Apache CloudStack is a turnkey orchestration platform to deliver IaaS clouds. As a cloud infrastructure scales to hundreds or thousands of servers, with production environments supporting multiple applications and services, high availability becomes a key requirement. Just as for OpenStack, it is possible to deploy the CloudStack management server in a multi-node installation. Since the management server uses a MySQL database to store the state of all its objects, the database could become a single point of failure. The CloudStack manual recommends MySQL replication with manual failover in the event of database loss. We believe there is a better way.

In this blog post, we’ll show you how to deploy redundant CloudStack management servers with …

Recently, we create a mysql data warehouse which is based on message queue.

Most companies must prepare for particular queries in their systems if they consider to split their databases or tables into many pieces.

some problems should be solved in this situation:

1. how to get correct results in-time
2. how to build strong data warehouse for future analyst

These policies were used by YHD

They have already deployed a middle-ware layer to support these requests (between web apps and databases). Every aggregation SQL was splited into many small SQLs and runs in every data nodes.The Final result is the aggregation of these all small SQLs. In this procedure, everything was computed in memory to get high performance.

In data warehouse layer, they use self-defined ETL tools to extract data from different databases to oracle-Exadata platform. Log-based data was put into hadoop and hbase.

A few days ago I wrote about MySQL performance implications of InnoDB isolation modes and I touched briefly upon the bizarre performance regression I found with InnoDB handling a large amount of versions for a single row. Today I wanted to look a bit deeper into the problem, which I also filed as a bug.

First I validated in which conditions the problem happens. It seems to happen only in REPEATABLE-READ isolation mode and only in case there is some hot rows which get many row versions during a benchmark run. For example the problem does NOT happen if I run sysbench with “uniform” distribution.

In terms of concurrent selects it also seems to require some very special conditions – you need to have the connection to let some …

On a recent consulting engagement, the PSCE team were charged with what can be considered a fairly common task of synchronising tables between master and slave in MySQL Replication. On this occasion the  schema contained both foreign key constraints and triggers, this post describes how we avoided the potential problems related to such an operation.

The process to synchronise tables in MySQL is to first identify the differences between tables and then execute queries which bring those tables into a consistent state. The first part of the process can be handled by the pt-table-checksum tool, which steps through the table analysing sets of rows (chunks) and recording a checksum value. Then taking advantage of replication, the same process occurs on each of the slaves and the checksums can then be compared. Once the entire table has been processed, a second tool pt-table-sync can be used …

MariaDB 10.1.2 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.1.2/

This is the third alpha release of MariaDB 10.1, so there are still a lot of new changes, functionalities added, defaults changed, and many bugs fixed (I counted 117, which is *way* down from the 637 fixed in 10.1.1). Since it’s alpha, I’ll only cover the major changes and additions, and omit covering general bug fixes (feel free to browse them all here).

To me, these are the highlights of the new features:

• –mysql56-temporal-format option to use the MySQL-5.6 low level formats to store …

MariaDB 10.0.15 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.0.15/

This is the sixth GA release of MariaDB 10.0, and 16th overall release of MariaDB 10.0.

This release has an important InnoDB/XtraDB fix, a new addition, security enhancements (and improvement) – all related to yaSSL, so be sure to check out these fixes if you’re running MariaDB 10.0, and not up to 10.0.15 yet. (MariaDB 10.0 is the current stable series of MariaDB. It is an evolution of the MariaDB 5.5 with several entirely new features not found anywhere else and with backported and reimplemented features from MySQL 5.6.)

Here are the main items of note:

1. This release fixes a serious bug in InnoDB and XtraDB that sometimes could cause a hard lock up of the server ( …

In my recent travels, I’ve been speaking with database users at various meetups and trade shows worldwide. Very often, I got questions centering around the best use cases for our products, be it TokuDB, our MySQL storage engine, or, TokuMX, our distribution of MongoDB. Over 90% of the time, I responded Cloud, Big Data or both. You see, in the software industry we’re like kindergartners, we like things to fit into neat categories. If you know any software sales people, you’ll recognize this as a fitting analogy (at least in terms of energy and attention span), but I digress. This strategy helps allocate resources where they are most likely to make an impact, and, thus, optimize our return on investment. In this blog series, I’m going to go slightly against the grain and explain why the Fractal Tree makes databases work in these environments.

Before I get into more detail, let me …

New version of JSON UDF functions has been just released. This is maintenance release which only contains fix for 4 bugs:

74090/19821398 `INSTALL_JSONUDFS` ISSUES A WARNING DUE TO TRUNCATION OF `VERSION_COMPILE_OS`
74091/19692634 `JSON_DEEP_MERGE`: DEEP CRASH IN `MERGE_TREE`
74092/19692628 CRASH WITH SECOND-HAND NULL IN PARAMETERS
74097/19693198 `CREATE_NEW_VALUE`: STACK BUFFER OVERFLOW, %LLD CAN'T FIT IN CHAR[20]

Also 0.3 branch becomes stable branch and no new features will be pushed to this branch in future. Previous stable branch (0.2) removed from MySQL Labs website.

…

In the MySQL Labs version of MySQL version 5.7, there is a new HTTP plugin. The HTTP plugin documentation from the labs site provides this information (from MySQL Labs):

The HTTP Plugin for MySQL adds HTTP(S) interfaces to MySQL. Clients can use the HTTP respectively HTTPS (SSL) protocol to query data stored in MySQL. The query language is SQL but other, simpler interfaces exist. All data is serialized as JSON. This version of MySQL Server HTTP Plugin is a Labs release, which means it’s at an early development stage. It contains several known bugs and limitation, and is meant primarily to give you a rough idea how this plugin will look some day. Likewise, the user API is anything but finalized. Be aware it will change in many respects.

In …

My dear colleagues,  Liz van Dijk, Dimitri Vanoverbeke, Kenny Gryp, also known as the “Party Team” are organizing the “Fosdem MySQL & Friends Devroom Community Dinner” !

Like last year, we’ll be renting a private space to allow for easy socializing. However, in light of this year’s 20th Anniversary of MySQL in May, as well as MariaDB’s 5th Anniversary in February, we want to take things to the next level, and give the night a true community feel. Our new location is available to us until 2AM, and is part of the ICAB buildings, closer to the ULB (more detailed directions on the eventbrite page).

As such, prepare for an evening of food prepared for the Community, by the Community. That’s right, your hosts will be firing up the pizza …