Category Archives: General
Background
Eventual consistency is a consistency model used in many large distributed databases which requires that all changes to a replicated piece of data eventually reach all affected replicas; conflict resolution is not handled and responsibility is pushed up to the application author in the event of conflicting updates [13].
Eventual consistency is a specific form of weak consistency; the storage system guarantees that if no new updates are made to the object, eventually all accesses will return the last updated value [14]. If no failures occur, the maximum size of the inconsistency window can be determined based on factors such as communication delays, the load on the system, and the number of replicas involved in the replication scheme [3]. …
A MariaDB Howto authored by: Erkan Yanar.
This is a Howto about installing MariaDB Galera Cluster on Debian/Ubuntu. Because a lot of people were having problems installing MariaDB Galera Cluster, elenst from #maria on freenode forced me to write this Howto 🙂
Installing MariaDB Galera Cluster is in fact quite easy and actually kind of boring in the end. This Howto is written for (and tested on) on Debian 7.1 (Wheezy) and Ubuntu 12.04 (Precise).
What we need
In our setup we assume 3 nodes (node01, node02, node03) with one interface each. We assume following IP addresses: 172.16.8.5, 172.16.8.6, and 172.16.8.4. …
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Lets start by considering a scenario where records are being inserted in a single auto-increment table via different nodes of a multi-master cluster. One issue that might arise is ‘collision’ of generated auto-increment values on different nodes, which is precisely the subject of this article.
As the cluster is multi-master, it allows writes on all master nodes. As a result of which a table might get same auto-incremented values on different nodes on INSERTs. This issue is discovered only after the writeset is replicated and that’s a problem!
Galera cluster suffers with the similar problem.
Lets try to emulate this on a 2-node Galera cluster :
1) On node #1:
MariaDB [test]> …
I’ve continued building on my MariaDB GIS and node.js example application that I wrote about two weeks back, https://blog.mariadb.org/node-js-mariadb-and-gis/. The application shows how to load GPX information into MariaDB, using some MariaDB GIS functionality, and making use of the node.js platform together with MariaDB’s non-blocking client.
With the GPX data converted into GIS points in the MariaDB database, I wanted to further expand a little on both the GIS aspect and also look at how some additional data could be shown in the application by using jQuery’s Ajax calls to update a piece of the web based application UI.
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The availability of the node.js binding for MariaDB’s non-blocking client library together with the GIS capabilities of MariaDB inspired me to make an example of using node.js and MariaDB to import so-called GPX tracks to a MariaDB database and then show them on a map. GPX tracks are what are stored by many GPS devices including running watches and smartphones.
My project makes use of MariaDB’s non-blocking client library together with the node.js platform and on top of that uses the GIS functionality found in MariaDB 5.5 and 10.0.
To start with let’s go through the software and components I’m using:
- Node.js – The popular Node.js platform built on Chrome’s JavaScript runtime.
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Last night, after my previous blog post, everyone in attendance at the SkySQL developer meeting in Barcelona gathered for dinner at El Cangrejo Loco, which, if my High School Spanish is working, translates as The Crazy Crab. After the excellent food, the tradition of singing at MySQL/MariaDB developer meetings was preserved.
Today the MariaDB developers in attendance at the SkySQL developer meeting in Barcelona got together to work on plans for MariaDB 10.1. We also paused for a group photo:
Many tasks have been identified for possible inclusion in 10.1. Some have already been marked as such in JIRA.
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Several MariaDB developers are attending SkySQL’s annual engineering meeting being held this week in Barcelona. While some of the discussions are SkySQL-specific (customers, internal projects, and so on), there are, naturally, lots of MariaDB discussions happening.
Patrik Sallner, CEO of SkySQL, opened the meeting this morning with a short presentation about SkySQL’s goals for 2014. While the plan includes standard business-like things that include growing the company and sales goals, the top two goals for 2014 are:
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Help make MariaDB into the leading open source database
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Help increase awareness and adoption of MariaDB
Looking back at 2013, it was an excellent year for MariaDB.
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The MariaDB project is pleased to announce the immediate availability of MariaDB 5.5.34. This is a Stable (GA) release. See the Release Notes and Changelog for detailed information on this release and the What is MariaDB 5.5? page in the MariaDB Knowledge Base for general information about the MariaDB 5.5 series.
Release Notes Changelog What is MariaDB 5.5?
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