Practical Technology

for practical people.

March 29, 2017
by sjvn01

Enterprise container DevOps steps up its game with Kubernetes 1.6

Managing containers isn’t easy. That’s where such programs as Docker swarm mode, Kubernetes, and Mesosphere can make or break your containers initiatives. Perhaps the most popular of these, Kubernetes, has a new release, Kubernetes 1.6, that expands its reach by 50 percent to 5,000 node clusters. Conservatively, that means Kubernetes can manage 25,000 Docker containers at once.

Enterprise container DevOps steps up its game with Kubernetes 1.6. More>

March 28, 2017
by sjvn01

How to fix disappearing iPhone passwords

Last week, to protect myself from the Apple iCloud crack, I changed my password for my Apple ID, which is also the iCloud. So far, so good. Then, I discovered that my 6th generation iPod Touch, running iOS 10.2.1, wouldn’t remember my new Apple/iCloud password. Soon afterwards, some friends using iPhone 7 and iPhone 6s smartphones were having the same trouble. In fact, one of them is still having trouble after updating to the brand new iOS 10.3.

How to fix disappearing iPhone passwords. More>

March 24, 2017
by sjvn01

How search worked before Google

When I started using the Internet in the 1970s, it didn’t look anything like it does today, and our search tools were primitive. But when all you have is stone knives and bear skins, you make do.

Before I ever turned my hand to writing for a living, I put myself through graduate school by doing research on the very first online database systems: NASA RECON; Dialog, now ProQuest; and OCLC. These systems, which are still around, are part of what’s called the Matrix—and, no, I don’t mean the movies. The Matrix, as defined by Carl Malamud, is the superset of all interconnected networks. Today, you can get to ProQuest and OCLC over the Internet, but you’ll find yourself blocked from getting very deep into them without permission.

As for the pre-Web Internet itself, at first it didn’t have search tools. It wasn’t until the late 1980s that the Internet became searchable. When I started using it, we had to go through FTP file directories screen by screen and hope that the file we wanted was in there somewhere.

Then came Archie and Veronica

How search worked before Google. More>

March 24, 2017
by sjvn01

How to protect your Apple iCloud account

Maybe the London-based hacker group — which goes by the name “Turkish Crime Family” — doesn’t have access to 250-million Apple iCloud account names and passwords. But they do have access to some indeterminate number of accounts, and that’s more than enough reason to exercise caution: Protect your iCloud password and data today or risk losing it tomorrow.

How to protect your Apple iCloud account. More>

March 23, 2017
by sjvn01

Thanks for the Memcached…

How do you handle lots and lots of database reads and writes? That’s a question some of the biggest websites on the planet, such as Wikipedia and Facebook, face every day. (What? You thought all those up-to-the-minute updates happened by magic?) Their answer?—?and the solution used by many other companies?—?is Memcached, pronounced mem-cash-dee.

Memcached is an open-source, high-performance, distributed, object-caching system. It’s commonly used as an in-memory key-value store for small chunks of arbitrary data. These can include strings and objects from database calls, API calls, or page rendering. No matter the data type, Memcached saves data as strings.

The net result? You can use it to speed up any storage-based interactions. But Memcached is also meant to speed up dynamic web applications by reducing your database load.

Memcached is best known for being used in social networks. Indeed Memcached was created by LiveJournal’s programmers to deal with the massive data I/O requirements of dynamic social-network applications. Now, you may not be running a social network on your servers?—?although you could with programs such as Elgg?—?but you can also use Memcached to give your virtual private servers a speed boost by caching your web-server-session data.

Fundamentally, Memcached works by sending any program’s first attempt to retrieve data to its cache before querying the database. Like all caches, the program fills itself with recently retrieved server data. Thus, when a user asks for data, Memcached provides it from fast memory, rather than the slower hard-drive-based database.

Memcached doesn’t use RAM dynamically. You must set the Memcached-daemon up at the start with the memory it will use for caching. Because of this, once you’ve dedicated memory to Memcached, it’s reserved expressly for its use.

Within the cache itself, Memcached keeps its data “fresh” by using a Least Recently Used (LRU) algorithm. With this technique, Memcached automatically deletes the item that hasn’t been used for the longest time when it starts to run out of space.

Set up properly, Memcached can take a long while before it runs out of room. Unlike the caches you may already have been using on servers or PCs, Memcached is a distributed cache. That means it caches its data across multiple servers. This means, in turn, you can grow it in size and transactional capacity to where it can handle the largest interactive applications, such as Facebook.

Memcached is also multi-threaded. That makes it easy to scale up its performance by boosting its CPU when necessary.

Now, you might ask yourself, “Why do I need Memcached for this when I can use, say, Alternative PHP Cache (APC) to cache both code and data?” The answer is, you don’t. For a small site or one containing mostly static data, you don’t need Memcached. But, if you do need it, if your site has many users running dynamic web programs constantly pulling and pushing data to a DBMS, then Memcached is your friend. Embrace it.

While Memcached is typically used with PHP, you can deploy it with almost any language. Its API is available for most popular languages.

This is an important point. Memcached is not something you can simply install and expect to get better performance from your WordPress site. As the Memcached GitHub site explains, it’s “a developer tool, not a ‘code accelerator,’ nor is it database middleware. If you’re trying to set up an application you have downloaded or purchased to use Memcached, read your app’s documentation.”

If that sounds like a lot of work, well, it can be, but Memcached can really boost your website’s performance once you get your hands around it. There are some people who say that other caching programs, usually Redis, are better. Redis is fine, but in my experience, for a simple, easy way to get complex web applications working efficiently, it’s hard to beat Memcached.

So, thanks… for reducing database bottlenecks, and speeding up dynamic web apps. And thanks… for freed up RAM with an LRU, streamlined deployment, and simplified dev design. Thanks for the Memcached.

This story first appeared in Linode-Cube.

March 21, 2017
by sjvn01

Old Linux kernel security bug bites

OK, hands up, who knows what High-Level Data Link Control (HDLC) is? It’s an archaic networking data framing protocol that’s used in modems, X.25, frame-relay, ISDN, and other now uncommon networking technologies. I know it because I used to work with them back in the day. You’ll get to know it now because a researcher discovered a security hole hidden within the Linux kernel driver that implements it.

Old Linux kernel security bug bites. More>

March 17, 2017
by sjvn01

Shut up already! How to turn off unwanted web page sound

Are you sick and tired of opening a new web page and being greeted by a loud, obnoxious advertisement? I sure am. Pop-up and pop-under ads were bad enough, but now it seems like I can hardly go to a site without having a video start up with a blaring voice braying about a great diet, deal, or the like. I’m looking at you, Facebook.

Shut up already! How to turn off unwanted web page sound. More>

March 16, 2017
by sjvn01

Daimler joins Linux’s Open Invention Network patent-protection group

When you think of Linux and open-source companies, the automobile industry is not the first business to spring to mind. But maybe it should be. Daimler, Mercedes-Benz’s parent company, has joined the Open Invention Network (OIN), the Linux and open-source non-aggression patent consortium.

Daimler joins Linux’s Open Invention Network patent-protection group, More>