I've used subversion for quite a while now – I vaguely remember using CVS when working with some Sourceforge projects, but most of my experience is with subversion.

I've used the command svn status (or svn st, for short) to show me what changes there are in my working copy. However, I've occasionally thought it would be nice to see what updates are available in the repository but I've never bothered to find out how to do it. Until now…

Continue reading

I'm using the net-snmp-lvs module to interface LVS statistics to SNMP so I can graph them (I'm using OpenNMS).

I have a virtual HTTP service that is balanced across eight real servers. In testing, everything seemed to work just fine and I got some nice graphs that show the Connection Rate, Packet Rate, and Byte Rate for the virtual service and each of the real servers.

This morning, we attempted a cutover, ie. we re-directed real traffic to the new service. Sadly, our perimeter firewall hit > 90% CPU so we had to revert. But, in the time that we were live, I noticed that the Connection Rate statistics were missing for both the virtual service and the real servers for the period in which the service was under high load:

LVS Connection Rate

LVS Packet Rate

LVS Byte Rate

Notice the gap in the Connection Rate graph when the Packet & Byte rate graphs show high values.

I am currently investigating the cause of this issue.

As I mentioned in a previous post, the MySQL RPMs provided for RHEL/CentOS by percona are not actually compatible with RHEL/CentOS. They use the same package layout as the MySQL-provided RPMs.

Here's how I create my own RPMs having the same package layout as the RHEL/CentOS packages but with the percona highperf patchset applied.

Continue reading

ourdelta provide MySQL packages for various platforms, built with assorted performance/feature patchsets.

Sadly, like the percona builds, the RPM packages for RHEL/CentOS are not upstream-compatible, ie. they package MySQL differently.

I was planning to re-build the ourdelta packages to use the upstream RPM package layout but I've decided to stick with re-building the percona packages as I've already done the work for that.

Anyway, in case it helps someone, here's how to rebuild the ourdelta packages from the SRPM:

rpmbuild --rebuild \
  MySQL-OurDelta-5.0.87.d10-65.el5.src.rpm \
  --define 'ourdelta 1' \
  --define 'mysqlversion 5.0.87' \
  --define 'elversion 5' \
  --define 'patchset d10'

I use puppet to distribute my sshd configuration, including pre-generated ssh certificates.

Here's how I bulk create certificates for a bunch of new nodes named b001-b034:

for n in $(seq -w 1 34); do
    ssh-keygen -q -t rsa -f b0$n -C '' -N ''

Having got racadm working on my workstation (see my previous post), the next step is to perform initial DRAC configuration, ie. change the root password, set the SSL cert values, etc.

First I checked that all DRACs were pingable:

for h in $(seq -w 1 34); do
    if ping -q -c 1 $hn >& /dev/null ; then
        echo OK
        echo failed

Next, I created a drac config file (named drac.cfg) containing the settings that are common to all devices:

# cfgUserAdminIndex=2
# cfgRacSecCsrCommonName=
cfgRacSecCsrOrganizationUnit=Web Services
cfgRacSecCsrLocalityName=My City
cfgRacSecCsrStateName=My State

I then ran a script to apply the common configuration to all devices. I also set the device-specific settings in the same script:

for n in $(seq -w 1 34); do
    racadm -r $fullname -u root -p calvin config -g cfgLanNetworking -o cfgDNSRacName $host
    racadm -r $fullname -u root -p calvin config -g cfgRacSecurity -o cfgRacSecCsrCommonName $fullname
    racadm -r $fullname -u root -p calvin config -f drac.cfg

Notice that I don't change the default password until last.

Now, I just need to work out how to generate the CSR, sign it, and upload the new cert…