Search Results for: how to work with in mysql

SELinux and the MySQL init script

I recently worked with a customer who had a weird issue: when their MySQL server was started (Percona Server 5.5), if they try to run service mysql start a second time, the init script was not able to detect that an instance was already running. As a result, it tried to start a second instance […]

MySQL QA Episode 7: Reducing Testcases for Beginners – single-threaded reducer.sh!

Welcome to MySQL QA Episode #7 – Reducing Testcases for Beginners: single-threaded reducer.sh! In this episode we’ll learn how to use reducer.sh. Topics discussed; reducer.sh introduction/concepts Basic configurable variables & their default reducer.sh settings INPUTFILE options MODE=x TEXT=”text” WORKDIR_LOCATION & WORKDIR_M3_DIRECTORY MYEXTRA MYBASE PQUERY_MOD & PQUERY_LOC MODE5_COUNTTEXT, MODE5_ADDITIONAL_TEXT & MODE5_ADDITIONAL_COUNTTEXT How to learn more about each […]

MongoDB benchmark: sysbench-mongodb IO-bound workload comparison

In this post I’ll share the results of a sysbench-mongodb benchmark I performed on my server. I compared MMAP, WiredTiger, RocksDB and TokuMXse (based on MongoDB 3.0) and TokuMX (based on MongoDB 2.4) in an IO-intensive workload. The full results are available here, and below I’ll just share the summary chart: I would like to […]

MySQL QA Episode 5: Preparing Your QA Run with pquery

Welcome to MySQL QA Episode #5! In this episode we’ll be setting up and running pquery for the first time… and I’ll also trigger some actual bugs (fun guaranteed)! I’ll also introduce you to mtr_to_sql.sh and pquery-run.sh. pquery-run.sh (the main wrapper around pquery) is capable of generating 80-120 MySQL Server crashes – per hour! See how […]

Using Cgroups to Limit MySQL and MongoDB memory usage

Quite often, especially for benchmarks, I am trying to limit available memory for a database server (usually for MySQL, but recently for MongoDB also). This is usually needed to test database performance in scenarios with different memory limits. I have physical servers with the usually high amount of memory (128GB or more), but I am […]

Oracle license revenue and the MySQL ecosystem

Oracle was in the news recently with the story of its license revenue declining as much as 17% in the recent quarter. This is blamed on transitioning to the cloud in some publications, but others, such as Bloomberg and TechRepublic, look deeper, seeing open source software responsible for the bulk of it. Things are especially […]

Q&A: High availability when using MySQL in the cloud

Last week I hosted a webinar on using MySQL in the cloud for High Availability (HA) alongside 451 Research analyst Jason Stamper. You can watch the recording and also download the slides (free) here. Just click the “Register” button at the end of that page. We had several excellent questions and we didn’t have time […]

Getting EXPLAIN information from already running queries in MySQL 5.7

When a new version of MySQL is about to be released we read a lot of blog posts about the performance and scalability improvements. That’s good but sometimes we miss some small features that can help us a lot in our day-to-day tasks. One good example is the blog post that Aurimas wrote about a […]

Auditing MySQL with McAfee and MongoDB

Greetings everyone! Let’s discuss a 3rd Party auditing solution to MySQL and how we can leverage MongoDB® to make sense out of all of that data. The McAfee MySQL Audit plugin does a great job of capturing, at low level, activities within a MySQL server. It does this through some non-standard APIs which is why installing […]

MaxScale: A new tool to solve your MySQL scalability problems

Ever since MySQL replication has existed, people have dreamed of a good solution to automatically split read from write operations, sending the writes to the MySQL master and load balancing the reads over a set of MySQL slaves. While if at first it seems easy to solve, the reality is far more complex. First, the […]