Re: [9fans] FileServer grid
* Giacomo Tesio giac...@tesio.it wrote: Hi, I'd like to move our softwares to Linux + Apache (where mounting a 9p fileserver would be easy), but actually it's a Windows + IIS. my serious condolescense ;-) But what if a node of the grid goes down? There would be a way to keep files in it replicated in other cpu node? I'm not a Plan9 expert, but I dont know if there's already a (working) really distributed filesystem on Plan9. You can run multiple fossil instances from different machines in the them venti, but the venti itself isnt distributed, neither can the fossils directly synchronize, IMHO. Actually, I'm working on something like that: A) an distribute version of venti (not really venti, but the same idea, and hopefully compatible w/ it ;-o) - it not just stores blocks locally, but can also ask its peers for blocks and push own blocks to them (there will also be some TTL or GC mechanism to kick off stale data). B) an distributed filesystem which stores all data in venti and just synchronizes the head pointers (root dirs or heavily changing files) directly with its neighbours. (venti nodes and fileservers could also sit on different machines) There's nothing usable yet, but perhaps you'd like to join ? cu -- - Enrico Weigelt== metux IT service - http://www.metux.de/ - Please visit the OpenSource QM Taskforce: http://wiki.metux.de/public/OpenSource_QM_Taskforce Patches / Fixes for a lot dozens of packages in dozens of versions: http://patches.metux.de/ -
Re: [9fans] FileServer grid
So far it seems that there are no ready-made 9P-based solutions available for what you have in mind. At least I don't know of any. In any solution available there are costs to pay (economical or temporary ones). So I could write the code missinig, if the time required to write the filesystem sincronization and the session state handler would be a month. For more than a month the economical cost would be (more or less) equal to the prebuild solutions in the market. For writing the session state handler over 9P I estimate a week... If a sincronization system for the grid nodes (or a sintetic filesystem providing access to the grid and replicating writes among node) would require more than 3 weeks of man work probably I've no chance to get this solution approved. Thanks, Roman. Thanks you! Giacomo
Re: [9fans] FileServer grid
On Tue, Feb 10, 2009 at 12:06 AM, Giacomo Tesio giac...@tesio.it wrote: If a sincronization system for the grid nodes (or a sintetic filesystem providing access to the grid and replicating writes among node) would require more than 3 weeks of man work probably I've no chance to get this solution approved. 3 weeks? I think you have a problem here. Stop now. This is a non trivial problem. At least from what I know. ron
Re: [9fans] FileServer grid
is it too much for a syntetic filesystem 9P based? or too few? On Tue, Feb 10, 2009 at 5:37 PM, ron minnich rminn...@gmail.com wrote: On Tue, Feb 10, 2009 at 12:06 AM, Giacomo Tesio giac...@tesio.it wrote: If a sincronization system for the grid nodes (or a sintetic filesystem providing access to the grid and replicating writes among node) would require more than 3 weeks of man work probably I've no chance to get this solution approved. 3 weeks? I think you have a problem here. Stop now. This is a non trivial problem. At least from what I know. ron
Re: [9fans] FileServer grid
On Tue, 2009-02-10 at 09:06 +0100, Giacomo Tesio wrote: So far it seems that there are no ready-made 9P-based solutions available for what you have in mind. At least I don't know of any. In any solution available there are costs to pay (economical or temporary ones). On the side of existing tools/solutions you may find this one interesting: http://www.ultramonkey.org/ Thanks, Roman.
Re: [9fans] FileServer grid
starting with something like /sys/src/cmd/nfs.c or ramfs.c and a setup like this: mount /stuff /n/node0 import node1 /stuff /n/node1 import node2 /stuff /n/node2 fscreate and fsopen would create or open /n/node[012]/file and fswrite would write to /n/node[012]/file. a good developer (not necessarily a superstar) could write it in a week. but this assumption -- that this would work better than if all the nodes accessed a reliable file server -- is wrong. is it too much for a syntetic filesystem 9P based? or too few? On Tue, Feb 10, 2009 at 5:37 PM, ron minnich rminn...@gmail.com wrote: On Tue, Feb 10, 2009 at 12:06 AM, Giacomo Tesio giac...@tesio.it wrote: If a sincronization system for the grid nodes (or a sintetic filesystem providing access to the grid and replicating writes among node) would require more than 3 weeks of man work probably I've no chance to get this solution approved. 3 weeks? I think you have a problem here. Stop now. This is a non trivial problem. At least from what I know. ron
Re: [9fans] FileServer grid
Have you done a literature search? I don't get the feeling that you have. You are right, I searched over the net only about Plan 9 filesystem replication and so... But I was always searching for a plan 9 based solution. I already have some alternative solution (linux based), but I would like to use plan 9 in a prodution environment (to emancipate it to my collegue eyes...) Thanks ron Thanks you too! I will get a look to your suggestions! Giacomo
Re: [9fans] FileServer grid
On Feb 7, 2009, at 9:32 AM, Giacomo Tesio wrote: I'd like to move our softwares to Linux + Apache (where mounting a 9p fileserver would be easy), but actually it's a Windows + IIS. I would write a session state service for ASP.NET connecting it in 9p (using c# and the 9pc implementation linked by http://9p.cat-v.org/implementations ... actually the link is broken...) I see. Well, these are the things I have no personal experience with. Hopefully, somebody else on this alias can help you. If the filesystem grid work as I've understood, there would be only ONE filesystem. So, saving session state in the grid would make it available to all web servers connected to the filesystem, allowing load balance and high availability for the web servers (when one crash, the user sessions it was handling would be available to the others web server). So far it seems that there are no ready-made 9P-based solutions available for what you have in mind. At least I don't know of any. Thanks, Roman.
Re: [9fans] FileServer grid
Sorry Uriel... I was meaning that I wouldn't be able to download it. BTW my main problem is to know if, in a grid of plan 9 fileservers, there could be any kind of replication, keeping files reachable when a node goes down. Giacomo On Sat, Feb 7, 2009 at 11:57 PM, Uriel urie...@gmail.com wrote: The link is *not* broken, plan9.bell-labs.com is, sadly and unsurprisingly, broken. uriel On Sat, Feb 7, 2009 at 6:32 PM, Giacomo Tesio giac...@tesio.it wrote: I'd like to move our softwares to Linux + Apache (where mounting a 9p fileserver would be easy), but actually it's a Windows + IIS. I would write a session state service for ASP.NET connecting it in 9p (using c# and the 9pc implementation linked by http://9p.cat-v.org/implementations... actually the link is broken...) If the filesystem grid work as I've understood, there would be only ONE filesystem. So, saving session state in the grid would make it available to all web servers connected to the filesystem, allowing load balance and high availability for the web servers (when one crash, the user sessions it was handling would be available to the others web server). But what if a node of the grid goes down? There would be a way to keep files in it replicated in other cpu node? Giacomo On Fri, Feb 6, 2009 at 11:41 PM, Roman V. Shaposhnik r...@sun.com wrote: On Fri, 2009-02-06 at 23:26 +0100, Giacomo Tesio wrote: Hello every one... In a context of really heavy load and high availability needs, I'm evaluating plan 9 to implement a fileserver grid to be used by a web server for temporary storage (session's serializations, for example). What OS do you web servers run under? I'd like to build a Plan 9 grid exposing a unique filesystem mounted by all the web servers. Are you going to talk to this filesystem using 9P or something else? Each session could be accessible from any web server instantly, but what if a fileserver in the grid break? Is there a way to mantain such a session (actually the file storing the session data) available by keeping it sincronized beetween the Plan 9 fileservers? This is unclear. Please restate. Thanks, Roman.
Re: [9fans] FileServer grid
On Sun, Feb 8, 2009 at 7:24 AM, Giacomo Tesio giac...@tesio.it wrote: BTW my main problem is to know if, in a grid of plan 9 fileservers, there could be any kind of replication, keeping files reachable when a node goes down. This sort of thing was done to death IIRC in the 80s. It was dropped for a while because, at the scale of file server usage in the 90s, nfs file servers were fine. At least from what I read today, google does it now in GFS. There is an open source version of something that claims to do provide it based on Hadoop (http://hadoop.apache.org/core/) although the hadoop setups I have seen use NFS for distributing files (!). I vaguely remember gluster talking about failover and recovery (http://www.gluster.org/). Have you done a literature search? I don't get the feeling that you have. Thanks ron
Re: [9fans] FileServer grid
I'd like to move our softwares to Linux + Apache (where mounting a 9p fileserver would be easy), but actually it's a Windows + IIS. I would write a session state service for ASP.NET connecting it in 9p (using c# and the 9pc implementation linked by http://9p.cat-v.org/implementations... actually the link is broken...) If the filesystem grid work as I've understood, there would be only ONE filesystem. So, saving session state in the grid would make it available to all web servers connected to the filesystem, allowing load balance and high availability for the web servers (when one crash, the user sessions it was handling would be available to the others web server). But what if a node of the grid goes down? There would be a way to keep files in it replicated in other cpu node? Giacomo On Fri, Feb 6, 2009 at 11:41 PM, Roman V. Shaposhnik r...@sun.com wrote: On Fri, 2009-02-06 at 23:26 +0100, Giacomo Tesio wrote: Hello every one... In a context of really heavy load and high availability needs, I'm evaluating plan 9 to implement a fileserver grid to be used by a web server for temporary storage (session's serializations, for example). What OS do you web servers run under? I'd like to build a Plan 9 grid exposing a unique filesystem mounted by all the web servers. Are you going to talk to this filesystem using 9P or something else? Each session could be accessible from any web server instantly, but what if a fileserver in the grid break? Is there a way to mantain such a session (actually the file storing the session data) available by keeping it sincronized beetween the Plan 9 fileservers? This is unclear. Please restate. Thanks, Roman.
Re: [9fans] FileServer grid
It isn't http://plan9.bell-labs.com/sources/plan9/sys/src/ uriel On Sun, Feb 8, 2009 at 12:00 AM, erik quanstrom quans...@quanstro.net wrote: The link is *not* broken, plan9.bell-labs.com is, sadly and unsurprisingly, broken. this is incorrect. bell labs web site is working just fine. - erik
[9fans] FileServer grid
Hello every one... In a context of really heavy load and high availability needs, I'm evaluating plan 9 to implement a fileserver grid to be used by a web server for temporary storage (session's serializations, for example). I'd like to build a Plan 9 grid exposing a unique filesystem mounted by all the web servers. Each session could be accessible from any web server instantly, but what if a fileserver in the grid break? Is there a way to mantain such a session (actually the file storing the session data) available by keeping it sincronized beetween the Plan 9 fileservers? Hoping to have been clear... Thanks for your help Giacomo
Re: [9fans] FileServer grid
On Fri, 2009-02-06 at 23:26 +0100, Giacomo Tesio wrote: Hello every one... In a context of really heavy load and high availability needs, I'm evaluating plan 9 to implement a fileserver grid to be used by a web server for temporary storage (session's serializations, for example). What OS do you web servers run under? I'd like to build a Plan 9 grid exposing a unique filesystem mounted by all the web servers. Are you going to talk to this filesystem using 9P or something else? Each session could be accessible from any web server instantly, but what if a fileserver in the grid break? Is there a way to mantain such a session (actually the file storing the session data) available by keeping it sincronized beetween the Plan 9 fileservers? This is unclear. Please restate. Thanks, Roman.
Re: [9fans] FileServer grid
Hello every one... In a context of really heavy load and high availability needs, I'm evaluating plan 9 to implement a fileserver grid to be used by a web server for temporary storage (session's serializations, for example). I'd like to build a Plan 9 grid exposing a unique filesystem mounted by all the web servers. Each session could be accessible from any web server instantly, but what if a fileserver in the grid break? Is there a way to mantain such a session (actually the file storing the session data) available by keeping it sincronized beetween the Plan 9 fileservers? my 2ยข. before plan 9 got a shiny osi license, i did something like this on linux. since it was linux, the backend server took commands much like a scsi device does rather than use 9p. since there were no reasonable threading option in those days, it worked like a task-based operating system. we used select to schedule work. all state was written to disk so that the death of the server was not fatal. horrible, i know. but it worked reasonably well without declaring war on the system we needed to use. having two web servers would have been easy in this setup. having multiple back-end servers was not possible. but neither was ever a performance limitation for us so it remained unexplored. this is because all the work was pushed to a cluster of workers fronted by the backend server. they were always the limitation. at some level of throughput, this server would be a limitation. i would be suprised if the limitation would not be the speed of your network. since the amount of traffic this server sees should be much less than the amount of web traffic, one machine with a 10gbe card could move a lot of data. - erik
