The binary version for MySQL Cluster 7.1.13 has now been made available at http://www.mysql.com/downloads/cluster/
A description of all of the changes (fixes) that have gone into MySQL Cluster 7.1.13 (compared to 7.1.10) can be found in the official MySQL Cluster documentation for Cluster 7.1.13, 7.1.12 & 7.1.11.
The binary version for MySQL Cluster 7.1.9 has now been made available at http://www.mysql.com/downloads/cluster/
A description of all of the changes (fixes) that have gone into MySQL Cluster 7.1.9 (compared to 7.1.8) can be found in the official MySQL Cluster documentation. In addition, there is a great BLOG posting from Johan Anderson explaining how to use the new table added to ndbinfo to tune DiskPageBufferMemory when storing tables on disk.
The binary version for MySQL Cluster 6.3.39 has now been made available at http://www.mysql.com/downloads/cluster/
A description of all of the changes (fixes) that have gone into MySQL Cluster 6.3.39 (compared to 6.3.38) can be found in the official MySQL Cluster documentation.
MySQL Cluster Push-Down Joins
A great chance to find out about the “SPJ” project that’s under way to improve the performance of complex table JOINs. A free webinar has been scheduled for Thursday, November 04 at 09:00 Pacific time (16:00 UK; 17:00 Central European Time) – just register for the webinar at mysql.com. Even if you can’t attend, by registering you’ll get an email telling you where to watch the replay shortly after the webinar.
MySQL Cluster performance has always been extremely high and scalable when the work load is primarily primary key reads and write but complex JOINS (many tables in the JOIN and/or a large number of results from the first part of the query) have traditionally been much slower than when using other storage engines. Work is underway to address this and SPJ is the name we’ve been using.
Traditionally, JOINs have been performed as Nested Loop JOINs in the MySQL Server which is fine when all of the data is held there (e.g. MyISAM) but when the data is held externally (in Cluster’s case, in the data nodes) it can result in a massive amount of messaging. SPJ works by pushing the processing of JOINs down into the data nodes where they can be performed much more efficiently as the data is local.
As well as finding out about the implementation, you’ll also learn:
Note that (as always) Oracle reserves the right to alter the timing and/or existence of new product releases.
The binary version for MySQL Cluster 7.1.8 has now been made available at http://www.mysql.com/downloads/cluster/
A description of all of the changes (fixes) that have gone into MySQL Cluster 7.1.8 (compared to 7.1.5) can be found in the MySQL Cluster 7.1.8 Change Log.
As part of “MySQL Sunday” at this year’s Oracle Open World, Mat Keep and I will be presented on the MySQL Cluster architecture and the latest features. If you weren’t able to attend then you can watch/listen to the replay here.
MySQL Cluster in iBooks
MySQL documentation has now been made available in ePub format (fetch the MySQL Cluster versions from http://dev.mysql.com/doc/index-cluster.html ). This format is intended for various book readers.
I’ve tried it on 2 iPhone applications; Apple’s iBooks and the iPhone version of Stanza. The documents render well in both applications but as with most reference books you get the best results if you reduce the font size so that you get more on the screen at once.
With both applications, you can add the books through iTunes but Stanza also has the advantage that if you browse to the document in Opera on the iPhone then it gives you the option of opening it in Stanza – cutting out the need to use iTunes. I also prefer the rendering in Stanza. The only problems I’ve come across with Stanza is that you have to add the cover images yourself (if you care) – not a huge problem.
Page in iBooks
MySQL Cluster docs in Stanza library
Page in Stanza
Browse MySQL Cluster ePub docs on iPhone
On Wednesday 25 August, Johan Anderson and Mat keep will be presenting a free webinar on the best practices for deploying MySQL Cluster. If you’d like to attend then just register here.
Johan has years of MySQL Cluster professional services experience – and so if you’re interested in deploying a product ready MySQL Cluster database then this is a must-view session. Even if you can’t make it live, register anyway and you’ll be sent a link to the recording and charts afterwards.
Content
An invaluable session for those who are about to, or who already have, deployed MySQL Cluster. Delivered by the lead MySQL Cluster professional services consultant in Oracle, this session will present best practices on deploying MySQL Cluster in order to accelerate time to service with the highest levels of availability and performance to support your most critical web and telecoms applications.
The session will cover:
There is often confusion as to how it can be claimed that MySQL Cluster delivers in-memory performance while also providing durability (the “D” in ACID). This post explains how that can be achieved as well as how to mix and match scalability, High Availability and Durability.
MySQL Cluster deployment options
As an aside, the user can specify specific MySQL Cluster tables or columns to be stored on disk rather than in memory – this is a solution for extra capacity but you don’t need to take this performance hit just to have the data persisted to disk. This post focuses on the in-memory approach.
There is a great deal of flexibility in how you deploy MySQL Cluster with in-memory data – allowing the user to decide which features they want to make use of.
The simplest (and least common) topology is represented by the server sitting outside of the circles in the diagram. The data is held purely in memory in a single data node and so if power is lost then so is the data. This is an option if you’re looking for an alternative to the MEMORY storage engine (and should deliver better write performance as well as more functionality). To implement this, your configuration file would look something like this:
config.ini (no Durability, Scalability or HA)
[ndbd default] NoOfReplicas=1 datadir=E:\am233268\Documents\MySQL_Cluster\My_Cluster\data [ndbd] hostname=localhost [ndb_mgmd] hostname=localhost [mysqld] hostname=localhost
By setting NoOfReplicas to 1, you are indicating that data should not be duplicated on a second data node. By only having one [ndbd] section you are specifying that there should be only 1 data node.
To indicate that the data should not be persisted to disk, make the following change:
mysql> SET ndb_table_no_logging=1;
Once ndb_table_no_logging has been set to 1, any Cluster tables that are subsequently created will be purely in-memory (and hence the contents will be volatile).
Durability can be added as an option. In this case, the changes to the in-memory data is persisted to disk asynchronously (thus minimizing any increase in transaction latency). Persistent is implemented using 2 mechanisms in combination:
This checkpointing to disk is enabled by default but if you’ve previously turned it off then you can turn it back on with:
mysql> SET ndb_table_no_logging=0;
Following this change, any new Cluster tables will be asynchronously persisted to disk. If you have existing, volatile MySQL Cluster tables then you can now make them persistent:
mysql> ALTER TABLE tab1 ENGINE=ndb;
High Availability can be implemented by including extra data node(s) in the Cluster and increasing the value of NoOfReplicas (2 is the normal value so that all data is held in 2 data nodes). The set (pair) of data nodes storing the same set of data is referred to as a node group. Data is synchronously replicated between the data nodes in the node group and so changes cannot be lost unless both data nodes fail at the same time. If the 2 data nodes making up a node group are run on different servers then the data can remain available for use even if one of the servers fails. The configuration file for single, 2 data node node group Cluster would look something like:
config.ini (HA but no scalability)
[ndbd default] NoOfReplicas=2 datadir=E:\am233268\Documents\MySQL_Cluster\My_Cluster\data
[ndbd] hostname=192.168.0.1
[ndbd] hostname=192.168.0.2
[ndb_mgmd] hostname=192.168.0.3
[mysqld] hostname=192.168.0.1
[mysqld] hostname=192.168.0.2
[ndbd default] NoOfReplicas=1 datadir=E:\am233268\Documents\MySQL_Cluster\My_Cluster\data
[ndbd] hostname=192.168.0.1
[ndbd] hostname=192.168.0.2
[ndb_mgmd] hostname=192.168.0.1
[mysqld] hostname=192.168.0.1
[mysqld] hostname=192.168.0.2
[ndbd default] NoOfReplicas=2 datadir=E:\am233268\Documents\MySQL_Cluster\My_Cluster\data
[ndbd] hostname=192.168.0.1
[ndbd] hostname=192.168.0.2
[ndbd]
hostname=192.168.0.3
[ndbd]
hostname=192.168.0.4
[ndb_mgmd] hostname=192.168.0.5
[ndb_mgmd]
hostname=192.168.0.6
[mysqld] hostname=192.168.0.5
[mysqld] hostname=192.168.0.6
Mat Keep and I will be presenting this free webinar on Wednesday 14 July.
The MEMORY storage engine has been widely adopted by MySQL users to provide near-instant responsiveness with use cases such as caching and web session management. As these services evolve to support more users, so the scalability and availability demands can start to exceed the capabilities of the MEMORY storage engine.
The MySQL Cluster database, which itself can be implemented as a MySQL storage engine, is a viable alternative to address these evolving web service demands. MySQL Cluster can be configured and run in the same way as the MEMORY storage engine (ie on a single host with no replication and no persistence). As web services evolve, any of these attributes can then be added in any combination to deliver higher levels of scalability, availability and database functionality, especially for those workloads which predominately access data by the primary key.
The MEMORY storage engine has been widely adopted by MySQL users to provide near-instant responsiveness with use cases such as caching and web session management. As these services evolve to support more users, so the scalability and availability demands can start to exceed the capabilities of the MEMORY storage engine.
The MySQL Cluster database, which itself can be implemented as a MySQL storage engine, is a viable alternative to address these evolving web service demands. MySQL Cluster can be configured and run in the same way as the MEMORY storage engine (ie on a single host with no replication and no persistence). As web services evolve, any of these attributes can then be added in any combination to deliver higher levels of scalability, availability and database functionality, especially for those workloads which predominately access data by the primary key.
As always, the webinar is free of charge but you will need to register here.
Time:
If you can’t make the live webinar then register anyway and you’ll get sent a link to the recording after the event.