Replication just stopped in one Slave server with error: The table xtable is full which means no more records are permitted to insert in this table by MySQL and hence this has broken the replication.

I checked that xtable is having storage engine as Memory. In such tables, the max. no. of records you can insert is controlled by variable max_heap_table_size. When checking the size of this variable, I found that this is having default value:

mysql> show variables like 'max_heap_table_size';
+---------------------+----------+
| Variable_name       | Value    |
+---------------------+----------+
| max_heap_table_size | 16777216 |
+---------------------+----------+
1 row in set (0.00 sec)

So we need to increase the value of this variable and then issue Alter Table command to make it effective. Also do not …

I am a minimalist at heart, and I love command line interfaces and text files.

However, I’m also pragmatic, and so for a long time my blog has been powered by Wordpress, which made it relatively easy to manage content and design. I just didn’t want the hassle of maintaining something myself.

Somewhere along the way recently I stumbled across Jekyll, and the idea of generating a static site from templates.

I’d seen a few sites I liked the look of, and I loved the idea of simplifying my site (and editing posts in vim!), and so the end result is the site you see now. The theme is based on skim.la’s site.

I pondered implementing something like disqus for comments, but honestly I get so few proper responses, compared to the hundreds and hundreds of spam …

In response to the release of our new MySQL monitoring plugins on Friday, one commenter asked why the new Nagios plugins don’t use caching. It’s worth answering in a post rather than a comment, because there is an important principle that needs to be understood to monitor servers correctly. But first, some history.

When I wrote a set of high-quality Cacti templates for MySQL a few years ago (which are now replaced by the new project), making the Cacti templates use caching was important for two reasons:

1. Performance. Cacti runs some of its polling processes serially, so if each graph has to reach out to the MySQL server and retrieve a bunch of data, the polling can take too long. I’ve seen cases where a Cacti server that’s graphing too many MySQL servers doesn’t …

Right after you finish your installation, you need to execute the below command from the shell.

mysql_secure_installation

By executing this command, mysql will remove all anonymous access in your database including the test database. It will also require you to set password for root account as well if you want remote access to your database.

Taxonomy upgrade extras: High Availabilitymysqlconsultingclusterinnodbfromdualsupportgaleracodershipmysql-supportmysql-consulting

Helsinki, …

MariaDB 5.3 has reached the release candidate milestone, and the 5.3 version promises a lot of new features and optimization (i.e in optimizer http://kb.askmonty.org/en/what-is-mariadb-53#query-optimizer). No surprise I wanted to check how all improvements affect general performance.

So I why don’t we run old good sysbench benchmark.

For the benchmark I took:

• HP ProLiant DL380 G6 box
• sysbench multitables oltp rw workload, 16 tables, 500mil rows each, total datasize about 30GB
• working threads from 1 to 256
• Versions: MariaDB 5.3.4, MySQL 5.5.20
• Data is stored on RAID10 HDD partition
• Like in all my recent benchmarks, I make throughput measurements each …

MySQL Settings (also known as Server Variables) have interesting property. When you set variable in running server this change is not persisted in any way and server will be back to old value upon restart. MySQL also does not have option to re-read config file without restarting as some other software so approach to change config file and when instruct server to re-read it also does not work. This leads to runtime settings being different from settings set in config file, and unexpected change on restart a frequent problem.

pt-config-diff is the tool which can help with this problem a lot, being able to compare settings in my.cnf to those server is currently running with. The problem however this only works well if settings are set in my.cnf as if default option was used and we change it in run time we can’t detect such change easily …

Hello Folks,

I have never been consistent with blogging and most of the time
I create a blog hoping that I would  share my thoughts and plans
with everyone, but as It has to happen, I neglect it.

On this new year I made a resolution that I will work on this blog
(actually it was to create one) and maintain it throughout. This
blog will be the reflection of my ideas, and an attempt to get a feedback on
my work in MySQL replication, together with providing tips and tricks
on using MySQL in distributed environment.

So, last July I joined MySQL replication development team, straight out of
college and it is kind of a big thing for me. In past 7 odd months I have
worked with great people and learnt a lot of things and this has finally lead
to an idea of starting this blog, and posting my thoughts in my spare time.

This …

Links to performance numbers posted wrt various NoSQL solutions:

A top 20 global website announced they have migrated from MySQL to Redis. There will be a keynote and everything. It doesn't say how big the Redis Cluster is, but they serve 100M pages / day, and clock 300k Redis queries / second.
https://groups.google.com/forum/?fromgroups#!topic/redis-db/d4QcWV0p-YM

Btw, they mention that MySQL remains as the master data store from which the Redis indexes are generated.
(The reason I don't mention the name of this Redis user is simply I feat my mom is sometimes reading my blog...)

read more

New features in the 2.0 release:

• Galera 2.0
• MySQL-wsrep 5.5.20
• MySQL-wsrep 5.1.60

This is a major feature and bugfix release including support for Incremental State Transfer, foreign keys, and many critical bugfixes. For details follow download links.
Download