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Linux Users of Victoria (LUV) Announce: LUV Beginners May Meeting: Apache Cassandra Workshop

Wed, 2016-05-11 23:02
Start: May 21 2016 12:30 End: May 21 2016 16:30 Start: May 21 2016 12:30 End: May 21 2016 16:30 Location: 

Infoxchange, 33 Elizabeth St. Richmond

Link:  http://luv.asn.au/meetings/map

This hands-on workshop will provide participants with an introduction to the Cassandra distributed "NoSQL" database management system, including deployment, keyspace and table manipulation, replication, creating multiple datacenters and creating users.

Participants will:

  • Install a Cassandra server
  • Create a keyspace
  • Create a table and insert data
  • Replicate data across a three-node cluster
  • Replicate data across a two-datacenter cluster
  • Set up Cassandra and JMX authentication

The meeting will be held at Infoxchange, 33 Elizabeth St. Richmond 3121 (enter via the garage on Jonas St.)

Late arrivals, please call (0490) 049 589 for access to the venue.

LUV would like to acknowledge Infoxchange for the venue.

Linux Users of Victoria Inc., is an incorporated association, registration number A0040056C.

May 21, 2016 - 12:30

read more

Jan Schmidt: Towards GStreamer 1.0 talk

Wed, 2016-05-11 15:01

 

I gave my talk titled “Towards GStreamer 1.0” at the Gran Canaria Desktop Summit on Sunday. The slides are available here

My intention with the talk was to present some of the history and development of the GStreamer project as a means to look at where we might go next. I talked briefly about the origins of the project, its growth, and some of my personal highlights from the work we’ve done in the last year. To prepare the talk, I extracted some simple statistics from our commit history. In those, it’s easy to see both the general growth of the project, in terms of development energy/speed, as well as the increase in the number of contributors. It’s also possible to see the large hike in productivity that switching to Git in January has provided us.

The second part of the talk was discussing some of the pros and cons around considering whether to embark on a new major GStreamer release cycle leading up to a 1.0 release. We’ve successfully maintained the 0.10 GStreamer release series with backwards-compatible ABI and API (with some minor glitches) for 3.5 years now, and been very successful at adding features and improving the framework while doing so.

After 3.5 years of stable development, it’s clear to me that when we made GStreamer 0.10, it really ought to have been 1.0. Nevertheless, there are some parts of GStreamer 0.10 that we’re collectively not entirely happy with and would like to fix, but can’t without breaking backwards compatibility – so I think that even if we had made 0.10 at that point, I’d want to be doing 1.2 by now.

Some examples of things that are hard to do in 0.10:

  • Replace ugly or hard to use API
  • ABI mistakes such as structure members that should be private having been accidentally exposed in some release.
  • Running out of padding members in public structures, preventing further expansion
  • Deprecated API (and associated dead code paths) we’d like to remove

There are also some enhancements that fall into a more marginal category, in that they are technically possible to achieve in incremental steps during the 0.10 cycle, but are made more difficult by the need to preserve backwards compatibility. These include things like adding per-buffer metadata to buffers (for extensible timestamping/timecode information, pan & scan regions and others), variable strides in video buffers and creating/using more base classes for common element types.

In the cons category are considerations like the obvious migration pain that breaking ABI will cause our applications, and the opportunity cost of starting a new development cycle. The migration cost is mitigated somewhat by the ability to have parallel installations of GStreamer. GStreamer 0.10 applications will be able to coexist with GStreamer 1.0 applications.

The opportunity cost is a bit harder to ignore. When making the 0.9 development series, we found that the existing 0.8 branch became essentially unmaintained for 1.5 years, which is a phenomenon we’d all like to avoid with a new release series. I think that’s possible to achieve this time around, because I expect a much smaller scope of change between 0.10 and 1.0. Apart from the few exceptions above, GStreamer 0.10 has turned out really well, and has become a great framework being used in all sorts of exciting ways that doesn’t need large changes.

Weighing up the pros and cons, it’s my opinion that it’s worth making GStreamer 1.0. With that in mind, I made the following proposal at the end of my talk:

  • We should create a shared Git playground and invite people to use it for experimental API/ABI branches
  • Merge from the 0.10 master regularly into the playground regularly, and rebase/fix experimental branches
  • Keep developing most things in 0.10, relying on the regular merges to get them into the playground
  • After accumulating enough interesting features, pull the experimental branches together as a 0.11 branch and make some released
  • Target GStreamer 1.0 to come out in time for GNOME 3.0 in March 2010

This approach wasn’t really possible the last time around when everything was stored in CVS – it’s having a fast revision control system with easy merging and branch management that will allow it.

GStreamer Summit

On Thursday, we’re having a GStreamer summit in one of the rooms at the university. We’ll be discussing my proposal above, as well as talking about some of the problems people have with 0.10, and what they’d like to see in 1.0. If we can, I’d like to draw up a list of features and changes that define GStreamer 1.0 that we can start working towards.

Please come along if you’d like to help us push GStreamer forward to the next level. You’ll need to turn up at the university GCDS venue and then figure out on your own which room we’re in. We’ve been told there is one organised, but not where – so we’ll all be in the same boat.

The summit starts at 11am.

Jan Schmidt: Proof of life – A New Adventure!

Wed, 2016-05-11 15:01

Hi world! It’s been several years since I used this blog, and there’s been a lot of things happen to us since then. I don’t even live on the same continent as I did.

More on that in a future post. Today, I have an announcement to make – a new Open Source company! Together with fellow GStreamer hackers Tim-Philipp Müller and Sebastian Dröge, I have founded a new company: Centricular Ltd.

From 2007 until July, I was working at Oracle on Sun Ray thin client firmware. Oracle shut down the project in July, and my job along with it – opening up this excellent opportunity to try something I’ve wanted for a while and start a business, while getting back to Free Software full time.

Our website has more information about the Open Source technologies and services we plan to offer. This list is not complete and we will try to broaden it over time, so if you have anything interesting that is not listed there but you think we can help with, get in touch

As Centricular’s first official contribution to the software pool, here’s my Raspberry Pi Camera GStreamer module. It wraps code from Raspivid to allow direct capture from the official camera module and hardware encoding to H.264 in a GStreamer pipeline – without the shell pipe and fdsrc hack people have been using to date. Take a look at the README for more information.

Sebastian, Tim and I will be at the GStreamer Conference in Edinburgh next week.

Jan Schmidt: New York trip, DVD stuff

Wed, 2016-05-11 15:01

We’re leaving tomorrow afternoon for 11 days holiday in New York and Washington D.C. While we’re there, I’m hoping to catch up with Luis and Krissa and Thom May. It’s our first trip to either city, so we’re really excited – there’s a lot of fun, unique stuff to do in both places and we’re looking forward to trying to do all of it in our short visit.

On the GStreamer front, I just pushed a bunch of commits I’ve been working on for the past few weeks upstream into Totem, gst-plugins-base and gst-plugins-bad. Between them they fix a few DVD issues like multiangle support and playback in playbin2. The biggest visible feature though is the API that allowed me to (finally!) hook up the DVD menu items in Totem’s UI. Now the various ‘DVD menu’, ‘Title Menu’ etc menu items work, as well as switching angles in multiangle titles, and it provides the nice little ‘cursor switches to a hand when over a clickable button’ behaviour.

I actually had it all ready yesterday, but people told me April 1 was the wrong day to announce any big improvements in totem-gstreamer DVD support

Jan Schmidt: DVD playback in GStreamer 1.0

Wed, 2016-05-11 15:01

Some time in 2012, the GStreamer team was busy working toward the GStreamer 1.0 major release. Along the way, I did my part and ported the DVD playback components from 0.10. DVD is a pretty complex playback scenario (let’s not talk about Blu-ray)

I gave a talk about it at the GStreamer conference way back in 2010 – video here. Apart from the content of that talk, the thing I liked most was that I used Totem as my presentation tool

With all the nice changes that GStreamer 1.0 brought, DVD playback worked better than ever. I was able to delete a bunch of hacks and workarounds from the 0.10 days. There have been some bugs, but mostly minor things. Recently though, I became aware of a whole class of DVDs that didn’t work for a very silly reason. The symptom was that particular discs would error out at the start with a cryptic “The stream is in the wrong format” message.

It turns out that these are DVDs that begin with a piece of video that has no sound.

Sometimes, that’s implemented on a disc as a video track with accompanying silence, but in the case that was broken the DVDs have no audio track for that initial section at all. For a normal file, GStreamer would handle that by not creating any audio decoder chain or audio sink output element and just decode and play video. For DVD though, there are very few discs that are entirely without audio – so we’re going to need the audio decoder chain sooner or later. There’s no point creating and destroying when the audio track appears and disappears.

Accordingly, we create an audio output pad, and GStreamer plugs in a suitable audio output sink, and then nothing happens because the pipeline can’t get to the Playing state – the pipeline is stuck in the Paused state. Before a pipeline can start playing, it has to progress through Ready and Paused and then to Playing state. The key to getting from Paused to Playing is that each output element (video sink and audio sink) in our case, has to receive some data and be ready to output it. A process called Pre-roll. Pre-rolling the pipeline avoids stuttering at the start, because otherwise the decoders would have to race to try and deliver something in time for it to get on screen.

With no audio track, there’s no actual audio packets to deliver, and the audio sink can’t Pre-roll. The solution in GStreamer 1.0 is a GAP event, sent to indicate that there is a space in the data, and elements should do whatever they need to to skip or fill it. In the audio sink’s case it should handle it by considering itself Pre-rolled and allowing the pipeline to go to Playing, starting the ring buffer and the audio clock – from which the rest of the pipeline will be timed.

Everything up to that point was working OK – the sink received the GAP event… and then errored out. It expects to be told what format the audio samples it’s receiving are so it knows how to fill in the gap… when there’s no audio track and no audio data, it was never being told.

In the end, the fix was to make the dummy place-holder audio decoder choose an audio sample format if it gets a GAP event and hasn’t received any data yet – any format, it doesn’t really matter as long as it’s reasonable. It’ll be discarded and a new format selected and propagated when some audio data really is encountered later in playback.

That fix is #c24a12 – later fixed up a bit by thiagoss to add the ‘sensible’ part to format selection. The initial commit liked to choose a samplerate of 1Hz

If you have any further bugs in your GStreamer DVD playback, please let us know!

Jan Schmidt: Network clock examples

Wed, 2016-05-11 15:01

Way back in 2006, Andy Wingo wrote some small scripts for GStreamer 0.10 to demonstrate what was (back then) a fairly new feature in GStreamer – the ability to share a clock across the network and use it to synchronise playback of content across different machines.

Since GStreamer 1.x has been out for over 2 years, and we get a lot of questions about how to use the network clock functionality, it’s a good time for an update. I’ve ported the simple examples for API changes and to use the gobject-introspection based Python bindings and put them up on my server.

To give it a try, fetch play-master.py and play-slave.py onto 2 or more computers with GStreamer 1 installed. You need a media file accessible via some URI to all machines, so they have something to play.

Then, on one machine run play-master.py, passing a URI for it to play and a port to publish the clock on:

./play-master.py http://server/path/to/file 8554

The script will print out a command line like so:

Start slave as: python ./play-slave.py http://server/path/to/file [IP] 8554 1071152650838999

On another machine(s), run the printed command, substituting the IP address of the machine running the master script.

After a moment or two, the slaved machine should start playing the file in synch with the master:

If they’re not in sync, check that you have the port you chose open for UDP traffic so the clock synchronisation packets can be transferred.

This basic technique is the core of my Aurena home media player system, which builds on top of the network clock mechanism to provide file serving and a simple shuffle playlist.

For anyone still interested in GStreamer 0.10 – Andy’s old scripts can be found on his server: play-master.py and play-slave.py

Jan Schmidt: 2014 GStreamer Conference

Wed, 2016-05-11 15:01

I’ve been home from Europe over a week, after heading to Germany for the annual GStreamer conference and Linuxcon Europe.

We had a really great turnout for the GStreamer conference this year

as well as an amazing schedule of talks. All the talks were recorded by Ubicast, who got all the videos edited and uploaded in record time. The whole conference is available for viewing at http://gstconf.ubicast.tv/channels/#gstreamer-conference-2014

I gave one of the last talks of the schedule – about my current work adding support for describing and handling stereoscopic (3D) video. That support should land upstream sometime in the next month or two, so more on that in a bit.

There were too many great talks to mention them individually, but I was excited by 3 strong themes across the talks:

  • WebRTC/HTML5/Web Streaming support
  • Improving performance and reducing resource usage
  • Building better development and debugging tools

I’m looking forward to us collectively making progress on all those things and more in the upcoming year.

Jan Schmidt: OSSbarcamp 2 – GNOME 3.0 talk

Wed, 2016-05-11 15:01

I gave a talk at the second Dublin OSSbarcamp yesterday. My goal was to provide some insight into the goals for GNOME 3.0 for people who didn’t attend GCDS.

Actually, the credit for the entire talk goes to Vincent and friends, who gave the GNOME 3.0 overview during the GUADEC opening at GCDS and to Owen for his GNOME Shell talk. I stole content from their slides shamelessly.

The slides are available in ODP form, or as a PDF

Jan Schmidt: New gst-rpicamsrc features

Wed, 2016-05-11 15:01

I’ve pushed some new changes to my Raspberry Pi camera GStreamer wrapper, at https://github.com/thaytan/gst-rpicamsrc/

These bring the GStreamer element up to date with new features added to raspivid since I first started the project, such as adding text annotations to the video, support for the 2nd camera on the compute module, intra-refresh and others.

Where possible, you can now dynamically update any of the properties – where the firmware supports it. So you can implement digital zoom by adjusting the region-of-interest (roi) properties on the fly, or update the annotation or change video effects and colour balance, for example.

The timestamps produced are now based on the internal STC of the Raspberry Pi, so the audio video sync is tighter. Although it was never terrible, it’s now more correct and slightly less jittery.

The one major feature I haven’t enabled as yet is stereoscopic handling. Stereoscopic capture requires 2 cameras attached to a Raspberry Pi Compute Module, so at the moment I have no way to test it works.

I’m also working on GStreamer stereoscopic handling in general (which is coming along). I look forward to releasing some of that code soon.

 

Jan Schmidt: Mysterious Parcel

Wed, 2016-05-11 15:01

I received a package in the mail today!

Everything arrived all nicely packaged up in a hobby box and ready for assembly.

Lots of really interesting goodies in the box!

After a little while, I’ve got the first part together.

The rest will have to wait for another day. In the meantime, have fun guessing what it is, and enjoy this picture of a cake I baked on the weekend:

See you later!

Jan Schmidt: A glimpse of audio nirvana

Wed, 2016-05-11 15:01

This is post is basically a love letter to the Pulseaudio and Gnome Bluetooth developers.

I upgraded my laptop to Ubuntu Karmic recently, which brought with it the ability to use my Bluetooth A2DP headphones natively. Getting them running is now as simple as using the Bluetooth icon in the panel to pair the laptop with the headphones, and then selecting them in the Sound Preferences applet, on the Output tab.

As soon as the headphones are connected, they show up as a new audio device. Selecting it instantly (and seamlessly) migrates my sounds and music from the laptop sound device onto the headphones. The Play/Pause, Next Track and Previous Track buttons all generate media key keypresses – so Rhythmbox and Totem behave like they’re supposed to. It’s lovely.

If that we’re all, it would already be pretty sweet in my opinion, but wait – there’s more!

A few days after starting to use my bluetooth headphones, my wife and I took a trip to Barcelona (from Dublin, where we live for the next few weeks… more on that later). When we got to the airport, the first thing we learned was that our flight had been delayed by 3 hours. Since I occasionally hack on multimedia related things, I typically have a few DVDs
with me for testing. In this case, I had Vicky Christina Barcelona on hand, and we hadn’t watched it yet – a perfect choice for 2 people on their way to Barcelona.

Problem! There are four sets of ears wanting to listen to the DVD, and only 2 audio channels produced. I could choose to send the sound to either the in built sound device, and listen on the earbuds my wife had, or I could send it to my bluetooth headphones, but not both.

Pulseaudio to the rescue! With a bit of command-line fu (no GUI for this, but that’s totally do-able), I created a virtual audio device, using Pulseaudio’s “combine” module. Like the name suggests, it combines multiple other audio devices into a single one. It can do more complex combinations (such as sending some channels hither and others thither), but I just needed a straight mirroring of the devices. In a terminal, I ran:

pactl load-module module-combine sink_name=shared_play adjust_time=3 slaves=”alsa_output.pci-0000_00_1b.0.analog-stereo,bluez_sink.00_15_0F_72_70_E1″

Hey presto! Now there’s a third audio device available in the Sound Preferences to send the sound to, and it comes out both the wired ear buds and my bluetooth headphones (with a very slight sync offset, but close enough for my purposes).

Also, for those interested – the names of the 2 audio devices in my pactl command line came from the output of ‘pactl list’.

This kind of seamless migration of running audio streams really isn’t possible to do without something like Pulseaudio that can manage stream routing on the fly. I’m well aware that Pulseaudio integration into the distributions has been a bumpy ride for lots of people, but I think the end goal justifies the painful process of fixing all the sound drivers. I hope you do too!

edit
Lennart points out that the extra paprefs application has a “Add virtual output device for simultaneous output on all local sound cards” check-box that does the same thing as loading the combine module manual, but also handles hot-plugging of devices as they appear and disappear.

Michael Davies: Planet Linux Australia... rebooted

Wed, 2016-05-11 13:55
Recently Linux Australia needed to move its infrastructure to a different place, and so we took the opportunity to build a fresh new instance of the Planet Linux Australia blog aggregator.

It made me realise how crusty the old site had become, how many things I had planned to do which I had left undone, and how I hadn't applied simple concepts such as Infrastructure as Code which have become accepted best-practices in the time since I originally set this up.

Of course things have changed in this time.  People blog less now, so I've also taken the opportunity to remove what appear to be dead blogs from the aggregator.   If you have a blog of interest to the Linux Australia community, you can ask to be added via emailing planet at linux dot org dot au. All you need is a valid Atom or RSS feed.

The other thing that is that the blog aggregator software we use hasn't seen an update since 2011. It started out as PlanetPlanet, then moved on to Venus, and so I've taken a fork to hopefully improve this some more when I find my round tuit. Fortunately I don't still need to run it under python 2.4 which is getting a little long in the tooth.

Finally, the config for Planet Linux Australia is up on github.  Just like the venus code itself, pull requests welcome.  Share and Enjoy :-)

Matthew Oliver: Simple Squid access log reporting.

Wed, 2016-05-11 13:07

Squid is one of the biggest and most used proxies on the interwebs. And generating reports from the access logs is already a done deal, there are many commercial and OSS apps that support the squid log format. But I found my self in a situation where I wanted stats but didn’t want to install a web server on my proxy or use syslog to push my logs to a centralised server which was running such software, and also wasn’t in a position to go buy one of those off the shelf amazing wiz bang Squid reporting and graphing tools.

As a Linux geek I surfed the web to see what others have done. I came across a list provided by the Squid website. Following a couple of links, I came across a awk script called ‘proxy_stats.gawk’ written by Richard Huveneers.

I downloaded it and tried it out… unfortunately it didn’t work, looking at the code.. which he nicely commented showed that he had it set up for access logs  from version 1.* of squid. Now the squid access log format from squid 2.6+ hasn’t changed too much from version 1.1. all they have really done is add a “content type” entry at the end of each line.

So as a good Linux geek does, he upgrades the script, my changes include:

  • Support for squid 2.6+
  • Removed the use a deprecated switches that now isn’t supported in the sort command.
  • Now that there is a an actual content type “column” lets use it to improve the ‘Object type report”.
  • Add a users section, as this was an important report I required which was missing.
  • And in a further hacked version, an auto generated size of the first “name” column.

Now with the explanation out of the way, let me show you it!

For those who are new to awk, this is how I’ve been running it:

zcat <access log file> | awk -f proxy_stats.gawk > <report-filename>

NOTE: I’ve been using it for some historical analysis, so I’m running it on old rotated files, which are compressed thus the zcat.

You can pass more then one file at a time and it order doesn’t matter, as each line of an access log contains the date in epoch time:

zcat `find /var/log/squid/ -name "access.log*"` |awk -f proxy_stats.gawk

The script produces an ascii report (See end of blog entry for example), which could be generated and emailed via cron. If you want it to look nice in any email client using html the I suggest wrapping it in <pre> tags.:

<html>
<head><title>Report Title</title></head>
Report title<body>
<pre>
... Report goes here ...
</pre>
</body>
</html>

For those experienced Linux sys admins out there using cron + ‘find -mtime’ would be a very simple way of having an automated daily, weekly or even monthly report.
But like I said earlier I was working on historic data, hundreds of files in a single report, hundreds because for business reasons we have been rotating the squid logs every hour… so I did what I do best, write a quick bash script to find all the files I needed to cat into the report:

#!/bin/bash ACCESS_LOG_DIR="/var/log/squid/access.log*" MONTH="$1" function getFirstLine() { if [ -n "`echo $1 |grep "gz$"`" ] then zcat $1 |head -n 1 else head -n 1 $1 fi } function getLastLine() { if [ -n "`echo $1 |grep "gz$"`" ] then zcat $1 |tail -n 1 else tail -n 1 $1 fi } for log in `ls $ACCESS_LOG_DIR` do firstLine="`getFirstLine $log`" epochStr="`echo $firstLine |awk '{print $1}'`" month=`date -d @$epochStr +%m` if [ "$month" -eq "$MONTH" ] then echo $log continue fi #Check the last line lastLine="`getLastLine $log`" epochStr="`echo $lastLine |awk '{print $1}'`" month=`date -d @$epochStr +%m` if [ "$month" -eq "$MONTH" ] then echo $log fi done

So there you go, thanks to the work of Richard Huveneers there is a script that I think generates a pretty good acsii report, which can be automated or integrated easily into any Linux/Unix work flow.

If you interested in getting hold of the most up to date version of the script you can get it from my sysadmin github repo here.

As promised earlier here is an example report:

Parsed lines  : 32960 Bad lines     : 0 First request : Mon 30 Jan 2012 12:06:43 EST Last request  : Thu 09 Feb 2012 09:05:01 EST Number of days: 9.9 Top 10 sites by xfers           reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- 213.174.155.216                   20   0.1% 100.0%   0.0%        0.0   0.0%   0.0%       1.7       2.5 30.media.tumblr.com                1   0.0% 100.0%   0.0%        0.0   0.0%   0.0%      48.3      77.4 28.media.tumblr.com                1   0.0% 100.0%   0.0%        0.1   0.0%   0.0%      87.1       1.4 26.media.tumblr.com                1   0.0%   0.0%      -        0.0   0.0%      -         -         - 25.media.tumblr.com                2   0.0% 100.0%   0.0%        0.1   0.0%   0.0%      49.2      47.0 24.media.tumblr.com                1   0.0% 100.0%   0.0%        0.1   0.0%   0.0%     106.4     181.0 10.1.10.217                      198   0.6% 100.0%   0.0%       16.9   0.9%   0.0%      87.2    3332.8 3.s3.envato.com                   11   0.0% 100.0%   0.0%        0.1   0.0%   0.0%       7.6      18.3 2.s3.envato.com                   15   0.0% 100.0%   0.0%        0.1   0.0%   0.0%       7.5      27.1 2.media.dorkly.cvcdn.com           8   0.0% 100.0%  25.0%        3.2   0.2%   0.3%     414.1     120.5 Top 10 sites by MB              reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- zulu.tweetmeme.com                 2   0.0% 100.0% 100.0%        0.0   0.0% 100.0%       3.1     289.6 ubuntu.unix.com                    8   0.0% 100.0% 100.0%        0.1   0.0% 100.0%       7.5     320.0 static02.linkedin.com              1   0.0% 100.0% 100.0%        0.0   0.0% 100.0%      36.0     901.0 solaris.unix.com                   2   0.0% 100.0% 100.0%        0.0   0.0% 100.0%       3.8     223.6 platform.tumblr.com                2   0.0% 100.0% 100.0%        0.0   0.0% 100.0%       1.1     441.4 i.techrepublic.com.com             5   0.0%  60.0% 100.0%        0.0   0.0% 100.0%       6.8    2539.3 i4.zdnetstatic.com                 2   0.0% 100.0% 100.0%        0.0   0.0% 100.0%      15.3     886.4 i4.spstatic.com                    1   0.0% 100.0% 100.0%        0.0   0.0% 100.0%       4.7     520.2 i2.zdnetstatic.com                 2   0.0% 100.0% 100.0%        0.0   0.0% 100.0%       7.8    2920.9 i2.trstatic.com                    9   0.0% 100.0% 100.0%        0.0   0.0% 100.0%       1.5     794.5 Top 10 neighbor report          reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- www.viddler.com                    4   0.0% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 www.turktrust.com.tr              16   0.0% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 www.trendmicro.com                 5   0.0% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 www.reddit.com                     2   0.0% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 www.linkedin.com                   2   0.0% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 www.google-analytics.com           2   0.0% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 www.facebook.com                   2   0.0% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 www.dynamicdrive.com               1   0.0% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 www.benq.com.au                    1   0.0% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 wd-edge.sharethis.com              1   0.0% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 Local code                      reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- TCP_CLIENT_REFRESH_MISS         2160   6.6% 100.0%   0.0%        7.2   0.4%   0.0%       3.4      12.9 TCP_HIT                          256   0.8% 100.0%  83.2%       14.0   0.8% 100.0%      56.0    1289.3 TCP_IMS_HIT                      467   1.4% 100.0% 100.0%       16.9   0.9% 100.0%      37.2    1747.4 TCP_MEM_HIT                      426   1.3% 100.0% 100.0%       96.5   5.3% 100.0%     232.0    3680.9 TCP_MISS                       27745  84.2%  97.4%   0.0%     1561.7  85.7%   0.3%      59.2      18.2 TCP_REFRESH_FAIL                  16   0.0% 100.0%   0.0%        0.2   0.0%   0.0%      10.7       0.1 TCP_REFRESH_MODIFIED             477   1.4%  99.8%   0.0%       35.0   1.9%   0.0%      75.3    1399.4 TCP_REFRESH_UNMODIFIED          1413   4.3% 100.0%   0.0%       91.0   5.0%   0.0%      66.0     183.5 Status code                     reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- 000                              620   1.9% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 200                            29409  89.2% 100.0%   2.9%     1709.7  93.8%   7.7%      59.5     137.1 204                              407   1.2% 100.0%   0.0%        0.2   0.0%   0.0%       0.4       1.4 206                              489   1.5% 100.0%   0.0%      112.1   6.1%   0.0%     234.7     193.0 301                               82   0.2% 100.0%   0.0%        0.1   0.0%   0.0%       0.7       1.5 302                              356   1.1% 100.0%   0.0%        0.3   0.0%   0.0%       0.8       2.7 303                                5   0.0% 100.0%   0.0%        0.0   0.0%   0.0%       0.7       1.5 304                              862   2.6% 100.0%  31.2%        0.4   0.0%  30.9%       0.4      34.2 400                                1   0.0%   0.0%      -        0.0   0.0%      -         -         - 401                                1   0.0%   0.0%      -        0.0   0.0%      -         -         - 403                               47   0.1%   0.0%      -        0.0   0.0%      -         -         - 404                              273   0.8%   0.0%      -        0.0   0.0%      -         -         - 500                                2   0.0%   0.0%      -        0.0   0.0%      -         -         - 502                               12   0.0%   0.0%      -        0.0   0.0%      -         -         - 503                               50   0.2%   0.0%      -        0.0   0.0%      -         -         - 504                              344   1.0%   0.0%      -        0.0   0.0%      -         -         - Hierarchie code                 reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- DIRECT                         31843  96.6%  97.7%   0.0%     1691.0  92.8%   0.0%      55.7      44.3 NONE                            1117   3.4% 100.0% 100.0%      131.6   7.2% 100.0%     120.7    2488.2 Method report                   reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- CONNECT                         5485  16.6%  99.2%   0.0%      132.8   7.3%   0.0%      25.0       0.3 GET                            23190  70.4%  97.7%   4.9%     1686.3  92.5%   7.8%      76.2     183.2 HEAD                            2130   6.5%  93.7%   0.0%        0.7   0.0%   0.0%       0.3       1.1 POST                            2155   6.5%  99.4%   0.0%        2.9   0.2%   0.0%       1.4       2.0 Object type report              reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- */*                                1   0.0% 100.0%   0.0%        0.0   0.0%   0.0%       1.6       3.2 application/cache-digest         396   1.2% 100.0%  50.0%       33.7   1.8%  50.0%      87.1    3655.1 application/gzip                   1   0.0% 100.0%   0.0%        0.1   0.0%   0.0%      61.0      30.8 application/javascript           227   0.7% 100.0%  12.3%        2.2   0.1%   7.7%       9.9      91.9 application/json                 409   1.2% 100.0%   0.0%        1.6   0.1%   0.0%       4.1       6.0 application/ocsp-response        105   0.3% 100.0%   0.0%        0.2   0.0%   0.0%       1.9       2.0 application/octet-stream         353   1.1% 100.0%   6.8%       81.4   4.5%   9.3%     236.1     406.9 application/pdf                    5   0.0% 100.0%   0.0%       13.5   0.7%   0.0%    2763.3      75.9 application/pkix-crl              96   0.3% 100.0%  13.5%        1.0   0.1%   1.7%      10.6       7.0 application/vnd.google.sa       1146   3.5% 100.0%   0.0%        1.3   0.1%   0.0%       1.1       2.4 application/vnd.google.sa       4733  14.4% 100.0%   0.0%       18.8   1.0%   0.0%       4.1      13.4 application/x-bzip2               19   0.1% 100.0%   0.0%       78.5   4.3%   0.0%    4232.9     225.5 application/x-gzip               316   1.0% 100.0%  59.8%      133.4   7.3%  59.3%     432.4    3398.1 application/x-javascript        1036   3.1% 100.0%   5.8%        9.8   0.5%   3.4%       9.7      52.1 application/xml                   46   0.1% 100.0%  34.8%        0.2   0.0%  35.1%       3.5     219.7 application/x-msdos-progr        187   0.6% 100.0%   0.0%       24.4   1.3%   0.0%     133.7     149.6 application/x-pkcs7-crl           83   0.3% 100.0%   7.2%        1.6   0.1%   0.4%      19.8      10.8 application/x-redhat-pack         13   0.0% 100.0%   0.0%       57.6   3.2%   0.0%    4540.7     156.7 application/x-rpm                507   1.5% 100.0%   6.3%      545.7  29.9%   1.5%    1102.2     842.8 application/x-sdlc                 1   0.0% 100.0%   0.0%        0.9   0.0%   0.0%     888.3     135.9 application/x-shockwave-f        109   0.3% 100.0%  11.9%        5.4   0.3%  44.5%      50.6     524.1 application/x-tar                  9   0.0% 100.0%   0.0%        1.5   0.1%   0.0%     165.3      36.4 application/x-www-form-ur         11   0.0% 100.0%   0.0%        0.1   0.0%   0.0%       9.9      15.4 application/x-xpinstall            2   0.0% 100.0%   0.0%        2.5   0.1%   0.0%    1300.6     174.7 application/zip                 1802   5.5% 100.0%   0.0%      104.0   5.7%   0.0%      59.1       2.5 Archive                           89   0.3% 100.0%   0.0%        0.0   0.0%      -       0.0       0.0 audio/mpeg                         2   0.0% 100.0%   0.0%        5.8   0.3%   0.0%    2958.2      49.3 binary/octet-stream                2   0.0% 100.0%   0.0%        0.0   0.0%   0.0%       5.5      14.7 font/ttf                           2   0.0% 100.0%   0.0%        0.0   0.0%   0.0%      15.5      12.5 font/woff                          1   0.0% 100.0% 100.0%        0.0   0.0% 100.0%      42.5    3539.6 Graphics                         126   0.4% 100.0%   0.0%        0.1   0.0%   0.0%       0.6       2.5 HTML                              14   0.0% 100.0%   0.0%        0.0   0.0%   0.0%       0.1       0.1 image/bmp                          1   0.0% 100.0%   0.0%        0.0   0.0%   0.0%       1.3       3.9 image/gif                       5095  15.5% 100.0%   2.4%       35.9   2.0%   0.7%       7.2       9.5 image/jpeg                      1984   6.0% 100.0%   4.3%       52.4   2.9%   0.6%      27.0      62.9 image/png                       1684   5.1% 100.0%  10.3%       28.6   1.6%   1.9%      17.4     122.2 image/vnd.microsoft.icon          10   0.0% 100.0%  30.0%        0.0   0.0%  12.8%       1.0       3.3 image/x-icon                      72   0.2% 100.0%  16.7%        0.2   0.0%   6.0%       3.2      15.0 multipart/bag                      6   0.0% 100.0%   0.0%        0.1   0.0%   0.0%      25.2      32.9 multipart/byteranges              93   0.3% 100.0%   0.0%       16.5   0.9%   0.0%     182.0     178.4 text/cache-manifest                1   0.0% 100.0%   0.0%        0.0   0.0%   0.0%       0.7       3.1 text/css                         470   1.4% 100.0%   7.9%        3.4   0.2%   5.8%       7.4      59.7 text/html                       2308   7.0%  70.7%   0.4%        9.6   0.5%   0.6%       6.0      14.7 text/javascript                 1243   3.8% 100.0%   2.7%       11.1   0.6%   5.2%       9.1      43.3 text/json                          1   0.0% 100.0%   0.0%        0.0   0.0%   0.0%       0.5       0.7 text/plain                      1445   4.4%  99.4%   1.5%       68.8   3.8%   5.5%      49.0      41.9 text/x-cross-domain-polic         24   0.1% 100.0%   0.0%        0.0   0.0%   0.0%       0.7       1.7 text/x-js                          2   0.0% 100.0%   0.0%        0.0   0.0%   0.0%      10.1       6.4 text/x-json                        9   0.0% 100.0%   0.0%        0.0   0.0%   0.0%       3.0       8.5 text/xml                         309   0.9% 100.0%  12.9%       12.9   0.7%  87.5%      42.8     672.3 unknown/unknown                 6230  18.9%  99.3%   0.0%      132.9   7.3%   0.0%      22.0       0.4 video/mp4                          5   0.0% 100.0%   0.0%        3.2   0.2%   0.0%     660.8      62.7 video/x-flv                      117   0.4% 100.0%   0.0%      321.6  17.6%   0.0%    2814.9     308.3 video/x-ms-asf                     2   0.0% 100.0%   0.0%        0.0   0.0%   0.0%       1.1       4.7 Ident (User) Report             reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- -                              32960 100.0%  97.8%   3.5%     1822.6 100.0%   7.2%      57.9     129.0 Weekly report                   reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- 2012/01/26                     14963  45.4%  97.6%   3.6%      959.8  52.7%   1.8%      67.3     104.5 2012/02/02                     17997  54.6%  98.0%   3.4%      862.8  47.3%  13.2%      50.1     149.4 Total report                    reqs   %all %xfers   %hit         MB   %all   %hit     kB/xf      kB/s ------------------------- ------------------------------- ------------------------ ------------------- All requests                   32960 100.0%  97.8%   3.5%     1822.6 100.0%   7.2%      57.9     129.0 Produced by : Mollie's hacked access-flow 0.5 Running time: 2 seconds

Happy squid reporting!

Matthew Oliver: Use xmllint and vim to format xml documents

Wed, 2016-05-11 13:07

If you want vim to nicely format an XML file (and a xena file in this example, 2nd line) then add this to your ~/.vimrc file:
" Format *.xml and *.xena files by sending them to xmllint
au FileType xml exe ":silent 1,$!xmllint --format --recover - 2>/dev/null"
au FileType xena exe ":silent 1,$!xmllint --format --recover - 2>/dev/null"

This uses the xmllint command to format the xml file.. useful on xml docs that aren’t formatted in the file.

Matthew Oliver: I’m now an OpenStack developer.

Wed, 2016-05-11 13:07

Hello world,

It’s been a while since I have blogged on this site, I apologise for that. My previous position was a tad proprietary, so although I worked with Linux, what I was doing needs to be sanitised before I can post about it. I have a bunch of posts in the cooker from those days still awaiting sanitation. But I have some great news… I am now an Openstack developer.

It’s been a busy year, married moved over to the UK to work for an amazing company who needs no introduction, Rackspace. Over there I was working with Linux in a Support/DevOps style role, but am back in Oz now with a new team at Rackspace! The Rackspace Cloud Builders. In this role I’ll be getting my development hat on and developing for upstream Openstack again and am so excited about it.

Watch this space!!!

Matt

Matthew Oliver: chkconfig-ify an exising init script.

Wed, 2016-05-11 13:07

If you are using a 3rd party application / package installer to install a service onto a system that using chkconfig to manage your run-levels, or writing your own which are incompatible with chkconfig. That is to say when trying to add them you get the following error:

# chkconfig <service> on
service <service> does not support chkconfig

Then it needs to be converted to support chkconfig. Don’t worry, it isn’t a rewrite, its just adding some meta-data to the init script.
Just edit the config and add the following lines just below the sha-bang (#!/bin/bash or #!/bin/sh).

# chkconfig: 2345 95 05
# description:
# processname:

NOTE: The numbers on the chkconfig line mean:

That on runlevels 2,3,4 and 5, this subsystem will be activated with priority 95 (one of the lasts), and deactivated with priority 05 (one of the firsts).

The above quote comes from this post where I found this solution, so I am passing it on.

For those playing along at home, chkconfig is the Redhat/Centos/Fedora way of managing your run-levels.

Matthew Oliver: Centos 4 / RHEL 4 Bind 9.7.3-8 RPMs.

Wed, 2016-05-11 13:07

In case anyone out there in internet land happen to have a BIND DNS server still running RHEL 4 or Centos 4 and require a version that has been back ported from the Centos 6.2 source, one that has the CVE-2012-1667 fix. Then you can download the RPMs I build from here.

NOTE: I’ve only just built them, so haven’t tested them yet, but thought it’ll be better to share. Also they aren’t x86_64, if you need them, let me know and I’ll build some.

Matthew Oliver: Debian 6 GNU/KFreeBSD Grub problems on VirtualBox

Wed, 2016-05-11 13:07

Debian 6 was released the other day, with this release they not only released a Linux kernel version but they now support a FreeBSD version as well!
So I decided to install it under VirtualBox and check it out…

The install process went smoothly until I got to the end when it was installing and setting up grub2. It installed ok on the MBR but got an error in the installer while trying to set it up. I jumped into the console to take a look around.

I started off trying to run the update-grub command which fails silently (checking $? shows the return code of 1). On closer inspection I noticed the command created an incomplete grub config named /boot/grub/grub.cfg.new

So all we need to do is finish off this config file. So jump back into the installer and select continue without boot loader, this will pop up a message about what you must set the root partition as when you do set up a boot loader, so take note of it.. mine was /dev/ad0s5.

OK, with that info we can finish off our config file. Firstly lets rename the incomplete one:
cp /boot/grub/grub.cfg.new /boot/grub/grub.cfg

Now my /boot/grub/grub.cfg ended like:
### BEGIN /etc/grub.d/10_kfreebsd ###
menuentry 'Debian GNU/kFreeBSD, with kFreeBSD 8.1-1-amd64' --class debian --class gnu-kfreebsd --class gnu --class os {
insmod part_msdos
insmod ext2

set root='(hd0,1)'
search --no-floppy --fs-uuid --set dac05f8a-2746-4feb-a29d-31baea1ce751
echo 'Loading kernel of FreeBSD 8.1-1-amd64 ...'
kfreebsd /kfreebsd-8.1-1-amd64.gz

So I needed to add the following to finish it off (note this I’ll repeat that last part):
### BEGIN /etc/grub.d/10_kfreebsd ###
menuentry 'Debian GNU/kFreeBSD, with kFreeBSD 8.1-1-amd64' --class debian --class gnu-kfreebsd --class gnu --class os {
insmod part_msdos
insmod ext2
insmod ufs2

set root='(hd0,1)'
search --no-floppy --fs-uuid --set dac05f8a-2746-4feb-a29d-31baea1ce751
echo 'Loading kernel of FreeBSD 8.1-1-amd64 ...'
kfreebsd /kfreebsd-8.1-1-amd64.gz
set kFreeBSD.vfs.root.mountfrom=ufs:/dev/ad0s5
set kFreeBSD.vfs.root.mountfrom.options=rw
}

Note: My root filesytem was UFS, thus the ‘ufs:/dev/ad0s5′ in the mountfrom option.

That’s it, you Debian GNU/kFreeBSD should now boot successfully

Matthew Oliver: NTLM Authentication in Squid using Winbind.

Wed, 2016-05-11 13:07

Some old windows servers require authentication through the old NTLM protocol, luckily with the help from squid, samba and winbind we can do this under Linux.

Some URLs a much of this information was gathered from are:

  • http://wiki.squid-cache.org/ConfigExamples/Authenticate/NtlmCentOS5
  • http://wiki.squid-cache.org/ConfigExamples/Authenticate/Ntlm

HOW TO

In order to authenticate through winbind we will be using that and samba to connect to a windows domain, so you will need to have a domain and the details for it or all this will be for naught. I’ll use some fake credentials for this post.

Required Packages
Let’s install all the required packages:

yum install squid krb5-workstation samba-common ntp samba-winbind authconfig

NTP (Network Time Protocol)
Kerberos and windbind can be a little thingy about date and time, so its a good idea to use NTP for your network, I’ll assume your domain controller (DC) will be also your NTP server in which case lets set it up.

Comment out any lines that begin with server and create only one that points to your Active Directory PDC.

# vim /etc/ntp.conf
server pdc.test.lan

Now add it to the default runlevels and start it.

chkconfig ntpd on
/etc/init.d/ntpd start

Samba, Winbind and Kerberos
We will the use the authconfig package/command we installed earlier to configure Samba, Winbind and perform the join in one step, this makes things _SO_ much
easier!!!

NOTE: If you don’t have DNS set up then you will need to add the DC to your hosts file, and it is important to use the name the DC machine knows itself as in AD.


authconfig --enableshadow --enablemd5 --passalgo=md5 --krb5kdc=pdc.test.lan \
--krb5realm=TEST.LAN --smbservers=pdc.test.lan --smbworkgroup=TESTLAN \
--enablewinbind --enablewinbindauth --smbsecurity=ads --smbrealm=TEST.LAN \
--smbidmapuid="16777216-33554431" --smbidmapgid="16777216-33554431" --winbindseparator="+" \
--winbindtemplateshell="/bin/false" --enablewinbindusedefaultdomain --disablewinbindoffline \
--winbindjoin=administrator --disablewins --disablecache --enablelocauthorize --updateall

NOTE: Replace pdc.test.lan with that of your FQDN of your DC server, TESTLAN with your domain, TEST.LAN with the full name of the domain/realm, and make sure you set ‘–winbindjoin’ with a domain admin.

If that succeeds lets test it:

# wbinfo -u
# wbinfo -g

If you are able to enumerate your Active Directory Groups and Users, everything is working.

Next lets test that we can authenticate with winbind:

# wbinfo -a

E.G:

# wbinfo -a testuser
Enter testuser's password:
plaintext password authentication succeeded
Enter testuser's password:
challenge/response password authentication succeeded

Great, we have been added to the domain, so now we can setup squid for NTLM authentication.

SQUID Configuration
Squid comes with its own ntlm authentication binary (/usr/lib64/squid/ntlm_smb_lm_auth) which uses winbind, but as of Samba 3.x, samba bundle their own which is the recommended binary to use (according to the squid and samba projects). So the binary we use comes from the samba-winbind package we installed earlier:

/usr/bin/ntlm_auth

Add the following configuration elements to the squid.conf to enable NTLM authentication:

#NTLM
auth_param ntlm program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp
auth_param ntlm children 5
auth_param ntlm keep_alive on

acl ntlm proxy_auth REQUIRED
http_access allow ntlm

NOTE: The above is allowing anyone access as long as they authenticate themselves via NTLM, you could use further acl’s to restrict this more.

The ntlm_auth binary has other switches that might be of use, such as restricting users by group membership:

auth_param ntlm program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp --require-membership-of=EXAMPLE+ADGROUP

Before we are complete there is one more thing we need to do, for squid to be allowed to use winbind, the squid user (which was created when the squid package was installed) needs to be a member of a wbpriv group:

gpasswd -a squid wbpriv

IMPORTANT!
NTLM authentication WILL FAIL if you have “cache_effective_group squid” set, if you do then remove it! As this overrides the effective group and squid then isn’t seen as part of the ‘wbpriv’ group which breaks authentication!!!
/IMPORTANT!

Add squid to the runlevels and start it:

# chkconfig squid on
# /etc/init.d/squid start

Trouble shooting
Make sure you open the port in iptables, if squid is listening on 3128 then:

# iptables -I INPUT 1 -p tcp --dport 3128 -j ACCEPT
# /etc/init.d/iptables save

NOTE: The ‘/etc/init.d/iptables save’ command saves the current running configuration so the new rule will be applied on reboot.

Happy squid-ing.

Matthew Oliver: Posfix – Making sense of delays in mail

Wed, 2016-05-11 13:07

The maillog

The maillog is easy enough to follow, but when you understand what all the delay and delays numbers mean then this may help really understand what is going on!
A standard email entry in postfix looks like:

Jan 10 10:00:00 testmtr postfix/smtp[20123]: 34A1B160852B: to=, relay=mx1.example.lan[1.2.3.4]:25, delay=0.49, delays=0.2/0/0.04/0.25, dsn=2.0.0, status=sent

Pretty straight forward: date, email identifier in the mailq (34A1B160852B), recipient, which server the email is being sent to (relay). It is the delay and delays I’d like to talk about.

Delay and Delays
If we take a look at the example email from above:

Jan 10 10:00:00 testmtr postfix/smtp[20123]: 34A1B160852B: to=, relay=mx1.example.lan[1.2.3.4]:25, delay=0.49, delays=0.2/0/0.04/0.25, dsn=2.0.0, status=sent

The delay parameter (delay=0.49) is fairly self explanatory, it is the total amount of time this email (34A1B160852B) has been on this server. But what is the delays parameter all about?

delays=0.2/0/0.04/0.25

NOTE: Numbers smaller than 0.01 seconds are truncated to 0, to reduce the noise level in the logfile.

You might have guessed it is a break down of the total delay, but what do each number represent?

Well from the release notes we get:

delays=a/b/c/d:
a=time before queue manager, including message transmission;
b=time in queue manager;
c=connection setup time including DNS, HELO and TLS;
d=message transmission time.

There for looking at our example:

  • a (0.2): The time before getting to the queue manager, so the time it took to be transmitted onto the mail server and into postfix.
  • b (0): The time in queue manager, so this email didn’t hit the queues, so it was emailed straight away.
  • c (0.04): The time it took to set up a connection with the destination mail relay.
  • d (0.25): The time it took to transmit the email to the destination mail relay.

However if the email is deferred, then when the email is attempted to be sent again:

Jan 10 10:00:00 testmtr postfix/smtp[20123]: 34A1B160852B: to=, relay=mx1.example.lan[1.2.3.4]:25, delay=82, delays=0.25/0/0.5/81, dsn=4.4.2, status=deferred (lost connection with mx1.example.lan[1.2.3.4] while sending end of data -- message may be sent more than once)

Jan 10 testmtr postfix/smtp[20123]: 34A1B160852B: to=, relay=mx1.example.lan[1.2.3.4]:25, delay=1092, delays=1091/0.2/0.8/0.25, dsn=2.0.0, status=sent

This time the first entry shows how long it took before the destination mail relay took to time out and close the connection:

delays=0.25/0/0.5/81
Therefore: 81 seconds.

The email was deferred then about 15 minutes later (1009 seconds [delays – <total delay from last attempt> ]) another attempt is made.
This time the delay is a lot larger, as the total time this email has spent on the server is a lot longer.

delay=1092, delays=1091/0.2/0.8/0.25

What is interesting though is the value of ‘a’ is now 1091, which means when an email is resent the ‘a’ value in the breakdown also includes the amount of time this email has currently spend on the system (before this attempt).

So there you go, those delays values are rather interesting and can really help solve where bottlenecks lie on your system. In the above case we obviously had some problem communicating to the destination mail relay, but worked the second time, so isn’t a problem with our system… or so I’d like to think.