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Displaying posts with tag: Databases (reset)
MySQL 8.0.0 first impressions: been running for 60 days

While headlines likes this are really silly I thought it might be worth sharing some experience with 8.0.0 on a few servers I use. I tend to test new versions of MySQL first as a slave. That is easy as it requires little work: make a copy of a working 5.7 slave, upgrade the server … Continue reading MySQL 8.0.0 first impressions: been running for 60 days

MMUG16: MySQL document store: SQL and NoSQL united

The Madrid MySQL Users Group has its next meeting on Tuesday, 22nd November 2016.  Giuseppe Maxia will be giving a presentation MySQL document store: SQL and NoSQL united and I’ll be providing a brief summary of the new MySQL 8.0 and MariaDB 10.2 beta versions which were announced recently. There will also be an opportunity to … Continue reading MMUG16: MySQL document store: SQL and NoSQL united

Juggling Databases Between Datacenters

    Recently we went through an exercise where we moved all of our database masters between data centers. We planned on doing this online with minimal user impact. Obviously when performing this sort of action there are a variety of considerations such as cache consistency and other pieces of shared state in stores like HBase, but the focus of this post will be primarily on MySQL.

    During this move we had a number of constraints. As mentioned above this was to be online when serving production traffic with minimal user impact. In aggregate we service hundreds of thousands of database queries per second. Additionally we needed to encrypt all data transferring between data centers. MySQL replication supports encryption, but connections to the servers themselves present several challenges. Specifically, from a performance standpoint the handshake to establish a connection across a WAN can impact latency if …

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OOW16 talk – MySQL X protocol – Talking to MySQL directly over the Wire

Oracle Open World 2016 has just finished in San Francisco and we are now about to embark on Percona Live Europe in Amsterdam. I offered a presentation in San Francisco on the MySQL X protocol, the new protocol that Oracle is using to make the DocumentStore work. This new protocol also allow you to send … Continue reading OOW16 talk – MySQL X protocol – Talking to MySQL directly over the Wire

Q: Does MySQL support ACID? A: Yes

I was recently asked this question by an experienced academic at the NY Oracle Users Group event I presented at.

Does MySQL support ACID? (ACID is a set of properties essential for a relational database to perform transactions, i.e. a discrete unit of work.)

Yes, MySQL fully supports ACID, that is Atomicity, Consistency, Isolation and Duration. (*)

This is contrary to the first Google response found searching this question which for reference states “The standard table handler for MySQL is not ACID compliant because it doesn’t support consistency, isolation, or durability”.

The question is however not a simple Yes/No because it depends on timing …

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Do you control your database outages?

Working with a client last week I noted in my analysis, “The mysql server was restarted on Thursday and so the [updated] my.cnf settings seems current”. This occurred between starting my analysis on Wednesday and delivering my findings on Friday.

# more /var/lib/mysql/ip-104-238-102-213.secureserver.net.err
160609 17:04:43 [Note] /usr/sbin/mysqld: Normal shutdown

The client however stated they did not restart MySQL and would not do that at 5pm which is still a high usage time of the production system. This is unfortunately not an uncommon finding, that a production system had an outage and that the client did not know about it and did not instigate this.

There are several common causes and the “DevOps” mindset for current production systems has made this worse.

  • You have managed hosting and they perform software updates with/without your knowledge. I have for example worked with several Rackspace …
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Utilizing OpenStack Trove DBaaS for deployment management

Trove is used for self service provisioning and lifecycle management for relational and non-relational databases in an OpenStack cloud. Trove provides a RESTful API interface that is same regardless of the type of database. CLI tools and a web UI via Horizon are also provided wrapping Trove API requests.

In simple terms. You are a …

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The differences between IDEMPOTENT and AUTO-REPAIR mode

I posted recently Lossless RBR for MySQL 8.0 about a concern I have about moving to minimal RBR in MySQL 8.0.  This seems to be the direction that Oracle is considering, but I am not sure it is a good idea as a default setting. I talked about a hypothetical new replication mode lossless RBR and also about … Continue reading The differences between IDEMPOTENT and AUTO-REPAIR mode

Lossless RBR for MySQL 8.0?

Lossless RBR TL/DR: There’s been talk of moving the next release of MySQL to minimal RBR: I’d like to suggest an alternative: lossless RBR For MySQL 5.8 there was talk / suggestions about moving to minimal RBR as the default configuration (http://mysqlserverteam.com/planning-the-defaults-for-mysql-5-8/).  I’m not comfortable with this because it means that by default you do not have … Continue reading Lossless RBR for MySQL 8.0?

MySQL 5.7 Introduces a JSON Data Type

There's a new JSON data type available in MySQL 5.7 that I've been playing with. I wanted to share some examples of when it's useful to have JSON data in your MySQL database and how to work with the new data types (not least so I can refer back to them later!)

MySQL isn't the first database to offer JSON storage; the document databases (such as MongoDB, CouchDB) work on a JSON or JSON-ish basis by design, and other platforms including PostgreSQL, Oracle and SQL Server also have varying degress of JSON support. With such wide adoption as MySQL has, the JSON features are now reaching a new tribe of developers.

Why JSON Is Awesome

Traditional database structures have us design table-shaped ways of storing all our data. As long as all your records (or "rows") are the same shape and have the same sorts of data in approximately the same quantities, this works brilliantly well. There are some common problems that aren't a good …

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