and own a server of 2.5TB of demo and other popular material...

At such lanparties, it is commen to have a large DChub setup with manny manny people on it. We've had local lan hubs of 100TB and bigger... so it's a widely used method of distributing what you have to offer.

My server is a Dual Xeon 3.0Ghz EMT64, 2.5GB memory and with 10 physical disks. No raid, etc.

Now this setup is faster then any RAID setup, etc. because it has the most chance of a user being on a disk by itself and not being bothered by other transfers that might be going on on other disks. With a multiuser enviroment of people downloading many big files, RAID only tends to slow things down in the end. This is because you are losing potential spindel speeds, anyway, whole different discussion.

So a feature that would make it possible to set a maximum ammount of users per phsyical volume would actually be a good thing, thinking of that, this would be considering any setup that you might have.

Myself, 8 of my 10 disks have NCQ. Thus best performance is often achieved with 3 or 4 users. Without it though, performance is horribly slow, for all of them, making all the transfers slower in the end, if they'd wait for eachother to finnish up, all together they would be quicker.

So my vote is definately a yes to develop the feature. It would be greatly appreciated by my and many of my fellow lanparty visitors.

lordadmira
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Post by lordadmira » 2006-04-26 23:14

I think it would be useful to restate the problem. This is a situation where the network speed is vastly outstripping the IO bus speed. This leads to drive thrashing. So the solution is the same as the solution to every other drive thrashing problem. Serialize access to the drive. This can be accomplished by creating a new Experts setting to set the read buffer size. Then all u have to do is set it to a really large value. I seem to remember requesting a read buffer setting a long time ago. If DC is not currently blocking on concurrent disk reads it should be reletively easy to implement with a lock variable or semaphore.

LA
Anata ga baka da! Repent!

FormatFTP
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Post by FormatFTP » 2006-04-27 14:51

I have to agree with blackgoth and Quindor. I have the same system as Quindor (less CPU and mem, but ok). I also have a +2TB system with 9 harddisks.

The last lanparty I went to was a drama for one of my harddisks. I had like 8-9 people downloading from that disk what caused a dramatic decrease in speed. People were downloading with 300-600KB/sec!

Ok it's a Western Digital 250GB 8MB disk without NCQ, but still. I truly support this proposal as it would solve alot of trouble for many people (specially the hosters).

HappyTheMan
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Post by HappyTheMan » 2006-09-12 00:57

On the dcpp.net site the firt sentence is
"DC++ announces the freedom to share! Direct Connect allows you to share files over the Internet" It is not made to upload on lan nework.

ullner
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Post by ullner » 2006-09-12 04:37

It's not meant to be literally...

PseudonympH
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Post by PseudonympH » 2006-09-12 16:53

Often, LANs are connected to the greater internet and therefore constitute a part of it. Most college campus networks, for example.

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