In the last two years we were suffering from jenkins CPU and memory utilization. The following switches made miracle:

We see ~60% CPU usage at peaks(!) on a Xeon E5504 2.00GHz, instead of constant 400%.
Currently there are 80 executors.

There are number of howtos about changing a lost password in iLO. They’re all talking about properly formatted xml file and hponcfg.

But what if you get this message?

$ hponcfg 
HP Lights-Out Online Configuration utility
Version 4.0.0 Date 12/08/2011 (c) Hewlett-Packard Company, 2011
ERROR:  Could not find the Management Processor Device Node.
  Please check if the iLO driver module is installed and running properly.
  ACTION REQUIRED: Install/Re-install hp Lights-Out driver package('hp-ilo' RPM) for iLO. 

It’s worth verifying, that it’s really iLO not Lights-Out 100!

Lights-Out 100 (or LO100) is a standard IPMI device.

It’s easy to manage:

run-all () {
    GROUP=$1
    shift
    for host in `cat /root/.hosts.$GROUP`; do
        echo $host
        ssh $host "$*"
    done
}

usage:

$ run-all web-servers apt-get upgrade -y

/root/.hosts.web-servers

w1
w2
w3

There are messages like this in glusterfs mount point’s log:

Although it’s not identified as an error, it is. Some of the clients cannot access the affected files.

For fix, run this command on each(?) cluster node:

When you install ant from tarball, according to http://ant.apache.org/manual/install.html library dependencies need to be downloaded and installed.
If you recieve 404 (Not found) you should check this post.
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This come up in many cases. Typical secanario for tomcat based applications.

This is an easy to use mysql backup script. Optionally you can choose whether you want to dump or only copy the database files which are created with an lvm snapshot in a safe way.

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The official wiki page at http://munin-monitoring.org/wiki/HowToContactNagios says, the system can be configured by telnet. But no, you will get timeout.

Actually it can be tested via send_nsca like this:

In syslog this must be appeared if debug is enabled:

Jun 27 17:46:40 nagiospro nsca[6122]: Connection from 127.0.0.1 port 48773
Jun 27 17:46:40 nagiospro nsca[6122]: Handling the connection…
Jun 27 17:46:50 nagiospro nsca[6122]: End of connection…
Jun 27 17:46:54 nagiospro nsca[6129]: Connection from 127.0.0.1 port 49285
Jun 27 17:46:54 nagiospro nsca[6129]: Handling the connection…
Jun 27 17:46:58 nagiospro nsca[6129]: SERVICE CHECK -> Host Name: ‘test’, Service Description: ‘test’, Return Code: ‘0’, Output: ‘test-output’
Jun 27 17:46:58 nagiospro nagios3: EXTERNAL COMMAND: PROCESS_SERVICE_CHECK_RESULT;test;test;0;test-output
Jun 27 17:46:58 nagiospro nagios3: Warning: Passive check result was received for service ‘test’ on host ‘test’, but the host could not be found!
Jun 27 17:47:04 nagiospro nsca[6129]: End of connection…
Jun 27 17:49:32 nagiospro nagios3: Auto-save of retention data completed successfully.

Topology:

WEB [10.0.0.1] – fw1 [1.1.1.1] —– INTERNET —– [2.2.2.2] fw2 – CAMERA [192.168.0.1]

On fw1:

On fw2:

After installing custom openssl certificate it cannot be properly restarted with this failure message:

Starting logger…Failed.
Starting logswatch…ERROR: service.FAILURE (system failure: ZimbraLdapContext) (cause: javax.net.ssl.SSLHandshakeException sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target)
zimbra logger service is not enabled! failed.

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Everybody needs it and bigger crews also use ldap authentication.

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/etc/ssh/sshd_config:

Keep everything for 1 month.
Keep every sunday backup for 3 months
Never erase a backup of the the first day of months.

Problem: After success password change with the plugin change_sqlpass the next page is:

This page request could not be verified and appears to have expired.

This patch get it working on newer systems, for example on Ubuntu 10.04 Lucid Lynx.

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How to load config into varnish with no restart?

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