In my recent benchmarks for MongoDB, we can see that the two engines WiredTiger and TokuMX struggle from periodical drops in throughput, which is clearly related to a checkpoint interval – and therefore I correspond it to a checkpoint activity.
The funny thing is that I thought we solved checkpointing issues in InnoDB once and for good. There are bunch of posts on this issue in InnoDB, dated some 4 years ago. We did a lot of research back then working on a fix for Percona Server
[Read more]Combining Galera and asynchronous replication in the same MariaDB setup, aka Hybrid Replication, can be useful - e.g. as a live backup node in a remote datacenter or reporting/analytics server. We already blogged about this setup for Codership/Galera or Percona XtraDB Cluster users, but master failover did not work for MariaDB because of its different GTID approach. In this post, we will show you how to deploy an asynchronous replication slave to MariaDB Galera Cluster 10.x (with master failover!), using GTID with ClusterControl v1.2.10.
Preparing the Master
First and foremost, you must ensure that the master and slave nodes are running on MariaDB Galera 10.0.2 or later. MariaDB replication slave requires at least a master with GTID among the Galera nodes. However, we would recommend users to configure …
[Read more]VividCortex is sponsoring and exhibiting at AWS Re:Invent October 6 - 9 this year. We will be serving up hats and database monitoring demos, so come check us out!
Click here for more details and registration.
I have been working for a very large Australian website for over
six years and during this period have been fortunate enough to
hire many Infrastructure Operations Engineers that now work for
that company. I want to detail the evolution of the hiring
process and what I have driven it to over the last six
years.
How was I hired This is the interview process I went through at
my current company:
http://dom.as/2015/07/30/on-order-by-optimization/
An insightful exploration by Domas (Facebook) on how some of the MySQL optimiser’s decision logic is sometimes naive, in this case regarding ORDER BY optimisation.
Quite often, “simple” logic can work better than complex logic as chasing all the corner cases can just make things worse – but sometimes, logic can be too simple.
Everything must be made as simple as possible, but no
simpler.
— Albert Einstein / Roger Sessions
VividCortex is sponsoring and exhibiting at Percona Live EU in Amsterdam September 21 - 23rd. Stop by our booth to get a free product demo and see how we can revolutionize your database monitoring.
Baron Schwartz will also be speaking on Redis Eye for the MySQL Guy, so be sure to learn from his experience.
Click here for more details and registration.
This Log Buffer Edition throws spotlight on some of the salient blog posts from Oracle, SQL Server and MySQL.
Fri, 2015-07-31 12:14guillaumelefranc
Mandatory disclaimer: the techniques described in this blog post are experimental, so use at your own risk. Neither me nor MariaDB Corporation will be held responsible if anything bad happens to your servers.
Context
MaxScale 1.2.0 and above can call external scripts on monitor events. In the case of a classic Master-Slave setup, this can be used for automatic failover and promotion using MariaDB Replication Manager. The following use case is exposed using three MariaDB servers (one master, two slaves) and a MaxScale server. Please refer to my Vagrant files if you want to jumpstart such a testing platform.
Requirements
Article on Information Age:
From obscurity to the mainstream, the journey of MySQL shows the power of the open source community to drive innovation. Read the full article here: http://goo.gl/bqFZPb
Welcome to the 10th episode in the MySQL QA series! Today we’ll talk about reproducing and simplifying: How to get it Right.
Note that unless you are a QA engineer stuck on a remote, and additionally difficult-to-reproduce or difficult-to-reduce bug, this episode will largely be non-interesting for you.
However, what you may like to see – especially if you watched episodes 7 (and possibly 8 and 9) – is how reducer automatically generates handy start/stop/client (cl) etc. scripts, all packed into a handy bug tarball, in combination with the reduced SQL testcase.
This somewhat separate part is covered directly after the introduction (ends at 11:17), as well as with an example towards the end of the video (starts at time index 30:35).
The “in between part” (11:17 to 30:35) is all about reproducing and simplifying, which – unless you are working on a remote case – can likely be skipped by …
[Read more]