Background: If you did not read my first blog post about why I am sharing my thoughts on the benchmarks published by Mark Callaghan on Small Datum you may want to skim through it now for a little context: “Thoughts on Small Datum – Part 1”

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Last time, in “Thoughts on Small Datum – Part 2” I shared my cliff notes and a graph on Mark Callaghan’s (@markcallaghan) March 11th insertion rate benchmarks using flash storage media. In those tests he compares MySQL outfitted with the …

Installing Nginx With PHP5 (And PHP-FPM) And MySQL Support (LEMP) On Ubuntu 14.04 LTS

Nginx (pronounced "engine x") is a free, open-source, high-performance HTTP server. Nginx is known for its stability, rich feature set, simple configuration, and low resource consumption. This tutorial shows how you can install Nginx on an Ubuntu 14.04 server with PHP5 support (through PHP-FPM) and MySQL support (LEMP = Linux + nginx (pronounced "engine x") + MySQL + PHP) .

“As the database gets used, shards can grow at an uneven rate and one shard might carry a majority of the load. MongoDB corrects this by balancing shards, but because of MongoDB’s lack of concurrency this operation can stall the database unacceptably.”–John Partridge.

I have interviewed John Partridge, President & CEO of Tokutek, Inc.

RVZ

Q1. Tokutek recently announced to have eliminated performance issues of MongoDB sharding. What was the problem?

John Partridge: The problem occurs after a shard is created. As the database gets used, shards can grow at an uneven rate and one shard might carry a majority of the load. MongoDB corrects this by balancing shards, but because of MongoDB’s lack of concurrency this operation can stall the database unacceptably (see the …

One of the MySQL 5.6 features many people are interested in is Global Transactions IDs (GTIDs). This is for a good reason: Reconnecting a slave to a new master has always been a challenge while it is so trivial when GTIDs are enabled. However, using GTIDs is not only about replacing good old binlog file/position with unique identifiers, it is also using a new replication protocol. And if you are not aware of it, it can bite.

Replication protocols: old vs new

The old protocol is pretty straightforward: the slave connects to a given binary log file at a specific offset, and the master sends all the transactions from there.

The new protocol is slightly different: the slave first sends the range of GTIDs it has executed, and then the master sends every missing transaction. It also guarantees that a transaction with a given …

Percona is glad to announce the release of Percona XtraDB Cluster 5.5.37-25.10 on May 8, 2014. Binaries are available from the downloads area or from our software repositories.

Based on Percona Server 5.5.37-35.0 including all the bug fixes in it, Galera Replicator 2.10 (including fixes in 2.9 and 2.10 milestones) and on wsrep API 25.10 (including fixes in 25.10), Percona XtraDB …

Overview

Percona XtraDB Cluster 5.6 has been GA for several months now and people are thinking more and more about moving from 5.5 to 5.6. Most people don’t want to upgrade all at once, but would prefer a rolling upgrade to avoid downtime and ensure 5.6 is behaving in a stable fashion before putting all of production on it. The official guide to a rolling upgrade can be found in the PXC 5.6 manual. This blog post will attempt to summarize the basic process.

However, there are a few caveats to trying to do a rolling 5.6 upgrade from 5.5:

1. If you mix Galera 2 and Galera 3 nodes, you must set wsrep_provider_options=”socket.checksum=1″ on the Galera 3 nodes for backwards …

Percona is glad to announce the release of Percona XtraBackup 2.2.2-beta1 on May 8th 2014. Downloads are available from our download site here. This BETA release, will be available in our Debian experimental and CentOS testing repositories.

This is a BETA quality release and it is not intended for production. If you want a high …

The German Unix User Group (GUUG) will hold their annual conference "Frühjahrsfachgespräch" on September 23-26 this year (I know, not really "Frühjahr" anymore, but this is how it is).

The Call for Presentations is still open until May 31st. Talks can be proposed in German and English, and there are slots for longer tutorials as well.

The range of possible topics is broad, so if you think you have anything interesting to share with a very passionate and technical audience of sysadmins and developers, here are some suggestions:

• Operating Systems/Applications: architectures, privilege concepts, new developments, administration, mobile systems
• Relevant new OS Kernel features: new developments in Linux-, BSD- or other Spen …

Many Sphinx users utilize MySQL as a data source. Divendo is one of them. This blog post will relay the story of how Divendo got going with Sphinx after MySQL fulltext search became unwieldy. Enjoy! Divendo Divendo is a meta-search engine for classified ads serving the following continents and countries: Europe: Spain, Italy, Portugal, United Kingdom Americas: Mexico, Argentina, Brazil, Chile, Colombia, Peru, Venezuela Asia: India Australia [...]

I ran into an issue the other day where Xtrabackup was not completing and threw the following error:

xtrabackup: error: log block numbers mismatch:
xtrabackup: error: expected log block no. 134860907,
but got no. 176803931 from the log file.
xtrabackup: Error: xtrabackup_copy_logfile() failed.

When researching this error, I found that this error is generally caused when the following 2 conditions must are met, and this is generally when “xtrabackup cannot catch up with log writing activity on the server, so the log wraps around before xtrabackup can copy records before they are overwritten”:

1. The log block numbers must wrap around, which only happens once per 1 GB of log writes.
2. The wrap-around point must be between the last checkpoint and the current log tail at the time the backup starts.

Discussed here:
…