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Displaying posts with tag: maintenance (reset)
Maintenance Windows in the Cloud

Recently, I’ve been working with a customer to evaluate the different cloud solutions for MySQL. In this post I am going to focus on maintenance windows and requirements, and what the different cloud platforms offer.

Why is this important at all?

Maintenance windows are required so that the cloud provider can do the necessary updates, patches, and changes to our setup. But there are many questions like:

  • Is this going to impact our production traffic?
  • Is this going to cause any downtime?
  • How long does it take?
  • Any way to avoid it?

Let’s discuss the three most popular cloud provider: AWS, Google, Microsoft. These three each have a MySQL based database service where we can compare the maintenance settings.

AWS

When you create an instance you can define your maintenance window. It’s a 30 minutes block when AWS can update and restart …

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Reclaiming space on your Docker PMM server deployment

Recently we had a customer that had issues with a filled disk on the server hosting their Docker pmm-server environment. They were not able to access the web UI, or even stop the pmm-server container because they had filled the /var/ mount point.

Setting correct expectations

The best way to avoid these kinds of issues in the first place is to plan ahead, and to know exactly with what you are dealing with in terms of disk space requirements. Michael Coburn has written a great blogpost on this matter:

https://www.percona.com/blog/2017/05/04/how-much-disk-space-should-i-allocate-for-percona-monitoring-and-management/

We are now using …

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Worldwide Multimaster Cluster Administration Using Tungsten Dashboard

Continuent Clustering support true distributed multimaster clustering. In this topology, there are cross-site replicator services for each remote site. In a 3-site configuration, there are a total of 9 replication streams to manage.

Continuent Clustering also offers a graphical administration tool called the Tungsten Dashboard to help with your management burden. The GUI makes the deployment much easier to visualize and administer.

For our example, we will have a Composite Multimaster dataservice called global with three active, writable member clusters (one per site), east, west and north.

Dashboard Summary View

In the summary, collapsed view, the composite service and all member clusters are listed with associated information and controls. Note that the Type for the composite dataservice global is CompMM

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ProxySQL-Assisted Percona XtraDB Cluster Maintenance Mode

In this blog post, we’ll look at how Percona XtraDB Cluster maintenance mode uses ProxySQL to take cluster nodes offline without impacting workloads.

Percona XtraDB Cluster Maintenance Mode

Since Percona XtraDB Cluster offers a high availability solution, it must consider a data flow where a cluster node gets taken down for maintenance (through isolation from a cluster or complete shutdown).

Percona XtraDB Cluster facilitated this by introducing a maintenance mode. Percona XtraDB Cluster maintenance mode reduces the number of abrupt workload failures if a node is taken down using ProxySQL (as a load balancer).

The central idea is delaying the core node action …

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By all means, learn from my mistakes as a DBA!

Here are 3 recent ' oops... wish I hadn't done that :/ ' mistakes I've made since joining moz that you might as well avoid (I'm sure there will be more, but they better not be the same)

Reviewing config files for MySQL, but not all of the defaults 

    We recently migrated a few MySQL databases to a new datacenter, and took advantage of the migration to upgrade the MySQL version(s) at the

MySQL binlogs - Don't forget to do your homework!

Now that I'm back doing just database stuff, I've come to realize I've gotten a little sloppy about doing my homework.  Homework's never been my favorite thing in the world, but it often reduces stress when your under the gun during an outage or upgrade...

We had a MySQL database server that's been slow on DML changes, and based on the slowest statements being 'COMMIT', we had a good mind

Installing and administering Tungsten Replicator - Part 2 : advanced

Switching roles

To get a taste of the power of Tungsten Replicator, we will show how to switch roles. This is a controlled operation (as opposed to fail-over), where we can decide when to switch and which nodes are involved.

In our topology, host1 is the master, and we have three slaves. We can either ask for a switch and let the script select the first available slave, or tell the script which slave should be promoted. The script will show us the steps needed to perform the operation.

IMPORTANT! Please note that this operation is not risk free. Tungsten replicator is a simple replication system, not a complete management tool like Continuent Tungsten. WIth the replicator, you must make sure that the applications have stopped writing to the master before starting the switch, and then you should address the application to the new master when the …

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innodb_file_per_table, shrinking table spaces and the data dictionary

INNODB has some irritating gotchas that makes disk space management hard. In 2002ish INNODB, added innodb_file_per_table to get around allot of these issues, but it does not fix everything.

If you are running innodb_file_per_table, you will notice in your database directory


  • db.opt - database characteristics file.
  • tablename.frm - the table structure.
  • tablename.ibd - the actual innodb table space file



Imagine that you have a table with 10 million rows and you delete say 5 million rows in multiple chunks around 400K chunks, because deletes are slow. Next, you notice that the table space file did not shrink. So what do you do? OPTIMIZE tablename, tada all the wasted space is reclaimed, but here is the PROBLEM the ibdata file grew!

ibdata stores all of the UNDO LOGS thus GROWS due to the deletes and …

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MySQL schema maintenance



At CodeBits I had my first session about MySQL schema maintenance. I covered the basic command line possibilities before coming to the recommended tool, MySQL Workbench.
The slides are available at slideshare.


Interesting questions: ([updated] with answers from the development team

  • [Q] Are there plans to administer MySQL Cluster with Workbench?
    [A] Not that we know of.
  • [Q] Can Workbench deal with user permission maintenance across servers? (especially in cases where development and production users can't have …
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Variable's Day Out #16: innodb_log_file_size

Properties: 

Applicable To InnoDB
Server Startup Option --innodb_log_file_size=<value>
Scope Global
Dynamic Yes
Possible Values Integer: Range: 1M - 4G
<1M will be adjusted to 1M
Default Value 5M
Category Performance, Maintenance


Description:

This variable defines the size of each log file in a log group. While setting this variable it should be noted that combined size of all log files should be less than …

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