Re: Apache clustering w/ load balancing and failover
Why not using 'roundrobin' ??? Install a couple of Web-Servers, give each Server an IP and then setup for each Server a A-Record on your DNS-Server pointing to the same hostname. The problem with round robin is that when one server fails over it keeps sending them connections, I once saw a DNS server implemented in Perl which worked in a round robin fashion but making some kind of test to know if the server was up and running correctly, I remeber it was called something like lb-named Mario. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
RE: Apache clustering w/ load balancing and failover
Mathieu Martin wrote: Mario Lopez wrote: Why not using 'roundrobin' ??? Install a couple of Web-Servers, give each Server an IP and then setup for each Server a A-Record on your DNS-Server pointing to the same hostname. The problem with round robin is that when one server fails over it keeps sending them connections, I once saw a DNS server implemented in Perl which worked in a round robin fashion but making some kind of test to know if the server was up and running correctly, I remeber it was called something like lb-named Mario. Why not use (keepalived?) with round robin dns then?. You get load balancing, redundancy, and you don't need unnecessary additionnal servers or kernel patches or whatever. Even with a lot of servers, it should scale pretty well. Works too with servers in several locations on different internet pipes, as long as there are at least two servers on each pipe for redundancy. You're wrong. round robin dns isn't HA, isn't load balancing, it's just request spreading. You can't control how many (DNS-)clients cache one of the RR IP's, therefore you won't get even load on your RR'ed servers. Plus you _have_ to use a tool like lb-named to keep your round robin dns from giving out the IP of a failed server. It really comes down to using LVS+(keepalived|heartbeat|...) or pen. Thomas -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
Thomas Lamy wrote: Mathieu Martin wrote: Mario Lopez wrote: Why not using 'roundrobin' ??? Install a couple of Web-Servers, give each Server an IP and then setup for each Server a A-Record on your DNS-Server pointing to the same hostname. The problem with round robin is that when one server fails over it keeps sending them connections, I once saw a DNS server implemented in Perl which worked in a round robin fashion but making some kind of test to know if the server was up and running correctly, I remeber it was called something like lb-named Mario. Why not use (keepalived?) with round robin dns then?. You get load balancing, redundancy, and you don't need unnecessary additionnal servers or kernel patches or whatever. Even with a lot of servers, it should scale pretty well. Works too with servers in several locations on different internet pipes, as long as there are at least two servers on each pipe for redundancy. You're wrong. round robin dns isn't HA, isn't load balancing, it's just request spreading. You can't control how many (DNS-)clients cache one of the RR IP's, therefore you won't get even load on your RR'ed servers. Plus you _have_ to use a tool like lb-named to keep your round robin dns from giving out the IP of a failed server. It really comes down to using LVS+(keepalived|heartbeat|...) or pen. Thomas If you use keepalived to switch IP's, you don't care about your dns server giving the IP of a failed server because your working server(s) keep answering on the ip of the failed server. And BIG isp's caches cache entire dns query results (all ip's, not only one). It's up to the client's dns resolver to use one IP at random. If you've got enough volume that you need load sharing, you should have enough randomness to split the load _almost_ equally. Of course, I'm not saying this is as good as a real LVS setup, but it could be a good compromise. Mathieu -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
RE: Apache clustering w/ load balancing and failover
On Sun, 2003-09-21 at 15:05, Thomas Lamy wrote: You're wrong. round robin dns isn't HA, isn't load balancing, it's just request spreading. You can't control how many (DNS-)clients cache one of the RR IP's, therefore you won't get even load on your RR'ed servers. Plus you _have_ to use a tool like lb-named to keep your round robin dns from giving out the IP of a failed server. It really comes down to using LVS+(keepalived|heartbeat|...) or pen. Thanks for all the feedback. What about mod_proxy + wackamole ? anybody have experience with this combination ? Shri -- Shri Shrikumar U R Byte Solutions Tel: 0845 644 4745 I.T. Consultant Edinburgh, Scotland Mob: 0773 980 3499 Web: www.urbyte.com Email: [EMAIL PROTECTED] signature.asc Description: This is a digitally signed message part
Re: Apache clustering w/ load balancing and failover
Am 2003-09-17 01:49:31, schrieb Shri Shrikumar: Hi, I am looking to implement an Apache cluster with Load Balancing and failover and after going through several options, the only one that is not too complex and does everything that I need seems to be pen Why not using 'roundrobin' ??? Install a couple of Web-Servers, give each Server an IP and then setup for each Server a A-Record on your DNS-Server pointing to the same hostname. Have a nice evening Michelle -- Registered Linux-User #280138 with the Linux Counter, http://counter.li.org. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
RE: Apache clustering w/ load balancing and failover
Michelle Konzack wrote: Am 2003-09-17 01:49:31, schrieb Shri Shrikumar: Hi, I am looking to implement an Apache cluster with Load Balancing and failover and after going through several options, the only one that is not too complex and does everything that I need seems to be pen Why not using 'roundrobin' ??? Install a couple of Web-Servers, give each Server an IP and then setup for each Server a A-Record on your DNS-Server pointing to the same hostname. Because this is only poor man's load balancing. You maybe get (more or less) equal load on rr'ed servers, but you can't fix your DNS servers (and every other one caching your results) to not give out the A record of a failed server. It really comes donw to using LVS/keepalived or pen (I didn't even know it exists before this discussion), or an expensive black-box solution (From F5, Cisco, ). Thomas -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Fri, 2003-09-19 at 16:41, Jeremy Zawodny wrote: On Thu, Sep 18, 2003 at 06:38:44PM +0200, S?bastien Lefebvre wrote: You might want to use keepalived which includes a vrrp implementation. I'm running it on the clusters I set up : http://keepalived.sourceforge.net/ I even use it on Netfilter firewalls without any trouble (without the LVS support) Are there any good docs or howtos that describe how to do that? Setting up two web servers with vrrp/keepalived should be easy, but everything I looked at seemed intimately tied to LVS. Did you take a look at the keepalived documentation? http://keepalived.sourceforge.net/documentation.html All you have to do is patch your kernel with LVS or use the appropriate netfilter-ipvs-modules, compile and install keepalived and configure it according to the documentation and/or your special requirements. Now you can (should) test all possible failover scenarios with your balancer-cluster and check if the real-server are added and removed from the pool correctly. A web server itself doesn't need any special configuration at all (well, maybe a little routing/firewalling if you choose to use direct-routing or tunneling instead of NAT behind your balancer) and can be integrated in the cluster within a few minutes. best regards, Markus -- Markus Oswald [EMAIL PROTECTED] \ Unix and Network Administration Graz, AUSTRIA \ High Availability / Cluster Mobile: +43 676 6485415\ System Consulting Fax:+43 316 428896 \ Web Development -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Fri, Sep 19, 2003 at 06:46:13PM +0200, Markus Oswald wrote: On Fri, 2003-09-19 at 16:41, Jeremy Zawodny wrote: On Thu, Sep 18, 2003 at 06:38:44PM +0200, S?bastien Lefebvre wrote: You might want to use keepalived which includes a vrrp implementation. I'm running it on the clusters I set up : http://keepalived.sourceforge.net/ I even use it on Netfilter firewalls without any trouble (without the LVS support) Are there any good docs or howtos that describe how to do that? Setting up two web servers with vrrp/keepalived should be easy, but everything I looked at seemed intimately tied to LVS. Did you take a look at the keepalived documentation? http://keepalived.sourceforge.net/documentation.html Yes. All you have to do is patch your kernel with LVS or use the appropriate netfilter-ipvs-modules, compile and install keepalived and configure it according to the documentation and/or your special requirements. Well there's the confusing part. You had said: I even use it on Netfilter firewalls without any trouble (without the LVS support). It's the 'without the LVS support' that caught my eye. The docs didn't make it clear that I could do any of this without LVS-related kernel patches. Further backing that, you now say: All you have to do is patch your kernel with LVS or use the appropriate netfilter-ipvs-modules, compile and install keepalived and configure it according to the documentation and/or your special requirements. So I guess I've either misunderstood or asked the wrong question(s). Because the documentation all seems to revolve around LVS implementations. It's not clear which pieces are optional--unless I'm interpreting it incorrectly. Jeremy -- Jeremy D. Zawodny | Perl, Web, MySQL, Linux Magazine, Yahoo! [EMAIL PROTECTED] | http://jeremy.zawodny.com/ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Fri, 2003-09-19 at 19:58, Jeremy Zawodny wrote: Well there's the confusing part. You had said: I even use it on Netfilter firewalls without any trouble (without the LVS support). It's the 'without the LVS support' that caught my eye. Yes, you can use keepalive without LVS (just the VRRP part) since some months... The docs didn't make it clear that I could do any of this without LVS-related kernel patches. Further backing that, you now say: All you have to do is patch your kernel with LVS or use the appropriate netfilter-ipvs-modules, compile and install keepalived and configure it according to the documentation and/or your special requirements. So I guess I've either misunderstood or asked the wrong question(s). Because the documentation all seems to revolve around LVS implementations. It's not clear which pieces are optional--unless I'm interpreting it incorrectly. That's because keepalived was first written as a management-program for your LVS server pools. Later the VRRP part was introduced to allow redundant balancers without the need for additional programs like heartbeat. As far as I remember it's possible to compile keepalived without the LVS (ipvs) part if you just need VRRP. Because the thread started with Apache clustering and you said something about two web servers I assumed you wanted redundant balancers. VRRP (Virtual Router Redundancy Protocol) is indented for router redundancy (and firewalls, balancer, ...), not necessarily for redundant (application) server. For setting up a failover cluster (i.e. two machines, active/standby - for redundant - but not balanced - Apache, MySQL, Samba, ... ) you might want to take a look at heartbeat, piranha, failsafe or something like that. best regards, Markus -- Markus Oswald [EMAIL PROTECTED] \ Unix and Network Administration Graz, AUSTRIA \ High Availability / Cluster Mobile: +43 676 6485415\ System Consulting Fax:+43 316 428896 \ Web Development -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Wed, 2003-09-17 at 20:52, Shri Shrikumar wrote: Thanks for the response. Let me just clarify. If I have two boxes, I can configure both of them to be webservers and one of them to be the lvs node. I dont need a third machine to be a dedicated node. Is this correct ? No, I don't think this would work. You'll need a third box which will do the balancing (well, maybe you could get it to work but it's not intended this way). As I said before, the balancer doesn't have to be a fast machine - almost anything you can find will be sufficient. best regards, Markus -- Markus Oswald [EMAIL PROTECTED] \ Unix and Network Administration Graz, AUSTRIA \ High Availability / Cluster Mobile: +43 676 6485415\ System Consulting Fax:+43 316 428896 \ Web Development -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Thu, Sep 18, 2003 at 04:46:45PM +0200, Markus Oswald wrote: On Wed, 2003-09-17 at 20:52, Shri Shrikumar wrote: Thanks for the response. Let me just clarify. If I have two boxes, I can configure both of them to be webservers and one of them to be the lvs node. I dont need a third machine to be a dedicated node. Is this correct ? No, I don't think this would work. You'll need a third box which will do the balancing (well, maybe you could get it to work but it's not intended this way). As I said before, the balancer doesn't have to be a fast machine - almost anything you can find will be sufficient. Has anybody played with vrrpd for creating a failover pair? I have a quite a low load, but would like to be able to handle a failure cleanly, so a pair of machines would do fine. The only other issue I have is a lack of external IP space, can you get vrrpd to do it's keep alive thing via a subinterface on a seperate ip range? McC -simonm (E: [EMAIL PROTECTED] W: +44 28 9072 5060 M: +44 7710 836915) One line sigs are cool. This isn't one of them. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
No, I don't think this would work. You'll need a third box which will do the balancing (well, maybe you could get it to work but it's not intended this way). As I said before, the balancer doesn't have to be a fast machine - almost anything you can find will be sufficient. Strangely enough, you might find FreeBSD (or one of the BSDs) working better as the forwarded than Linux, due to it's better ability to handle many multiple concurrent connections. YMMV of course. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Thu, 2003-09-18 at 17:44, Jason Lim wrote: Strangely enough, you might find FreeBSD (or one of the BSDs) working better as the forwarded than Linux, due to it's better ability to handle many multiple concurrent connections. YMMV of course. Is the balancer-functionality build into the FreeBSD kernel like LVS? How does *BSD handle it? Any URL? best regards, Markus -- Markus Oswald [EMAIL PROTECTED] \ Unix and Network Administration Graz, AUSTRIA \ High Availability / Cluster Mobile: +43 676 6485415\ System Consulting Fax:+43 316 428896 \ Web Development -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
Has anybody played with vrrpd for creating a failover pair? I have a quite a low load, but would like to be able to handle a failure cleanly, so a pair of machines would do fine. The only other issue I have is a lack of external IP space, can you get vrrpd to do it's keep alive thing via a subinterface on a seperate ip range? You might want to use keepalived which includes a vrrp implementation. I'm running it on the clusters I set up : http://keepalived.sourceforge.net/ I even use it on Netfilter firewalls without any trouble (without the LVS support) Sébastien -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Wed, 2003-09-17 at 09:50, Markus Oswald wrote: On Wed, 2003-09-17 at 02:49, Shri Shrikumar wrote: Hi, I am looking to implement an Apache cluster with Load Balancing and failover and after going through several options, the only one that is not too complex and does everything that I need seems to be pen http://siag.nu/pen/ I am curious about other peoples experience with this / other clustering software. I have already looked at software like lvs / heartbeat but it feels like using a sledgehammer to crack a nut. Personally I would suggest LVS / keepalived - IMHO it's the most robust and powerful solution you can currently get. Definitely worth a look... It's not as hard to setup as you think - you need a little bit of experience for planing your cluster setup, but the software installation and configuration is probably the easier part. I installed/run multiple clusters, some with quite a lot of traffic (well, that's what load-balancing is good for) some just needed the HA features. No serious problems with keepalived and no problems at all with LVS. You can also have a look at www.ultramonkey.org , deb packages avaialble. Simplifies the installation of LVS a lot. Recently, there was a article in Sysadmin mag. about clustering. There was an interesting part about openSSI, it can be found here: http://www.samag.com/documents/s=8817/sam0313b/0313b.htm -- Joost best regards, Markus -- Markus Oswald [EMAIL PROTECTED] \ Unix and Network Administration Graz, AUSTRIA \ High Availability / Cluster Mobile: +43 676 6485415\ System Consulting Fax:+43 316 428896 \ Web Development -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
RE: Apache clustering w/ load balancing and failover
By the way, what filysystem do you recomend for these kind of clusters?? NFS?? Coda?? -Mensaje original- De: Joost Veldkamp [mailto:[EMAIL PROTECTED] Enviado el: miércoles, 17 de septiembre de 2003 12:05 Para: [EMAIL PROTECTED] Asunto: Re: Apache clustering w/ load balancing and failover On Wed, 2003-09-17 at 09:50, Markus Oswald wrote: On Wed, 2003-09-17 at 02:49, Shri Shrikumar wrote: Hi, I am looking to implement an Apache cluster with Load Balancing and failover and after going through several options, the only one that is not too complex and does everything that I need seems to be pen http://siag.nu/pen/ I am curious about other peoples experience with this / other clustering software. I have already looked at software like lvs / heartbeat but it feels like using a sledgehammer to crack a nut. Personally I would suggest LVS / keepalived - IMHO it's the most robust and powerful solution you can currently get. Definitely worth a look... It's not as hard to setup as you think - you need a little bit of experience for planing your cluster setup, but the software installation and configuration is probably the easier part. I installed/run multiple clusters, some with quite a lot of traffic (well, that's what load-balancing is good for) some just needed the HA features. No serious problems with keepalived and no problems at all with LVS. You can also have a look at www.ultramonkey.org , deb packages avaialble. Simplifies the installation of LVS a lot. Recently, there was a article in Sysadmin mag. about clustering. There was an interesting part about openSSI, it can be found here: http://www.samag.com/documents/s=8817/sam0313b/0313b.htm -- Joost best regards, Markus -- Markus Oswald [EMAIL PROTECTED] \ Unix and Network Administration Graz, AUSTRIA \ High Availability / Cluster Mobile: +43 676 6485415\ System Consulting Fax:+43 316 428896 \ Web Development -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
RE: Apache clustering w/ load balancing and failover
On Wed, 2003-09-17 at 12:07, Javier Castillo Alcibar wrote: By the way, what filysystem do you recomend for these kind of clusters?? NFS?? Coda?? Depends on what you want to do - for instance: Build a balanced server farm to handle a lot of traffic: Just use a NFS server as centralized storage for your document root and let all cluster-nodes access it. Your balancer(s) can handle the HA part and manage your server-pool. Your NFS server is your SPOF though if it's not a cluster itself. Build a (two node) failover cluster: Take a look at DRBD - it's a redundant network block device. You can use almost any filesystem on top of it. Preferably journaling of course. best regards Markus -- Markus Oswald [EMAIL PROTECTED] \ Unix and Network Administration Graz, AUSTRIA \ High Availability / Cluster Mobile: +43 676 6485415\ System Consulting Fax:+43 316 428896 \ Web Development -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Wed, 2003-09-17 at 08:50, Markus Oswald wrote: Personally I would suggest LVS / keepalived - IMHO it's the most robust and powerful solution you can currently get. Definitely worth a look... It's not as hard to setup as you think - you need a little bit of experience for planing your cluster setup, but the software installation and configuration is probably the easier part. I installed/run multiple clusters, some with quite a lot of traffic (well, that's what load-balancing is good for) some just needed the HA features. No serious problems with keepalived and no problems at all with LVS. Looking at the documentation for LVS, it mentions that it needs two nodes, a primary node and a backup node which then feeds into n real servers. Does this mean that I will need two additional machines to be able to do LVS or would I be able to double up a couple of the webservers as the nodes ? Thanks for the feedback, Best wishes, Shri -- Shri Shrikumar U R Byte Solutions Tel: 0845 644 4745 I.T. Consultant Edinburgh, Scotland Mob: 0773 980 3499 Web: www.urbyte.com Email: [EMAIL PROTECTED] signature.asc Description: This is a digitally signed message part
Re: Apache clustering w/ load balancing and failover
On Wed, 2003-09-17 at 15:00, Shri Shrikumar wrote: Looking at the documentation for LVS, it mentions that it needs two nodes, a primary node and a backup node which then feeds into n real servers. Actually I never saw this mentioned in the documentation - I haven't looked at it for quite some time now, tough. LVS definitely works with ONE machine which acts as the loadbalancer. You can use a second machine for failover if you need the redundancy, but as far as I know, LVS can't handle this by itself so you would have to use keepalived or heartbeat for that. The balancer hardly needs any resources - if it wasn't for the quality of the hardware (i.e. you don't want to see your balancer die and take the whole farm offline because of some el cheapo motherboard) you could use any old Pentium lying around to handle quite a bit of traffic. Even the cheapest Celeron rackserver can probably handle some hundred Megabit throughput... To sum it up: You take some machine which will act as a loadbalancer and distributes the HTTP (SMTP/POP/...) requests to you pool of real-server. To achieve this, patch your kernel or load the ipvs modules. Define a service and add real-servers... If you build some high-performance and/or high-availability farm with this setup you should also consider some other things (i.e. planing the cluster environment so you don't run into bottlenecks later), but for a first test-setup you could probably start right away... If you have further questions, we can discuss details off-list as I may become OT. best regards, Markus Oswald -- Markus Oswald [EMAIL PROTECTED] \ Unix and Network Administration Graz, AUSTRIA \ High Availability / Cluster Mobile: +43 676 6485415\ System Consulting Fax:+43 316 428896 \ Web Development -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Wed, 2003-09-17 at 12:05, Joost Veldkamp wrote: You can also have a look at www.ultramonkey.org , deb packages avaialble. Simplifies the installation of LVS a lot. Recently, there was a article in Sysadmin mag. about clustering. There was an interesting part about openSSI, it can be found here: http://www.samag.com/documents/s=8817/sam0313b/0313b.htm I didn't read trough the whole article, but openSSI seems to do the clustering at process-level (somewhat like Mosix). If this is the case: Technically you could probably run a webserver on top of such a cluster, but I doubt it would be a good idea as it will probably have quite a bit overhead which doesn't seem necessary for a Apache cluster. In the end the cluster would either need some really beefy hardware (especially network for the I/O I guess) and/or won't deliver the performance you would expect. A dedicated loadbalancer is probably the better solution as it doesn't add much overhead - its only job is to distribute incoming requests. Anyway: please correct me if I'm wrong! ;o) best regards Markus -- Markus Oswald [EMAIL PROTECTED] \ Unix and Network Administration Graz, AUSTRIA \ High Availability / Cluster Mobile: +43 676 6485415\ System Consulting Fax:+43 316 428896 \ Web Development -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Wed, 2003-09-17 at 18:46, Markus Oswald wrote: On Wed, 2003-09-17 at 15:00, Shri Shrikumar wrote: Looking at the documentation for LVS, it mentions that it needs two nodes, a primary node and a backup node which then feeds into n real servers. Actually I never saw this mentioned in the documentation - I haven't looked at it for quite some time now, tough. LVS definitely works with ONE machine which acts as the loadbalancer. You can use a second machine for failover if you need the redundancy, but as far as I know, LVS can't handle this by itself so you would have to use keepalived or heartbeat for that. Hi, Thanks for the response. Let me just clarify. If I have two boxes, I can configure both of them to be webservers and one of them to be the lvs node. I dont need a third machine to be a dedicated node. Is this correct ? Thanks, Shri -- Shri Shrikumar U R Byte Solutions Tel: 0845 644 4745 I.T. Consultant Edinburgh, Scotland Mob: 0773 980 3499 Web: www.urbyte.com Email: [EMAIL PROTECTED] signature.asc Description: This is a digitally signed message part
RE: Apache clustering w/ load balancing and failover
Shri Shrikumar wrote: On Wed, 2003-09-17 at 18:46, Markus Oswald wrote: On Wed, 2003-09-17 at 15:00, Shri Shrikumar wrote: Looking at the documentation for LVS, it mentions that it needs two nodes, a primary node and a backup node which then feeds into n real servers. Actually I never saw this mentioned in the documentation - I haven't looked at it for quite some time now, tough. LVS definitely works with ONE machine which acts as the loadbalancer. You can use a second machine for failover if you need the redundancy, but as far as I know, LVS can't handle this by itself so you would have to use keepalived or heartbeat for that. Hi, Thanks for the response. Let me just clarify. If I have two boxes, I can configure both of them to be webservers and one of them to be the lvs node. I dont need a third machine to be a dedicated node. Is this correct ? Ascii art: internet +---+ +---+ + - - - - - - - + | LVS Director | | Director 2 | +---+ +- - - - - - - -+ | | ---| SWITCH | -+ | | | +---+ | +---+ | | | +---+ +---+ + - - - - - - - + | Webserver | | Webserver | | Webserver | +---+ +---+ +- - - - - - - -+ You need at least 1 LVS Director (balancer) and two servers to start. The second LVS director and additional server are optional. Thomas -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Apache clustering w/ load balancing and failover
On Wed, Sep 17, 2003 at 02:00:35PM +0100, Shri Shrikumar wrote: Looking at the documentation for LVS, it mentions that it needs two nodes, a primary node and a backup node which then feeds into n real servers. We're using a single LVS server to balance things out to 4 webserver, 2 POP mail and 2 SMTP mail servers. Actually, it's 3 webservers right now, as a hardware failure required us to steal a webserver for 'other uses' ;) All of the servers behind the LVS are netbooting from an NFS machine. This sucks because we have a single point of failure (LVS) but the intent is to get a second eLViS (hehe) running with heartbeat between the two. It's on the network map ;) So you can run it with a single LVS, but I wouldn't prefer to. Since it's simply redirecting stuff, it doesnt' need to be that powerful. j -- == + It's simply not | John Keimel+ + RFC1149 compliant!| [EMAIL PROTECTED]+ + | http://www.keimel.com + == -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
