Tag: Performance_Schema

Feed: Planet MySQL; Author: MySQL Performance Blog; PREVIOUS POST Quickly Add a Node to an InnoDB Cluster or Group Replication (Shutterstock) In this blog, we’ll look at how to quickly add a node to an InnoDB Cluster or Group Replication using Percona XtraBackup. Adding nodes to a Group Replication cluster can be easy (documented here), but it only works if the existing nodes have retained all the binary logs since the creation of the cluster. Obviously, this is possible if you create a new cluster from scratch. The nodes rotate old logs after some time, however. Technically, if the gtid_purged set ... Read More

Feed: Planet MySQL; Author: MySQL High Availability; Version 8.0.12 added many great new features to MySQL. One of the new features included is the memory instrumentation of the XCom cache, which allows users to view and monitor the memory utilization of the cache by querying Performance Schema (PS). This blog post will tell you all about this latest addition. The XCom Cache The XCom cache is the message cache used by the Group Communication System (GCS) of GR to hold the messages exchanged between GR nodes as part of the consensus protocol. It is the single most important consumer of ... Read More

Feed: Planet MySQL; Author: MySQL High Availability; MySQL 8.0.13 improves replication lag monitoring by extending the instrumentation for transaction transient errors. These temporary errors, which include lock timeouts caused by client transactions executing concurrently as the slave is replicating, do not stop the applier thread: instead, they cause a transaction to retry. In this new release, we add eight new columns to the Performance Schema table replication_applier_status_by_worker reporting for both the last applied and the currently applying transaction:– the number of times the transaction was retried by the worker after the first attempt (if the transaction was applied at the ... Read More

Feed: Planet MySQL; Author: MySQL High Availability; Failure detection is a cornerstone of distributed systems as it determines which components are working properly or not, allowing it to tackle both network and host instabilities and failures. Like many other distributed systems, Group Replication (GR) requires a majority of correctly operating group members to work properly. Each GR member comprises a failure detector that is responsible for determining the state of the remaining group members by analyzing all exchanged messages. If it doesn’t receive any message from another member for some time, it creates a suspicion. When that suspicion times out, ... Read More

Feed: Planet MySQL; Author: MySQL High Availability; Having a server acting as a primary with multiple secondaries is the most common setup when using Group Replication. Until now though, there was no way to change the current primary member while the group was running without causing some sort of disruption. Now, those times are over. On this new release of the MySQL 8.0.13 server and Group Replication we now give you, the user, new tools to choose which server should be the primary member but also in what mode the group is operating without any server downtime. Online primary election ... Read More

Feed: Planet MySQL; Author: Alexander Rubin; PREVIOUS POST The short version I created > one billion InnoDB tables in MySQL 8.0 (tables, not rows) just for fun. Here is the proof: $ mysql -A Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 1425329 Server version: 8.0.12 MySQL Community Server - GPL Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or 'h' for help. Type 'c' to clear ... Read More

Feed: Planet MySQL; Author: MySQL Performance Blog; PREVIOUS POST pt-query-digest is one of the most commonly used tool when it comes to query auditing in MySQL®. By default, pt-query-digest reports the top ten queries consuming the most amount of time inside MySQL. A query that takes more time than the set threshold for completion is considered slow but it’s not always true that tuning such queries makes them faster. Sometimes, when resources on server are busy, it will impact every other operation on the server, and so will impact queries too. In such cases, you will see the proportion of slow ... Read More

Feed: Planet MySQL; Author: MySQL Performance Blog; PREVIOUS POST The second alpha build of Percona XtraBackup 8.0.2 is now available in the Percona experimental software repositories. Note that, due to the new MySQL redo log and data dictionary formats, the Percona XtraBackup 8.0.x versions will only be compatible with MySQL 8.0.x and Percona Server for MySQL 8.0.x. This release supports backing up Percona Server 8.0 Alpha. For experimental migrations from earlier database server versions, you will need to backup and restore and using XtraBackup 2.4 and then use mysql_upgrade from MySQL 8.0.x PXB 8.0.2 alpha is available for the following ... Read More

Feed: Planet MySQL; Author: MySQL Performance Blog; PREVIOUS POST Probably not well known but quite an important optimization was introduced in MySQL 5.6 – reduced overhead for “read only transactions”. While usually by a “transaction” we mean a query or a group of queries that change data, with transaction engines like InnoDB, every data read or write operation is a transaction. Now, as a non-locking read operation obviously has less impact on the data, it does not need all the instrumenting overhead a write transaction has. The main thing that can be avoided, as described by documentation, is the transaction ... Read More

Feed: Planet MySQL; Author: Searce Engineering; MySQL Adventures: How max_prepared_stmt_count can bring down productionWe recently moved an On-Prem environment to GCP for better scalability and availability. The customer’s main database is MySQL. Due to the nature of customer’s business, it’s a highly transactional workload (one of the hot startups in APAC). To deal with the scale and meet availability requirements, we have deployed MySQL behind ProxySQL — which takes care of routing some of the resource intensive SELECTs to chosen replicas. The setup consists of:One MasterTwo slavesOne Archive database serverPost migration to GCP, everything was nice and calm for a couple of ... Read More