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Displaying posts with tag: Performance (reset)
Troubleshooting XA transactions in MySQL

This is one of the exciting troubleshooting related to XA transactions let’s dive in. Let me provide a few backgrounds.

For one of our clients, when we try to drop a table, it is waiting for metadata lock. On debugging it is one of the XA transactions is holding the shared write lock and causing metadata lock on all the other local transactions.

Let us view the metadata locks from the Performance Schema.

mysql> select OBJECT_TYPE,OBJECT_SCHEMA,OBJECT_NAME, LOCK_TYPE,LOCK_STATUS,SOURCE from performance_schema.metadata_locks\G
******************* 1. row *********************
OBJECT_TYPE: TABLE
OBJECT_SCHEMA: sbtest
OBJECT_NAME: sbtest_table1
LOCK_TYPE: SHARED_WRITE
LOCK_STATUS: GRANTED

SOURCE: xa.cc:284
******************* 2. row *********************
OBJECT_TYPE: TABLE …
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MySQL Performance : Benchmark kit (BMK-kit)

The following is a short HOWTO about deployment and use of Benchmark-kit (BMK-kit). The main idea of this kit is to simplify your life in running various MySQL benchmark workloads with less blood and minimal potential errors.

Generally as simple as the following :

$ bash /BMK/sb_exec/sb11-Prepare_50M_8tab-InnoDB.sh 32   # prepare data

$ for users in 1 2 4 8 16 32 64 128 256 512 1024
do   
  # run OLTP_RW for 5min each load level..
  bash /BMK/sb_exec/sb11-OLTP_RW_50M_8tab-uniform-ps-trx.sh $users 300
  sleep 15
done

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Explore & visualize your MySQL HeatWave data with Superset

In this article I will show you how to properly configure Apache Superset in order to take advantage of a high performance, in-memory query accelerator: MySQL HeatWave.

The post Explore & visualize your MySQL HeatWave data with Superset first appeared on dasini.net - Diary of a MySQL experts.

Faster Load data outfile in MySQL

While exporting the table with MySQL native utility, we don’t have any control on the process, and also there will be no progress update as well on the process completion. So when exporting the larger table will consume high resource utilization and also the disk space usage will also be high.

MySQL shell utility will make the process easier. It will export the table and we can import the data back with a parallel thread and also will provide the current progress status on export/import progress.

util.exportTable() utility was introduced in Shell – 8.0.22 version, will export the data in a controlled manner. We can store the data in either local or Cloud Infrastructure Object Storage bucket as well.

We will see about the compression ratio along with the time taken for native MySQL vs Shell utility

Feature :

  • Compression
  • Progress status
  • Supported output …
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Scale-up MySQL NDB Cluster 8.0.26 to +1.5M QPS the easy way with AMD EPYC 7742

On July 20th, 2021, we’ve celebrated the release of MySQL NDB Cluster 8.0.26. MySQL NDB Cluster (or NDB for short) is part of the MySQL family of open-source products providing an in-memory, distributed, shared-nothing, high-availability storage engine usable on its own or with MySQL servers as front-ends. For the complete changeset see release notes. Download it here.

Choosing a database can be an overwhelming task, requiring to consider performance (throughput and latency), high availability, data volume, scalability, ease of use/operations, etc. These considerations are affected by where the database runs — whether that is in a cloud provider such as …

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Measuring the Impact of Dynimize on Your MySQL Workload

While it's easier to measure the impact of Dynimize if you are running a MySQL benchmark with clear metrics, it can sometimes be a challenge on a production workload where you don't have precise performance analytics or metrics available. There are many great MySQL performance analysis tools out there, however they can often take time and effort to setup.

The simple measureDyniMysql script was created for this exact reason, and does not incur any MySQL downtime. You can find it at /opt/dynimize/measureDyniMysql after installing Dynimize. It will report the change in MySQL queries per second and mysqld CPU usage after applying Dynimize. Here is how to use it.


1. Install and start dynimize, and get your mysqld process into the dynimized state. For example, the …

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Database Performance Archaeology

… an expedition to uncover (and fix) database performance issues!

© 2021 Tiago L. Alves. All rights reserved.

One of the worse things that can happen when upgrading to a newer database version is discovering that the performance is not as good as before. Despite the effort put into gate-keeping MySQL NDB Cluster’s strict performance requirements, one of our customers found a performance regression when upgrading from our 7.4 version to our 7.6 version. How did that happen when our automated performance test suite failed to show it? To answer that, and fix the issue we enrolled on a database performance archaeology expedition…

When your performance is not good enough

MySQL NDB Cluster is an open-source in-memory distributed database developed for high-availability (99.999% or more) and predictable query times. It can be found at the core of gaming, banking, telecommunication, and online services. …

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The MySQL Clone Wars: Plugin vs. Percona XtraBackup

Large replication topologies are quite common nowadays, and this kind of architecture often requires a quick method to rebuild a replica from another server.

The Clone Plugin, available since MySQL 8.0.17, is a great feature that allows cloning databases out of the box. It is easy to rebuild a replica or to add new nodes to a cluster using the plugin. Before the release of the plugin, the best open-source alternative was Percona XtraBackup for MySQL Databases.

In this blog post, we compare both alternatives for cloning purposes. If you need to perform backups, Percona XtraBackup is a better tool as it supports compression and incremental backups, among other features not provided by the plugin. The plugin supports compression only for network transmission, not for storage.

But one of the plugin’s strong points is simplicity. …

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dim_STAT : v.9.0 CoreUpdate-20-12

Just realized I did not post any notes about dim_STAT CoreUpdates during the last 3 years, so will try to fix it now with the following short summary ;-))

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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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