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Displaying posts with tag: tuning (reset)
MySQL Performance : Understanding InnoDB IO Internals & "Checkpointing"

Few weeks ago with a big curiosity I was reading several articles published by Percona about TPCC Benchmark results and MySQL 8.0 "checkpointing" issues..

Unfortunately, in these articles there was no any explanation nor any tentative to understand what is going on, an probably at least try and validate some "first coming in mind" tuning / troubleshooting options.. (And even no any try to show in action so often advertised PMM, and see on what it'll point ?)..

All in all, in the following article I'll try to feel up the "white holes" left in this TPCC testing..

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Enabling Autorecovery for the Tungsten Replicator

The Replicator is a critical piece of the Tungsten Clustering solution for MySQL / MariaDB, as well as its own stand-alone data replication product. Automatic recovery is a feature that enables the Replicator to go back online in the event of a transient failure. In this blog we discuss how to enable Automatic Recovery. For more information about Auto-Recovery, please click here to visit the online documentation page.

The Question Recently, a customer asked us:

We see that the replicators receive a transaction which has a deadlock error in it:

pendingError : Event application failed: seqno=82880882 fragno=0 message=java.sql.SQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction

If one performs a service online, it comes back online without issue and continues …

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What is the Best Way to Check the Health of a Tungsten Cluster Before a Switch?

The Question Recently, a customer asked us:

What would cause a node switch to fail in a Tungsten Cluster?

For example, we saw the following during a recent session where a switch failed:

cctrl> switch to db3 

SELECTED SLAVE: db3@alpha 
SET POLICY: MAINTENANCE => MAINTENANCE 
PURGE REMAINING ACTIVE SESSIONS ON CURRENT MASTER 'db1@alpha' 
PURGED A TOTAL OF 0 ACTIVE SESSIONS ON MASTER 'db1@alpha' 
FLUSH TRANSACTIONS ON CURRENT MASTER 'db1@alpha' 
Exception encountered during SWITCH. 
Failed while setting the replicator 'db1' role to 'slave' 
ClusterManagerException: Exception while executing command 'replicatorStatus' on manager 'db1' 
Exception=Failed to execute '/alpha/db1/manager/ClusterManagementHelper/replicatorStatus alpha db3' 
Reason= 
CLUSTER_MEMBER(true) 
STATUS(FAIL) 
+----------------------------------------------------------------------------+ 
|alpha | …
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Webinar Tues 19/6: MySQL: Scaling and High Availability – Production Experience from the Last Decade(s)


Please join Percona’s CEO, Peter Zaitsev as he presents MySQL: Scaling and High Availability – Production Experience Over the Last Decade(s) on Tuesday, June 19th, 2018 at 7:00 AM PDT (UTC-7) / 10:00 AM EDT (UTC-4).

Register Now

 

Percona is known as the MySQL performance experts. With over 4,000 customers, we’ve studied, mastered and executed many different ways of scaling applications. Percona can help ensure your application is highly available. Come learn from our playbook, and leave this …

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Monyog MySQL Monitor v8.5.0: Introducing Audit Log Analysis

Changes as compared to Monyog MySQL Monitor v8.4.1 include:

This release fixes a few minor bugs only and implements a number of user requests.

Features:

  • Monyog can now analyze MariaDB and MySQL enterprise Audit log.
  • Added support for LDAP with StartTLS and SSL.
  • The default path for MONyog.log can be changed using the parameter “MONyogLogPath” from the MONyog.ini file.

Bug Fixes:

  • Monyog logged bogus SQLite errors on fresh installation.
  • Monyog displayed console error if LDAP group name contained inverted comma.
  • Changed alert condition for “Seconds behind master” monitor to consider “NULL” as an alertable condition. It considered the value “NULL” stable condition earlier.
  • On upgrading, Monyog filled the mail alert field for sniffer with the bogus email id “admin@mydomain.com”.
  • On selecting a …
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MySQL Performance Tuning Tips for the Shopping Season

With Halloween all but a distant memory, the time has come to turn our attention to the upcoming holiday season. First, Thanksgiving, then Black Friday and Cyber Monday, culminating in the Christmas/boxing week shopping bonanza. For business owners, this time of the year marks the long-awaited year’s end profit taking. For some DBA’s, it brings fear, trepidation, and even sleepless nights toiling away to bring systems back online.

Thankfully, this need not be the case. With a little proactive tweaking of MySQL performance variables, you can insulate your database server(s) against the onslaught of increased demand that the shopping season brings.

Tip #1: Determine the Maximum Number of MySQL Connections

A good starting estimate for the maximum number connections on MySQL is one for every five requests to your web server. A few of those five requests to your web server will be for resources like CSS style sheets, …

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A Metric for Tuning Parallel Replication in MySQL 5.7

MySQL 5.7 introduced the LOGICAL_CLOCK type of multi-threaded slave (MTS).  When using this type of parallel replication (and when slave_parallel_workers is greater than zero), slaves use information from the binary logs (written by the master) to run transactions in parallel.  However, enabling parallel replication on slaves might not be enough to get a higher replication throughput (VividCortex

Percona Live Featured Tutorial with Øystein Grøvlen — How to Analyze and Tune MySQL Queries for Better Performance

Welcome to another post in the series of Percona Live featured tutorial speakers blogs! In these blogs, we’ll highlight some of the tutorial speakers that will be at this year’s Percona Live conference. We’ll also discuss how these tutorials can help you improve your database environment. Make sure to read to the end to get a special Percona Live 2017 registration bonus!

In this Percona Live featured tutorial, we’ll meet Øystein Grøvlen, Senior Principal Software Engineer at Oracle. His tutorial is on How to Analyze and Tune MySQL Queries for Better Performance. SQL query …

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Maximizing Database Performance – MySQL Tuning Best Practices

With the added complexity of growing data volumes and ever changing workloads, database performance tuning is now necessary to maximize resource utilizations and system performance. However, performance tuning is often easier said than done.

Let’s face it, tuning is difficult for a number of reasons. For one thing, it requires a significant amount of expertise in order to understand execution plans, and often update or re-write good SQL. On top of that, tuning is usually very time consuming. There will always be a large volume of SQL statements to sort through, which may lead to uncertainty around which specific statement needs tuning; and given every statement is different, so too is the tuning approach.

As data volumes grow and technology becomes increasingly complex, it is becoming more important to tune databases properly to deliver end-user experience and to lower infrastructure costs. Performance tuning can help database …

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Real time query monitoring on MySQL - with 3rd party tool and without

I've tried out Idera's MySQL Query Explorer, a free tool and I found it easy to use and simple to setup. The only improvement that can be suggested is to add, on the technical requirements page, that your MySQL instance (MySQL Server version 5.5 and newer) must be running with the performance_schema turned on. Otherwise the tool will just display an empty grid. After you've successfully set

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