From MySQL 5.7, we had a Multi-threaded Slave (MTS) Applier mechanism called LOGICAL_CLOCK to overcome the problems of parallel replication within a database. To further improve the parallelisation mechanism, from MySQL 8 (5.7.22) we have write-set replication, so before going further , lets look at the difference between Logical clock (LC) and Writeset. LOGICAL_CLOCK Transactions that … Continue reading Fastest Parallel replication method in MySQL 8.
A few days ago one of our intern @mydbops reached me with a SQL query. The query scans only a row according to the execution plan. But query does not seems optimally performing. Below is the SQL query and its explain plan. ( MySQL 5.7 ) select username, role from user_roles where username= '9977223389' ORDER … Continue reading Row scanned equals to 1, Is the query is optimally tuned ?
This blog is about one of the issues encountered by our Remote DBA Team in one of the production servers. We have a setup of MySQL 5.7 Single Primary (Writer) GR with cluster size of 3 . Due to OOM, the MySQL process in the primary node got killed, this repeated over the course of … Continue reading MySQL Group Replication and its Memory consumption (troubleshooting).
ProxySQL is a high-performance load balancer that helps DBAs a lot and gives more control over MySQL Database. At Mydbops we use ProxySQL extensively to support our customers. We have seen a variety of use cases with ProxySQL and blogged a few We have written a series of blogs on ProxySQL (ProxySQL Series) MySQL replication … Continue reading Monitoring MySQL using ProxySQL
As a part of Mydbops Consulting we have a below problem statement from one of our client. "We have a high powered server for reporting which in turn powers our internal dashboard for viewing the logistics status.Even with a high end hardware, we had a heavy CPU usage and which in turn triggers spikes in … Continue reading Troubleshooting an OLAP system on InnoDB
Loading any large file into MySQL server using the LOAD DATA INFILE is a time consuming process , because it is single threaded and it is a single transaction too. But with modern hardwares system resource is not a bottle neck. At Mydbops we focus on improving the efficiency of process as we value performance … Continue reading MySQL load data infile made faster .
Recently, One of our client reached our Remote DBA team with a requirement to reduce the size of the table as it is having many text columns with huge number of records. At preliminary check , I have … Continue reading Save Space on MySQL data with Column Compression
We are well aware that MySQL Group Replication is one of the faster evolving clustering Technology for MySQL. Flow Control plays a key factor in Group Replication performance and data integrity . In this blog I am going to explain about the Flow Control mechanism and How it has evolved in MySQL 8 ? What … Continue reading MySQL 8.0 Flow Control in Group Replication
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 … Continue reading Flashback Recovery in MariaDB/MySQL Servers
Recently we had encountered a strange issue with replication and temp directory(tmpdir) change while working for one major client. All the servers under this were running with Percona flavor of MySQL versioned 5.6.38 hosted on a Debian 8(Jessie) The MySQL architecture setup is as follows one master with 5 direct slaves under it Through this … Continue reading Impact of “tmpdir” change in MySQL replication