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Displaying posts with tag: Architecture (reset)
Make It Faster: Improving MySQL Write Performance for Tungsten Cluster Slaves

Overview The Skinny

In this blog post we explore various options for performance tuning MySQL server for better slave replication performance.

A Tungsten Cluster relies upon the Tungsten Replicator to move events from the master node to the slaves. Once the event has been transferred to the slave as THL on disk, the slave applier will then attempt to write it to the database. The Replicator can only apply events as fast as MySQL allows. If the MySQL server is somehow slow or blocking, then the Replicator will be as well.

A properly-tuned database server in addition to infrastructure and SysAdmin best practices will go quite a long way towards high-performance slave apply.

The Question Recently, a customer asked us:

During one of our load tests, we had a peak of 60k writes/min, averaging …

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Zero-Downtime Cluster Maintenance: Comparing the Procedures for Upgrades versus DB/OS Maintenance

Overview The Skinny

Part of the power of Tungsten Clustering for MySQL / MariaDB is the ability to perform true zero-downtime maintenance, allowing client applications full access to the database layer, while taking out individual nodes for maintenance and upgrades. In this blog post we cover various types of maintenance scenarios, the best practices associated with each type of action, and the key steps to ensure the highest availability.

Important Questions Understand the Environment as a Whole First

There are a number of questions to ask when planning cluster maintenance that are critical to understand before starting.

For example:

  1. What is the cluster topology?
    • Standalone (connectors write to single cluster master)
      Single cluster: …
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How to move the Relay role to another node in a Composite Tungsten Cluster

The Question Recently, a customer asked us:

How would we manually move the relay role from a failing node to a slave in a Composite Tungsten Cluster passive site?

The Answer The Long and the Short of It

There are two ways to handle this procedure manually when the usual switch command fails to work as expected. One is short and reasonably automated, and the other is much more detailed and manual.

Of course, the usual procedure is to just issue the switch command in the passive cluster:

use west
set policy maintenance
switch
set policy automatic

The below article describes what to do when the switch command does not move the relay role to another node.

SHORT

Below is the list of cctrl commands that would be run for the basic, short version, which (aside from handling policy changes) is really only …

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Configuring the Tungsten Connector for PCI Compliance

The Question Recently, a customer asked us:

We were wondering if the Connectors would be able to bind to localhost/127.0.0.1 instead of 0.0.0.0:3306? Since the Connector is installed on the application servers, all of the connections are coming from localhost. We would like to limit this exposure so that the 3306 port is not exposed externally. We ask because we are failing PCI checks that are able to access the database port externally.

The Answer YES!

You may set the IP address for the Connector to listen on by using the tpm command option: property=server.listen.address={IP_ADDRESS}

To force the Connector to listen on the localhost only use the following example:

shell> tools/tpm configure alpha --property=server.listen.address=127.0.0.1
shell> tools/tpm update --replace-release

Use the IP …

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Using Keep-Alives To Ensure Long-Running MySQL & MariaDB Sessions Stay Connected

Overview The Skinny

In this blog post we will discuss how to use the Tungsten Connector keep-alive feature to ensure long-running MySQL & MariaDB/Percona Server client sessions stay connected in a Tungsten Cluster.

Agenda What’s Here?

  • Briefly explore how the Tungsten Connector works
  • Describe the Connector keep-alives – what are they and why do we use them?
  • Discuss why the keep-alive feature is not available in Bridge mode and why
  • Examine how to tune the keep-alive feature in the Tungsten Connector

Tungsten Connector: A Primer A Very Brief Summary

The Tungsten Connector is an intelligent MySQL database proxy located between the clients and the database servers, providing a single connection point, while routing queries to …

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Perform Complex Online Schema Changes on MySQL / MariaDB / Percona Server Leveraging Tungsten Clustering

Background The Skinny

Performing schema changes often requires extended downtime for applications. This is due to MySQL needing to rebuild tables for common schema change operations. Tools like pt-online-schema-change have been written to try to overcome the downtime associated with schema changes, however they are complex and put a high load on the database. Amazon’s Aurora improves some schema changes operations, but still requires a table rebuild for common operations like adding a column using before or after, or simply to add a column with a default value. Rebuilding a table with millions of rows can take hours and prevent writes to that table the entire time.

How Can Tungsten Clustering Keep Applications Running? How Does It All Work?

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[Platform] JK.cn Database operation and maintenance architect

Please download below ppt file,shared in Shenzhen 2019

The Important Role of a Tungsten Rollback Error

The Question Recently, a customer asked us:

What is the meaning of this error message found in trepsvc.log?

2019/05/14 01:48:04.973 | mysql02.prod.example.com | [east - binlog-to-q-0] INFO pipeline.SingleThreadStageTask Performing rollback of possible partial transaction: seqno=(unavailable)

Simple Overview The Skinny

This message is an indication that we are dropping any uncommitted or incomplete data read from the MySQL binary logs due to a pending error.

The Answer Safety First

This error is often seen before another error and is an indication that we are rolling back anything uncommitted, for safety. On a master this is normally very little and would likely be internal transactions in the trep_commit_seqno table, for example.

As you may know with the replicator we always extract complete transactions, and so this particular message is …

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Understanding Cross-Site Replication in a Tungsten Composite Multi-Master Cluster for MySQL, MariaDB and Percona Server

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. …

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Performance Tuning Tungsten Replication to MySQL

The Question Recently, a customer asked us:

Why would Tungsten Replicator be slow to apply to MySQL?

The Answer Performance Tuning 101

When you run trepctl status and see:
appliedLatency : 7332.394
like this on a slave, it is almost always due to the inability for the target database to keep up with the applier.

This means that we often need to look first to the database layer for the solution.

Here are some of the things to think about when dealing with this issue:

Architecture and Environment
 Are you on bare metal?
 Using the cloud?
 Dev or Prod?
 Network speed and latency?
 Distance the data needs to travel?
 Network round trip times? Is the …

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