Planet Munin

DebianAccepted 2.0.25-1+deb8u3 in jessie-security (high) (Salvatore Bonaccorso)

DebianAccepted 2.0.25-1+deb8u2 in jessie-security (high) (Salvatore Bonaccorso)

Debianmunin 2.0.33-1 MIGRATED to testing (Britney)

DebianAccepted 2.0.33-1 in unstable (medium) (Holger Levsen)

DebianAccepted 2.0.6-4+deb7u4 in wheezy-security (high) (Jonas Meurer)

DebianAccepted 2.0.32-1 in unstable (medium) (Holger Levsen)

Debianmunin 2.0.31-1 MIGRATED to testing (Britney)

DebianAccepted 2.0.31-1 in unstable (medium) (Holger Levsen)

DebianAccepted 2.0.25-1+deb8u1 in jessie-security (high) (Salvatore Bonaccorso)

DebianAccepted 2.0.6-4+deb7u3 in wheezy-security (high) (Jonas Meurer)

Debianmunin 2.0.30-1 MIGRATED to testing (Britney)

DebianAccepted 2.999.6-1 in experimental (medium) (Holger Levsen)

DebianAccepted 2.0.30-1 in unstable (medium) (Holger Levsen)

Debianmunin 2.0.29-1 MIGRATED to testing (Britney)

DebianAccepted 2.999.5-1 in experimental (medium) (Holger Levsen)

DebianAccepted 2.0.29-1 in unstable (medium) (Holger Levsen)

Debianmunin 2.0.28-1 MIGRATED to testing (Britney)

DebianAccepted 2.999.4-1 in experimental (medium) (Holger Levsen)

DebianAccepted 2.0.28-1 in unstable (medium) (Holger Levsen)

Debianmunin 2.0.27-1 MIGRATED to testing (Britney)

DebianAccepted 2.999.3-2 in experimental (medium) (Holger Levsen)

DebianAccepted 2.0.27-1 in unstable (medium) (Holger Levsen)

Debianmunin 2.0.26-4 MIGRATED to testing (Britney)

DebianAccepted 2.0.26-4 in unstable (medium) (Holger Levsen)

DebianAccepted 2.0.26-3 in unstable (medium) (Holger Levsen)

Debianmunin 2.0.26-2 MIGRATED to testing (Britney)

DebianAccepted 2.999.3-1 in experimental (medium) (Holger Levsen)

Debianmunin 2.0.26-1 MIGRATED to testing (Britney)

DebianAccepted 2.0.26-2 in unstable (medium) (Holger Levsen)

DebianAccepted 2.0.26-1 in unstable (medium) (Holger Levsen)

Stig Sandbeck MathisenMunin 3 packaging

The Munin project is moving slowly closer to a Munin 3 release. In parallel, the Debian packaging is changing, too.

The new web interface is looking much better than the traditional web-1.0 interface normally associated with munin.

New package layout

perl libraries

All the Munin perl libraries are placed in “libmunin-*-perl”, and split into separate packages, where the split is decided mostly on dependencies.

If you don’t want to monitor samba, or SNMP, or MySQL, there should be no need to have those libraries installed. That does mean more binary packages, on the other hand.

Munin master

Munin now runs as a standalone HTTPD, it no longer graphs from cron, nor does it run as CGI or FastCGI scripts.

The user “munin” grants read-write access, while the group “munin” grants read only access. The new web interface runs as the “munin-httpd” user, which is member of the “munin” group.

There is a “munin” service. For now, it runs rrdcached for the munin user and RRD directory.

munin node

The perl “munin-node” and the compiled “munin-node-c” should be interchangeable, and be able to run the same plugins.

Munin node, and Munin async node, should be wholly separate from the munin master. It should be possible to use the perl “munin-node” package, and the

munin plugins

The munin plugins are placed separate packages named “munin-plugins-*”. The split is based on monitoring subject, or dependencies. They depend on appropriate “libmunin-plugin-*-perl” packages

The “munin-plugins-c” package, which is is from the “munin-node-c” source, contains a number of compiled plugins which should use less resources than their shell, perl or python equivalents.

Plugins from other sources than “munin” must work similar to the ones from “munin”. More work on this is needed.

Testing

Late December 2015, I set up Jenkins, with jenkins-debian-glue to build packages, test with autopkgtest and and update my development apt repository on each commit. That helped developing and testing the new Munin packages.

The packages are not quite ready to upload to experimental, but they are continuously deployed to weed out bugs. They can be found in my packaging apt repo. (The usual non-guarantees apply, handle with care, keep away from small children, etc…)

Comments

Munin developers, packagers and users hang out on “#munin” on the OFTC network. Please drop by if you have questions or comments.

Stig Sandbeck MathisenFree software activities in September 2015

What did I do in September 2015?

Munin

Working on making the munin master fit inside Mojolicious.

The existing code is not written to make this trivial, but all the pieces are there. Most of the pieces need breaking up into smaller pieces to fit.

Debian

Packaging

New version of puppet-module-puppetlabs-apache which closes:

  • #788124 By default, produces a configuration incompatible with Apache 2.4
  • #788125 Missing directory referenced in SSL configuration
  • #788127 SSLv3 is not disabled

I like it when a new upstream version closes all bugs left in the bts for a package.

A new package, the TLS proxy hitch currently waiting in the queue.

(Update 2016-01-02: It’s not in NEW anymore)

Puppet

Lots of work on a new ceph puppet module.

Debianmunin 2.0.25-2 MIGRATED to testing (Britney)

DebianAccepted 2.0.25-2 in unstable (medium) (Stig Sandbeck Mathisen)

Debianmunin 2.0.25-1 MIGRATED to testing (Britney)

DebianAccepted 2.0.25-1 in unstable (medium) (Holger Levsen)

Debianmunin 2.0.24-1 MIGRATED to testing (Britney)

DebianAccepted 2.0.24-1 in unstable (medium) (Stig Sandbeck Mathisen)

Debianmunin 2.0.23-1 MIGRATED to testing (Britney)

DebianAccepted 2.0.23-1 in unstable (medium) (Holger Levsen)

DebianAccepted 2.0.22-1 in unstable (low) (Holger Levsen)

DebianAccepted 1.4.5-3+deb6u1 in squeeze-lts (low) (Holger Levsen)

DebianAccepted 2.1.9-1 in experimental (medium) (Stig Sandbeck Mathisen)

Debianmunin 2.0.21-2 MIGRATED to testing (Britney)

DebianAccepted 2.0.21-2 in unstable (medium) (Stig Sandbeck Mathisen)

DebianAccepted 2.0.21-1 in unstable (low) (Stig Sandbeck Mathisen)

DebianAccepted 2.1.6.1-1 in experimental (medium) (Stig Sandbeck Mathisen)

Stig Sandbeck MathisenMunin helps showing performance changes

Using btrfs on a networked backup server looked like a good idea, what with the data integrity checksumming and all. Problem was, we experienced massive performance issues.

Reformatting it to ext4 gave a decent increase in write performance, and will hopefully give fewer server crashes per week (from “many” to “none” is the goal) Just before this wipe-and-reinstall, “umount” had been hanging for a few hours, and the admin got a tad annoyed.

This is on Ubuntu 12.04.4 LTS (GNU/Linux 3.12.8-031208-generic x86_64). The “disk” in question is a single 28T device on a nearby disk shelf.

Now, why this performance difference? We have Munin installed, and showing graphs from before and after the change gives us a few clues.

Network througput

Network throughput increased to the limit. Looks like it is time to move to active/active bonding, instead of active/passive.

network

Storage graphs

The number of operations went down, while the request size increased massively. This allowed much more data to be written to the device.

iops latency throughput utilization

DebianAccepted 2.1.5-1 in experimental (medium) (Holger Levsen)

Debianmunin 2.0.19-3 MIGRATED to testing (Britney)

DebianAccepted 2.0.19-3 in unstable (medium) (Holger Levsen)

DebianAccepted 2.1.4-1 in experimental (medium) (Holger Levsen)

Steve SchneppTutorial - Setup a dev environment for Munin

I discovered some time ago the marvelous dev_scripts/ directory in the munin source code. So, as its usage is very easy, I'll just write a tutorial about how to use it

Prerequisites

To use it, one has to install all the packages needed for munin, and to grab a copy of the source code. Easiest is to use either a tarball, or to clone the git repository.

Note that the guidelines on contributing back are specified directly in the git repo.

Now, I just assume you want to contribute back, otherwise you would not care much about the said dev environment. That means using the git way of doing it.

Download the source code

First step is to clone the git repository. We will use $HOME/src/munin as the development directory.

mkdir -p $HOME/src
cd $HOME/src
git clone https://github.com/munin-monitoring/munin munin
cd munin

Compile munin

Now, we have to compile the source code. I know that it sounds strange as the code is mostly Perl, but there are some templates that need to be filled with the environment specifics, such as the Perl interpreter path, a POSIX compatible shell, ...

dev_scripts/install 1

Now all munin (and munin-node) should be compiled and installed in $HOME/src/munin/sandbox.

Note that the 1 at the end is explained below.

Using the dev tools

There are some different tools in dev_scripts/ :

install

This is the one you used already. You have to use it every time you want to recompile & deploy the package.

The 1 argument, does a full re-install (wipe & install), so you don't usually want to do that.

restart_munin-node

This is a tool to start the development node. Note that it listens on the port 4948, so you can use it alongside a normal munin-node.

run

The run command inside is used to launch all the executable parts of munin, such as munin-update, munin-html or munin-limits. It can also be used to launch munin-run and munin-node-configure.

The usage is very simple, just prefix the command to launch with dev_scripts/run, every environment variable and command line argument will be forwarded to the said command.

# launch munin-cron
dev_scripts/munin-cron

# launch manually some cron parts
dev_scripts/munin-update
dev_scripts/munin-limits
dev_scripts/munin-html
dev_scripts/munin-graph

# debug a plugin
dev_scripts/munin-run --debug cpu config

cgi

This is the same as run, only for CGI. It sets up the whole environment vars that emulates a CGI call. Usage is very easy :

dev_scripts/cgi munin-cgi-graph /localnet/localhost/cpu-day.png > out.dat

The out.dat will contain the whole HTTP output, with the HTTP headers and the PNG content. Everything that is sent to STDERR won't be catched, so you can liberally use it while debugging.

query_munin_node

The query_munin_node is used to send commands to the node in a very simple way. Node commands are just args of the tool.

dev_scripts/query_munin_node list
dev_scripts/query_munin_node config cpu
dev_scripts/query_munin_node fetch cpu

Real CGI usage with your web browser

That's the holy grail. You will have a development version that behaves the same as a real munin install.

First, let's assume you have a working user cgi configuration (ie ~user/cgi/whatever is working). If not you should refer yourself to the local documentation of your preferred webserver. Note that nginx will _not_ work, as it does not support CGI.

I wrote a very simple cgi wrapper script. The home dir is hard coded in the script.

#! /bin/sh

ROOT=/home/me/src/munin
eval "$(perl -V:version)"

PERL5LIB=$ROOT/sandbox/usr/local/share/perl/$version
#export DBI_TRACE=2=/tmp/dbitrace.log

exec perl -T -I $PERL5LIB $ROOT/sandbox/opt/munin/www/cgi/$CGI_NAME

Debianmunin 2.0.19-2 MIGRATED to testing (Britney)

DebianAccepted 2.0.6-4+deb7u2 in wheezy-security (high) (Stig Sandbeck Mathisen)

DebianAccepted 2.0.19-2 in unstable (low) (Holger Levsen)

DebianAccepted 2.0.19-1 in unstable (low) (Holger Levsen)

Debianmunin 2.0.18-1 MIGRATED to testing (Britney)

Steve SchneppExperimenting with a C munin node

Core plugins are designed for simplicity...

As I wrote about it earlier, Helmut rewrote some core plugins in C. It was maintly done with efficiency in mind.

As those plugins are only parsing one /proc file, there seemed no need to endure the many forks inherent with even trivial shell programming. It also acknowledges the fact that the measuring system shall be as light as possible

Munin plugin are highly driven towards simplicity. Therefore having shell plugins is quite logical. It conveys the educational sample purpose for users to write their own, while being quite easy to code/debug for the developpers. Since their impact on current systems is very small, there are not much incentive to change.

... but efficiency is coming !

Nonetheless, now monitored systems are becoming quite small.

It is mostly thanks to embedded systems like the RaspberryPi. This means that processing power available is much lower than on normal nodes[1].

Now the embedded C approach for plugins has a new rationale.

Notes

[1] Usually datacenter nodes are more in the high end of the spectrum than the low-end.

DebianAccepted 2.0.18-1 in unstable (high) (Stig Sandbeck Mathisen)

Footnotes