LVSKB - User contributions [en]

Net-SNMP-LVS-Module

2009-01-25T12:01:38Z

Galbum: /* Extrenal Links */

== GENERAL ==
net-snmpd-lvs-module is a dynamicaly loadable shared object for SNMP to get the configuration and some statistical information from the Linux kernel with [[IPVS|IP virtual server]] support.

== INSTALLATION ==
Get the source for this module ([[media:Net-snmp-lvs-module-0.0.4.tar.gz|local copy]] or [http://www.loadbalancer.org/download/SNMP/net-snmp-lvs-module-0.0.4.tar.gz Alternate source location]). From http://www.linuxvirtualserver.org/software/ipvs.html download the the correct version of ipvsadm, for kernel 2.6 use ipvsadm-1.24 or later, for kernel 2.4 use ipvsadm-1.21. Extract '''ipvsadm-''version''.tar.gz''', build the library and copy the subtree '''libipvs''' into the module's working directory.

Check that the Linux kernel is available under '''/usr/src/linux'''. Install net-snmp and its development headers and libraries. Invoke '''make''', this should build '''lvs.so'''. Copy LVS-MIB.txt and OC-MIB.txt to '''/usr/share/snmp/mibs/'''.

Check that the new MIB is visible by invoking
shell> snmptranslate -m LVS-MIB -On -IR lvsServiceEntry,
this should return '''.1.3.6.1.4.1.8225.4711.18.1'''
Copy '''lvs.so''' to '''/usr/lib/libnetsnmplvs.so''' and add the following line to
'''/etc/snmp/snmpd.conf''':
dlmod lvs /usr/lib/libnetsnmplvs.so
Restart your snmpd.

Try if everything works invoking:
shell> snmpwalk -c public -v 2c -m LVS-MIB localhost 1.3.6.1.4.1.8225.4711
LVS-MIB::lvsVersion.0 = STRING: "1.2.0"
LVS-MIB::lvsNumServices.0 = INTEGER: 2
LVS-MIB::lvsHashTableSize.0 = INTEGER: 4096
LVS-MIB::lvsTcpTimeOut.0 = INTEGER: 900
LVS-MIB::lvsTcpFinTimeOut.0 = INTEGER: 120
LVS-MIB::lvsUdpTimeOut.0 = INTEGER: 300
LVS-MIB::lvsDaemonState.0 = INTEGER: none(0)
...

In case you want to add additional snmp-values to your MIB:
Set export MIBS=ALL and create skeleton with
shell> mib2c -c mib2c.interate.conf lvsRealTable
or
shell> mib2c -c mib2c.interate.conf lvsServiceTable
this should create a file '''lvsRealTable.c''' and/or '''lvsServiceTable.c'''.
Use the generated code as a template for '''lvs.c''' and populate the missing parts.

== CREDITS ==
The code for this module currently is maintained by Jacob Rief. This code is based on ucd-snmpd-lvs written by Romeo Benzoni in 2002 and never modified since. As that code did not compile with the newer net-snmp headers, I decided to rewrite the complete code. The only unchanged parts from the ucd-snmpd-lvs project are LVS-MIB.txt and OC-MIB.txt.

== Extrenal Links ==
The official site does not exist any more, since I left that company.
If somebody gives me access to the repository, I will maintain the module there, otherwise I will have to create one at Google-code.

[[Category:LVS Software]]

Net-SNMP-LVS-Module

2009-01-25T12:00:03Z

Galbum: /* INSTALLATION */

== GENERAL ==
net-snmpd-lvs-module is a dynamicaly loadable shared object for SNMP to get the configuration and some statistical information from the Linux kernel with [[IPVS|IP virtual server]] support.

== INSTALLATION ==
Get the source for this module ([[media:Net-snmp-lvs-module-0.0.4.tar.gz|local copy]] or [http://www.loadbalancer.org/download/SNMP/net-snmp-lvs-module-0.0.4.tar.gz Alternate source location]). From http://www.linuxvirtualserver.org/software/ipvs.html download the the correct version of ipvsadm, for kernel 2.6 use ipvsadm-1.24 or later, for kernel 2.4 use ipvsadm-1.21. Extract '''ipvsadm-''version''.tar.gz''', build the library and copy the subtree '''libipvs''' into the module's working directory.

Check that the Linux kernel is available under '''/usr/src/linux'''. Install net-snmp and its development headers and libraries. Invoke '''make''', this should build '''lvs.so'''. Copy LVS-MIB.txt and OC-MIB.txt to '''/usr/share/snmp/mibs/'''.

Check that the new MIB is visible by invoking
shell> snmptranslate -m LVS-MIB -On -IR lvsServiceEntry,
this should return '''.1.3.6.1.4.1.8225.4711.18.1'''
Copy '''lvs.so''' to '''/usr/lib/libnetsnmplvs.so''' and add the following line to
'''/etc/snmp/snmpd.conf''':
dlmod lvs /usr/lib/libnetsnmplvs.so
Restart your snmpd.

Try if everything works invoking:
shell> snmpwalk -c public -v 2c -m LVS-MIB localhost 1.3.6.1.4.1.8225.4711
LVS-MIB::lvsVersion.0 = STRING: "1.2.0"
LVS-MIB::lvsNumServices.0 = INTEGER: 2
LVS-MIB::lvsHashTableSize.0 = INTEGER: 4096
LVS-MIB::lvsTcpTimeOut.0 = INTEGER: 900
LVS-MIB::lvsTcpFinTimeOut.0 = INTEGER: 120
LVS-MIB::lvsUdpTimeOut.0 = INTEGER: 300
LVS-MIB::lvsDaemonState.0 = INTEGER: none(0)
...

In case you want to add additional snmp-values to your MIB:
Set export MIBS=ALL and create skeleton with
shell> mib2c -c mib2c.interate.conf lvsRealTable
or
shell> mib2c -c mib2c.interate.conf lvsServiceTable
this should create a file '''lvsRealTable.c''' and/or '''lvsServiceTable.c'''.
Use the generated code as a template for '''lvs.c''' and populate the missing parts.

== CREDITS ==
The code for this module currently is maintained by Jacob Rief. This code is based on ucd-snmpd-lvs written by Romeo Benzoni in 2002 and never modified since. As that code did not compile with the newer net-snmp headers, I decided to rewrite the complete code. The only unchanged parts from the ucd-snmpd-lvs project are LVS-MIB.txt and OC-MIB.txt.

== Extrenal Links ==
Official site: http://homes.tiscover.com/jrief/net-snmp-lvs-module/ (unavailable as of13 July 2008)

[[Category:LVS Software]]

SorryServer

2008-01-14T13:15:23Z

Galbum: /* Setting up a Sorry-Server */

== Setting up a Sorry-Server ==

Sometime all of your real-servers might be down or overloaded. This can be due to a scheduled maintainace interval,
multiple hardware failure, badly written dynamic web-content, broken databases or script kiddies bringing your site down.
In such a situation it is much more polite to tell your customers that you are sorry but your site currently
is down, rather than just being unavailable.

To set up such a webserver you normally would serve only some static content telling your customers that
you are sorry, but your web-services currently are not available. However the requests your customers send,
are regular URLs which are not resolvable by your Sorry-Server, and therefore would be answered with an
Error-Code: '''404 - Not Found'''. This Error-Code can be very annoying, if at the moment of the outage a
robot (such as Googlebot) is indexing your webpages. In such a situation most of your webpages
will fall out of the Google-index and your web-site might have to wait for up to a week to return back to
the Google-index, depending on the number visits of Googlebot per month.

== Using TUX as Sorry-Server ==
[http://www.redhat.com/docs/manuals/tux/TUX-2.2-Manual/ TUX] is a tiny webserver which runs inside the Linux
kernel and is therefore predestined as a Sorry-Server. If your Loadbalancer is able to pass your web-traffic to
a number of real-servers, TUX running on the Loadbalancer is able to handle all that traffic by itself.

The only precaution using TUX is not to send a Status '''200 - Ok''' neither an Error-Code '''404 - Not Found'''
as as Sorry-Page. The best fitting Error-Code to send in such a situation is '''502 - Server Overloaded'''.

However this is not the default behaviour, nor can TUX be configured to do so. You must apply a tiny patch onto
the TUX-kernel-code, recompile that kernel-module and reinstall it onto your Loadbalancer.

Patch for Linux-kernel-2.4:
diff -u kernel-2.4.21/linux-2.4.21/net/tux/proto_http.c linux-2.4.21-tux502/net/tux/proto_http.c
--- linux-2.4.21/net/tux/proto_http.c 2005-03-07 15:09:45.000000000 +0100
+++ linux-2.4.21-tux502/net/tux/proto_http.c 2005-03-07 15:08:13.000000000 +0100
@@ -1172,7 +1172,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1838,7 +1838,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

Patch for Linux-kernel-2.6:
diff -ur linux-2.6.9/net/tux/proto_http.c linux-2.6.9-tux502/net/tux/proto_http.c
--- linux-2.6.9/net/tux/proto_http.c 2005-03-15 12:08:56.660827776 +0100
+++ linux-2.6.9-tux502/net/tux/proto_http.c 2005-03-15 13:13:49.437035840 +0100
@@ -1174,7 +1174,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1840,7 +1840,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

== Running the Sorry-Server ==
First start the TUX kernel-thread, by invoking
/etc/init.d/tux start
The Sorry-Server can run all the time, even if you don't need it.

In case all of your real-servers are down, you must reroute the traffic onto the Sorry-Server. First flush the Real-Server
Tables of your [[IPVS]] invoking
ipvsadm -d -t ''service-address'' -r ''server-address''
for each of your real-servers. Next add a route the web-traffic onto the Sorry-Server, this normally is done by invoking
ipvsadm -a -t ''service-address'' -r 127.0.0.1:80
once. All web-traffic now is redirected onto the Sorry-Server.

Depending on where the TUX-configuration says to have its '''DOCUMENTROOT''', go to that directory and edit the file '''404.html''' adding some text such as ''Momentary system interruption''. You may also add stylesheet- and image-files to the Sorry-Server DOCUMENTROOT, you should however delete any '''index.html''' file since this would be served by default and with a HTTP-Status '''200 - OK'''. This is certainly not your intention.

== Using keepalived ==
The [http://www.keepalived.org/ keepalived] is a program to check real-servers and manage the [[IPVS]]-Tables accordingly. [[Keepalived]] can be configured to automatically reroute all the web-traffic onto a Sorry-Server in case all real-servers are down. Simply add this line to each '''virtual_server''' section in the keepalived's configuration file:
virtual_server ''service_address'' {
''...snip...''
sorry_server 127.0.0.1 80
''...snip...''
}

== CREDITS ==
TUX is a Linux kernel-project maintained by [http://www.redhat.com RedHat].

This patch is maintained by Jacob Rief.

[[Category:LVS Software]]

SorryServer

2008-01-14T12:24:38Z

Galbum: /* CREDITS */

== Setting up a Sorry-Server ==

Sometime all of your real-servers might be down or overloaded. This can be due to a mantainace interval,
hardware failure, badly written dynamic web-content, broken databases or script kiddies bringing your site down.
In such a situation it is much more polite to tell your customers that you are sorry but your site currently
is down, rather than just being unavailable.

To set up such a webserver you normally would serve only some static content telling your customers that
you are sorry, but your web-services currently are not available. However the requests your customers send,
are regular URLs which are not resolvable by your Sorry-Server, and therefore would be answered with an
Error-Code: '''404 - Not Found'''. This Error-Code can be very annoying, if at the moment of the outage a
robot (such as Googlebot) is indexing your webpages. In such a situation most of your webpages
will fall out of the Google-index and your web-site might have to wait for up to a week to return back to
the Google-index, depending on the number visits of Googlebot per month.

== Using TUX as Sorry-Server ==
[http://www.redhat.com/docs/manuals/tux/TUX-2.2-Manual/ TUX] is a tiny webserver which runs inside the Linux
kernel and is therefore predestined as a Sorry-Server. If your Loadbalancer is able to pass your web-traffic to
a number of real-servers, TUX running on the Loadbalancer is able to handle all that traffic by itself.

The only precaution using TUX is not to send a Status '''200 - Ok''' neither an Error-Code '''404 - Not Found'''
as as Sorry-Page. The best fitting Error-Code to send in such a situation is '''502 - Server Overloaded'''.

However this is not the default behaviour, nor can TUX be configured to do so. You must apply a tiny patch onto
the TUX-kernel-code, recompile that kernel-module and reinstall it onto your Loadbalancer.

Patch for Linux-kernel-2.4:
diff -u kernel-2.4.21/linux-2.4.21/net/tux/proto_http.c linux-2.4.21-tux502/net/tux/proto_http.c
--- linux-2.4.21/net/tux/proto_http.c 2005-03-07 15:09:45.000000000 +0100
+++ linux-2.4.21-tux502/net/tux/proto_http.c 2005-03-07 15:08:13.000000000 +0100
@@ -1172,7 +1172,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1838,7 +1838,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

Patch for Linux-kernel-2.6:
diff -ur linux-2.6.9/net/tux/proto_http.c linux-2.6.9-tux502/net/tux/proto_http.c
--- linux-2.6.9/net/tux/proto_http.c 2005-03-15 12:08:56.660827776 +0100
+++ linux-2.6.9-tux502/net/tux/proto_http.c 2005-03-15 13:13:49.437035840 +0100
@@ -1174,7 +1174,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1840,7 +1840,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

== Running the Sorry-Server ==
First start the TUX kernel-thread, by invoking
/etc/init.d/tux start
The Sorry-Server can run all the time, even if you don't need it.

In case all of your real-servers are down, you must reroute the traffic onto the Sorry-Server. First flush the Real-Server
Tables of your [[IPVS]] invoking
ipvsadm -d -t ''service-address'' -r ''server-address''
for each of your real-servers. Next add a route the web-traffic onto the Sorry-Server, this normally is done by invoking
ipvsadm -a -t ''service-address'' -r 127.0.0.1:80
once. All web-traffic now is redirected onto the Sorry-Server.

Depending on where the TUX-configuration says to have its '''DOCUMENTROOT''', go to that directory and edit the file '''404.html''' adding some text such as ''Momentary system interruption''. You may also add stylesheet- and image-files to the Sorry-Server DOCUMENTROOT, you should however delete any '''index.html''' file since this would be served by default and with a HTTP-Status '''200 - OK'''. This is certainly not your intention.

== Using keepalived ==
The [http://www.keepalived.org/ keepalived] is a program to check real-servers and manage the [[IPVS]]-Tables accordingly. [[Keepalived]] can be configured to automatically reroute all the web-traffic onto a Sorry-Server in case all real-servers are down. Simply add this line to each '''virtual_server''' section in the keepalived's configuration file:
virtual_server ''service_address'' {
''...snip...''
sorry_server 127.0.0.1 80
''...snip...''
}

== CREDITS ==
TUX is a Linux kernel-project maintained by [http://www.redhat.com RedHat].

This patch is maintained by Jacob Rief.

[[Category:LVS Software]]

Talk:Main Page

2006-04-22T22:07:10Z

Galbum: add link to Net-SNMP-LVS-Module

Write some discussions about Main Page here. Also, please write Main Page change request here, I protect Main Page because it has been spammed too often and Main Page is the entry point.

== How to setup a Sorry-Server ==
Wensong, it would be nice to set a link onto [[SorryServer]] on the main page. I can well understand that you locked the main-page, since it has been spammed so often.

:Galbum, thanks a lot for adding page [[SorryServer]], will add a link right now, thanks again. --[[User:Wensong|Wensong]] 10:37, 22 Apr 2006 (CST)

:Wensong, at the end of the page [http://www.linuxvirtualserver.org/software/index.html Software], there is a link onto a lvs-snmp module. It seems as if this module is not mantained any more, but I added an alternative to it: [[Net-SNMP-LVS-Module]]. This module is actively mantained and works with the newer versions of Net-SNMP. In order not to confuse the people, I would suggest to replace that link.

== load balancing scheduling algorithm ==

hello friends,

how to calculate aggregated load value in load balancing algorthm.please help me.

:Please take a look at the page [[Dynamic Feedback Load Balancing Scheduling]], maybe it can give some ideas. --[[User:Wensong|Wensong]] 18:15, 12 Mar 2006 (CST)

SorryServer

2006-04-21T14:52:03Z

Galbum: /* Using keepalived */

== Setting up a Sorry-Server ==

Sometime all of your real-servers might be down or overloaded. This can be due to a mantainace interval,
hardware failure, badly written dynamic web-content, broken databases or script kiddies bringing your site down.
In such a situation it is much more polite to tell your customers that you are sorry but your site currently
is down, rather than just beeing not available.

To set up such a webserver you normally would serve only some static content telling your customers that
you are sorry, but your web-services currently are not available. However the requests your customers send,
are regular URLs which are not resolvable by your Sorry-Server, and therefore would be answered with an
Error-Code: '''404 - Not Found'''. This Error-Code can be very annoying, if at the moment of the outage a
robot (such as Googlebot) is indexing your webpages. In such a situation most of your webpages
will fall out of the Google-index and your web-site might have to wait for up to a week to return back to
the Google-index, depending on the number visits of Googlebot per month.

== Using TUX as Sorry-Server ==
[http://www.redhat.com/docs/manuals/tux/TUX-2.2-Manual/ TUX] is a tiny webserver which runs inside the Linux
kernel and is therefore predestined as a Sorry-Server. If your Loadbalancer is able to pass your web-traffic to
a number of real-servers, TUX running on the Loadbalancer is able to handle all that traffic by itself.

The only precaution using TUX is not to send a Status '''200 - Ok''' neither an Error-Code '''404 - Not Found'''
as as Sorry-Page. The best fitting Error-Code to send in such a situation is '''502 - Server Overloaded'''.

However this is not the default behaviour, nor can TUX be configured to do so. You must apply a tiny patch onto
the TUX-kernel-code, recompile that kernel-module and reinstall it onto your Loadbalancer.

Patch for Linux-kernel-2.4:
diff -u kernel-2.4.21/linux-2.4.21/net/tux/proto_http.c linux-2.4.21-tux502/net/tux/proto_http.c
--- linux-2.4.21/net/tux/proto_http.c 2005-03-07 15:09:45.000000000 +0100
+++ linux-2.4.21-tux502/net/tux/proto_http.c 2005-03-07 15:08:13.000000000 +0100
@@ -1172,7 +1172,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1838,7 +1838,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

Patch for Linux-kernel-2.6:
diff -ur linux-2.6.9/net/tux/proto_http.c linux-2.6.9-tux502/net/tux/proto_http.c
--- linux-2.6.9/net/tux/proto_http.c 2005-03-15 12:08:56.660827776 +0100
+++ linux-2.6.9-tux502/net/tux/proto_http.c 2005-03-15 13:13:49.437035840 +0100
@@ -1174,7 +1174,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1840,7 +1840,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

== Running the Sorry-Server ==
First start the TUX kernel-thread, by invoking
/etc/init.d/tux start
The Sorry-Server can run all the time, even if you don't need it.

In case all of your real-servers are down, you must reroute the traffic onto the Sorry-Server. First flush the Real-Server
Tables of your [[IPVS]] invoking
ipvs -d -t ''service-address'' -r ''server-address''
for each of your real-servers. Next add a route the web-traffic onto the Sorry-Server, this normally is done by invoking
ipvs -a -t ''service-address'' -r 127.0.0.1:80
once. All web-traffic now is redirected onto the Sorry-Server.

Depending on where the TUX-configuration says to have its '''DOCUMENTROOT''', go to that directory and edit the file '''404.html''' adding some text such as ''Momentary system interruption''. You may also add stylesheet- and image-files to the Sorry-Server DOCUMENTROOT, you should however delete any '''index.html''' file since this would be served by default and with a HTTP-Status '''200 - OK'''. This is certainly not your intention.

== Using keepalived ==
The [http://www.keepalived.org/ keepalived] is a program to check real-servers and manage the [[IPVS]]-Tables accordingly. Keepalived can be configured to automatically reroute all the web-traffic onto a Sorry-Server in case all real-servers are down. Simply add this line to each '''virtual_server''' section in the keepalived's configuration file:
virtual_server ''service_address'' {
''...snip...''
sorry_server 127.0.0.1 80
''...snip...''
}

== CREDITS ==
TUX is a Linux kernel-project mantained by [http://www.redhat.com RedHat].

This patch is maintained by Jacob Rief.

SorryServer

2006-04-21T14:50:29Z

Galbum: /* Using TUX as Sorry-Server */

== Setting up a Sorry-Server ==

Sometime all of your real-servers might be down or overloaded. This can be due to a mantainace interval,
hardware failure, badly written dynamic web-content, broken databases or script kiddies bringing your site down.
In such a situation it is much more polite to tell your customers that you are sorry but your site currently
is down, rather than just beeing not available.

To set up such a webserver you normally would serve only some static content telling your customers that
you are sorry, but your web-services currently are not available. However the requests your customers send,
are regular URLs which are not resolvable by your Sorry-Server, and therefore would be answered with an
Error-Code: '''404 - Not Found'''. This Error-Code can be very annoying, if at the moment of the outage a
robot (such as Googlebot) is indexing your webpages. In such a situation most of your webpages
will fall out of the Google-index and your web-site might have to wait for up to a week to return back to
the Google-index, depending on the number visits of Googlebot per month.

== Using TUX as Sorry-Server ==
[http://www.redhat.com/docs/manuals/tux/TUX-2.2-Manual/ TUX] is a tiny webserver which runs inside the Linux
kernel and is therefore predestined as a Sorry-Server. If your Loadbalancer is able to pass your web-traffic to
a number of real-servers, TUX running on the Loadbalancer is able to handle all that traffic by itself.

The only precaution using TUX is not to send a Status '''200 - Ok''' neither an Error-Code '''404 - Not Found'''
as as Sorry-Page. The best fitting Error-Code to send in such a situation is '''502 - Server Overloaded'''.

However this is not the default behaviour, nor can TUX be configured to do so. You must apply a tiny patch onto
the TUX-kernel-code, recompile that kernel-module and reinstall it onto your Loadbalancer.

Patch for Linux-kernel-2.4:
diff -u kernel-2.4.21/linux-2.4.21/net/tux/proto_http.c linux-2.4.21-tux502/net/tux/proto_http.c
--- linux-2.4.21/net/tux/proto_http.c 2005-03-07 15:09:45.000000000 +0100
+++ linux-2.4.21-tux502/net/tux/proto_http.c 2005-03-07 15:08:13.000000000 +0100
@@ -1172,7 +1172,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1838,7 +1838,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

Patch for Linux-kernel-2.6:
diff -ur linux-2.6.9/net/tux/proto_http.c linux-2.6.9-tux502/net/tux/proto_http.c
--- linux-2.6.9/net/tux/proto_http.c 2005-03-15 12:08:56.660827776 +0100
+++ linux-2.6.9-tux502/net/tux/proto_http.c 2005-03-15 13:13:49.437035840 +0100
@@ -1174,7 +1174,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1840,7 +1840,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

== Running the Sorry-Server ==
First start the TUX kernel-thread, by invoking
/etc/init.d/tux start
The Sorry-Server can run all the time, even if you don't need it.

In case all of your real-servers are down, you must reroute the traffic onto the Sorry-Server. First flush the Real-Server
Tables of your [[IPVS]] invoking
ipvs -d -t ''service-address'' -r ''server-address''
for each of your real-servers. Next add a route the web-traffic onto the Sorry-Server, this normally is done by invoking
ipvs -a -t ''service-address'' -r 127.0.0.1:80
once. All web-traffic now is redirected onto the Sorry-Server.

Depending on where the TUX-configuration says to have its '''DOCUMENTROOT''', go to that directory and edit the file '''404.html''' adding some text such as ''Momentary system interruption''. You may also add stylesheet- and image-files to the Sorry-Server DOCUMENTROOT, you should however delete any '''index.html''' file since this would be served by default and with a HTTP-Status '''200 - OK'''. This is certainly not your intention.

== Using keepalived ==
The [[http://www.keepalived.org/ keepalived]] is a program to check real-servers and manage the [[IPVS]]-Tables accordingly. Keepalived can be configured to automatically reroute all the web-traffic onto a Sorry-Server in case all real-servers are down. Simply add this line to each '''virtual_server''' section in the keepalived's configuration file:
sorry_server 127.0.0.1 80

== CREDITS ==
TUX is a Linux kernel-project mantained by [http://www.redhat.com RedHat].

This patch is maintained by Jacob Rief.

SorryServer

2006-04-21T14:50:07Z

Galbum: /* Using TUX as Sorry-Server */

== Setting up a Sorry-Server ==

Sometime all of your real-servers might be down or overloaded. This can be due to a mantainace interval,
hardware failure, badly written dynamic web-content, broken databases or script kiddies bringing your site down.
In such a situation it is much more polite to tell your customers that you are sorry but your site currently
is down, rather than just beeing not available.

To set up such a webserver you normally would serve only some static content telling your customers that
you are sorry, but your web-services currently are not available. However the requests your customers send,
are regular URLs which are not resolvable by your Sorry-Server, and therefore would be answered with an
Error-Code: '''404 - Not Found'''. This Error-Code can be very annoying, if at the moment of the outage a
robot (such as Googlebot) is indexing your webpages. In such a situation most of your webpages
will fall out of the Google-index and your web-site might have to wait for up to a week to return back to
the Google-index, depending on the number visits of Googlebot per month.

== Using TUX as Sorry-Server ==
[http://www.redhat.com/docs/manuals/tux/TUX-2.2-Manual/ TUX] is a tiny webserver which runs inside the Linux
kernel and is therefore predestined as a Sorry-Server. If your Loadbalancer is able to pass your web-traffic to
a number of real-servers, TUX running on the Loadbalancer is able to handle all that traffic by itself.

The only precaution using [TUX] is not to send a Status '''200 - Ok''' neither an Error-Code '''404 - Not Found'''
as as Sorry-Page. The best fitting Error-Code to send in such a situation is '''502 - Server Overloaded'''.

However this is not the default behaviour, nor can TUX be configured to do so. You must apply a tiny patch onto
the TUX-kernel-code, recompile that kernel-module and reinstall it onto your Loadbalancer.

Patch for Linux-kernel-2.4:
diff -u kernel-2.4.21/linux-2.4.21/net/tux/proto_http.c linux-2.4.21-tux502/net/tux/proto_http.c
--- linux-2.4.21/net/tux/proto_http.c 2005-03-07 15:09:45.000000000 +0100
+++ linux-2.4.21-tux502/net/tux/proto_http.c 2005-03-07 15:08:13.000000000 +0100
@@ -1172,7 +1172,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1838,7 +1838,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

Patch for Linux-kernel-2.6:
diff -ur linux-2.6.9/net/tux/proto_http.c linux-2.6.9-tux502/net/tux/proto_http.c
--- linux-2.6.9/net/tux/proto_http.c 2005-03-15 12:08:56.660827776 +0100
+++ linux-2.6.9-tux502/net/tux/proto_http.c 2005-03-15 13:13:49.437035840 +0100
@@ -1174,7 +1174,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1840,7 +1840,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

== Running the Sorry-Server ==
First start the TUX kernel-thread, by invoking
/etc/init.d/tux start
The Sorry-Server can run all the time, even if you don't need it.

In case all of your real-servers are down, you must reroute the traffic onto the Sorry-Server. First flush the Real-Server
Tables of your [[IPVS]] invoking
ipvs -d -t ''service-address'' -r ''server-address''
for each of your real-servers. Next add a route the web-traffic onto the Sorry-Server, this normally is done by invoking
ipvs -a -t ''service-address'' -r 127.0.0.1:80
once. All web-traffic now is redirected onto the Sorry-Server.

Depending on where the TUX-configuration says to have its '''DOCUMENTROOT''', go to that directory and edit the file '''404.html''' adding some text such as ''Momentary system interruption''. You may also add stylesheet- and image-files to the Sorry-Server DOCUMENTROOT, you should however delete any '''index.html''' file since this would be served by default and with a HTTP-Status '''200 - OK'''. This is certainly not your intention.

== Using keepalived ==
The [[http://www.keepalived.org/ keepalived]] is a program to check real-servers and manage the [[IPVS]]-Tables accordingly. Keepalived can be configured to automatically reroute all the web-traffic onto a Sorry-Server in case all real-servers are down. Simply add this line to each '''virtual_server''' section in the keepalived's configuration file:
sorry_server 127.0.0.1 80

== CREDITS ==
TUX is a Linux kernel-project mantained by [http://www.redhat.com RedHat].

This patch is maintained by Jacob Rief.

Talk:Main Page

2006-04-21T14:46:21Z

Galbum:

Write some discussions about Main Page here.

== How to setup a Sorry-Server ==
Wensong, it would be nice to set a link onto [[SorryServer]] on the main page. I can well understand that you locked the main-page, since it has been spammed so often.

== load balancing scheduling algorithm ==

hello friends,

how to calculate aggregated load value in load balancing algorthm.please help me.

:Please take a look at the page [[Dynamic Feedback Load Balancing Scheduling]], maybe it can give some ideas. --[[User:Wensong|Wensong]] 18:15, 12 Mar 2006 (CST)

SorryServer

2006-04-21T14:37:32Z

Galbum: /* Using keepalied */

== Setting up a Sorry-Server ==

Sometime all of your real-servers might be down or overloaded. This can be due to a mantainace interval,
hardware failure, badly written dynamic web-content, broken databases or script kiddies bringing your site down.
In such a situation it is much more polite to tell your customers that you are sorry but your site currently
is down, rather than just beeing not available.

To set up such a webserver you normally would serve only some static content telling your customers that
you are sorry, but your web-services currently are not available. However the requests your customers send,
are regular URLs which are not resolvable by your Sorry-Server, and therefore would be answered with an
Error-Code: '''404 - Not Found'''. This Error-Code can be very annoying, if at the moment of the outage a
robot (such as Googlebot) is indexing your webpages. In such a situation most of your webpages
will fall out of the Google-index and your web-site might have to wait for up to a week to return back to
the Google-index, depending on the number visits of Googlebot per month.

== Using TUX as Sorry-Server ==
[[http://www.redhat.com/docs/manuals/tux/TUX-2.2-Manual/ TUX]] is a tiny webserver which runs inside the Linux
kernel and is therefore predestined as a Sorry-Server. If your Loadbalancer is able to pass your web-traffic to
a number of real-servers, TUX running on the Loadbalancer is able to handle all that traffic by itself.

The only precaution using TUX is not to send a Status '''200 - Ok''' neither an Error-Code '''404 - Not Found'''
as as Sorry-Page. The best fitting Error-Code to send in such a situation is '''502 - Server Overloaded'''.

However this is not the default behaviour, nor can TUX be configured to do so. You must apply a tiny patch onto
the TUX-kernel-code, recompile that kernel-module and reinstall it onto your Loadbalancer.

Patch for Linux-kernel-2.4:
diff -u kernel-2.4.21/linux-2.4.21/net/tux/proto_http.c linux-2.4.21-tux502/net/tux/proto_http.c
--- linux-2.4.21/net/tux/proto_http.c 2005-03-07 15:09:45.000000000 +0100
+++ linux-2.4.21-tux502/net/tux/proto_http.c 2005-03-07 15:08:13.000000000 +0100
@@ -1172,7 +1172,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1838,7 +1838,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

Patch for Linux-kernel-2.6:
diff -ur linux-2.6.9/net/tux/proto_http.c linux-2.6.9-tux502/net/tux/proto_http.c
--- linux-2.6.9/net/tux/proto_http.c 2005-03-15 12:08:56.660827776 +0100
+++ linux-2.6.9-tux502/net/tux/proto_http.c 2005-03-15 13:13:49.437035840 +0100
@@ -1174,7 +1174,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1840,7 +1840,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

== Running the Sorry-Server ==
First start the TUX kernel-thread, by invoking
/etc/init.d/tux start
The Sorry-Server can run all the time, even if you don't need it.

In case all of your real-servers are down, you must reroute the traffic onto the Sorry-Server. First flush the Real-Server
Tables of your [[IPVS]] invoking
ipvs -d -t ''service-address'' -r ''server-address''
for each of your real-servers. Next add a route the web-traffic onto the Sorry-Server, this normally is done by invoking
ipvs -a -t ''service-address'' -r 127.0.0.1:80
once. All web-traffic now is redirected onto the Sorry-Server.

Depending on where the TUX-configuration says to have its '''DOCUMENTROOT''', go to that directory and edit the file '''404.html''' adding some text such as ''Momentary system interruption''. You may also add stylesheet- and image-files to the Sorry-Server DOCUMENTROOT, you should however delete any '''index.html''' file since this would be served by default and with a HTTP-Status '''200 - OK'''. This is certainly not your intention.

== Using keepalived ==
The [[http://www.keepalived.org/ keepalived]] is a program to check real-servers and manage the [[IPVS]]-Tables accordingly. Keepalived can be configured to automatically reroute all the web-traffic onto a Sorry-Server in case all real-servers are down. Simply add this line to each '''virtual_server''' section in the keepalived's configuration file:
sorry_server 127.0.0.1 80

== CREDITS ==
TUX is a Linux kernel-project mantained by [http://www.redhat.com RedHat].

This patch is maintained by Jacob Rief.

SorryServer

2006-04-21T14:36:10Z

Galbum:

== Setting up a Sorry-Server ==

Sometime all of your real-servers might be down or overloaded. This can be due to a mantainace interval,
hardware failure, badly written dynamic web-content, broken databases or script kiddies bringing your site down.
In such a situation it is much more polite to tell your customers that you are sorry but your site currently
is down, rather than just beeing not available.

To set up such a webserver you normally would serve only some static content telling your customers that
you are sorry, but your web-services currently are not available. However the requests your customers send,
are regular URLs which are not resolvable by your Sorry-Server, and therefore would be answered with an
Error-Code: '''404 - Not Found'''. This Error-Code can be very annoying, if at the moment of the outage a
robot (such as Googlebot) is indexing your webpages. In such a situation most of your webpages
will fall out of the Google-index and your web-site might have to wait for up to a week to return back to
the Google-index, depending on the number visits of Googlebot per month.

== Using TUX as Sorry-Server ==
[[http://www.redhat.com/docs/manuals/tux/TUX-2.2-Manual/ TUX]] is a tiny webserver which runs inside the Linux
kernel and is therefore predestined as a Sorry-Server. If your Loadbalancer is able to pass your web-traffic to
a number of real-servers, TUX running on the Loadbalancer is able to handle all that traffic by itself.

The only precaution using TUX is not to send a Status '''200 - Ok''' neither an Error-Code '''404 - Not Found'''
as as Sorry-Page. The best fitting Error-Code to send in such a situation is '''502 - Server Overloaded'''.

However this is not the default behaviour, nor can TUX be configured to do so. You must apply a tiny patch onto
the TUX-kernel-code, recompile that kernel-module and reinstall it onto your Loadbalancer.

Patch for Linux-kernel-2.4:
diff -u kernel-2.4.21/linux-2.4.21/net/tux/proto_http.c linux-2.4.21-tux502/net/tux/proto_http.c
--- linux-2.4.21/net/tux/proto_http.c 2005-03-07 15:09:45.000000000 +0100
+++ linux-2.4.21-tux502/net/tux/proto_http.c 2005-03-07 15:08:13.000000000 +0100
@@ -1172,7 +1172,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1838,7 +1838,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

Patch for Linux-kernel-2.6:
diff -ur linux-2.6.9/net/tux/proto_http.c linux-2.6.9-tux502/net/tux/proto_http.c
--- linux-2.6.9/net/tux/proto_http.c 2005-03-15 12:08:56.660827776 +0100
+++ linux-2.6.9-tux502/net/tux/proto_http.c 2005-03-15 13:13:49.437035840 +0100
@@ -1174,7 +1174,7 @@
"<HTML> Forbidden </HTML>";

static const char not_found[] =
- "HTTP/1.1 404 Not Found\r\n"
+ "HTTP/1.1 502 Service temporarily down\r\n"
"Connection: Keep-Alive\r\n" \
"Content-Length: 29\r\n\r\n"
"<HTML> Page Not Found </HTML>";
@@ -1840,7 +1840,7 @@
"HTTP/1.1 206 Partial Content"

#define HEADER_PART1C \
- "HTTP/1.1 404 Page Not Found\r\n" \
+ "HTTP/1.1 502 Service temporarily down\r\n" \
"Content-Type: "

#define HEADER_PART1D \

== Running the Sorry-Server ==
First start the TUX kernel-thread, by invoking
/etc/init.d/tux start
The Sorry-Server can run all the time, even if you don't need it.

In case all of your real-servers are down, you must reroute the traffic onto the Sorry-Server. First flush the Real-Server
Tables of your [[IPVS]] invoking
ipvs -d -t ''service-address'' -r ''server-address''
for each of your real-servers. Next add a route the web-traffic onto the Sorry-Server, this normally is done by invoking
ipvs -a -t ''service-address'' -r 127.0.0.1:80
once. All web-traffic now is redirected onto the Sorry-Server.

Depending on where the TUX-configuration says to have its '''DOCUMENTROOT''', go to that directory and edit the file '''404.html''' adding some text such as ''Momentary system interruption''. You may also add stylesheet- and image-files to the Sorry-Server DOCUMENTROOT, you should however delete any '''index.html''' file since this would be served by default and with a HTTP-Status '''200 - OK'''. This is certainly not your intention.

== Using keepalied ==
The [[http://www.keepalived.org/ keepalied]] is a program to check real-servers and manage the [[IPVS]]-Tables accordingly. Keepalived can be configured to automatically reroute all the web-traffic onto the Sorry-Server. Simply add this line to each '''virtual_server''' block in the keepalived's configuration file:
sorry_server 127.0.0.1 80

== CREDITS ==
TUX is a Linux kernel-project mantained by [http://www.redhat.com RedHat].

This patch is maintained by Jacob Rief.

FAQ

2006-04-21T13:15:31Z

Galbum: /* How do i get counters from ipvsadm in order to create graphs from? */

== General ==
=== What's LVS? ===

LVS stands for Linux Virtual Server, which is a highly scalable and highly available server built on a cluster of real servers, with the [[load balancer]] running on the Linux operating system. Users interact as if it were a single virtual server.

=== Is LVS software free? ===

Yes! All LVS software is released under the [http://www.gnu.org/copyleft/gpl.html GNU General Public License (GPL)].

=== Is there a FreeBSD port of LVS software? ===

Yes, there is a FreeBSD port of IPVS, which supports the [[LVS/DR]] and [[LVS/TUN]] methods now. See [http://dragon.linux-vs.org/~dragonfly/htm/lvs_freebsd.htm the LVS On FreeBSD page] for more information.

=== Does LVS cluster support Linux servers only? ===

No, real servers can almost run any operating systems in a LVS cluster, such as Linux, BSDs, Solaris, and Windows. [[LVS/NAT]] balance servers of the operating systems having TCP/IP support, [[LVS/TUN]] requires servers having IP Tunneling protocol, and [[LVS/DR]] requires servers having a non-arp device. Almost all the modern operating systems support non-arp device.

== Performance ==

=== How is the concurrent processing performance of current LVS software? ===

The ultimate performance of LVS depends on hardware that LVS runs on. An ordinary box with a single Pentium III processor and 100Mbps NIC card running [[LVS/DR]] can handle about 10,000 connections per second for web service. We have heard that a powerful box with good hardware and kernel tuning achieved 50,000 connections per second.

=== Can LVS handle more than 1 million simultaneous connections? ===

Yes, LVS can handle much more than 1 million simultaneous connections. One connection just costs 128 bytes in the LVS box, so an LVS box with 1G memory can handle more than 8 million simultaneous connections.

== Setup ==

=== How do I check to see if my kernel has IPVS enabled? ===

Try to run "modprobe ip_vs" and try to see if there is /proc/net/ip_vs. If so, your kernel has [[IPVS]] enabled. You can also run "cat /proc/net/ip_vs" or "ipvsadm -Ln" to see the version number of [[IPVS]].

== Statistics ==

=== How do i get counters from ipvsadm in order to create graphs from? ===

'''Answer 1:'''

The current kernel 2.6 version of ipvsadm (v1.24) supports
ipvsadm --list --stats --numeric --exact
which gives you non-human-readable counters for Connections, Packets and Bytes for each Service Address and Realserver.

'''Answer 2:'''

Install [http://oss.oetiker.ch/rrdtool/ RRDtool] and preferabely [http://www.cacti.net/ Cacti] onto a host of your choice. From your favorite Linux distribution, install the [http://www.net-snmp.org/ Net-SNMP daemon] onto the Loadbalancer host. Apply the [[Net-SNMP-LVS-Module]] to the Net-SNMP daemon. Using RRDtool and/or cacti you may query the Loadbalancer and create all kind of graphs using the statistics the Loadbalancers IPVS-module delivers.

Net-SNMP-LVS-Module

2006-03-02T10:23:27Z

Galbum:

== GENERAL ==
net-snmpd-lvs-module is a dynamicaly loadable shared object to get the configuration and some statistical information from the Linux kernel with IP virtual server support.

== INSTALLATION ==
Get the [http://homes.tiscover.com/jrief/net-snmp-lvs-module/net-snmp-lvs-module-0.0.4.tar.gz source] for this module. From http://www.linuxvirtualserver.org/software/ipvs.html download the the correct version of ipvsadm, for kernel 2.6 use ipvsadm-1.24 or later, for kernel 2.4 use ipvsadm-1.21. Extract '''ipvsadm-''version''.tar.gz''', build the library and copy the subtree '''libipvs''' into the module's working directory.

Check that the Linux kernel is available under '''/usr/src/linux'''. Install net-snmp and its development headers and libraries. Invoke '''make''', this should build '''lvs.so'''. Copy LVS-MIB.txt and OC.txt to '''/usr/share/snmp/mibs/'''.

Check that the new MIB is visible by invoking
shell> snmptranslate -m LVS-MIB -On -IR lvsServiceEntry,
this should return '''.1.3.6.1.4.1.8225.4711.18.1'''
Copy '''lvs.so''' to '''/usr/lib/libnetsnmplvs.so''' and add the following line to
'''/etc/snmp/snmpd.conf''':
dlmod lvs /usr/lib/libnetsnmplvs.so
Restart your snmpd.

Try if everything works invoking:
shell> snmpwalk -c public -v 2c -m LVS-MIB localhost 1.3.6.1.4.1.8225.4711
LVS-MIB::lvsVersion.0 = STRING: "1.2.0"
LVS-MIB::lvsNumServices.0 = INTEGER: 2
LVS-MIB::lvsHashTableSize.0 = INTEGER: 4096
LVS-MIB::lvsTcpTimeOut.0 = INTEGER: 900
LVS-MIB::lvsTcpFinTimeOut.0 = INTEGER: 120
LVS-MIB::lvsUdpTimeOut.0 = INTEGER: 300
LVS-MIB::lvsDaemonState.0 = INTEGER: none(0)
...

In case you want to add additional snmp-values to your MIB:
Set export MIBS=ALL and create skeleton with
shell> mib2c -c mib2c.interate.conf lvsRealTable
or
shell> mib2c -c mib2c.interate.conf lvsServiceTable
this should create a file '''lvsRealTable.c''' and/or '''lvsServiceTable.c'''.
Use the generated code as a template for '''lvs.c''' and populate the missing parts.

== CREDITS ==
The code for this module currently is maintained by Jacob Rief. This code is based on ucd-snmpd-lvs written by Romeo Benzoni in 2002 and never modified since. As that code did not compile with the newer net-snmp headers, I decided to rewrite the complete code. The only unchanged parts from the ucd-snmpd-lvs project are LVS-MIB.txt and OC.txt.

== Extrenal Links ==
Official site: http://homes.tiscover.com/jrief/net-snmp-lvs-module/