In one of the projects I have been working on, one requirement was the ability to stop traffic from reaching a MySQL host which has been lagging behind its master for longer than a specific amount of time and then bring it back online once the lag has gone away. Of course, this is all automated and no human intervention is required.

In this scenario, we are using HAProxy as the load balancer, and I will walk you through how to configure an agent so we can use HAProxy httpchk to flag the host as up or down, via systemd socket and then automatically set the host as being down/up when applicable, in HAProxy.

I will be setting up a systemd service (I’m running centos7 hosts) and creating a listening socket in the MySQL host we want to monitor so haproxy can have access to replication status.

Scenario:

master: po-mysql1
slaves: po-mysql2, po-mysql3, po-mysql4
secondary slaves: …

Generally, when I'm analyzing MySQL Performance on Linux with "localhost" test workloads, I'm configuring client connections to use IP port (loopback) to connect to MySQL Server (and not UNIX socket) -- this is still at least involving IP stack in the game, and if something is going odd on IP, we can be aware ahead about. And indeed, it already helped several times to discover such kind of problems even without network links between client/server (like this one, etc.). However, in the past we also observed a pretty significant difference in QPS results when IP port was used comparing to UNIX socket (communications via UNIX socket were going near 15% faster).. Over a time with newer OL kernel releases this gap became smaller and smaller. But in all such …

Both MongoDB and the MySQL Document Store are JSON document stores.  The syntax differences in the two products are very interesting.  This long will be a comparison of how commands differ between these two products and may evolve into a 'cheat sheet' if there is demand.

I found an excellent Mongo tutorial Getting Started With MongoDB that I use as a framework to explore these two JSON document stores.
The DataI am using the primer-dataset.json file that MongoDB has been using for years  in their documentation, classes, and examples. MySQL has created the world_x data set based on the world database used for years in documentation, classes and examples.  The data set is a collection of JSON documents filled with restaurants around Manhattan.
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I frequently talk to our customer base about what keeps them up at night. While there is a large variance of answers, they tend to fall into one of two categories. The first is the conditioned fear of some monster lurking behind the scenes that could pounce at any time. The second, of course, is the actual monster of downtime on a critical system. Ask most tech folks and they will tell you outages seem to only happen late at night or early in the morning. And that they do keep them up.

Entire companies and product lines have been built around providing those in the IT world with some ability to sleep at night. Modern enterprises have spent millions to mitigate the risk and prevent their businesses from having a really bad day because of an outage. Cloud providers are attuned to the downtime dilemma and spend lots of time, money, and effort to build in redundancy and make “High Availability” (HA) as easy as possible. The frequency of …

Next week I will be speaking at DataOps in Barcelona about MySQL 8.0 Document Store. If you don’t know it yet, I really invite you to join this talk, you will be very surprised about all MysQL can do in the NoSQL world !

There will be also a lot other MySQL related sessions by many good speakers of the MySQL Community.

As I will be in Barcelona, the Barcelona MySQL Meetup invited me to give a session about MySQL InnoDB Cluster and Group Replication and I will also share the stage with my friend and colleague …

Last time we looked at moving a JSON data set from MongoDB to the MySQL Document Store.  Let's move another and then see how to investigate this date.  We will use the primer-dataset.json that contains data on restaurants around New York City.

Loading Data
The loading of the JSON data set was covered last time but here is the gist. The first step is to fire up the MySQL Shell and login to the server.

 We need a new schema for this data and the example shows one created as nyeats.  The within that new schema a collection is created with the name restaurants.


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This Log Buffer edition covers Oracle, SQL Server and MySQL.

Cloud:

What DBAs need to know about Cloud Spanner, Part 1: Keys and indexes

Introducing sole-tenant nodes for Google Compute Engine — when sharing isn’t an option

A serverless solution for invoking AWS Lambda at a sub-minute frequency

Amazon Aurora MySQL DBA Handbook – …

Porting data from MongoDB to the MySQL Document Store is very easy.  The example I will use is an example data set from the good folks at Mongo named zips.json that contains a list of US Postal Codes and can be found at http://media.mongodb.org/zips.json for your downloading pleasure.

I copied the file into the Downloads directory on my Unbuntu laptop and then fired up the new MySQL Shell.  After login, I created a new schema creatively named zips with session.createSchema('zips').  When then set the db object to this new schema with the command \use zips.

MariaDB DBAs are accountable for auditing database infrastructure operations to proactively troubleshoot performance and operational issues, MariaDB Audit Plugin is capable of auditing the database operations of both MariaDB and MySQL. MariaDB Audit Plugin is provided as a dynamic library: server_audit.so (server_audit.dll for Windows).  The plugin must be located in the plugin directory, the directory containing all plugin libraries for MariaDB.

MariaDB [(none)]> select @@plugin_dir; 
+--------------------------+
| @@plugin_dir             |
+--------------------------+
| /usr/lib64/mysql/plugin/ |
+--------------------------+
1 row in set (0.000 sec)

There are two ways you can install MariaDB Audit Plugin:

INSTALL SONAME statement while logged into MariaDB, You need to use administrative account which has INSERT privilege for the mysql.plugin table.

MariaDB [(none)]> INSTALL SONAME 'server_audit'; …

In this article I will explain the partial update optimizations for smaller (LOBs) in InnoDB. Small here qualifies the size of the modification and not the size of the LOB.  For some background information about the partial update feature, kindly go through our previous posts on this (here, here and here).…