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 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
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 Administrao de Sistemas / Operaes || http://www.sapo.pt --
Load Balancing with qmail
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 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
LOAD-BALANCING WITH QMAIL.
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 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.
load balancing two qmail servers using nfs
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
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
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
