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10 Newer Entries Showing entries 61 to 70 of 380 10 Older Entries

Displaying posts with tag: Insight for DBAs (reset)

Why %util number from iostat is meaningless for MySQL capacity planning
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Earlier this month I wrote about vmstat iowait cpu numbers and some of the comments I got were advertising the use of util% as reported by the iostat tool instead. I find this number even more useless for MySQL performance tuning and capacity planning.

Now let me start by saying this is a really tricky and deceptive number. Many DBAs who report instances of their systems having a very busy IO subsystem said the util% in vmstat was above 99% and therefore they believe this number is …

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Getting to know TokuDB for MySQL
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During last April’s Percona Live MySQL Conference and Expo, TokuDB celebrated it’s first full-year as an open source storage engine. I still remember reading the official announcement and the expectations it created one year ago. The premises were very interesting as it had the potential of helping MySQL manage “big data” in a way InnoDB just couldn’t. It also provided additional interesting features like “hot schema changes,” all the while …

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How to setup Docker for Percona ClusterControl and add existing Percona XtraDB Cluster
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In my previous post I showed you how to setup Percona XtraDB Cluster 5.6 on Docker. This time I will show you how to setup Percona ClusterControl and add the existing Percona XtraDB Cluster 5.6 that we’ve managed to setup from the previous post.

Let us note the following details about our existing containers:

…  [Read more...]
“How to monitor MySQL performance” with Percona Cloud Tools: June 25 webinar
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We recently released a new version of Percona Cloud Tools with MySQL monitoring capabilities. Join me June 25 and learn the details about all of the great new features inside Percona Cloud Tools – which is now free in beta. The webinar is titled “Monitoring All (Yes, All!) MySQL Metrics with Percona Cloud Tools” and begins at 10 a.m. Pacific time.

In addition to MySQL metrics, Percona Cloud Tools also monitors OS performance-related stats. The new …

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mydumper [less] locking
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In this post I would like to review how my dumper for MySQL works from the point of view of locks. Since 0.6 serie we have different options, so I will try to explain how they work

As you may know mydumper is multithreaded and this adds a lot of complexity compared with other logical backup tools as it also needs to coordinate all threads with the same snapshot to be consistent. So let review how mydumper does this with the default settings.

By default mydumper uses 4 threads to dump data and 1 main thread

Main Thread

  • FLUSH TABLES WITH READ LOCK

Dump Thread X

  • START TRANSACTION WITH …
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Measure the impact of MySQL configuration changes with Percona Cloud Tools
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When you make a change to your MySQL configuration in production it would be great to know the impact (a “before and after” type of picture). Some changes are obvious. For many variables proper values can be determined beforehand, i.e. innodb_buffer_pool_size or innodb_log_file_size. However, there is 1 configuration variable which is much less obvious for many people working …

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Using MySQL 5.6 Performance Schema in multi-tenant environments
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Hosting a shared MySQL instance for your internal or external clients (“multi-tenant”) was always a challenge. Multi-tenants approach or a “schema-per-customer” approach is pretty common nowadays to host multiple clients on the same MySQL sever. One of issues of this approach, however, is the lack of visibility: it is hard to tell how many resources (queries, disk, cpu, etc) each user will use.

Percona Server contains …

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Do not trust vmstat IOwait numbers
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I’ve been running a benchmark today on my old test box with conventional hard drives (no raid with BBU) and noticed something unusual in the CPU utilization statistics being reported.

The benchmark was run like this:

sysbench --num-threads=64 --max-requests=0 --max-time=600000 --report-interval=10 --test=oltp --db-driver=mysql --oltp-dist-type=special  --oltp-table-size=1000000   --mysql-user=root --mysql-password=password  run

Which means: create 64 threads and hammer the database with queries as quickly as possible. As the test was run on the localhost I would expect the benchmark to completely saturate the system – being …

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High Availability with MySQL Fabric: Part II
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This is the third post in our MySQL Fabric series. If you missed the previous two, we started with an overall introduction, and then a discussion of MySQL Fabric’s high-availability (HA) features. MySQL Fabric was RC when we started this series, but it went GA recently. You can read the press release here, …

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How MySQL ‘queries’ and ‘questions’ are measured
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MySQL has status variables “questions” and “queries” which are rather close but also a bit different, making it confusing for many people. The manual describing it might not be very easy to understand:

Queries
The number of statements executed by the server. This variable includes statements executed within stored programs, unlike the Questions variable. It does not count COM_PING or COM_STATISTICS commands.
 Questions
The number of statements executed by the server. This includes only statements sent to the …
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10 Newer Entries Showing entries 61 to 70 of 380 10 Older Entries

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