Difference between revisions of "Net-SNMP-LVS-Module"

Latest revision as of 21:13, 20 January 2010

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 IP virtual server support.

INSTALLATION

Get the source for this module (local copy or 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.

Troubleshooting

If you find an output for like this:

[root@machine ~]# snmpwalk -c public -v 2c -m LVS-MIB localhost 1.3.6.1.4.1.8225.4711
LVS-MIB::lvs = No more variables left in this MIB View (It is past the end of the MIB tree)

I found the solution to be [quite] less conservative with snmpd.conf here:

«You can add following lines to snmpd.conf ('+' marks which line was added). This is an example and you should be very careful in granting access to your snmp coz potentially it can be a security issue:»

+view all    included  .1
view    systemview    included   .1.3.6.1.2.1.1

+access  notConfigGroup ""      any       noauth    exact  all none none
access  notConfigGroup ""      any       noauth    exact  systemview none none

This was verified in CentOS 5.2.

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.