(In the previous post, Part 5, we covered Data Reads.)

In this blog post, we continue our series of exploring MyRocks mechanics by looking at the configurable server variables and column family options. In our last post, I explained at a high level how reads occur in MyRocks, concluding the arc of covering how data moves into and out of MyRocks. In this post, we’re going to explore replication with MyRocks, more specifically read-free replication.

Some of you may already be familiar with the concepts of read-free replication as it was a key feature of the TokuDB engine, which leveraged fractal tree indexing. TokuDB was similar to MyRocks in the sense that it had a pseudo log-based storage …

Overview The Skinny

In this blog post we will discuss how the managed cross-site replication streams work in a Composite Multi-Master Tungsten Cluster for MySQL, MariaDB and Percona Server.

Agenda What’s Here?

• Briefly explore how managed cross-site replication works in a Tungsten Composite Multi-Master Cluster
• Describe the reasons why the default design was chosen
• Explain the pros and cons of changing the configuration
• Examine how to change the configuration of the managed cross-site replicators

Cross-Site Replication A Very Brief Summary

In a standard Composite Multi-Master (CMM) deployment, the managed cross-site replicators pull Transaction History Logs (THL) from every remote cluster’s current master node. …

In this blog, we will see how to do a flashback recovery or rolling back the data in MariaDB, MySQL and Percona.

As we know the saying  “All humans make mistakes”, following that in Database environment the data modified accidentally can bring havoc to any organisations.

Recover the lost data

• The data can be recovered from the latest full backup or incremental backup when data size is huge it could take hours to restore it.
• From backup of Binlogs.
• Data can also be recovered from delayed slaves, this case would be helpful when the mistake is found immediately, within the period of delay.

We can use anyone of the above ways or other that can help to recover the lost data, but what really matters is, What is the …

File/Pos Replication : Skip Slave's sql_thread error [COMMAND]

For binlog file & position based replication setup, To skip the slave's sql_thread error, run below command.


stop slave;  set global sql_slave_skip_counter=1; start slave; select sleep(3); show slave status\G

set --server-id to enable either a master or a slave
Below issue can be faced, when we run CHANGE MASTER command to setup replication.
mysql> change master to master_host='xx.xx.xx.xx',master_user='rep_user',master_password="xxxxxxx", master_log_file='db-01-test-bin.000064',master_log_pos=95854072,master_auto_position=0; ERROR 1794 (HY000): Slave is not configured or failed to initialize properly. You must at least set --server-id to enable either a master or a slave. Additional error messages can be found in the MySQL error log.
Solution :- Here It is assumed, We have already set server-id parameter value different on master and slave node but still, we have the above error.

It happens once, you performed the server packages upgrade(like from 5.6 to 5.7) and just started MySQL service and going to run CHANGE MASTER command.

So, to solve this issue, Run mysql_upgrade command to …

PORP LAB : ProxySQL/Orchestrator/Replication/PMM Summary PORP Lab will create 4 different nodes. Each node will have below packages/applications/db installed.

app
-- Percona Server 5.7
-- Percona Toolkit 
-- Percona XtraBackup 
-- Sysbench 
-- ProxySQL
-- Orchestrator 
-- PMM

mysql1 / mysql2 / mysql3
-- Percona Server 5.7
-- Percona Toolkit
-- pmm-client
-- Replication

PORP LAB have ProxySQL,Orchestrator and PMM properly configured, we can just create this lab and use it.

Install VirtualBox

Version 5.2.22 or Later

Install Vagrant

Version 2.2.2 or Later

Install Vagrant plugin hostmanager

vagrant plugin install vagrant-hostmanager

Update Vagrant Plugin

vagrant plugin update

Clone the repo

git clone …

Master has purged binary logs containing GTIDs that the slave requires Problem :  Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'The slave is connecting using CHANGE MASTER TO MASTER_AUTO_POSITION = 1, but the master has purged binary logs containing GTIDs that the slave requires.'

Solution : stop slave;
Query OK, 0 rows affected (0.00 sec)

CHANGE MASTER TO MASTER_AUTO_POSITION = 0;
Query OK, 0 rows affected (0.01 sec)

start slave;
Query OK, 0 rows affected (0.00 sec)

At the end of the month, some engineers of the MySQL Team will be present in Austin, TX !

We will attend the first edition of Percona Live USA in Texas.

During that show, you will have the chance to meet key engineers, product managers, as well as Dave and myself.

Let me present you the Team that will be present during the conference:

The week will start with the MySQL InnoDB Cluster full day tutorial by Kenny and myself. This tutorial is a full hands-on tutorial where we will start by migrating a classical asynchronous master-replicas topology to a new MySQL InnoDB Cluster. We will then experience …

Overview The Skinny

From time to time we are asked how to check whether or not there are data discrepancies between Master/Slave nodes within a MySQL (or MariaDB) cluster that’s managed with Tungsten Clustering. This is always a challenging task, not least because we hope and believe that our replication mechanism would avoid such occurrences, that said there can be factors outside of our control that can appear to “corrupt” data – such as inadvertent execution of DML against a slave using a root level user account.

Tungsten Replicator, the core replication component in our Tungsten Clustering solution for MySQL (& MariaDB), is just that, a replicator – it takes transactions from the binary logs and replicates them around. The replicator isn’t a data synchronisation tool in that respect, the …

GTID Replication (Skip Transaction using empty transaction) To skip SQL thread's error in GTID replication setup, Insert empty transaction. PROBLEM :  db-test (none)> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: xxxxx
                  Master_User: rep_user
                  Master_Port: 3306
        …