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Displaying posts with tag: MySQL (reset)
Re-Slaving a Crashed MySQL Master Server in Semisynchronous Replication Setup

In a MySQL 5.7 master-slave setup that uses the default semisynchronous replication setting for rpl_semi_sync_master_wait_point, a crash of the master and failover to the slave is considered to be lossless. However, when the crashed master comes back, you may find that it has transactions that are not present in the current master (which was previously a slave). This behavior may be puzzling, given that semisynchronous replication is supposed to be lossless, but this is actually an expected behavior in MySQL. Why exactly this happens is explained in full detail in the …

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MySQL Encryption: Talking About Keyrings

It has been possible to enable Transparent Data Encryption (TDE) in Percona Server for MySQL/MySQL for a while now, but have you ever wondered how it works under the hood and what kind of implications TDE can have on your server instance? In this blog posts series, we are going to have a look at how TDE works internally. First, we talk about keyrings, as they are required for any encryption to work. Then we explore in detail how encryption in Percona Server for MySQL/MySQL works and what the extra encryption features are that Percona Server for MySQL provides.

MySQL Keyrings

Keyrings are plugins that allow a server to fetch/create/delete keys in a local file (keyring_file) or on a remote server (for example, HashiCorp Vault). All keys are cached locally inside the keyring’s cache to speed up fetching keys. They can be separated into …

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NDB Parallel Query, part 4

In this part we will discuss how NDB batch handling works. Query execution of
complex SQL queries means that more rows can be delivered than the receiver is
capable of receiving. This means that we need to create a data flow from the
producer where the data resides and the query executor in the MySQL Server.

The MySQL Server uses a record where the storage engine have to copy the result
row into the record. This means that the storage of batches of rows is taken
care of by the storage engine.

When NDB performs a range scan it will decide on the possible parallelism before
the scan is started. The NDB API have to allocate enough memory to ensure that
we have memory prepared to receive the rows as they arrive in a flow of result
rows from the data nodes. It is possible to set batch size of hundreds and even
thousands of rows for a query.

The …

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Tungsten Clustering Makes The 2020 DBTA Top Trending Products List

We’re delighted to be able to share that Tungsten Clustering – our flagship product – is named in the DBTA 2020 List of Trend Setting Products!

Congratulations to all the products and their teams that were named in the 2020 list.

We have been at the forefront of the market need since 2004 with our solutions for platform agnostic, highly available, globally scaling, clustered MySQL databases that are driving businesses to the cloud (whether hybrid or not) today; and our software solutions are the expression of that.

Tungsten Clustering allows enterprises running business-critical MySQL database applications to cost-effectively …

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Upgrading from MySQL 5.7 to 8.0 on Windows

As you may know, I’m using MySQL exclusively on GNU/Linux. To be honest for me it’s almos 20 years that the year of Linux on the desktop happened. And I’m very happy with that.

But this week-end, I got a comment on an previous post about upgrading to MySQL 8.0, asking how to proceed on Windows. And in fact, I had no idea !

So I spent some time to install a Windows VM and for the very first time, MySQL on Windows !

The goal was to describe how to upgrade from MySQL 5.7 to MySQL 8.0.

So once MySQL 5.7 was installed (using MySQL Installer), I created some data using MySQL Shell:

Of course I used latest MySQL Shell, 8.0.18 in this case. Don’t forget that if you are using MySQL Shell or MySQL Router, you must always use the latest …

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NDB Parallel Query, part 3

In the previous part we showed how NDB will parallelise a simple
2-way join query from TPC-H. In this part we will describe how
the pushdown of joins to a storage engine works in the MySQL Server.

First a quick introduction to how a SQL engine handles a query.
The query normally goes through 5 different phases:
1) Receive query on the client connection
2) Query parsing
3) Query optimisation
4) Query execution
5) Send result of query on client connection

The result of 1) is a text string that contains the SQL query to
execute. In this simplistic view of the SQL engine we will ignore
any such things as prepared statements and other things making the
model more complex.

The text string is parsed by 2) into a data structure that represents
the query in objects that match concepts in the SQL engine.

Query …

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How to Deal with Triggers in Your MySQL Database When Using Tungsten Replicator


Over the past few days we have been working with a number of customers on the best way to handle Triggers within their MySQL environment when combined with Tungsten Replicator. We looked at situations where Tungsten Replicator was either part of a Tungsten Clustering installation or a standalone replication pipeline.

This blog dives head first into the minefield of Triggers and Replication.

Summary and Recommendations

The conclusion was that there is no easy one-answer-fits-all solution – It really depends on the complexity of your environment and the amount of flexibility you have in being able to adjust. Our top level summary and recommendations are as follows:

If using Tungsten Clustering and you need to use Triggers:

  • Switch to …
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Angular 9 CRUD Tutorial: Consume a Python/Django CRUD REST API

Angular 9 is in pre-release! Read about its new features in this article and how to update to the latest Angular version in this article.

You can also get our Angular 8 book for free or pay what you can.

This tutorial is designed for developers that want to use Angular 9 to build front-end apps for their back-end REST APIs. You can either use Python & Django as the backend or use JSON-Server to mock the API if you don't want to deal with Python. We'll be showing both ways in this tutorial.

Check out the other parts of this tutorial:

Adding Routing Building Navigation UI Using Angular Material 8

This tutorial deals with REST APIs and routing but you can also start with basic concepts by following this tutorial (part 1 and part 2) instead which you'll build a simple calculator.

If you would like to consume a third-party REST API instead of building your own API, make to check out this tutorial. …

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Angular 9/8 Tutorial By Example: REST CRUD APIs & HTTP GET Requests with HttpClient

In this Angular 9 tutorial, we'll learn to build an Angular 9 CRUD example application going through all the required steps from creating/simulating a REST API, scaffolding a new project, setting up the essential APIs, and finally building and deploying your final application to the cloud.

We'll learn by example how to send GET requests with URL query strings and parameters and process HTTP responses from REST API servers in your Angular 9/8 application using Httplient for fetching and consuming JSON data, how to do error handling for HTTP errors using the RxJS throwError() and catchError() operators, how to retry failed HTTP requests in poor network connections and cancel pending requests using the RxJS retry() and takeUntil() operators, and finally how to deploy the application to Firebase hosting using the latest Angular 8.3+ features. We'll also see how to use Angular services and RxJS Observables, and learn how to set up Angular …

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Percona Live 2020: Call For Papers

The Call For Papers (CFP) for Percona Live 2020 is now open!

Percona Live will be held in Austin, Texas from Monday, May 18 through Wednesday, May 20, 2020 at a new venue, the AT&T Hotel and Conference Center. The CFP is open for submissions from November 27, 2019, through January 13, 2020. We invite abstracts covering any and all aspects of open source databases, including on-premise, in the cloud, and across the multi-verse!

Hot Open Source Topics for 2020

All Open Source database themes are welcome, but these are our hot topics for 2020:

  • Success in the multi-verse: How to optimize performance, architecture, high-availability, replication, and more in a multi-cloud, multi-database environment.
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