Tungsten Replicator has offered shard-based
parallel replication to slaves since late 2010. The initial
implementation uses in-memory queues. Working purely in
memory keeps latency low and throughput high. On the other
hand, working in memory consumes valuable RAM. It also
forces us to buffer all in-flight transactions and therefore
greatly limits the span of time permissible between the slowest
and fastest shard.
Hence our newest improvement: on-disk parallel queues.
In this article I will cover how parallel replication works
in general, how on-disk queues help with parallel replication,
and then show how to set up from the latest builds.
First, let's review the basic mechanics. Parallel …
Jul
03
2011
Jul
03
2011
The purpose of this post is to describe what covering indexes are and how they can be used to improve the performance of queries. People mostly use indexes to filter or sort the results but not much thought is given to actually reduce the disk reads by using proper indexes. So I will show you how to reduce disk reads and hence improve the performance of queries by utilizing indexes properly.
Jul
03
2011
Vadim and others have pointed at the index->lock problems before, but I think they didn’t good job enough at pointing out how bad it can get (the actual problematic was hidden somewhere as some odd edge case). What ‘index lock’ means is generally the fact that InnoDB has table-level locking which will kill performance on big tables miserably.
InnoDB is a huge pie of layers, that have various locking behaviors, and are layered on top of each other, and are structured nicely as subdirectories in your innodb_plugin directory. Low level storage interfaces are done via os/ routines, then on top of that there’s some file space manager, fsp/, which allocates space for btr/ to live in, where individual page/ entities live, with multiple row/ pieces. There’re few other subsystems around, that got …
[Read more]
Jul
03
2011
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FISL is the biggest open source conference in Latin America and had about 7000 participants in the FISL 12 that concluded earlier this week. This was my third consecutive year (2010 and 2009) and as every year the conference was packed with lectures, workshops, demonstrations, booths, presentations, and lot more. |
Anil Gaur, VP of Java EE Platform and GlassFish, gave a
presentation on "Oracle GlassFish Server: A flexibly,
light-weight, and production-ready Java EE 6". There were about
100 attendees in the …
Jul
03
2011
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FISL is the biggest open source conference in Latin America and had about 7000 participants in the FISL 12 that concluded earlier this week. This was my third consecutive year (2010 and 2009) and as every year the conference was packed with lectures, workshops, demonstrations, booths, presentations, and lot more. |
Anil Gaur, VP of Java EE Platform and GlassFish, gave a
presentation on "Oracle GlassFish Server: A flexibly,
light-weight, and production-ready Java EE 6". There were about
100 attendees in the …
Jul
02
2011
We make a lot of posts that give IT tips and advice, as well as recommendations on how to use Monitis, so here is a summary of the posts for this week in case you missed them.
Monitoring IIS With VBScript via Monitis; It’s so Easy!
This post demonstrates how to monitor an IIS using Monitis Custom Monitors and VBscript. You can use the Monitis API to monitor your own custom metrics. This is very powerful because it lets you monitor any IIS metrics you like, set thresholds and receive notifications.
Top 4 Software Based IIS Server Performance Tips
These 4 …
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Jul
02
2011
An ideal summer day is when the sun is shining, the warm sunshine refreshes your body, the light breeze becomes naught with your hair, the birds sitting on intoxicated leaves smile at you, and you to top all of that you get the latest hot issue of the Log Buffer. Yes to put cherry on your cake, Log Buffer #227 is here.
Oracle:
David Kurts tells us about applying Hints to Objects inside Database Views.
Jonathan Lewis answers another burning question on on multi-column bitmap indexes and the inability of Oracle to create …
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Jul
01
2011
Today I was chatting with a technical friend, and she mentioned
that she has a "todo" of writing a decent node.js driver for
MySQL. A bit more chatting back and forth, and
http://nodejsdb.org/db-drizzle/ was discovered. It was written to
use libdrizzle and drizzled, but since libdrizzle can talk to
MySQL, it should work for her needs as well.
I would love to see some work done on how well libmysql+mysqld,
libdrizzle+mysqld, and libdrizzle+drizzled handle highly
concurrent asynchronous event-oriented workloads such as those
generated by all these new node.js applications.
I suspect that all sorts of surprising bugs will be
discovered.
Please help us discover those bugs.
Jul
01
2011
A herd of Hadoop announcements. Rockmelt raises $30m. And more.
A herd of Hadoop announcements
# Yahoo! and Benchmark Capital confirmed the formation of Hortonworks, an
independent company focused on the development and support of
Apache Hadoop.
# Cloudera announced the availability of Cloudera Enterprise 3.5 and the launch of Cloudera SCM Express, based on the new Service and Configuration Manager in Cloudera Enterprise 3.5.
# MapR …
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Jul
01
2011
We all know du command to get the size of a directory. But the
problem is when you use "du <directory name>" it will give
you the list of all subdirectory including the directory you want
with size.
Bt what if i only want the size of directory which i have passed
as an argument and not all the subdirectory?
In that senario we can use:
du -sh <directory
name>
Example 1:
du -h
/home/mysql/admin/
1K …