The Well House Newsletter - Sunday, 1st September 2013
About us and this newsletter [link] ...
Previous editions: July 2013 • May 2013 • March 2013 • January 2013 • November 2012 • September 2012 • July 2012 • May 2012 • March 2012 • or current edition

Public Transport • Training from Well House Consultants • And also ... • Tcl, Tcl/Tk and Expect • Programming in Lua • Python Programming • Well House Manor - Hotel and Training Centre • Apache HTTP and Tomcat Servers • The Perl Programming Language and its use • Ruby and Ruby on Rails • PHP - the language and its application • C and C++ Programming • Linux and Shell Programming • Melksham • SQL and MySQL • For the Webmaster, Postmaster and moderator • Java and the Java Environment • Fun and Flames • Running a training and hotel company • Around, about and nearby to Wiltshire • Client Side Languages (HTML, CSS, Javascript) • Keynote Articles • General Programming Topics
Keynote article ...

Clustering on Tomcat

Subject: Clustering, using Apache http server (version 2.2.14 in my example) with mod_proxy_balancer as the front load splitter and Apache Tomcat 6.0.20 as the replicated application engine. [[Tip should also work for other recent 2.2.x and 6.0.x versions]]

Background

This is a follow on article from Load balancing with sticky sessions (httpd / Tomcat), where I looked at sharing out the application work between a number instances of Tomcat from an Apache http server (httpd) that did the bookkeeping. In a nutshell, the Apache http server sent new arrivals to a 'random' Tomcat, and then used sticky sessions so that - when a visitor came back for their subsequent visit in the same series of accesses - they would always talk to the same Tomcat and could continue their conversation with the server having full knowledge of the position to date.

The balancer alone is a good solution as far as it goes but:
• What happens if the Tomcat that has been stuck to goes out of service?
• What happens if you have such a lot of traffic that you need to replicate your httpd front end?
• What happens if your httpd fails?
• What is you don't actually want to use sessions, but still need what appears to be a single Tomcat?

One possible option to addressing some of these is to use the clustering capability of Tomcat, which I'll describe below. But you should first consider if you really need the extra step:
(a) can I accept that a session will be lost on the rare occasions that a Tomcat goes offline?
(b) is writing to a backend database going to preserve sufficient information anyway?
and if the answer to either is "yes", you probably do NOT need to cluster.

How does clustering work?

You run your web application on a series of identical (or rather "near identical" - the IP address will differ!) servers. With clustering turned on, each of the servers in the cluster is broadcasting (via multicast) any changes made in sessions, cookies, etc to any other listening cluster members on that same multicast address. So that when a visitor comes back for his / her next access, all the machines know what's been going on and can knowledgeably handle the request, even if the original machine isn't available.

You can turn clustering on in Apache Tomcat 6.0.20 simply by uncommenting the line in the default server.xml file that relates to it:
  <Cluster className = "org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
and restating your Tomcat. Older versions of Tomcat (such as 5.5) had a long configuration section listing the ports, replication time, IP addresses to use, trigger files all of which are important but none of which actually needs to be changed from default in the current release that's the target of this article.

Once you have turned clustering on (yes, it's now that simple), your machines will be communicating ... it's rather like starting a rumor in an office - before you know it, EVERYONE who's around has heard the rumor.

Clustering with the balancer

If you have already implemented balancing with sticky sessions (as covered in the preceeding article), turning on clustering will cause the data to be shared around. Most of the time the data passed around will not be used - it will ONLY form a backup of the session, to be used if the balancer is unable to reach the sticky machine because it has done down or been taken out of service.

With sticky sessions activated, even a second front-end Apache http server won't cause a switch from one Tomcat to another unless a fail-over occurs, as the jvmroute is a part of the cookie so either (any) of the httpd front ends will correctly forward to the original Tomcat. And if you have an intelligent hardware load balancer, that too will be able to forward consistently and the the clustering will remain merely as a backup.

If you disable sticky sessions on your balancer, the metrics will change. Forwarding will now be at shared to each of the Tomcats in the balanced group / cluster group (take care that all members of the balance group are included in the cluster!) and so the visitor will get to a differnt back end box each time. But that's now perfectly fine, as they're sharing the data between them so will all know about the originator.

Testing if your cluster is working

Ironically, clustering and balancing is designed to be transparent, so how do you test whether it's working?

My first simple 'trick' is to change the background colour of the pages returned from each cluster member so that "if it's orange it must be Holt" and "if it's blue it must be Chippenham" (our servers are names after local towns and villages!). Going a little further, you can edit your servlet / JSP to return the name of the current host. In Java, the following line:
  String myname = InetAddress.getLocalHost().getHostName();
will return you the local name of your computer, so that you can then echo the name.

On last Tuesday's course, I took our sample "Barman" script that remembers how many drinks you've had in a session (visit counter!) and extended it into a "Pub Watch" script, where each of the barman communicates with his colleagues in neighboring pubs to keep track of who's out on the town, and how much they have had to drink in each establishment.

If you click on the links in the previous paragraph, you can download the source code for "Barman" and "PubWatch" and try the code out for yourself. Using the balancer manage that I introduced at the end of yesterday's article, you can open and close individual pubs and see how their customers go elsewhere for their next drink, and you can turn sticky sessions off in the balancer and see how faithful customers will then hit the road and go to a different pub each time for their next drink.

Some notes on clustering

1. The machines in the cluster communicate through multicast, so must be on the same subnet.

2. It's a good idea for the subnet you use to have plenty of capacity if your environment is busy, and for it to be firmly behind a strong firewall from your own company's general user traffic, let alone the Internet

3. If you have multiple Tomcat clusters on the same subnet, you'll need to configure one of the clusters away from the default settings - otherwise they'll end up as being one big cluster (you'll find the word 'tribe' creaping in here!)

At present, we mention clustering on our public deploying apache httpd and Tomcat course. Only a small proportion of our delegate want to go 'that far', and for newcomers who hadn't done any web server work when they first came along a couple of days earlier, it would be just too much for the one session.

An extra day on the end of a Tomcat course, coverage in a private course, or a special session set up for the purpose ... all are possible to help you learn how clustering and balancing work. We'll have a network of computers set aside at our training centre for the purpose of setting up a test case, experimenting with configurations, seeing what happens when machines are switched on and off. Something you wouldn't dare so with your own production environment, and might be reluctant to do even on your development of test networks (that's even assuming that you do HAVE multiple machines at the development or test level).
(this article written on 2009-10-30)

Other articles ...

Linux and Shell Programming
[4063] Backups by crossover between network centres - setting up automatic scp transfers
[4056] An overpractical test of our backup strategy!
[4045] Linux Web Server - User Roles, User Accounts, and shared administration
[3891] The components of an Apache httpd / Tomcat / MySQL stack and what each does
[3792] Managing daemons from a terminal session
Top or Show all for Linux and Shell Programming

Apache HTTP and Tomcat Servers
[4064] Apache httpd - a robust, open source web server
[3996] Tips on Tomcat - moving applications around
[3915] How does PHP work?
[3892] Distributed, Balanced and Clustered Load Sharing - the difference
[3862] Forwarding a whole domain, except for a few directories - Apache http server
Top or Show all for Apache HTTP and Tomcat Servers

C and C++ Programming
[4128] Allocating memory dynamically in a static language like C - (new - 2013-06-30)
[3982] Using a vector within an object - C++
[3811] Associated Classes - using objects of one class within another
[3809] Dwarf Exception Unwind Info
[3807] Reading (and writing) files in C++
Top or Show all for C and C++ Programming

Melksham
[4151] Tell me a bit about Melksham - (new - 2013-08-10)
[4145] After the storm - (new - 2013-07-29)
[4119] Melksham - Flower Town
[4116] International Melksham - industry, and beautiful countryside
[4103] Questions from children about Melksham Campus
[4101] POETS day at Well House Manor
[4097] Melksham Chamber of Commerce - Report for AGM, 21st May 2013
[4084] New Pictures - Melksham Pack Horse Bridge
[4048] Art, Catering, Transport - Melksham Campus Elements - reaching local experts
[4046] Over a hundred welcoming businesses - Melksham Town Centre
[4041] Report on the last year - Melksham Chamber of Commerce and Industry for Melksham Without Parish Council
[4040] Report on the last year - Melksham Railway Developement Group for Melksham Without Parish Council
[4039] Seed Swap at Well House Manor
[4020] Melksham Community - Annual Report / MCAP
[4018] Afternoon Teas and Breakfasts at Well House Manor
[4014] Costa Coffee in Melksham - is it a good idea?
[4002] Images of Melksham you havent seen before
[3987] Melksham Chamber of Commerce - join us in our future
[3967] Hotel bedroom - even larger TV!
[3960] Picture - between Lacock and Melksham
[3949] Melksham Spa from Woolmore Farm
[3948] Quiet little town? Advanced Technology Centre?
[3944] Melksham Christmas Lights, 2012
[3904] Want to help us improve transport in Wiltshire? Here is how!
[3901] How much parking should there be at Melksham Campus?
[3897] Autumn scenes from Melksham
[3889] Melksham Chamber of Commerce - whence in 2013 and beyond?
[3888] What a difference a year made - Melksham Campus
[3882] Community Transport - Pewsey, Taunton, and the whole picture too
[3880] Chamber of Commerce - looking forward in Melksham and in Wessex
[3869] How have Melksham shops changed in 60 years?
[3867] The difficult interface between the business, council and voluntary sectors
[3861] Melksham Food Festival - the food fayre - pictures
[3858] The apple crop of 2012
[3834] Geekmas 2012 - celebrating open source languages such as Perl, PHP and Python
[3828] Pimms and Croquet in Edwardian Melksham - 8th September 2012 - Food Festival Event
[3827] Melksham Community Apple Pressing Day
[3822] Town Clean - Melksham
[3821] Well House Manor at Dawn ... and later in the day
[3818] Making things happen - litter and ASB and lost dogs in Melksham
[3812] The Melksham News - July 2012 - Part 1, Campus and Chamber of Commerce
[3787] Melksham Pride - the Chamber of Commerce, and the future
[3774] Melksham - a new dawn
[3768] Melksham Chamber of Commerce - looking to our future shape. Pivotal meeting next Tuesday
[3767] How well do you know Melksham?
[3752] Melksham Visitors Map - Bus routes and train lines to and from the town
[3751] Public transport for international arrivals into Melksham
[3748] Not everyone has a computer - 9 more ways to learn about the Melksham Campus
[3744] Short Web Addresses for Melksham
[3741] Low carbon and other environmental lessons for the Melksham Campus?
[3739] Go green - business seminar in Melksham
[3735] A walk around Melksham this morning. Can you place all of these?
[3732] Ten more visitors to your premises every day?
[3719] Strawberry Cream Teas, Well House Manor, Melksham, starting this weekend
[3714] Just 12 winners? Or 371 or more? Town Centres.
[3712] Some unpublished and historic pictures - Museum of Melksham
[3710] Encouraging business in Melksham and its neighbourhood - keep business local??
[3706] An exciting Chamber of Commerce AGM - sound like an Oxymoron?
[3704] The Bowerhill Villager - a newsletter for Bowerhill, Melksham
[3703] A Museum for Melksham History. Open from 12th May 2012.
[3700] Why do people use chains rather than independent traders?
[3697] Events in Melksham - read all about them, and tell us about yours
[3696] Melksham government and business organisations
[3693] Wiltshire Business Support Service
[3692] Deeper than Art - An exhibition of the tattoo Canvas - Melksham
[3682] Melksham Business Newsreel
[3677] Some advise for guest speakers at meetings
[3672] Melksham Train Service - please support the TransWilts case for regular trains
[3663] Changing shops and organisations - Melksham, the last and next five years
[3659] Welcome to Melksham - our new communities
[3657] Basham Festival, Melksham, early August 2012 - a welcome
[3656] TrainWest 2012 - 14th and 15th April, Melksham, Wiltshire
[3647] Along the brook - East Melksham to Melksham
[3644] The way of the Prioress - Melksham history pictured today
[3643] Hotel food, Melksham - enjoy the variety of the American way
[3627] Meeting Report - Tuesday 21st Feb - to Melksham Chamber of Commerce from Shadow Community Operations Board
[3605] Snow comes to Melksham, Wiltshire - pictures
[3604] Melksham Campus - a blog you can read, and a place you can comment
[3598] Melksham Civic Awards - report and pictures
[3597] Niche businesses in Melksham. From glass painting to Tcl and Lua courses.
[3586] Emergency First Aid Provision at Well House Manor - part of the service
[3569] Images of the new year in Melksham
[3560] Melksham, Month by month through 2011
[3543] Some different pictures from Melksham
[3531] Blowing our trumpet about Melksham
[3527] Melksham - changing times, an opportunity for the future
[3526] Melksham has a Heart - Montage picture for sale
[3522] Networking - North and West Wilts FSB Style
[3520] Quintessentially English - scenes from our Wiltshire town
[3518] Melksham House / Melksham Campus - Seniors Input Sought
[3507] Melksham Forward - meeting summary and pictures
[3505] Well House Manor - Winter Warmers - Open 7 days a week, 11 to 5 ++
[3503] Melksham House - a community facility
[3502] Sunday Evening ... newest and oldest Melksham pictures
[3500] Campus Shadow - a great responsibility
[3499] Images of Melksham
[3496] Melksham - Business to Business Speed Networking - build ahead for 2012
[3495] Looking forward - Chamber of Commerce has 2012 and beyond on the agenda
[3492] Upcoming events in and about Melksham - more dates for your diary
[3481] Some thoughts in answer to some Melksham Campus questions
[3475] Havant - Shop Frontages.
[3470] Currently pictured in Melksham
[3438] Melksham to become a part of Trowbridge?
[3427] What is on the Melksham Agenda?
[3423] 1 + 1 + 1 + 1 = 12?
[3420] Making best use of the new enthusiasm for Melksham
[3405] Where do businessmen stay in Melksham?
[3389] Plenty to do in Melksham
[3383] Are people who walk into Melksham being asked to subsidise parking?
[3380] Melksham Jelly - An Occasional Office for Home Workers
[3344] Repost - some useful pages on our site
[3343] Summer Sunday Train Service Starts - Swindon Chippenham and Melksham to Weymouth
[3340] Summer Sunday Timetable - TransWilts Trains
[3337] Home Grown Pigs, near Melksham Station
[3334] A lesson from the sporran market?
[3327] Why are chefs miserable?
[3325] The Olympic Torch, and Melksham House
[3317] Self Portrait (in words)
[3307] Melksham Community Radio launches
[3305] Getting away from the madding crowd - an intercontinental journey
[3304] Scones with or without fruit?
[3299] Presidents Report to Melksham Chamber of Commerce, 24.5.2011
[3295] Strawberry Cream Teas, Coffee straight from the Bean and freshly squeezed orange juice - Melksham, every afternoon
[3279] Letter to The Editor
[3277] Between a rock and a hard place.
[3275] Melksham Chamber of Commerce - grows to appoint new Press Officer. Welcome. Sam
[3272] Melksham Car Parking - current charges and limits
[3258] Morning in Melksham
[3249] Events - Spring and Early Summer 2011 in Melksham
[3248] What have these pictures in common?
[3246] Melksham - the way forward. 26th April, Well House Manor
[3239] TrainWest, 2011 in pictures - Christie Miller, Bowerhill, Melksham
[3232] Around and about Melksham in more pictures
[3230] Whaddon - near us and yet so remote from us
[3229] Coincidence, or naturally repeating event?
[3227] Her favourite store
[3225] Campus - answer to business questions
[3221] How long is a speech?
[3217] Vandalism and riot from the minority - the effect
[3214] Melksham Campus - any last minute inputs from Melksham businesses?
[3209] Seeing Electricity Pylons near Melksham
[3199] Lunch for Melksham Businesses
[3194] Buses - what they cost and their future direction in the SW and in Wiltshire
[3193] Melksham Campus - what, why, questions, concerns and how you can input
[3188] What proportion of the British Workforce still works a Monday to Friday, 9 to 5, week?
[3182] What we look for in a lunchtime cafe restaurant in Melksham
[3173] What is the Melksham Chamber of Commerce?
[3172] On consultations, car parking, and Melksham town centre
[3162] Keep your business customer-friendly!
[3127] Burger me!
[3117] Opportunities for Melksham - new businesses in the town
[3088] Melksham - two many councils?
[3050] Views of Melksham - November 2010
[3032] Coincidence, or Conspiracy - a wrong email address
[2995] A river in Melksham is not just for boaters.
[2984] Customer Review - Hotel Room, Melksham
[2959] A Melksham news roundup
[2957] Welcome to Countrywides new Melksham store
[2954] Railway meetings, trips and meetups this autumn
[2932] Getting into and out of Wiltshire towns .. a.k.a. Car Parking?
[2902] Community consultation - a true open input
[2891] Wiltshire Council ask how they can help businesses
[2883] Melksham Oak - photos of the new community school
[2872] Moved - Melksham Lorry Park
[2869] Contact Information for Melksham Oak Community School
[2867] Cycling in Melksham, and looking forward
[2854] Melksham Food and Drink Fair and Town Crier Competition
[2853] Transport in Wessex - today and into the future
[2837] Lorry Parking in Melksham
[2829] Dauncey Gardens, Melksham
[2827] Melksham - a gem in Wiltshire
[2782] Tell the Melksham Chamber or you only have yourself to blame
[2779] The history and future of Melksham Chamber of Commerce
[2770] Melksham Chamber of Commerce - Presidents report to AGM
[2748] Monitoring the success and traffic of your web site
[2739] Melksham Scouts
[2725] How do our tactics help us meet the strategy, for the greater good?
[2716] Melksham in Pictures
[2708] The bull on the footpath
[2691] New brochures for the Melksham area
[2683] Car Parking in Melksham
[2666] Random thoughts on Melksham Town Planning and development
[2665] Early Spring walk in Melksham
[2664] Oliver Cromwell at Bristol Temple Meads
[2640] How is your tax pound spent?
[2597] Does my course include breakfast, lunch, dinner and a hotel room?
[2594] Melksham Area - your community view is sought
[2591] Melksham Hotel, B and B or business accommodation?
[2585] Consultation in Melksham, on Melkshams future
[2584] Melksham Food and Drink Festival, 2010
[2574] Summary of Wiltshire Core Strategy responses
[2546] How well do you know Melksham - a quiz for Christmas
[2544] Vision for Wiltshire
[2540] Rock and hard place .. and the relaxing right one won
[2531] Melksham - new Tuesday Market
[2524] An update on legal changes from the FSB?
[2521] Melksham Market - Tuesdays, 09:00 to 14:00
[2517] Blogging accuracy - open invitation for any corrections
[2514] The road show has been - where now?
[2512] Kim of the Castle
[2508] Community Area Partnership - inaugural AGM
[2497] Brown horses in Melksham
[2495] Planning the future of Wiltshire
[2487] Melksham Forum
[2480] Pantomimes around Melksham - 2009/2010 season
[2465] Melksham Town - asleep or awake?
[2459] New Web Site for Melksham Chamber of Commerce
[2438] Listening to The Minister
[2437] Wiltshire Unitary News - Chamber of Commerce Intelligence
[2349] Businesses effected by road works in Melksham
[2329] Great to be in Melksham
[2289] pre-Inaugural briefing - Melksham Community Area Partnership
[2288] Wiltshire Community Area Partnerships
[2271] Dogs Trust, Dog Show, Newbury
[2262] History is not always pretty
[2260] Important - the future of Melksham / Chamber of Commerce
[2239] Cornerstone Cafe, Melksham
[2236] Alumni - revisiting and supporting the old University
[2220] Melksham Traders - where do we go?
[2194] Melksham Business Map - Chamber of Commerce, Tourist Information and Town Council
[2181] You cannot please all of the people all of the time
[2175] Melksham in pictures
[2128] Wiltshire - where everybody matters
[2119] Make your business a DESTINATION business
[2111] Business Networking for Melksham - 23rd April
[2095] Blue Ridge and Melksham Chambers of Commerce
[2066] Melksham Industrial
[2043] Confidence, Customer Service and Tourism in Melksham
[2015] Service Excellence Awards
[2012] The Wiltshire Police
[1997] Travelling to a course - station pickups
[1987] One Cheer for Local Democracy - Asda in Melksham
[1979] Looking forward, in Melksham, in 2009
[1966] Background to the TransWilts Train Fiasco
[1937] Getting hold of the wrong end of the stick
[1934] Lidl opens in Melksham
[1928] Melksham Oak Community School, Melksham, Wiltshire
[1904] Ruby, Perl, Linux, MySQL - some training notes
[1894] Shopping in Melksham
[1892] Melksham Chamber of Commerce and Industry
[1883] Spa Road Garage and Convenience Store, Melksham
[1881] Wiltshire Council says - part 1
[1880] Melksham Chamber of Commerce, or the FSB
[1855] Volunteer v Employee - a skewed balance? (FSB)
[1843] How many cups of coffee?
[1823] FSB - an update.
[1792] All the pieces fall into place - hotel and courses
[1748] Hotel room prices - Melksham, Wiltshire
[1725] A future vision for Melksham
[1655] A date for your diary - 16th July 2008
[1654] The old sayings are the best (FSB)
[1642] Summer!
[1633] Changing a screen saver from a web page (PHP, Perl, OSX)
[1594] Please support improvements in our train service
[1560] HST Power Car TravelWatch SouthWest
[1559] Calling on Melksham / Trowbridge / Devizes / Chippenham businesses
[1544] FSB, EGM, AGM.
[1515] Keeping staff up to date on hotel room status
[1512] Summer Ball at Bowood - Saturday 12th July 2008
[1507] Comments on proposed Asda Superstore for Melksham
[1504] Flooding by Asda-s proposed new supermarket
[1479] FSB leaves its members feeling like mushrooms
[1476] Shopping for Christmas and looking forward
[1451] More PHP sample and demonstration programs
[1447] Refa Tandoori Indian Restaurant, Melksham
[1436] A little touring help during a business trip to England
[1432] Wiltshire County Council - Budget Consultation
[1429] Remembrance day - inside a church and inside the day
[1394] Business to Business Networking - North and West Wilts / Melksham
[1368] Getting the local voice heard
[1360] Asda in Melksham - Welcome or not?
[1359] Little Gems but not Lettuce
[1350] FSB (Federation of Small Businesses) Western Region
[1343] Melksham Laundrette
[1341] Moving to Melksham? Househunting map.
[1332] Melksham Hotel - Five Star Kitchen!
[1330] While waiting for Melksham Post Office
[1329] Subway Restaurant in Melksham, Wiltshire
[1286] A wasted evening?
[1284] An update on the West Wilts show ...
[1280] West Wilts - no longer Wet Wilts - show
[1278] West Wilts Show
[1271] Till the cows come home
[1266] Party in the Park
[1258] A day looking ahead for Well House Consultants
[1257] Data cabling (Cat 5e), Melksham, Wiltshire
[1253] Key new contacts
[1250] Business speed networking - a place tonight!
[1249] Is this how to run a business for businesses?
[1246] An oddball day. Strange experiences!
[1226] Melksham Art Cafe
[1223] Asda opening large new store in Melksham
[1208] Meet other local businesses in Melksham
[1206] Where and When - can you place the picture?
[1177] Sorting out for a site map
[1157] Speed Networking - a great evening and how we arranged it
[1137] Wiltshire Circles
[1133] B-2-B Networking, 20th April. Useful for YOUR business?
[1117] Newport Male Voice Choir
[1078] Wiltshire - multicultural community
[989] Melksham Quiz
[981] Finalist reception - Wiltshire Business of the Year
[977] Melksham and Norwich
[957] Improving the historic town of Melksham
[879] Tuesday night is party night
[866] A lazy programmer is a good programmer
[856] The train returns for a few weeks
[851] Emergency First Aid Training
[830] Butterflies in a Wiltshire garden
[811] Melksham in Bloom
[805] Melksham Carnival Parade
[796] Busy day in Melksham
[717] A customer service company
[715] First way to get rid of customers
[676] Melksham, Wiltshire
[606] Train service from December
[538] A company we can work with
[529] Halal in Melksham
[500] Bowerhill, Melksham, 2006 Calendar
[475] Where to stay in and near Melksham
[472] Are you free on 29th October - Charity ball
[437] Outside of the box
[413] Save the train
[354] Ballooning from Bath
[344] Walk in Bath
[329] the Stately Homes of England
[315] Supporting local business
[312] Maud Heath
[307] Farming yesterday
[305] Within about an hour
[291] Why are we no. 404
[269] Free parking for short errands in Melksham
[266] A beautiful place to live and learn
[176] Extra chips
[58] Call Centres, selling, and a pause for thought
[51] Gym and swimming - Melksham Blue Pool
[47] Effective fundraising
[40] Take the train to training
[5] Driving in the UK for new arrivals from the USA
Top or Show all for Melksham

Training from Well House Consultants
[4132] Using your own laptop on our courses - now even easier! - (new - 2013-07-05)
[4082] Training around the world - easy payment in pounds Sterling
[4015] Upcoming courses and availabiity
[3964] What is coming up from Well House in 2013 - public Open Source / IT courses.
[3950] 10 reasons why I travel the night before a course starts
Top or Show all for Training from Well House Consultants

Running a training and hotel company
[4156] A further chance to see Melksham on TV - (new - 2013-08-22)
[4147] A hidden hotel gem in Melksham - (new - 2013-07-31)
[4138] Should a hotel accept guests who book for just one night? - (new - 2013-07-11)
[4112] Really good friends - four in a bed!
[4109] What might you find at a tiny bed and breakfast?
Top or Show all for Running a training and hotel company

Well House Manor - Hotel and Training Centre
[4162] Pimms and Croquet at Well House Manor - 7th September 2013 - (new - 2013-08-28)
[4158] Wedding from Well House Manor - an excellent base in Melksham - (new - 2013-08-23)
[4155] Wedding Reception preps at Well House Manor - (new - 2013-08-21)
[4144] Getting the best hotel rates - customer and hotelier viewpoints - (new - 2013-07-27)
[4139] Out of doors (mostly) at Well House in Melksham - (new - 2013-07-12)
[4137] Early morning - welcoming business and leisure guests to Melksham - (new - 2013-07-10)
Top or Show all for Well House Manor - Hotel and Training Centre

For the Webmaster, Postmaster and moderator
[4135] Introducing your product to Well House Consultants - single, personally tuned email please - (new - 2013-07-08)
[4134] Setting up your MacBook Air as a mobile broadband router - (new - 2013-07-07)
[4121] Has your Twitter feed stopped working? Switching to their new API
[4115] More or less back - what happened to our server the other day
[4076] Web site - fully back!
Top or Show all for For the Webmaster, Postmaster and moderator

General Programming Topics
[4153] Rooms available tonight - how to code an algorithm from first principles - (new - 2013-08-19)
[4114] Teaching CodeIgniter - MVC and PHP
[4098] Using object orientation for non-physical objects
[4096] Perl design patterns example
[4066] MVC and Frameworks - a lesson from first principles in PHP
Top or Show all for General Programming Topics

PHP - the language and its application
[4136] How do I post automatically from a PHP script to my Twitter account? - (new - 2013-07-10)
[4106] Web server efficiency - saving repetition through caches
[4075] Further recent PHP examples
[4074] A comment on comments in PHP
[4073] Learning about Object Orientation in PHP - a new set of examples
Top or Show all for PHP - the language and its application

Java and the Java Environment
[3997] Servlet v JSP (Java Server Page). What is the difference?
[3573] New in Java 7 - and why we are not running public Java 7 courses
[3497] Not the same language - but based on the same constructs
[3365] Turning bright delegates into bright and knowledgable ones
[3293] Distributing the server load - yet ensuring that each user return to the same system (Apache httpd and Tomcat)
Top or Show all for Java and the Java Environment

Around, about and nearby to Wiltshire
[3989] Plenty to see and do - even in Winter - on a Well House Manor weekend
[3884] Pictures - across the park, French Weir and River Tone, Taunton
[3800] Fancy a weekend away? Try Well House Manor in Melksham, Wiltshire
[3729] Then and now pictures of Melksham - on show through the summer
[3723] Bank Holiday Monday, so it was pouring with rain.
Top or Show all for Around, about and nearby to Wiltshire

The Perl Programming Language and its use
[4100] Perl Dancer - from installation to your first real application
[4099] Perl Dancer - a Perl Framework - Installation and first test
[4031] Showing what programming errors look like - web site pitfall
[3941] Building an object based on another object in Perl
[3940] Run other processes from within your Perl program
Top or Show all for The Perl Programming Language and its use

Client Side Languages (HTML, CSS, Javascript)
[4037] Cascading Style Sheets and formatting your web page
[4036] HTML tags uses in these blog articles
[4035] Special characters in HTML
[4034] The VERY basics of a web page ... and web site
[3532] Sharing the user experience - designing a form with the customer in mind
Top or Show all for Client Side Languages (HTML, CSS, Javascript)

Ruby and Ruby on Rails
[4010] Really Simple Rails
[4009] Clear, concise examples - Ruby classes and objects.
[4008] Reading and checking user inputs - first lessons - Ruby
[4003] Web and console - same principle, same code - Ruby example
[3799] Ruby Documentation through rdoc
Top or Show all for Ruby and Ruby on Rails

SQL and MySQL
[4007] Which database should I use? MySQL v SQLite
[4006] Ruby / SQLite3 example program, showing JOIN v LEFT JOIN
[3928] Storing your intermediate data - what format should you you choose?
[3494] Databases - when to treat the rules as guidelines
[3455] MySQL, MySQLi, PDO or something else - how best to talk to databases from PHP
Top or Show all for SQL and MySQL

Tcl, Tcl/Tk and Expect
[3638] Sorting dicts and arrays in Tcl
[3629] Sharing lots of values in Tcl without having lots of global declarations
[3618] lists and struct::list in Tcl - Introduction to struct::list and examples
[3617] The fileutil package and a list of file system commands in Tcl
[3614] Tcl - dicts - a tutorial and examples
Top or Show all for Tcl, Tcl/Tk and Expect

Programming in Lua
[4117] Is Lua an Object Oriented language?
[4102] Installing Lua 5.2.2 on Mac OS X 10.7.4
[3730] What is a metatable? How do I set one up? How do I use them? Lua
[3727] Using Lua tables as objects
[3725] Lua Tables
Top or Show all for Programming in Lua

Python Programming
[4161] Python varables - checking existance, and call by name or by value? - (new - 2013-08-27)
[4129] Simple OO demonstration in C++, comparison to Python - (new - 2013-07-01)
[4118] We not only teach PHP and Python - we teach good PHP and Python Practice!
[4095] Django - first steps - Updated
[4094] Python Properties - how and why
Top or Show all for Python Programming

And also ...
[4157] Wedding Photos - Kim Ellis to Kyle Londors, 22nd August 2013 - (new - 2013-08-23)
[4141] My pictures of Melksham Carnival, 13th July 2013 - (new - 2013-07-14)
[4133] In the hills above Harlech, and on the coast too - (new - 2013-07-06)
[4130] Soft furnishings up a Welsh Mountain - (new - 2013-07-03)
[4126] Where are we now? On holiday!
Top or Show all for And also ...

Public Transport
[4160] Bank Holiday Monday - pictures of a great train trip to Weymouth - (new - 2013-08-27)
[4159] People WILL walk to the station in Melksham, but they need a path and trains - (new - 2013-08-25)
[4154] August Bank Holiday - day out from Melksham to London or Weymouth - (new - 2013-08-20)
[4152] Why are bus fares so high? - (new - 2013-08-18)
[4150] Melksham Regular Public Transport Map - as at August 2013 - (new - 2013-08-09)
[4149] Bus changes to Bath - good idea, but I despair at information available - (new - 2013-08-08)
[4148] Special General Meeting, Adoption of Constitution for TransWilts Community Rail Partnership - (new - 2013-08-01)
[4146] A few more trains means a LOT more passengers. Why? - (new - 2013-07-30)
[4143] Bus times - Melksham to Bath from 28th July 2013 - (new - 2013-07-25)
[4142] Passenger survey at Chippenham - report and pictures - (new - 2013-07-24)
[4131] West Coast (of Wales) - railway and stations in pictures - (new - 2013-07-04)
Top or Show all for Public Transport

Fun and Flames
[4140] Riots in Melksham - (new - 2013-07-13)
[4067] The woman, the television, the bullock and Darlington
[3922] Twerp - A person regarded as insignificant and contemptible
[3912] Sand to Arabia, Coals to Newcastle or Woodburners to Russia
[3900] The Xxxxx Guest House in Xxxxxxxxxxx - my stay reviewed
Top or Show all for Fun and Flames

Keynote Articles
[2483] Clustering on Tomcat
[2384] Looking ahead to the Autumn season of training and accommodation
[2144] Looking for a career change - Physician to Web Site Designer
[1955] How to avoid duplicating web page maintainance
[1857] November and December Public Course Schedule
Top or Show all for Keynote Articles

Unclassfied Articles
[4127] Exploring the area ... Ynys, near Harlech - (new - 2013-06-30)
[4054] On Salford Docks - mind over matter?
[4047] Looking for Creative Design, Catering and Transport inputs to help with Melksham Campus
[4044] What to do on a wet weekend in Melksham?
[4043] Bus stop audit - what is missing?
Top or Show all for unclassified

Public Transport • Training from Well House Consultants • And also ... • Tcl, Tcl/Tk and Expect • Programming in Lua • Python Programming • Well House Manor - Hotel and Training Centre • Apache HTTP and Tomcat Servers • The Perl Programming Language and its use • Ruby and Ruby on Rails • PHP - the language and its application • C and C++ Programming • Linux and Shell Programming • Melksham • SQL and MySQL • For the Webmaster, Postmaster and moderator • Java and the Java Environment • Fun and Flames • Running a training and hotel company • Around, about and nearby to Wiltshire • Client Side Languages (HTML, CSS, Javascript) • Keynote Articles • General Programming Topics

A little more about this newsletter ...

At Well House Consultants, we run niche IT training courses ... and we run a hotel for delegates on those courses and other visitors to Melksham too. And we make a lot of friends - have a lot of ambassadors with whom we want to keep in touch. So every day Graham (that's me, writing this piece) puts together an article or two which might include the latest sample programs that I've written during the current course, new information about Well House Manor - our business hotel, tips on search engine optimisation, announcements of upcoming public courses, pictures of local places, and even (on occasions) rants and whimsical pieces to keep those friends up to date and in touch. The feeds are available directlt via the Blog - "The Horse's Mouth", they're on our Twitter Feed and you can find me at my LinkedIn profile. But most people just want to look us up occasionally - every month or two, and then to catch up on the latest news just for their particular subjects of interest ... and that's what this newsletter is about

You'll find above the titles of ALL the new articles written in the last two months, listed by major subject area, and showing as (new) with their date of publication. You'll find additional articles in each category too - topping each category up to a minimum of five articles. And you'll find a link at the end of each section which lets you expand that section to show the titles of every article that's been published in that section. After all, "the old ones are often the best ones", aren't they?

go to Top or other editions July 2013 • May 2013 • March 2013 • January 2013 • November 2012 • September 2012 • July 2012 • May 2012 • March 2012 • or current edition

Training sample © 2024, WELL HOUSE CONSULTANTS LTD
This is http://www.wellho.net/demo/newsletter.php
Well House Manor • 48 Spa Road • Melksham, Wiltshire • United Kingdom • SN12 7NY
Phone: +44 (0) 1225 708 225 • EMAIL: info@wellho.net • WEB: http://www.wellho.net