ProxySQL Series: Handling resource expensive(bad) Queries in MySQL

This is our fourth blog in the ProxySQL Series MySQL Replication Read-write Split up Seamless Replication Switchover Using MHA Mirroring MySQL Queries This blog focuses on how to quickly find and address badly written queries using ProxySQL without any downtime and change in application code. When we get an incident about the high usage on … Continue reading ProxySQL Series: Handling resource expensive(bad) Queries in MySQL

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Presentation : MySQL Timeout Variables Explained

MySQL has multiple timeout variables these slides helps to give an overview of the different  timeout variables and their purposes briefly.

Handling long duration SST(timeout) in PXC with systemd

In this blog post, We will be explaining about the timeouts in SST on systemd implementation which we faced recently in Percona XtraDB Cluster  during our Consulting with a client. State Snapshot Transfers (SST) refers to complete data sync from one of the nodes from the cluster to the joining node. SST will happen for one or … Continue reading Handling long duration SST(timeout) in PXC with systemd

Investigating a MySQL dead lock

I was involved in one of the development support for MySQL. Here is an interesting case The application needs a Sequence generator as it was not present inbuilt with MySQL ( MariaDB will have it in 10.3 ) they have made sequence generator function with 'select for update' statement. But it tends to cause more locking … Continue reading Investigating a MySQL dead lock

Making Maxscale/ProxySQL Highly Available ( 2 > 1 )

As Mydbops we are implementing Load Balancer using Maxscale or ProxySQL ( Our presentation ) for lot our client,  but these load balancers will become a SPOF (Single Point of failure) .  We have tried to explore services like HAProxy, Nginx, and Keepalived etc. Except Keepalived, all the services need to run on the standalone instance … Continue reading Making Maxscale/ProxySQL Highly Available ( 2 > 1 )

Replication Will not Start On AWS RDS for MariaDB 10.2

AWS recently announced the release of MariaDB 10.2 for RDS. One of customer needs this release for GIS indexing .The recent encounter on a Replication issue with RDS MariaDB 10.2 is briefed here . Problem Statement: After the upgrade of replicas to MariaDB 10.2 on RDS, Once replication is stopped manually through “call mysql.rds_stop_replication;” or … Continue reading Replication Will not Start On AWS RDS for MariaDB 10.2

Disabling Multi-Source Replication in MySQL 5.7

Multi-channel replication is one of the  great feature shipped with MySQL 5.7, With allowed the capability of slave to have many masters, having a channel for each master by which they replicate. Each channel id has a unique “channel_name” In the above DB Architecture “channel_1, channel_2 and channel_3” represent the channel_name used for replication from … Continue reading Disabling Multi-Source Replication in MySQL 5.7

Ulimit conflict with PAM and Systemd​​​

As a part of the MySQL Support, we had a support request from a client.The issue is DB server runs out of open files limit, though it is configured. It causes the DB hang and crash at times. Sometimes they can't able to fix. So we plan to write our experience with configuring. We believe this … Continue reading Ulimit conflict with PAM and Systemd​​​

InnoDB and Linux mount point.

In this blog we are going to share my recent experience with an issue which we faced during migration between two Ubuntu servers. The activity was pretty simple, the client had bought a new machine with enhanced memory and faster disk, so the data has to be transferred to the new server and live MySQL replication … Continue reading InnoDB and Linux mount point.

InnoDB ‘Linux aio’ returned OS error 0. Cannot continue operation.

We had faced a weird error for one of our client under Emergency MySQL Support, it was a slave server. Client stated that whenever he tries to Start the replication it goes of loop of restarts. We had a sharing session with the client, At first we intended to rebuild the slave with a fresh … Continue reading InnoDB ‘Linux aio’ returned OS error 0. Cannot continue operation.