For those of you who would like a copy of the slides from my webinar, they are now online at slideshare . Thanks again if you attended!
I wasn’t able to answer all the questions that were submitted at the end, so I’m collecting those, and more from your emails, for the next post: Q&A.
Hi, I'm Ben Osheroff, an engineer on the infrastructure team at Zendesk. My team began this year with a single goal: to better scale Zendesk's view system.
If you haven't tried Zendesk yet, views are lists of tickets with user-specified constraints, generally consumed by support agents as a workflow tool. As implemented, views are a SQL generation and execution engine, and this poses some interesting scale challenges: giving your customers a fully-featured bridge to SQL means that they will find all sorts of creative ways to generate queries your databases aren't prepared to handle.
To solve this, we've beenbuilding a system based on adaptive caches, where Zendesk keeps "materialized views" of expensive-to-execute queries, created on the fly as needed. At the heart of this caching system is a data firehose, a change capture system like …
[Read more]If you attended my webinar, MySQL for Oracle DBAs, thank you! I hope you enjoyed it.
We ran out of time while I was answering questions for Q&A, so I apologize if I didn’t answer your question. Please email any questions to me at ben-dot-krug-at-oracle-dot-com. Also, if you were asking for a copy of the slides (or would like to ask), also email me – I’ll be happy to send them!
Thanks again!
State Snapshot Transfer (SST) at a glance
PXC uses a protocol called State Snapshot Transfer to provision a node joining an existing cluster with all the data it needs to synchronize. This is analogous to cloning a slave in asynchronous replication: you take a full backup of one node and copy it to the new one, while tracking the replication position of the backup.
PXC automates this process using scriptable SST methods. The most common of these methods is the xtrabackup-v2 method which is the default in PXC 5.6. Xtrabackup generally is more favored over other SST methods because it is non-blocking on the Donor node (the node contributing the backup).
The basic flow of this method is:
[…] (i.e. a MYSQL database is akin to an Oracle schema), I found Patrick Hurley’s introduction to MySQL for Oracle DBAs helpful when approaching these […]
I’m the kind of DBA that prefers to keep everything simple, BUT,
sometimes it’s not possible. Few days ago I’ve faced an issue
where none of the collations shipped by default with MySQL would
guarantee integrity of my database, and to avoid a massive
re-write of application code, we have explored an option that up
to the day, I didn’t know about.
Add your own collation to MySQL.
This option is described on this section of MySQL documentation . On this post I will show how to make MySQL identify volves with acute accent (fada) as a different letter:
First, let’s find out where is our character-set folder:
mysql [localhost] {msandbox} ((none)) > SHOW VARIABLES LIKE
'character_sets_dir';
+--------------------+---------------------------------------+
| Variable_name | Value |
…
We’re excited to announce the general availability of MONyog for Amazon Aurora. Amazon Web Services’ (AWS) latest offering, the Aurora database combines the speed and availability of commercial databases with the cost-effectiveness and simplicity of open source databases. Designed to provide up to 5x improved performance than MySQL at a price that’s one-tenth of any commercial RDBMS, Aurora definitely looks promising.
Aurora is fault-tolerant by design, since it replicates data into three locations, making it highly available. To monitor your Aurora databases, you can always rely on MONyog to do the job for you.
Aurora doesn’t allow to install anything on your Aurora database. Since MONyog is built on an agent-less architecture, it can connect to Aurora without any hassle.
Connecting to Aurora
Enter the DNS address of your …
We’re excited to announce the general availability of MONyog for Amazon Aurora. Amazon Web Services’ (AWS) latest offering, the Aurora database combines the speed and availability of commercial databases with the cost-effectiveness and simplicity of open source databases. Designed to provide up to 5x improved performance than MySQL at a price that’s one-tenth of any commercial RDBMS, Aurora definitely looks promising.
Aurora is fault-tolerant by design, since it replicates data into three locations, making it highly available. To monitor your Aurora databases, you can always rely on MONyog to do the job for you.
Aurora doesn’t allow to install anything on your Aurora database. Since MONyog is built on an agent-less architecture, it can connect to Aurora without any hassle.
Connecting to Aurora
Enter the DNS address of your …
I have heard this question quite often: “At busy times, our replicas start lagging quite frequently. We are using N schemas, so which performance boost could we expect from MySQL 5.6 parallel replication?” Here is a quick way to give you a rough estimate of the potential benefit.
General idea
In MySQL 5.6, parallelism is added at the schema level. So in theory, if you have N schemas and if you use N parallel threads, replication could be up to N times faster. This assumes at least 2 things:
Both assumptions are of course not realistic. But it is easy to know the distribution of writes, and that can already give you an idea about how much you could benefit from parallel replication.
Writes are stored in binary logs but it is much easier to work with the …
[Read more]Oracle released a GA version of MySQL 5.6 in February 2013, Codership released the first GA in their patched 5.6 series in November 2013. Galera Cluster for MySQL 5.6 has been around for almost 2 years now, so what are you waiting for? :-)
Okay, this is a major upgrade so there are risks! Therefore, an upgrade must be carefully plan and tested. In this blog post, we’ll look into how to perform an online upgrade of your Galera Cluster (the Codership build of Galera) to MySQL 5.6.
Offline Upgrade
An offline upgrade requires downtime, but it is more straightforward. If you can afford a maintenance window, this is probably a safer way to reduce the risk of upgrade failures. The major steps consists of stopping the cluster, upgrading all nodes, bootstrap and starting the nodes. We covered the procedure in details in …
[Read more]