What can we say, we needed a way for clients to let us know they were in the lobby. The sounds also cuts through even the deepest coding trance.

http://kb.cs-cart.com/display-subcategories-multicolumns#3

If you have a question about CS-Cart, please feel free to contact us to see if we can help you.

We’ve recently deployed:

• Coverall Stone / Cascade Stone Works – a CS-Cart build that sells by the Sq. ft for tile, pebble tile and hardscapes. It also includes a freight integration for CS-Cart (CSCart freight module add-on) that also offers multiple shipping options depending on what you have in your cart. We literally have it able to calculate up to 20,000 lbs of different materials ranging from stone columns -to- boxes of tile -to- fountains and accessories.
• Bamboo Flooring by Plyboo.com – an Estees & CS-Cart deployment with custom buying options and shipping methods, a SugarCRM to CS-Cart integration as a chat system.

Common usages are:

• Find and replace a word across all WordPress posts
• Find and replace an HTMl Tag that appears in a line of code in a database
• Find and replace part of a URL or image reference in a database
• Find and replace an incorrect spelling in a database table or piece of content

As a baseline, the command is easy:

 UPDATE `your_table_name` SET `your_field_name` = replace(your_field_name, 'text you want to find', 'text you want to replace')

That’s it. It is that simple. Of course, you will want to backup your database before doing this like a good little developer, but we assume you already knew that. You can execute this command from command line within your MySQL account, or you can do this in a web-based tool such as PHPMyAdmin.

You can get an overview on how to grow a single dedicated server or VPS into a cluster in our previous post.

You can view our Drupal Cluster & Drupal Load Balancer vendor here.

Mo’ users Mo’ Problems.

Upgrading Drupal to run on a cluster involves changing the way you think about the resource calls to Drupal’s individual components.

Our client’s traffic averaged about 800,000 visitors - A DAY, essentially jumping from about 120,000 daily visits, which the single server setup, as large as it was, was struggling to keep up.

With that many visitors, it is not always easy to just identify the bottlenecks from looking at the server side of the equation, its processes, MySQL usage and so on. This is because almost a million visitors a day magnifies everything to where even the smallest process running at a single point in time has a great impact.

Since we did not develop this client’s sites, we did not have the luxury of building things in a scalable fashion with running Drupal on a cluster as the intended goal. Instead we took the path of least resistance and began changing, optimizing, shutting off things as so:

You’re logging what?

In a world where Google analyitics knows all and see all, you probably do not need to be logging every piece of information Drupal or your server can collect. With high traffic Drupal sites, every request counts and if your Drupal build is logging to the database, these tables are going to grow, and grow and grow in size. More tables, more things to get fragmented and corrupt. We removed a tracking module one site had that had MILLIONS of entries per day and was GIGS in size, greater than the rest of the databases on this server combined. Removing that module increase performance significantly and reduced the load of MySQL.

As long as you do not need the stats for some other reason you should consider:

• Turn off Drupal logging, Drupal Error Reporting and any other information being collected.
• Turn off statistics packages running on your servers, including AWStats, Webalizer, Analog or Logaholic Stats packages.
• Turn off statistics processing as some of these jobs run for hours and hours, even days if you are dealing with logs involving millions of visits a day.
• Turn off error logging or have a process for paring down logs to a reasonable level, even small errors and warning add up when talking traffic of this magnitude.
• Consider how you are logging and storing you /var/logs data. If you server setup is using multiple web servers at a glance these logs are less useful if you are using a load balancer that is splitting traffic across your network. I am not saying you do not need these, I am just saying that with “great traffic comes great responsibility” and you should set up a retainment policy for logs that does not increase your load or create storage problems. We encountered a 300GIG instance that ran out of storage within 1.5 days because it was logging everything and also had a runaway caching system, which leads us to:

Cache me if you can!

Hey, this pun works and you know it. Drupal caching can be very powerful and a boon to your deployment of Drupal in a cluster environment. The two caches we usually work with are Memcache/Memcached and Varnish. Memcache you set up as a service and run continuously, while Varnish is code-side.

Drupal 7+ has its own caching system built-in while older versions of Drupal, 5,6 etc often reply on third party modules like Boost cache.

IMPORTANT! Depending on the nature of your website and whether you make use of unique dynamic content such as :

• Ad-serving technologies, where each unit carries unique information.
• Video-serving technologies, where each load is considered unique.
• Other dynamic content such as comments, related content (off-site usually) or syndication partnerships.

Depending on how your caching is set up to cache these blocks, templates or content that contains additional dynamic content (yes, even a single unique ID will trigger a whole new page to be cached), you can quickly overwhelm your CPU or worse yet, fill up your disk with millions and millions of cache files when talking about the traffic a cluster would probably warrant.

The Drupal Admin on a cluster – logging into Drupal

When you have a cluster of servers running Drupal, you have to plan ahead for you you are going to administer the website or do future development.

Obviously, you could make changes and then push them to each individual web server individually, but this is inefficient  slow, may cause downtime or cause problems with your cluster during the time to takes you to put or get files since only one server will have the updates at a time.

This means you have to create a deployment strategy involving something like a versioning system, Git, Github or other deployment system, which we will cover in a different post.

Drupal is now in session.

As far as staying logged into Drupal on a cluster with an external database server, it is all about the load balancer I’m afraid. We get our Drupal Loadbalancer

Your load balancer will have a mode called “session persistence” which needs to be set in order to stay logged into Drupal’s admin. If this is not set, every request you make may ping pong off the different servers in your cluster and you will get the dreaded “you are not authorized to access this site” message.

The reason is simple, if you are not using session persistence with your load balancer and Drupal, then you are logging into one session on one server, then the next click “may” have you on a different server, then another and so on.

Even if you continued to log in over and over again, the sessions would not match and Drupal will kick you out.

With session persistence, you stay logged in and so long as all of your Web Servers in the cluster are using the one remote database host, the changes you make will appear fine since they are in the single database.

It is also important when you create your database server to have your host or data center put the database server on a private network which will allow the web server to access the database lightning fast instead of going over traditional network connections.

This ends our post for now, next time we’ll cover other optimization of Drupal in a Cluster environment and focus more on how your development and deployment needs to change to accommodate such a monster. Click here if you need a good vendor for putting Drupal in the Cloud and Drupal enterprise hosting.

One of the things that a website or server may have to do in its lifetime is scale up to a cluster of servers.

What’s a cluster?

A cluster can mean several things, but at a bare minimum it means “more than one server”. Yes, I realize that is not all that helpful to understanding all of this just yet, but stay with me.

Typical cluster configurations:

One web server – One database server:

With this set up we do not need to employ a load balancer that sends traffic requests to one or the other serve.

Wait. What’s a load balancer?

A load balancer is a device that sends traffic to one or more location. It can be set to do this a number of different ways, including:

• Round robin – where it alternates between each server in turn.
• Lowest process – where it sends it to the server with the least number of processes running (lesser bogged down of servers on load balancer)
• Historical – the load balancer keeps track of which server is better to send traffic to at a given time. This is helpful if one or more of your servers has periods where it consumes more resources, like during scheduled backups, log analysis, data imports, etc.

You set up your different domains, sites, etc to point their A records at the load balancer rather than to a particular server.

The first server just runs Apache (Web Server) or IIS (Windows Web Server) and the second server just runs the database server (MySQL, MS SQL, etc)

You update your web applications to run off the database server, often by IP address or using a private network.

This is helpful for applications where the MySQL load interferes with the Web Server or vice versa,

Load Balancer + 2 Web Servers running their own Databases

In this configuration you have a load balancer that detects and sends traffic to one or more servers, each running as a separate instance of your entire website or web application.

The assumption is that you either:

1. Do not need real time synchronization of data between each instance/server – meaning you probably do not have users that add content, comments, posts, transactions to the server. This is helpful for static sites or sites that delivery one-way content to its audience.-or-
2. You have implemented an rsynch of files or other method for keeping data up to date. In short, having two whole servers means two places to update and edit and is not the best configuration for a lot of businesses.

Load Balancer + 2 Web Servers and a third database server.

Here’s where we get to true performance enhancing and scalability. (Also, is it just me or with the whole Lance Armstrong thing has that word lost all meaning?)

With a 3 server setup you offload the database functions to one server, balance two web servers and set each of them up to look at just that single database server.

The challenges with this are usually:

1. You need to develop a workflow for working on your server’s websites and web applications. Whether this means you log into all web server to push updates, or you develop an rsynch script or other method to copy files – or you make use of a CVS (Concurrent Versioning System) to deploy your code across multiple platforms at once – you will need to start thinking of your design & development in terms of working on a network and not in a single server or single account setting.
2. Logging into CMS systems like Drupal, WordPress, Joomla or any other administration panel becomes a nightmare unless you set up your local environment to look at just one server (e.g. change your localhost file) – or, you work on a local server and push your changes up that way.

Summary: We’ve assisted a number of companies in upgrading to clusters for single server (or VPS. shared hosting, whatever) and each deployment is uniquely different based on what you want to accomplish.

Usually, a client has or will be experiencing such high traffic or resource usage that their current server is overwhelmed and simply re-sizing the server is not going to cut it for them. This is where we develop a strategy for re-sizing to a cluster based on the individual domains, sites and web application that are running on the server.

The most overlooked items we see clients having to deal with when they resize to a cluster are:

• Making Drupal run on a cluster and dealing with persistent logins and caching.
• Making WordPress run on a cluster of servers and dealing with plugins looking for files, cache file, tmp files or other resources that are not present fuly in a two server environment
• Making Joomla run on a cluster where administrator are not staying logged or need better session management.
• Making forums run in a cluster where posts and comments come in so fast that any delay or lag creates chaos and frustration
• Making CS-Cart, Zen Cart, Magento, OSCommerce or any other ecommerce function, keep users logged in, keep them able to checkout and not dump their cart now that they are running on a cluster.

Upgrading to a cluster is not necessarily the saving grace or the next logical step for a site that needs to scale. Often talking with a programmer can reveal other ways that you can adjust your user experience and gain additional performance out of your current system.

A note on shared hosts.

If you are on a shared host trying to do this, there’s probably no hope for you. Sorry, we’re not talking the same language at this point. A shared account’s next step is to move up to a VPS (Virtual Private Server). A VPS’s next step is to move to a larger VPS or true dedicated system running in its own space or hardware.

After that, it’s time to talk clusters - which you can contact us any time on.

Often, clients will have us customize their CS-Cart builds in such as may that making use of any automatic upgrade process will overwrite core functions in their CS Cart build.

Some recent custom CS-Cart develop projects of ours have included:

• Creating an ApparelMagic to CS-Cart integration bridge as an add-on (or call it Apparel Magic CS-Cart Add-on if you prefer) that syncs inventory in ApparelMagic to CS-Cart’s inventory process.
• Creating a custom square foot calculator for CS-Cart
• Creating a California Sales Tax add-on for adhering to the Department of Revenue city-tax rate system.
• Custom shipping options for CS-Cart LTL Freight and Fed Ex ground (so it picks which is better for a particular order)
• A custom framing application for CS-Cart that allows users to select images and checkout with framing options.
• CS-Cart and online eLearning integration, where you can see online courses through CS-Cart and have it unlock.

So, in the end .. you can see where it would not really be wise to reply on an upgrader included with a cart like CS-Cart to try and upgrade all of your files automatically.

To disable such notices, you browse to:

fn_set_notification('W', fn_get_lang_var('notice'), $msg, 'S', 'upgrade_center');

And comment out this line. Easy. Fast. Effective.

Hosts file instructions:

Make sure you shut down your browser before doing anything to the hosts file, or the browser may not pick up the changes you have made.

your hosts file is located here:

C:\WINDOWS\system32\drivers\etc\hosts

There is no file extension for your hosts file, you will need to open it in notepad or another text editing program.

After the preamble on the page, you will find at least one entry:

127.0.0.1 localhost

below this, type the line in this format

[IP ADDRESS] [DOMAIN NAME]

e.g.

192.168.1.1 www.whatever.com

…then save and close the hosts file (note – you do not need brackets.

…now open your browser and go to that url/domain, you should be able to see the site, log in as you normally would to see your mail, website, development area – whatever.

This is what “hacking your localhost file” means.

If you need help with a project like this, anf we mean any project involving importing data to or between:

• OSCommerce to Zen Cart Import
• OSCommerce to CS-Cart Import
• Zen Cart to Magento Import
• OSCommerce to Magento Import
• Zen cart to CS-Cart Import
• OSCommerce to Shopify Import
• Zen cart to Shopify Import
• Yahoo Store to CS-Cart import
• any other cart -to -cart imports.

We’ve love to assist you with a custom quote. Just use our contact page to get in touch.

The following is an example of a code commenting standard we use, whetehrver applicable – and it doesn’t matter if it is to be used for HTML or scripting languages.

Comment indicator Start – FDG – Name – Date as MM-DD-YYYY Comment indicator
php, javascript, css
/*Start – FDG – Name – MM-DD-YYYY*/
smarty
{*Start – FDG – Name – MM-DD-YYYY*}
HTML

or in the case of HTML:

<!– FDG – Name – MM-DD-YYYY –>

 

Note – Not all code will always be commented, otherwise, before you know it – it would become bloated in of itself.

As evidenced by this email message we received recently from one reader:

Tom,

Lotus Notes [DELETED] won’t display [DELETED] properly. I’m ready to [DELETED] throw the [CENSORED, DELETED, ETC] using a pogo stick.

-Ted

We feel your pain Ted..really..we do.

Lotus Notes can be a very frustrating Email client to test your HTML Email Messages against. There is a general lack of information on how the Lotus Notes email client renders and displays HTML for the end-user. Many designers and firms tend to skip over the whole Lotus Notes compatibility issue due to the fact that the majority of recipients received

The problem is that there is a tremendous amount of corporate Lotus Notes users. One client of ours found out after a brief survey (and all of the negative feedback from their mailings to users who received a hodgepodge of mismatched code from them) – that nearly 40% of their entire mailing list were Lotus Notes clients due to the fact that their mailing list was made up of corporate clients.

So, whether you realize it or not, Lotus Notes may make a very significant portion of your existing mailing list. Unlike AOL recipients, who you can easily filter and send alternate content to as you mail, Lotus Notes users look and act just like the rest of us. Scary.

That being said, let’s dive into some of the more common concerns we get on an almost daily basis. The following is a guide which you may find helpful in diagnosing and trouble shooting common Lotus Email Marketing issues. Due to the wide variety of settings, open source tweaks and other variables that separate the Lotus Environment from your more common Exchange & Oracle systems, you’ll need to consult some of the resource links & forums we’ve collected below for additional help. However, with the little bit we are going to arm you with, you’ll be able to fake it just fine.

“Dear Template Kit,

A handful of employees that receive different emails in HTML format cannot seem to be able to view the pictures or images in Lotus Notes. The text seems to retain its HTML formatting, but the images appear as a box with a red “x” in them. What is going on?”

-Judy

If you are a current user of Lotus Notes, whether R5.07 – R5.10 or even the R6 and beyond releases, you’ve no doubt heard much of the following:

“We opened an HTML Email which looked fine in Outlook, but expanded to fill the entire page in Lotus, distorting the intended design, what happened?”

We’ve documented numerous accounts where Lotus Notes has completely ignored some HTML coding during rendering, while displaying other HTML coding just fine. This is especially true when it comes to width parameters for TABLE tags, nested TABLE tags and finally, TABLE tags that are not constrained within another table.

Example:

One of the “Best Practices” we’ve established in consulting for clients is using one master table to constrain your entire email. Often, clients will be taking bits and pieces of code from various projects, emails, websites, catalogs, etc and placing them into their HTML Email Marketing. All of the various parameters can easily conflict with one another when rendered. By “wrapping” your HTML Email in one master table, you help reign in all of those various width=% and other “ambiguous” attributes and parameters which can wreck havoc on how your HTML Email is rendered by the viewer’s browser.

Wrapping your HTML Email message in a master table and then setting the TABLE Padding to equal at least “5” is also a good way to thwart certain Web-based systems that only render your code from after the what comes after the BODY tag. A good example of the differences can be found here: TemplateKit.com

By comparison, our TemplateKit.com newsletter uses cell padding of “18”. While you do not have to be as zealous as we may be in this regard, it is better to be safe than sorry.

Lotus “Punts” our stylesheet!

HAH! The most common complaint we get around the office. Disappearing style sheets when rendered in Lotus Notes. Your meticulously designed, corporate schema conforming

You send an email to a Lotus client and suddenly the text appears HUGE! Your beautifully design masterpiece, lovingly handcrafted 14pt, Helvetica with slight shades on the sidebar tables can completely come undone. Almost exactly like we’ve displayed here & here.

If you are going to be relying on style sheets to format your HTML Email, then you must be aware that Lotus just doesn’t like them. Most common style sheet applications are ignored by Lotus Notes nearly each and every time you try to use one. The same is often true for many Web-based email systems (Hotmail, AOL, Yahoo, etc) who want to avoid any style sheet conflicts between their own and yours.

If you are going to send HTML Email to a Lotus recipient, and your design is fairly dependent on that style sheet to keep the continuity of your design in place, then you can count on problems.

Except, if you do the following:

A normal Stylesheet Entry in thesection of your HTML document looks like this:

>

Even if you link to your style sheets, you are still using the above format which is called into your document when rendered by the email client.

The above style sheet will immediately be ignored by most Lotus Notes clients, ruining your email. However, if you were to comment out each line of the Stylesheet one by one, then your style sheet is suddenly recognized by the Lotus Environment, like so: