August 20, 2014

MariaDB: Selective binary logs events

In the first post in a series on MariaDB features we find interesting, we begin with selectively skipping replication of binlog events. This feature is available on MariaDB 5.5 and 10. By default when using MySQL’s standard replication, all events are logged in the binary log and those binary log events are replicated to all slaves […]

max_allowed_packet and binary log corruption in MySQL

The combination of max_allowed_packet variable and replication in MySQL is a common source of headaches. In a nutshell, max_allowed_packet is the maximum size of a MySQL network protocol packet that the server can create or read. It has a default value of 1MB (<= 5.6.5) or 4MB (>= 5.6.6) and a maximum size of 1GB. […]

Binary log file size matters (sometimes)

I used to think one should never look at max_binlog_size, however last year I had a couple of interesting cases which showed that sometimes it may be very important variable to tune properly. I meant to write about it earlier but never really had a chance to do it. I have it now!

Faster Point In Time Recovery with LVM2 Snaphots and Binary Logs

LVM snapshots is one powerful way of taking a consistent backup of your MySQL databases – but did you know that you can now restore directly from a snapshot (and binary logs for point in time recovery) in case of that ‘Oops’ moment? Let me show you quickly how. This howto assumes that you already […]

Troubleshooting MySQL Upgrade Performance Regressions

So lets say you upgraded from MySQL 5.1 to Percona Server 5.5 and instead of expected performance improvement you see your performance being worse. What should you do ? First if you followed MySQL upgrade best practices such as testing your workload with pt-upgrade the chances of this happening are rather slim. But lets assume […]

Flexviews – part 3 – improving query performance using materialized views

Combating “data drift” In my first post in this series, I described materialized views (MVs). An MV is essentially a cached result set at one point in time. The contents of the MV will become incorrect (out of sync) when the underlying data changes. This loss of synchronization is sometimes called drift. This is conceptually […]

MySQL Limitations Part 2: The Binary Log

This is the second in a series on what’s seriously limiting MySQL in certain circumstances (links: part 1). In the first part, I wrote about single-threaded replication. Upstream from the replicas is the primary, which enables replication by writing a so-called “binary log” of events that modify data in the server. The binary log is […]

Storing MySQL Binary logs on NFS Volume

There is a lot of discussions whenever running MySQL storing data on NFS is a good idea. There is a lot of things for and against this and this post is not about them. The fact is number of people run their databases on NetApp and other forms of NFS storage and this post is […]

Just how useful are binary logs for incremental backups?

We’ve written about replication slaves lagging behind masters before, but one of the other side effects of the binary log being serialized, is that it also limits the effectiveness of using it for incremental backup.  Let me make up some numbers for the purposes of this example: We have 2 Servers in a Master-Slave topology. […]

Impact of logging on MySQL’s performance

Introduction When people think about Percona’s microslow patch immediately a question arises how much logging impacts on performance. When we do performance audit often we log every query to find not only slow queries. A query may take less than a second to execute, but a huge number of such queries may significantly load a […]