When looking at high availability for any CMS, and particularly for Drupal, the list of contenders for part or all of the solution is growing and can be daunting. We'll take a look at the various parts of a solution and what options we have.
Go Cloud?
It seems nearly every answer to every problem in IT these days is "The Cloud", but is it?
When looking at high availability for any CMS, and particularly for Drupal, the list of contenders for part or all of the solution is growing and can be daunting. We'll take a look at the various parts of a solution and what options we have.
Go Cloud?
It seems nearly every answer to every problem in IT these days is "The Cloud", but is it?
Engine condition pushdown is a MySQL internal mechanism that is intended to avoid to send non matching rows from the storage engine to the SQL layer. This is very important when the storage engine involves traffic over the network. This mechanism was initially created to optimize MySQL Cluster (NDB) behavior. For the NDB storage engine [...]
One of my coworkers came across a strange quirk in MySQL with default values for not null columns. Take a look at this table:
Create Table Posts
(
PostID Int Auto_Increment Primary Key
,Title Varchar(30) Not Null
,Body Text Not Null
,Summary Varchar(25) Not Null Default ''
);
Note the column Summary that is marked not null but has a default value of an empty string. Now, try to insert a null value into this column.
Insert Into Posts (Title, Body, Summary) Values ('A title', 'A body', null);
You’ll get this error:
ERROR 1048 (23000): Column 'Summary' cannot be null
Now, using an extended insert (where you specify multiple rows in an insert statement), we can insert the same data and it will complete successfully, although there will be warnings.
Insert Into Posts (Title, Body, Summary) Values ('A title', 'A body', null), ('2nd body', '2nd body', null);
Query OK, 2 rows …[Read more]
It’s been written about everywhere, but since we keep spotting installations in the wild where people don’t know about it, it probably deserves another mention.
By default, Linux uses the atime option on a disk mount, which means it writes a timestamp (e.g. a write to the drive) every time it reads anything. So in this case, reads cause writes – and also disk seeks, because a read from a file will then trigger having to write to the directory that contains the file. This even occurs if a file is read from the file system’s page cache (reading from the machine’s memory rather than the drive).
Unless you require an audit trail of users reading files, you generally you don’t want this. Thus, you want to add the noatime option to the disk mount in /etc/fstab. If you have just the defaults in there, you just make it defaults,noatime. It’ll doesn’t necesarily require a reboot as you …
[Read more]In my prior post on the problems with open source, I wrote that one issue that impacts open source revenues is the macro economy, and how a declining or difficult macro economy can result in reduction of revenues to open source companies. The following article talks about how financially troubled Spain is saving a "fortune" by moving to open source. The Spanish government's savings are coming at the expense of proprietary server software companies--most likely Microsoft--but I would be willing to bet that none of this "savings" is flowing to the open source vendors. That is what happens in a difficult macro economy.
In my prior post on the problems with open source, I wrote that one issue that impacts open source revenues is the macro economy, and how a declining or difficult macro economy can result in reduction of revenues to open source companies. The following article talks about how financially troubled Spain is saving a “fortune” by moving to open source. The Spanish government’s savings are coming at the expense of proprietary server software companies–most likely Microsoft–but I would be willing to bet that none of this “savings” is flowing to the open source vendors. That is what happens in a difficult macro economy.
The post Problems with Open …
[Read more]Ever wondered how a database cluster ticks? Here’s how! During my talk at the International PHP Conference (#ipc13) I tried to build a cluster. I brought a soldering iron, sold, pink, orange and brown cables with me. Then, I tried to sold the thick (reliable, high throughput) brown cable at my company notebook (video coming). Eventually, I failed. Probably, I lacked the theoretical background?! Luckily, I got very theoretical slides with me…
DIY: A distributed database cluster, or: MySQL Cluster from Ulf Wendel
…
[Read more]ClouSE 1.0b.1.8 is released
OblakSoft is pleased to announce the release of ClouSE Beta version 1.0b.1.8. This is a minor maintenance release that addresses a couple pain points, while we’re working on a release candidate that will bring the built-in point-in-time recovery and other major features.
Here is the summary of changes:
Now ClouSE sets the cache control headers for Weblobs. The
cache control headers specify the max-age directive
that allows caching content for one year. This makes
proxies and content delivery networks (CDN) more efficient.
The change resolves this support issue.
Now database requests fail if …
[Read more]Read the original article at Five More Things Deadly to Scalability
Join 6000 others and follow Sean Hull on twitter @hullsean. 1. Slow Disk I/O – RAID 5 – Multi-tenant EBS Disk is the grounding of all your servers, and the base of their performance. True with larger and larger main memory, much is available in cache, a server still needs to constantly read from disk [...]
For more articles like these go to Sean Hull's Scalable Startups
Related posts:
[Read more]