Checksum is a standard practice among DBAs to verify the data consistency across replicated nodes. In this post we’re going to review the syncing options for an inconsistent MySQL slave of Galera cluster node.

Here we’re assuming a setup of regular replication to a MySQL instance from one of the Galera cluster nodes.

In the usual MySQL replication setup, standard practice involves the usage of the pt-table-checksum tool to identify the discrepancies and usage of pt-table-sync to bring them in sync. The checksum tool, pt-table-checksum, can run across Galera cluster node to verify the data consistency and confirm if the MySQL slave is consistent with a chosen primary node.

What happens if this Galera cluster’s regular MySQL slave sees data inconsistency on it? Will pt-table-sync work there? The answer to this depends…
pt-table-sync when used with –sync-to-master …

MariaDB CONNECT storage engine handles access to JSON files through standard SQL. It comes with a set of UDFs (user defined functions) to manipulate the JSON format. This JSON content can be stored in a normal text column. This approach can be used to implement dynamic columns. The dynamic column concept was first introduced with ...continue reading "Using JSON as Dynamic Columns with MariaDB"

Here’s a step-by-step guide on how to invert roles for master and slave so you can perform a master server upgrade, and then switch roles back to the original setup.

* While following this guide consider server-A as your original master and server-B as your original slave. We will assume server-B already produces binlogs and that both nodes have log-slave-updates=1 in my.cnf

Check this following link for more details on log-slave-updates: https://dev.mysql.com/doc/refman/5.6/en/replication-options-slave.html#option_mysqld_log-slave-updates

1. Prepare the original Slave to invert roles.

Make sure the slave is …

The client library — libmysqlclient — is part of the same source code repository as the server. It comes both as a dynamic link library (.so), also called a shared library, and as a static link library (.a). During the 5.7 development cycle, we’ve made several improvements to the library, which has resulted in a bump from ABI version 18 to version 20.…

Recently, I was working on a MySQL support ticket where a customer was facing an issue while transporting tablespace from MySQL 5.6 to MySQL 5.7.
After closely reviewing the situation, I saw that while importing tablespace they were getting errors such as:

ERROR 1808 (HY000): Schema mismatch (Table flags don't match, server table has 0x10 and the meta-data file has 0x1)

After some research, I found that there is a similar bug reported to MySQL for this issue (https://bugs.mysql.com/bug.php?id=76142), but no solution is mentioned. I tested the scenario locally and found a solution …

The Percona Live Data Performance Conference 2016 isn’t until 18-21 April 2016, but community voting is now open. So if you’re going, and want to see lots of MariaDB talks, please click on the buttons below and vote! You have to be logged in to the Percona site to vote. Once logged in, scroll to […]

The post MariaDB Talks at Percona Live Data Performance Conference 2016 appeared first on MariaDB.org.

I’ve made two session proposals for Percona Live conference:

• Window functions in MariaDB covers Window functions, a new feature in MariaDB 10.2. As far as I know, this the first attempt to have a talk about this feature.
• Exploring MariaDB Query Optimizer with ANALYZE for statements is about making use of ANALYZE (actually, ANALYZE FORMAT=JSON mostly) from …

So this year the Percona Live conference has a new name — it is the “Data Performance Conference” (presumably for a much broader appeal and the fact that Percona is now in the MongoDB world as well). And the next new thing to note? You have to go through a process of “community voting”, i.e. the speaker has to promote their talks before via their own channels to see how many votes they can get (we tried this before at the MySQL & Friends Devroom at FOSDEM; in this case, please remember you also need to create a new account and actually vote while logged in).

I hope you vote for Sergei, Monty and my proposals!

1. Using and Managing MariaDB – a tutorial, which has …

The show goes on. This Log Buffer Edition picks some blogs which are discussing new and old features of Oracle, SQL Server and MySQL.

Oracle:

• Directory Usage Parameters (ldap.ora) list the host names and port number of the primary and alternate LDAP directory servers.
• Data Visualization Cloud Service (DVCS) is a new Oracle Cloud Service. It is a subset offering of the currently supported Business Intelligence Cloud Service (BICS).
• ORA-24247: network access denied by access control list (ACL).
• Latches are low level …

This article is continuing the MySQL 5.7 Performance story, started from 1.6M QPS on MySQL 5.7 details post , then 1M QPS on mixed OLTP_RO with MySQL 5.7 article, and detailed story about why the Point-Selects performance is so critical (and why the 1M result published by MariaDB is not fair)..

The current story will be about Connect/sec (connect/disconnect) performance improvement in MySQL 5.7 - such kind of metric is very critical for any application which cannot use persistent connections all the …