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Displaying posts with tag: ndb (reset)
HopsFS based on MySQL Cluster 7.5 delivers a scalable HDFS

The swedish research institute, SICS, have worked hard for a few years on
developing a scalable and a highly available Hadoop implementation using
MySQL Cluster to store the metadata. In particular they have focused on the
Hadoop file system (HDFS) and the YARN. Using features of MySQL
Cluster 7.5 they were able to achieve linear scaling in number of name
nodes as well as in number of NDB data nodes to the number of nodes
available for the experiment (72 machines). Read the press release from
SICS here

The existing metadata layer of HDFS is based on a single Java server
that acts as name node in HDFS. There are implementations to ensure
that this metadata layer have HA by using a backup name node and to
use ZooKeeper for heartbeats and a number of …

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MySQL Cluster 7.5 is GA, best cluster release ever

I have been fairly quiet on my blog for some time. We've been very busy
developing new features for MySQL Cluster 7.5 and ensuring that the
quality is improved even further.

We're now very pleased to release a new version of MySQL Cluster.

MySQL Cluster 7.5 contains a number of new things that makes MySQL
Cluster even better.
1) You can declare a table as a READ_BACKUP table. This means that
the updating transactions will receive the commit acknowledge
a little bit later to ensure that we can always use any of the
replicas for reading. We will use the nearest replica for
committed reads, for locking reads we will still use the primary
replica to avoid deadlocks.

For applications that are mostly read-focused one can make it easier
to set this variable by setting the ndb-read-backup config variable
to 1 in the MySQL Server …

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MySQL Support People - The Next Generation

My first post in this series caused quite an active discussion on Facebook. Readers correctly noted some mistakes in dates and missing names in the list. I've corrected some of the mistakes already and will correct some others later. What was also noted is that initially support for MySQL was provided by developers (this is really important, we'll get back to this later), and of them many had never even got a title of Support engineer. Of those who had not I listed only Monty...

I just want to explain why I made these mistakes and/or why I (intentionally) had not listed developers etc. First of all, I based my post on my memories (so I could be also wrong about start dates and many details) and that's why I could not …

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MySQL Support People - Those Who Were There First

I'd like to devote this long weekend post, the first in a new series, to my current and former colleagues who once worked or still work in a company that provided public MySQL Support service and had a job role of MySQL Support engineer. The list of companies include MySQL AB/Inc ("good old MySQL"), Sun, Oracle, Percona, MariaDB, FromDual, maybe more (I named only those that surely provided or provides MySQL Support for customers outside of the company).

This is not the first time that I write about "people of MySQL", in a wider sense "those who contribute to MySQL Community". Last time it was about …

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MySQL Cluster: Una introducción en Español.

MySQL Cluster: El ‘qué’ y el ‘cómo’.

Para aquellos que encuentran mucho sobre MySQL en Inglés pero poco en Español: mi pequeña aportación.
En el enlace tenéis información sobre qué es MySQL Cluster y cómo funciona. Incluso con ejemplos técnicos para romper las barreras y ayudar a simplificarlo (espero).

¡A disfrutar!

Load Balancing for MySQL with HAProxy - Webinar Replay in English & French

January 30, 2015 By Severalnines

In this joint webinar series with our friends from the HAProxy team, we covered the concepts around the popular open-source HAProxy load balancer, and demonstrated how to use it with SQL-based database clusters. We also discussed HA strategies for HAProxy with Keepalived and Virtual IP. 


Thanks to everyone who participated in these two sessions this week! Please see below for details on next week’s follow up session 'Performance Tuning for HAProxy & MySQL'.


The topics covered this week included: 

  • What is HAProxy?
  • SQL Load balancing for MySQL
  • Failure detection using MySQL health checks
  • High Availability with Keepalived and Virtual IP
  • Use cases: MySQL/MariaDB Galera Cluster, MySQL NDB …
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Galera Cluster for MySQL vs MySQL (NDB) Cluster: A High Level Comparison - Webinar Replay & Slides


Thanks to everyone who attended and participated in last week’s webinar on 'Galera Cluster for MySQL vs MySQL (NDB) Cluster: A High Level Comparison'. If you missed the sessions or would like to watch the webinar again & browse through the slides, they are now available online.


In this webinar, Severalnines VP of Products, Alex Yu, who was part of the team at Ericsson who originally developed the NDB storage engine in 2001, gave an overview of the two clustering architectures and discussed their respective strengths and weaknesses: 

  1. MySQL Cluster architecture: strengths and limitations
  2. Galera Architecture: strengths and limitations
  3. Deployment scenarios
  4. Data migration
  5. Read and write workloads (Optimistic/pessimistic locking)
  6. WAN/Geographical replication
  7. Schema changes
  8. Management and monitoring …
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MySQL Cluster – Java Connector / Bindings

While working with MySQL Cluster, i was looking for a monitoring framework for the cluster.

i came across a library @ – which had java and other connectors to NDB, the library was a wrapper of the existing C++ NDB Api.

This library allowed me to connect to the management node , get the state of the cluster and get real time notifications about heartbeat misses/node disconnections.

The library error-ed out on some conditions, with a small fix, it can work with MySQL Cluster 7.3.

I have listed down steps for compilation and running a sample program at github

Preliminary MySQL Cluster benchmark results on POWER8

Yesterday, I got the basics going for MySQL Cluster on POWER. Today, I finished up a couple more patches to improve performance and ran some benchmarks.

This is on a 3.7Ghz POWER8 machine with non-balanced memory (only 2 of the 4 NUMA nodes have memory, so we have less total memory bandwidth than we could have, plus I’m going to bind ndbmtd to the CPUs in these NUMA nodes)

With a setup of a single replica and two data nodes on the one machine (each bound to a specific NUMA node), running the flexAsync benchmark on MySQL Cluster 7.3.7, I could get around:

  • 3.2 million reads/sec
  • 2.6 million deletes/sec
  • 2.4 million updates/sec
  • 2.4 million inserts/sec.

So, that’s at least in the right ballpark for a first go.

(I’m running this on a big endian host …

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MySQL Cluster on POWER8

So, I’ve written previously on MySQL on POWER, and today is a quick bit of news about MySQL Cluster on POWER – specifically MySQL Cluster 7.3.7.

I ran into three main issues in getting some flexAsync benchmark results. One of them was the fact that I wanted to do this in the middle of all the POWER8 machines I usually use moving buildings (hard to run benchmarks when computers are packed up in boxes on a truck).

The next issue was that ndbmtd (the multi-threaded data node) needs memory barriers for the magic message passing stuff between threads. So, that’s pretty easy (about an eight line patch).

The next issue was in the results from flexAsync, it turns out 32bit math is a bad idea with results from my POWER8 box.

My preliminary performance numbers are fairly promising (actually… what is the world record for a single machine and NDB these days? Single data node?). I think there’s a bit more low …

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