Category: Generic
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Scripts for migrating bug reporting from Launchpad to JIRA
About two and a half years ago I wrote about how the MariaDB project moved bug reporting from Launchpad to JIRA. Every now and then I get contacted about how it was done and whether I would be willing to share the tools used for doing it and of course I’ve done that. Especially in one occasion the scripts were even further developed by one company that was in the process of doing exactly the same, i.e. moving bugs from […]
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Causal Consistency
Introduction
Causal consistency [1] is one of the consistency criteria that can be used on distributed databases as consistency criteria.
Distributed database provides causal consistency if read and write operations that are causally related are seen by every node of the distributed system in the same order. Concurrent writes may be seen in different order in diffrent nodes. Causal consistency is waker than sequential consistency [2] but stronger than eventual consistency [3]. See earlier blog for more detailed description on […]
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MariaDB Rhein/Neckar Usergroup meeting in Heidelberg/Germany
On February 26th 2015 the first meeting of Germany’s Rhein/Neckar User group will take place in Heidelberg.
Georg Richter, lead of MariaDB’s connectors team will give a talk “Don’t! No! Never!- common mistakes in relational database systems”.
Two special guests (Sanja Byelin, MariaDB Server Core Developer and Lawrin Novitsky, lead developer of MariaDB’s Connector/ODBC) will be available too for answering your questions and discussing/collecting your ideas around MariaDB, Percona, MySQL related and other database management systems.
Celebrate free speech, but […]
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MariaDB 10.1.2 : INFORMATION_SCHEMA tables for Galera membership & status
MariaDB Galera server logs all the cluster related information like node status, cluster status, membership, etc. in the error log. MariaDB 10.1.2 introduces a new INFORMATION SCHEMA plugin WSREP_INFO that enables querying these information via INFORMATION SCHEMA tables. The WSREP_INFO plugin adds two new tables to the Information Schema, WSREP_MEMBERSHIP and WSREP_STATUS. The plugin is not enabled by default, so in order to use it, it needs to be installed first :
Now that WSREP_INFO plugin is installed, lets look […]
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MariaDB 10.1.1: Galera support
MariaDB 10.1 server is now “Galera ready” with the latest 10.1.1 release. It includes wsrep (write set replication) patch that enables server to load the wsrep provider (galera) library and interact with it to provide multi-master synchronous replication support. The patch implements hooks inside server and storage engines to populate and apply the write sets on sender and receiver nodes in a cluster respectively. The wsrep patch also adds a number of system and status variables (prefixed with wsrep) that […]
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MariaDB 10.1.1: triggers for RBR
Sometimes users ask for something that doesn’t really make sense. On the first glance. But then you start asking and realize that the user was right, you were wrong, and it is, actually, a perfectly logical and valid use case.
I’ve had one of these moments when I’ve heard about a request of making triggers to work on the slave in the row-based replication. Like, really? In RBR all changes made by triggers are replicated from the master to slaves […]
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MariaDB 10.1.1: engine_condition_pushdown flag deprecated
Let me start with a little story. You sit in your house near the fireplace in the living room and need a book from the library… Eh, no, sorry, wrong century. You’re building a robotic arm that will open your beer or brew your coffee or supply you with whatever other drinks of your choice… while you’ll be building the next robotic arm. So, you — soldering iron in one hand and Arduino in another — ask your little brother […]
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MariaDB 10.1.1: system variables and their metadata
I don’t think it’ll surprise anybody if I say that MariaDB or MySQL server knows a lot more about server system variables, then just their values. Indeed, every variable can be session or global only, read-only or writable, it has an associated help text (that is printed on mysqld –help –verbose), certain variables only accept values from a given set of strings (this set of allowed values is also printed in mysqld –help –verbose since MariaDB 10.1.0), numeric variables have […]