SSH Sessions Timing Out?

Now this might be common knowledge but it took me while searching and scratching about to find the right solution.

As many others do I’m sure, I use ssh terminal sessions a lot. I’ve often got half a dozen open at once either in separate terminals or in Terminator for example. Sometimes if I don’t update them for a reasonable length of time they simply lock up so that I have no response at all. I’ve not actually timed this issue but I expect it is happening somewhere between 10 and 30 minutes of inactivity.

After getting annoyed for the umpteenth time today I finally did some serious searching… I concluded that this lock-up is probably due to my broadband router. It wasn’t happening across the local LAN or when I was connecting from other locations so I already suspected my broadband service. I suspect that it’s a NAT cache timeout or something but that’s not really important.

Several howtos I found discussing various timeout problems suggested editing the ssh config file on the server. This is fine if you know which server(s) you will be connecting too all the time and of course if there don’t happen to be hundreds of them that you need to re-configure. But if you don’t know or do use many machines then that’s not an ideal solution at all.

I think this is though 🙂

If you haven’t already got one, make a file in your home ssh directory (on Ubuntu it is normally found in ~/.ssh):


touch ~/.ssh/config


Open it with your favourite editor and enter a line something like this:


ServerAliveInterval 120


Then save and close it. From my initial tests this seems to do the trick nicely.

According to the manual it:

Sets a timeout interval in seconds after which if no data has been received from the server, ssh(1) will send a message through the encrypted channel to request a response from the server. The default is 0, indicating that these messages will not be sent to the server, or 300 if the BatchMode option is set. This option applies to protocol version 2 only. ProtocolKeepAlives and SetupTimeOut are Debian-specific compatibility aliases for this option.

This is one of those things I should have done ages ago. I hope this help others who find their ssh sessions mysteriously hanging.

The Ubuntu UK Christmas Party

The decorations have been in the shops for months, the clocks have changed, sooner or later we are going to have to face up to the inevitability of another Christmas, and there  is nothing we can do to prevent it.

Take a moment to look forward to your long weekend of seasonal festivities with close family, distant relatives, and the not-quite-distant-enough ones. Think of the present opening, the joy of seeing another pair of socks, the screams of rage that inform you that Ben 10 was last years hot thing and a completely inappropriate present to have given this year. Just think about the meal of curiously burned stuffing inside a not-quite-cooked turkey which you will then smother with cranberry jam for no apparent culinary purpose. Spare a moment to consider the bowl of sprouts and the fun of watching adults attempting to fool children into thinking they are edible. Perhaps after the meal someone will suggest that you all play a board game together, won’t that be fun! The best you can hope for is that they will all be asleep before the Dr Who Christmas special starts.

If these thoughts of Christmas have left you in need of a stiff drink, don’t worry you are not alone, and we have a plan. The Ubuntu UK Christmas event will be held at The Hub Islington on December 21st from 7PM. You can register your attendance here (launchpad account required). We would invite you to bring some Christmas and/or Ubuntu themed nibbles and optionally a bottle of something to ward off the cold. Take an evening out to relax with friends and steel yourself for what is to come.

Ubingo!

Next week is a rather special week in the Ubuntu development cycle, it is the Ubuntu Developer Summit. This is a gathering hosted by Canonical, this time in Orlando, Florida, where developers and all those interested in the future direction of Ubuntu can discuss in person the plans for the next 6 month development cycle leading up to the Natty Narwhal release.

It isn’t just a random talking shop though, there is a very structured and full schedule, in fact you can see it all here http://summit.ubuntu.com/uds-n/ the times are all local to Florida, which means the day starts at 2PM UK time. To participate remotely there are IRC channels for each room and there will be remote audio to listen to, so wherever you are in the world you can get your thoughts and opinions across, and choose bits that you want to contribute to in this cycle.

The whole thing kicks off with a keynote address by Mark Shuttleworth on Monday, where he will set out some of the major themes of the week and of the cycle. To spice things up a bit for all the remote participants we have created a little game to play along from home, click the link to start playing:

ubingo

Rules

• One gulp of $drink for each word said during Mark Shuttleworth’s keynote speech at the Natty Narwhal Ubuntu Developer Summit
• Finish the glass you are on when you complete a line (and pour another)
• Have a shot glass lined up to down if you get all the words
• If you are in a timezone where the sun is not yet over the yard arm, or are not of drinking age or inclination then you might want to use a non-alcoholic beverage, this is of course perfectly acceptable
• Players attending UDS in person should probably not be drinking (or shouting out “House!”)
• Players should join the #ubuntu-UDS channel on freenode to shout out the words they spot (although we might move to a different channel if play becomes disruptive)

How to remove Mono from Ubuntu 10.10 Maverick Meerkat

sudo apt-get purge libmono* cli-common

The following packages will be REMOVED
cli-common* gbrainy* libappindicator0.1-cil* libart2.0-cil* libgconf2.0-cil*
libglade2.0-cil* libglib2.0-cil* libgmime2.4-cil* libgnome-vfs2.0-cil*
libgnome2.24-cil* libgnomepanel2.24-cil* libgtk2.0-cil*
liblaunchpad-integration1.0-cil* libmono-addins-gui0.2-cil*
libmono-addins0.2-cil* libmono-cairo2.0-cil* libmono-corlib2.0-cil*
libmono-i18n-west2.0-cil* libmono-management2.0-cil* libmono-posix2.0-cil*
libmono-security2.0-cil* libmono-sharpzip2.84-cil* libmono-system2.0-cil*
libndesk-dbus-glib1.0-cil* libndesk-dbus1.0-cil* mono-2.0-gac*
mono-csharp-shell* mono-gac* mono-gmcs* mono-runtime* tomboy*
0 upgraded, 0 newly installed, 31 to remove and 0 not upgraded.

Maverick Meerkat Release Parties in the UK

This weekend the date on Sunday will be 10/10/10 and this being a rather special number it has been declared a global day of doing for reducing carbon outputs and participating in environmentally worthy projects as well as a good day to get married as 101010 in binary is 42 in decimal it has also been declared fourty two day in celebration of the Hitchhiker books of Douglas Adams. We will be doing something much more important however as it is the release day of Ubuntu 10.10 the Maverick Meerkat. In the UK there will be a release party on Sunday, which is also a 42 day celebration including screening of the HHGTTG film. The event will continue into the evening and I am sure a good time will be had by all those who don’t come dressed as Marvin the paranoid android.

A somewhat more civilized and sensible event follows on Tuesday 12th at Fossbox in London, mainly aimed at charities and the voluntary sector, introducing attendees to the Ubuntu desktop.

On Wednesday 13th there is another event, this one hosted by University College London and aimed mostly at students, but open to all.

On Saturday 16th in Swindon there will be demos and info about Ubuntu at the Museum of Computing, again this event is open to all.

If you are in the area of any of these events then do pop along, either if you haven’t used Ubuntu before and want to find out more, or if you are a seasoned veteran and want to meet other people in your area and talk about Ubuntu.

If you are wondering why there is a bit of a London focus to the events (apart from the Swindon one of course) and you want an event in a city near you then don’t forget *you* can organise events, and ask for help in the ubuntu-uk mailing list to gather support for an event where you want it.

vtiger on demand – Open Source as a Service

Today we are adding a new offering to our regular line up of consultancy services and comprehensive on-site bundles and this time it is out in the cloud.

There is a clear general trend towards outsourced software as a service, back when this first became a viable concept technically it seemed complete madness to me to have all your valuable data locked up on some server you never even get to see. You would be at the mercy of the vendor, subject to them raising their prices or going out of business and with very little recourse when they do. This remains a major business risk with proprietary software as a service, but the benefits of not requiring in-house hardware and expertise to install and manage a useful and scalable solution are still quite compelling.

With Open Source as a Service things are somewhat different, you still get to wash your hands of the installation and management of the hardware and software, upgrades just happen and they are someone else’s problem. You get the low cost of entry and prices that that are in proportion to the amount of users that are getting value from it. You also get Freedom instead of lock-in. You can take your hosted cloud based software and run the same code somewhere else. Either on another bit of remote hardware you never see, or on a box with flashing lights that sits quietly in a broom cupboard somewhere in your building. You are not at all locked in to Open Source as a Service, you are using it because it provides benefits you want at a price that is good value, as well as financially supporting the further development of the software.

So the announcement today is that The Open Learning Centre is partnering with vtiger CRM to bring the vtiger on demand Open Source as a Service to the UK market. This is hosted out in the cloud (Amazon EC2 to be precise) and managed on a day to day basis by the vtiger engineers. We can provide an optional on-site training day to complement the hosted service and of course at any time you can transition from the hosted CRM to one of our Ubuntu based Libertus servers (or the other way round if you like). This is just one example of how Software Freedom makes total business sense and it illustrates the difference between free as in no cost and the much more important free as in Freedom.