Oracle have just made availble the Release Candidate for MySQL Cluster 7.4 (MySQL Cluster 7.4.3) – it can be downloaded from the development release tab here. Note that this is not a GA release and so we wouldn’t recommend using it in production.

The delta between this RC and the 7.4.2 DMR can be viewed in the MySQL Cluster 7.4.3 Release Notes

There are three main focus areas for this RC and the purpose of this post is to briefly introduce them:

• Active-Active (Multi-Master) Replication
• Performance
• Operational improvements (speeding up of restarts; enhanced memory …

I was surprised by the recent announcement that MySQL are going to start to conceal the hidden function calls in their C connector. Surprised because although this is great news I had expected them to do this years ago. Working for HP's Advanced Technology Group I realise I take such things for granted. For this blog post I'm going to talk about why it is important and how to do it.

So, when you create a dynamic library in C the default thing that happens is every function call in that library effectively becomes a potential API call. Whether you document every single function or not to make it official API is up to you but I suspect in 99.99% of cases there are private functions you don't want users to mess with. Additionally holding the symbol information for every function so that you can link your application to it takes a …

As many know, I have been working within the Espresso team at LinkedIn since 2012. Espresso is a schema-ed document store built upon MySQL.

Introducing Espresso - LinkedIn's hot new distributed document store

We eventually hope to open-source a version of Espresso which doesn't use LinkedIn's internal proprietary APIs.

About one and a half years ago we created MySQL StatsD to keep get insights of any MySQL server using a local daemon that frequently queries the MySQL server and pushes its data to StatsD locally. In the past year we have seen the usage of the MySQL StatsD project increase and more and more […]

The post MySQL StatsD release 0.1.3 appeared first on Spil Games Engineering.

We plan to hide (not export) the symbols of the SSL library used by the MySQL client library. As step one in that effort, we plan to hide all of the non-documented symbols because we want to stop polluting the MySQL client program’s namespace.

Consider a requirement where there the OpenSSL and MySQL client library functions are both used directly to generate a binary. If the order of linking used is 1. MySQL client library (i.e libmysqlclient) and then 2. OpenSSL library (i.e libcrypto), then using the created binary will result in a crash.

The Reason why it will crash is as follows: The libmysqlclient library already has the built-in yaSSL library and has exported its symbols. The yaSSL and OpenSSL libraries share some of the same symbol names, so the executable which is prepared in the above said order, will resolve the OpenSSL symbols indirectly using the libmysqlclient library (yaSSL) rather than using …

Mydumper is known as the faster (much faster) mysqldump alternative. So, if you take a logical backup you will choose Mydumper instead of mysqldump. But what about the restore? Well, who needs to restore a logical backup? It takes ages! Even with Myloader. But this could change just a bit if we are able to take advantage of Fast Index Creation.

As you probably know, Mydumper and mysqldump export the struct of a table, with all the indexes and the constraints, and of course, the data. Then, Myloader and MySQL import the struct of the table and import the data. The most important difference is that you can configure Myloader to import the data using a certain amount of threads. The import steps are:

1. Create the complete struct of the table
2. Import the data

When you execute Myloader, internally it first creates the tables executing the “-schema.sql” files and then takes all the filenames …

A Percona Xtradb (Galera) Cluster node may fail to join it due to many possible mistakes causing SST to fail. It could be a configuration item or purely setup requirement. In this article we will be troubleshooting step by step the SST issues faced.

The post Debugging Percona Xtradb (Galera) Cluster node startup / SST errors first appeared on Change Is Inevitable.

As a MySQL DBA/consultant, it is part of my job to decode the MySQL binary logs – and there are a number of reasons for doing that. In this post, I’ll explain how you can get the important information about your write workload using MySQL row-based binary logs and a simple awk script.

First, it is important to understand that row-based binary logs contain the actual changes done by a query. For example, if I run a delete query against a table, the binary log will contain the rows that were deleted. MySQL provides the mysqlbinlog utility to decode the events stored in MySQL binary logs. You can read more about mysqlbinlog in detail in the reference manual here.

The following example illustrates how mysqlbinlog displays row events that specify data modifications. These correspond to events with the WRITE_ROWS_EVENT, UPDATE_ROWS_EVENT, …

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.