Re: Load Balancing with qmail
Hum, or you can use iptables. On Wed, Feb 14, 2001 at 03:23:14AM -0500, tc lewis wrote: > > On Wed, 14 Feb 2001, Andrew Wafula wrote: > > > > Is there any way one can do load balancing with qmail, i.e I have two > > machines both with qmail set up and running. Is there a way that I can have > > them both serving as smtp servers without the clients knowing which machine > > is sending the ail for them? > > > > you can use dns mx preferences for smtp. > you can use dns round-robin a records. > you can use a load balancer like http://www.linuxvirtualserver.org/, or an f5 bigip, >or alteon's, or cisco's, etc etc. > > -tcl. > > -- Jose AP Celestino <[EMAIL PROTECTED]> || SAPO / PT Multimedia Administração de Sistemas / Operações || http://www.sapo.pt --
Re: Load Balancing with qmail
On Wed, 14 Feb 2001, Andrew Wafula wrote: > > Is there any way one can do load balancing with qmail, i.e I have two > machines both with qmail set up and running. Is there a way that I can have > them both serving as smtp servers without the clients knowing which machine > is sending the ail for them? > you can use dns mx preferences for smtp. you can use dns round-robin a records. you can use a load balancer like http://www.linuxvirtualserver.org/, or an f5 bigip, or alteon's, or cisco's, etc etc. -tcl.
Re: Load Balancing with qmail
Yes and no, well actually just yes but one option is easy the other is not. If you are talking about desktop clients where you manually can enter a hostname to use as SMTP server then it is easy. If you on the other hand mean to loadbalance your MX records that will be a bit tricky (or atleast expensive). Anyhow, to loadbalance yuor desktop clients all you need to do is setup DNS roundrobin for the SMTP host. DNS roundrobin is not perfect but will suffice for the most of us. MX records rarely need loadbalancing since you have the prefference setting in the MX record itself. If the most preffered server is "full" the sending host will simply pick the MX record with the second best prefference and so on. However if you really want _real_ loadbalancing I would recommend thirdparty software or hardware. /Martin On Wed, Feb 14, 2001 at 10:33:01AM +0300, Andrew Wafula mumbled: > Hi, > > Is there any way one can do load balancing with qmail, i.e I have two > machines both with qmail set up and running. Is there a way that I can have > them both serving as smtp servers without the clients knowing which machine > is sending the ail for them? > > Andrew >
Re: Load Balancing
>
> I have a server called MLM and 4 servers called
> MLM1,2,3,4
> .
>
> MLM is a central server with Qmail and EZMLM, and the other servers are
> the RELAY
>
Run this to start your load balancing:
perl -e'chdir"/var/control/";while(1){sleep(1);system "echo :MLM${\(++$n%4 + 1)}>sr_";
rename "sr_","smtproutes"}'
you might want to change the sleep interval to something higher.
Or change your relays to MLM0,1,2,3 so you can leave out the +1
Multi-level marketing sucks though
--
David Nicol 816.235.1187 [EMAIL PROTECTED]
"I don't care how they do it in New York"
Re: LOAD-BALANCING WITH QMAIL.
Unfortunately no one did reply to me, so I found some resource on the web and will try to investigate it. Good luck. qmailu writes: > Hi Ian, > > Have you got this working ?? Noticed none had replied to this. Thought I'll > get help from you. If you have , can you pls lemme know how you did this. > > Raghu > - Original Message - > From: Ian Matyssik <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Friday, January 19, 2001 11:42 AM > Subject: Re: LOAD-BALANCING WITH QMAIL. > > >> Hello, >> >> I am writing to this message again. Just to confirm that the qmqp >> supports round-robin natively. I was reading all about it and did not >> understand. What I understood is if we keep mini-qmail on the clients and >> have 4 servers for relaying, we just need to list all servers in >> /var/qmail/control/qmqpservers and it will load balance them in > round-robin >> manner. If that is true what about if one of the relay servers goes down, >> will it spoil something from the client side. >> >> Please confirm that or give some advice, >> Regards, >> Ian Matyssik. >> >> Ian Matyssik writes: >> >> > Hello, >> > >> >I am new on this list but have bin using qmail for 2 years. Now my >> > company desided to expand mail relaying and my task is to find good >> > sollution how to load-balance "qmqp" relays with nullmailer or qmail. I >> > tried to look in the archive and found one thread on that topic but did >> > not understand exactly if there is a patch for that or native capability >> > of qmail allow that. Please help me on that. I just want to round-robin > 4 >> > servers for now. >> > >> > Thank you, >> > Ian Matyssik. >> > > > _ > Do You Yahoo!? > Get your free @yahoo.com address at http://mail.yahoo.com >
Re: Load Balancing
On Mon, Jan 22, 2001 at 03:07:27PM -0300, Federico Edelman Anaya wrote: > Can I change the ROUNDROBIN DNS for a Load Balancing system? Round Robin is Round Robin, no load balancing possible. > Exist any > software for this implementation? halinux.org (or was it linuxha.org?) comes to my mind, . Unfortunately I havent found anything running on *BSD yet - if anybody knows something... -- Henning Brauer | BS Web Services Hostmaster BSWS| Roedingsmarkt 14 [EMAIL PROTECTED] | 20459 Hamburg http://www.bsws.de | Germany
Re: LOAD-BALANCING WITH QMAIL.
Hello, I am writing to this message again. Just to confirm that the qmqp supports round-robin natively. I was reading all about it and did not understand. What I understood is if we keep mini-qmail on the clients and have 4 servers for relaying, we just need to list all servers in /var/qmail/control/qmqpservers and it will load balance them in round-robin manner. If that is true what about if one of the relay servers goes down, will it spoil something from the client side. Please confirm that or give some advice, Regards, Ian Matyssik. Ian Matyssik writes: > Hello, > >I am new on this list but have bin using qmail for 2 years. Now my > company desided to expand mail relaying and my task is to find good > sollution how to load-balance "qmqp" relays with nullmailer or qmail. I > tried to look in the archive and found one thread on that topic but did > not understand exactly if there is a patch for that or native capability > of qmail allow that. Please help me on that. I just want to round-robin 4 > servers for now. > > Thank you, > Ian Matyssik.
RE: load balancing two qmail servers using nfs
Both servers are NIS clients from the same master, which happens to be the NFS server. So the user information is identical across all machines involved. The tcpserver init scripts on the second machine were copied from the first machine, and so are also identical. Both good points, but not the problem, I'm afraid. Thanks, Mike > -Original Message- > From: chuck [mailto:[EMAIL PROTECTED]] > Sent: Saturday, June 24, 2000 12:10 PM > To: Mike Denka > Cc: [EMAIL PROTECTED] > Subject: Re: load balancing two qmail servers using nfs > > > > Mike, > > You might make sure that the UID/GIDs map the same on both servers and the > NFS machine. > i.e.- If the qmaild user is user 500 on the first server, but is a > different UID number on the second server or the NFS machine you > might have > problems. > > Also, what do your tcpserver init scripts look like for both servers? They > should be identical. > > Regards, > Charles Werbick > The Wirehouse > > > Mike Denka writes: > > > Hmmm . . . that's a good thought. I really hadn't considered > using rsync > > since NFS seems to be working fine at least in terms of > handling large mail > > volumes. But rsync would have some distinct advantages. > However, I don't > > think that is the source of my problems because I had access problems > > getting to the control files when first setting up the server > and the error > > messages in /var/log/syslog are pretty clear (e.g., > "Can't_read_control", or > > something to that affect). > > > > Thanks for the rsyinc tip. I will try it out. Meanwhile, any other > > thoughts on why the second server suddenly cannot make smtp > connections to > > the outside world or chdir to Mailbox? > > > > Mike > > > > > -Original Message- > > > From: steve j. kondik [mailto:[EMAIL PROTECTED]] > > > Sent: Saturday, June 24, 2000 12:39 AM > > > To: [EMAIL PROTECTED] > > > Subject: Re: load balancing two qmail servers using nfs > > > > > > > > > you might consider using rsync to sync your conffiles, instead of > > > sharing them over nfs. this would eliminate alot of problems > > > and latency i'd think. > > > > > > On 06/24/00 @ 12:11AM, Mike Denka wrote: > > > > I've got two qmail servers running inside a load balancer. > > > They both access > > > > the same /var/mail/username/Maildir directories on an NFS > > > server. They also > > > > share many of the same configuration files in > > > /var/qmail/control on the NFS > > > > server. The files they share are local symbolic links to the > > > shared volume > > > > on the NFS server. A few hours after bringing up the second > > > qmail server, > > > > the first one, which had been running fine for two weeks, quit > > > working. The > > > > errors I am getting in the syslog file on the failing server are > > > > "Can't_connect_to_SMTP_server" and "Can't_chdir_to_Maidir". > > > Anyone have any > > > > success with this configuration or have any idea what could be > > > causing the > > > > first server to loose its way? > > > > > > > > Running qmail and NFS on Solaris 2.7 (first server and NFS > > > server) and 2.8 > > > > (second qmail server). The first server (the one failing) > responds to > > > > connections on port 25 but can't send or deliver and is not > spawning any > > > > qmail processes. The second server is now doing all the work. > > > > > > > > Thanks, > > > > > > > > Mike > > > > > > > > > > > > > > -- > > > Steve J. Kondik <[EMAIL PROTECTED]> > > > Stargate Industries, LLC - Network Operations Center > > > > > > > > >
Re: load balancing two qmail servers using nfs
Mike, You might make sure that the UID/GIDs map the same on both servers and the NFS machine. i.e.- If the qmaild user is user 500 on the first server, but is a different UID number on the second server or the NFS machine you might have problems. Also, what do your tcpserver init scripts look like for both servers? They should be identical. Regards, Charles Werbick The Wirehouse Mike Denka writes: > Hmmm . . . that's a good thought. I really hadn't considered using rsync > since NFS seems to be working fine at least in terms of handling large mail > volumes. But rsync would have some distinct advantages. However, I don't > think that is the source of my problems because I had access problems > getting to the control files when first setting up the server and the error > messages in /var/log/syslog are pretty clear (e.g., "Can't_read_control", or > something to that affect). > > Thanks for the rsyinc tip. I will try it out. Meanwhile, any other > thoughts on why the second server suddenly cannot make smtp connections to > the outside world or chdir to Mailbox? > > Mike > > > -Original Message- > > From: steve j. kondik [mailto:[EMAIL PROTECTED]] > > Sent: Saturday, June 24, 2000 12:39 AM > > To: [EMAIL PROTECTED] > > Subject: Re: load balancing two qmail servers using nfs > > > > > > you might consider using rsync to sync your conffiles, instead of > > sharing them over nfs. this would eliminate alot of problems > > and latency i'd think. > > > > On 06/24/00 @ 12:11AM, Mike Denka wrote: > > > I've got two qmail servers running inside a load balancer. > > They both access > > > the same /var/mail/username/Maildir directories on an NFS > > server. They also > > > share many of the same configuration files in > > /var/qmail/control on the NFS > > > server. The files they share are local symbolic links to the > > shared volume > > > on the NFS server. A few hours after bringing up the second > > qmail server, > > > the first one, which had been running fine for two weeks, quit > > working. The > > > errors I am getting in the syslog file on the failing server are > > > "Can't_connect_to_SMTP_server" and "Can't_chdir_to_Maidir". > > Anyone have any > > > success with this configuration or have any idea what could be > > causing the > > > first server to loose its way? > > > > > > Running qmail and NFS on Solaris 2.7 (first server and NFS > > server) and 2.8 > > > (second qmail server). The first server (the one failing) responds to > > > connections on port 25 but can't send or deliver and is not spawning any > > > qmail processes. The second server is now doing all the work. > > > > > > Thanks, > > > > > > Mike > > > > > > > > > > -- > > Steve J. Kondik <[EMAIL PROTECTED]> > > Stargate Industries, LLC - Network Operations Center > > >
RE: load balancing two qmail servers using nfs
Hmmm . . . that's a good thought. I really hadn't considered using rsync since NFS seems to be working fine at least in terms of handling large mail volumes. But rsync would have some distinct advantages. However, I don't think that is the source of my problems because I had access problems getting to the control files when first setting up the server and the error messages in /var/log/syslog are pretty clear (e.g., "Can't_read_control", or something to that affect). Thanks for the rsyinc tip. I will try it out. Meanwhile, any other thoughts on why the second server suddenly cannot make smtp connections to the outside world or chdir to Mailbox? Mike > -Original Message- > From: steve j. kondik [mailto:[EMAIL PROTECTED]] > Sent: Saturday, June 24, 2000 12:39 AM > To: [EMAIL PROTECTED] > Subject: Re: load balancing two qmail servers using nfs > > > you might consider using rsync to sync your conffiles, instead of > sharing them over nfs. this would eliminate alot of problems > and latency i'd think. > > On 06/24/00 @ 12:11AM, Mike Denka wrote: > > I've got two qmail servers running inside a load balancer. > They both access > > the same /var/mail/username/Maildir directories on an NFS > server. They also > > share many of the same configuration files in > /var/qmail/control on the NFS > > server. The files they share are local symbolic links to the > shared volume > > on the NFS server. A few hours after bringing up the second > qmail server, > > the first one, which had been running fine for two weeks, quit > working. The > > errors I am getting in the syslog file on the failing server are > > "Can't_connect_to_SMTP_server" and "Can't_chdir_to_Maidir". > Anyone have any > > success with this configuration or have any idea what could be > causing the > > first server to loose its way? > > > > Running qmail and NFS on Solaris 2.7 (first server and NFS > server) and 2.8 > > (second qmail server). The first server (the one failing) responds to > > connections on port 25 but can't send or deliver and is not spawning any > > qmail processes. The second server is now doing all the work. > > > > Thanks, > > > > Mike > > > > > > -- > Steve J. Kondik <[EMAIL PROTECTED]> > Stargate Industries, LLC - Network Operations Center >
Re: load balancing two qmail servers using nfs
you might consider using rsync to sync your conffiles, instead of sharing them over nfs. this would eliminate alot of problems and latency i'd think. On 06/24/00 @ 12:11AM, Mike Denka wrote: > I've got two qmail servers running inside a load balancer. They both access > the same /var/mail/username/Maildir directories on an NFS server. They also > share many of the same configuration files in /var/qmail/control on the NFS > server. The files they share are local symbolic links to the shared volume > on the NFS server. A few hours after bringing up the second qmail server, > the first one, which had been running fine for two weeks, quit working. The > errors I am getting in the syslog file on the failing server are > "Can't_connect_to_SMTP_server" and "Can't_chdir_to_Maidir". Anyone have any > success with this configuration or have any idea what could be causing the > first server to loose its way? > > Running qmail and NFS on Solaris 2.7 (first server and NFS server) and 2.8 > (second qmail server). The first server (the one failing) responds to > connections on port 25 but can't send or deliver and is not spawning any > qmail processes. The second server is now doing all the work. > > Thanks, > > Mike > > -- Steve J. Kondik <[EMAIL PROTECTED]> Stargate Industries, LLC - Network Operations Center
Re: load balancing
"Muhammad Ali" <[EMAIL PROTECTED]> wrote: >I have three qmail servers for my LAN. Two are directly connected to >Internet for receiving and sending of mails for my LAN. Third one is >POP3 server. All users first send their mails to POP3 server which >then forwards outgoing mails to one of the two servers which are >directly connected to Internet. For load balancing feature, I want >that if my POP3 server is queued with lot of mails. He then forward >rest of the mails to second server automatically. So the mails may be >cleared form both of the servers. I have done this configuration but >haven't tested yet: > >/var/qmail/control/ >smtproutes > >:firstqmail.server >:secondqmail.server > > >will this alteration work for load balancing???/ No, that'll either send everything to both systems, or only one of them--I'd have to check the code to see which. What you could do is install DJB's dnscache and use pickdns to balance the load. -Dave
Re: Load balancing / qmqp / transferring messages
: If you think about it this needs a rather clever system to manage. I give you : the following scenario : you send 30,000 messages a day to mail servers in domain x. eg : bittwiddlers.com there is a catastrophic network failure in the network and : it is impossible to send mail to that domain. Your fast system passes all of : the mail during that day the network is out to the slow system all 30,000 : messages. The slow server now has to do the task. or worse your servers : start madly passing the mail around amongst themselves in the vain beleif : that one of the others will be able to get through. I can agree that that is possible but in this particular case this mail is very time dependant such that if it remains in the queue for more than six hours it is considered useless. So, in as case like you have outlined above we wouldn't worry about it much as long as the network came back up in time to send out the mail the next day. I'm just trying to figure out if I can push the delayed messages off somewhere else under the assumption that the recipient addresses will come up in the next few hours. I don't want to delay my fast servers by having all these possible bad messages in the queue. : I think what you need is a distributed processing version of qmail. : Any takers ??? Actually, I would love that. I have a distributed front end that parses the mail and through socket connections passes it to a series of qmail servers out there to push it out. It would be nice if I could just have a distributed qmail or a distributed queue that multiple qmails could operate on. -- Matthew Harrell Never raise your hand to your Bit Twiddlers, Inc. children - it leaves your [EMAIL PROTECTED] midsection unprotected.
RE: Load balancing / qmqp / transferring messages
f you think about it this needs a rather clever system to manage. I give you the following scenario you send 30,000 messages a day to mail servers in domain x. eg bittwiddlers.com there is a catastrophic network failure in the network and it is impossible to send mail to that domain. Your fast system passes all of the mail during that day the network is out to the slow system all 30,000 messages. The slow server now has to do the task. or worse your servers start madly passing the mail around amongst themselves in the vain beleif that one of the others will be able to get through. I think what you need is a distributed processing version of qmail. Any takers ??? > -Original Message- > From: Matthew Harrell [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, 24 August 1999 13:19 > To: Qmail List > Subject: Load balancing / qmqp / transferring messages > > > > A couple of questions: > Can qmqp be used to transfer messages from one overloaded > server to another >in order to balance the load somewhat? > > Along those same lines, is there a way to transfer messages > which have missed >their first delivery attempt to another machine in order to > reduce the queue >size? For instance if there are three fast machines > processing messages >and passing those that had problems to another slower machine > to send out >when it can. > > Thanks > > -- > Matthew Harrell You're just jealous because the > Bit Twiddlers, Inc. voices only talk to me. > [EMAIL PROTECTED] >
Re: Load Balancing Of 2 Qmail servers
On Thu, 15 Jul 1999, Tony Wade wrote: TW>Hi all , TW> TW>Has anyone ever attempted to have a single config file for Qmail ie. TW> TW>/var/qmail/control being shared by 2 servers. TW> TW>and then the servers will be identical. Both running Redhat 6.0 with kernel TW>2.2.10 TW>and both be a DELL PowerEdge 2300 with Duel PII 400 chips and 256M Ram. TW>and a 18G hdd. TW> TW>with the /var/qmail dir set to +- 9G TW> TW>could i get them to share the configs and load balance ? rsync/rdist the config, and NFS mount the mailstore (assuming that you are using maildir). -- --Matt Schnierle --mgs at stargate dot net --Stargate Industries, LLC --#include --"It's not that simple."
Re: Load Balancing Of 2 Qmail servers
On Thu, Jul 15, 1999 at 10:58:41PM -0400, Victor Tavares wrote: > There can be problems with load-balancing over two mail servers, depending > on their purpose. If they only provide outgoing mail, or are a mail hub for > internal mail, then load-balancing with a localdirector or similar device > is not a problem. However, if your users need to pick up the mail from > either one of the servers - i.e. mbox or maildir - then the mail needs to > be delivered to a shared volume - eg NFS, storage appliance, third server, > etc. Oops- i should have mentioned that. Ideally i suppose you could use something like a netapp for the user volumes connected to the qmail machine via a private segment. Whatever works i suppose. > The above was done more for availability than performance, but man, the > performance is pretty good. Qmail has always given me stellar performance on a single machine- i imagine a scenario such as you've described could only yield even better performance. Cheers, Jonathan
Re: Load Balancing Of 2 Qmail servers
On Thu, Jul 15, 1999 at 03:04:51PM +0200, Tony Wade wrote: > Hi all , > > Has anyone ever attempted to have a single config file for Qmail ie. > > /var/qmail/control being shared by 2 servers. > > and then the servers will be identical. Both running Redhat 6.0 with kernel > 2.2.10 > and both be a DELL PowerEdge 2300 with Duel PII 400 chips and 256M Ram. > and a 18G hdd. > > with the /var/qmail dir set to +- 9G > > could i get them to share the configs and load balance ? You might want to look into Foundry Networks ServerIron products, or Cisco's Local Director products. They're a little pricey, but if you're buying Dell Poweredge 2300's in the first place, i suspect this is not a problem =) Personally, i'll vouch for the ServerIron. Cheers, Jonathan
Re: Load Balancing Of 2 Qmail servers
Tony Wade wrote: > Hi all , > > Has anyone ever attempted to have a single config file for Qmail ie. > > /var/qmail/control being shared by 2 servers. > > and then the servers will be identical. Both running Redhat 6.0 with kernel > 2.2.10 > and both be a DELL PowerEdge 2300 with Duel PII 400 chips and 256M Ram. > and a 18G hdd. > > with the /var/qmail dir set to +- 9G > > could i get them to share the configs and load balance ? Maybe joining the two servers in a Beowulf cluster would be less problematic? begin:vcard n:Castro;Juan tel;work:540-9100 Ramal 46 x-mozilla-html:FALSE url:http://www.appi.com.br/~jcastro org:APPI Informática;Desenvolvimento adr:;;Av. Ataulfo de Paiva, 135/1410 - Leblon;Rio de Janeiro;RJ;22499-900;Brasil version:2.1 email;internet:[EMAIL PROTECTED] title:Consultor note;quoted-printable:One man alone cannot fight the future. USE LINUX!=0D=0A=0D=0A-- The X Racer fn:Juan Carlos Castro y Castro end:vcard
RE: Load Balancing Of 2 Qmail servers
The way I do it is with rdist. I have one machine the "master" and I rdist the files to the 2ndary machine. Just make sure you kill/restart qmail to ensure that any control file changes get read in and activated. > -Original Message- > From: Tony Wade [SMTP:[EMAIL PROTECTED]] > Sent: Thursday, July 15, 1999 9:05 AM > To: [EMAIL PROTECTED] > Subject: Load Balancing Of 2 Qmail servers > > Hi all , > > Has anyone ever attempted to have a single config file for Qmail ie. > > /var/qmail/control being shared by 2 servers. > > and then the servers will be identical. Both running Redhat 6.0 with > kernel > 2.2.10 > and both be a DELL PowerEdge 2300 with Duel PII 400 chips and 256M > Ram. > and a 18G hdd. > > with the /var/qmail dir set to +- 9G > > could i get them to share the configs and load balance ? > > > Tony Wade > The Internet Solution > Tel: (+27 11) 283 5483 > Fax: (+27 11) 283 5401 > E-mail: [EMAIL PROTECTED] > Web: http://www.is.co.za > BOFH excuse for the day: > Due to the CDA, we no longer have a root account. >
