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Displaying posts with tag: Insight for DBAs (reset)
Does the Version Number Matter?

Yes, it does! In this blog post, I am going to share my recent experiences with ProxySQL and how important the database software version number can be.

Migration

I was working on a migration to Percona XtraDB Cluster (PXC) with ProxySQL, fortunately on a staging environment first so we could catch any issues (like this one).

We installed Percona XtraDB Cluster and ProxySQL on the staging environment and repointed the staging application to ProxySQL. At first, everything looked great. We were able to do some application tests and everything looked good. I advised the customer to do more testing to make sure everything works well. …

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How Binary Logs Affect MySQL 8.0 Performance

As part of my benchmarks of binary logs, I’ve decided to check how the recently released MySQL 8.0 performance is affected in similar scenarios, especially as binary logs are enabled by default. It is also interesting to check how MySQL 8.0 performs against the claimed performance improvements in redo logs subsystem.

I will use a similar setup as in my last blog with MySQL 8.0, using the utf8mb4 charset.

I have a few words about MySQL 8.0 tuning. Dimitri’s recommends in his blog posts using innodb_undo_log_truncate=off and …

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How Binary Logs (and Filesystems) Affect MySQL Performance

I want to take a closer look at MySQL performance with binary logs enabled on different filesystems, especially as MySQL 8.0 comes with binary logs enabled by default.

As part of my benchmarks of the MyRocks storage engine, I’ve noticed an unusual variance in throughput for the InnoDB storage engine, even though we spent a lot of time making it as stable as possible in Percona Server for MySQL. In the end, the culprit was enabled binary logs. There is also always the question, “If there is a problem with EXT4, does XFS perform differently?” To answer that, I will repeat the same benchmark on the EXT4 and XFS filesystems.

You can find our previous experiments with binary logs here: …

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Causes and Workarounds for Slave Performance Too Slow with Row-Based Events

Recently I worked on one customer issue that I would describe as “slave performance too slow”. During a quick analysis, I’ve found that the replication slave SQL thread cannot keep up while processing row-based events from the master’s binary log.

For example:

mysql> SHOW SLAVE STATUSG
*************************** 1. row ***************************
                          ...
              Master_Log_File: binlog.0000185
          Read_Master_Log_Pos: 86698585
                          ...
        Relay_Master_Log_File: binlog.0000185
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
                          ...
          Exec_Master_Log_Pos: 380
              Relay_Log_Space: 85699128
                          ...
                  Master_UUID: …
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ProxySQL Query Rewrite Use Case

In this blog post, I’m going to revisit the ProxySQL Query Rewrite feature. You may have seen me talking about possible use case scenarios in the past few conferences, but the reason I’m starting with this is that query rewriting was the original intention for building ProxySQL.

Why would you need to rewrite a query?

  • You’ve identified a query that’s causing bottleneck or slowness
  • A special operation requires query routing
  • You cannot modify application code

So here we have a case of a bad query hitting the backend database. You as a DBA have identified the query as causing severe slowdown, which could lead to a site-wide outage. This query needs to be optimized, and you have asked the developer …

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A Look at MyRocks Performance

In this blog post, I’ll look at MyRocks performance through some benchmark testing.

As the MyRocks storage engine (based on the RocksDB key-value store http://rocksdb.org ) is now available as part of Percona Server for MySQL 5.7, I wanted to take a look at how it performs on a relatively high-end server and SSD storage. I wanted to check how it performs for different amounts of available memory for the given database size. This is similar to the benchmark I published a while ago for InnoDB (https://www.percona.com/blog/2010/04/08/fast-ssd-or-more-memory/).

In this case, I plan to use a sysbench-tpcc benchmark ( …

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Percona Live 2018: Migrating to Vitess at (Slack) Scale

Percona Live 2018 is moving along, and the first person I got a chance to talk with is Michael Demmer, Senior Staff Engineer at Slack. His talk was on Migrating to Vitess at (Slack Scale).

MySQL is the backbone of Slack’s data storage infrastructure. It handles billions of queries per day across thousands of sharded database hosts. Slack is migrating this system to use Vitess’ flexible sharding and topology management instead of simple application-based shard routing and manual administration. This effort aims to provide an architecture that scales to meet the growing demands of our largest customers and features while under pressure to maintain a stable and performant service.

This talk presented the core motivations behind our decision, why Vitess won out as the best option, and how Slack laid the groundwork for the …

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Congratulations to Our Friends at Oracle with the MySQL 8.0 GA Release!

It is a great today for whole MySQL community: MySQL 8.0 was just released as GA!

Geir Høydalsvik has a great summary in his “What’s New in MySQL 8.0” blog post. You can find additional information about MySQL 8.0 Replication and MySQL 8.0 Document Store that is also worth reading.

If you can’t wait to upgrade to MySQL 8.0, please make sure to read the  …

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Why Analyze Raw MySQL Query Logs?

In this blog post, I’ll examine when looking at raw MySQL query logs can be more useful than working with tools that only have summary data.

In my previous blog post, I wrote about analyzing MySQL Slow Query Logs with ClickHouse and ClickTail. One of the follow-up questions I got is when do you want to do that compared to just using tools like Percona Monitoring and Management or VividCortex, which provide a beautiful interface for detailed analyses (rather than spartan SQL interface).    

MySQL Logs

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Binlog and Replication Improvements in Percona Server for MySQL

Due to continuous development and improvement, Percona Server for MySQL incorporates a number of improvements related to binary log handling and replication. This results in replication specifics, distinguishing it from MySQL Server.

Temporary tables and mixed logging format Summary of the fix:

As soon as some statement involving temporary tables was met when using a mixed binlog format, MySQL switched to row-based logging for all statements until the end of the session (or until all temporary tables used in the session were dropped). This is inconvenient when you have long-lasting connections, including replication-related ones. Percona Server for MySQL fixes the situation by switching between …

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