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 […]
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. […]
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!
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 […]
Backing up binary logs are essential part of creating good backup infrastructure as it gives you the possibility for point in time recovery. After restoring a database from backup you have the option to recover changes that happend after taking a backup. The problem with this approach was that you had to do periodic filesystem […]
If you’ve used MySQL’s mysqlbinlog tool, you’ve probably seen something like the following in the output: “exec_time=0″ What is the exec_time? It seems to be the query’s execution time, but it is not.
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 […]
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 […]
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.Â Let me make up some numbers for the purposes of this example: We have 2 Servers in a Master-Slave topology. […]
Recently I had an interesting surprise with concurrent inserts into a MyISAM table. The inserts were not happening concurrently with SELECT statements; they were blocking and the process list was filling up with queries in Locked status. My first thought was that the customer had deleted from the table, which leaves “holes” in the middle […]