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Displaying posts with tag: Alexey Stroganov (reset)
Percona Server: Thread Pool Improvements for Transactional Workloads

In a previous thread pool post, I mentioned that in Percona Server we used an open source implementation of MariaDB’s thread pool, and enhanced/improved it further. Below I would like to describe some of these improvements for transactional workloads.

When we were evaluating MariaDB’s thread pool implementation, we observed that it improves scalability for AUTOCOMMIT statements. However, it does not scale well with multi-statement transactions. The UPDATE_NO_KEY test which was run as an AUTOCOMMIT statement and inside a transaction gave the following results:

After analysis, we identified the major cause of that inefficiency: …

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Memory allocators: MySQL performance improvements in Percona Server 5.5.30-30.2

In addition to the problem with trx_list scan we discussed in Friday’s post, there is another issue in InnoDB transaction processing that notably affects MySQL performance – for every transaction InnoDB creates a read view and allocates memory for this structure from heap. The problem is that the heap for that allocation is destroyed on each commit and thus the read view memory is reallocated on the next transaction.

There are two aspects of this problem:

1) memory allocation is an costly operation and if memory …

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MySQL performance: Impact of memory allocators (Part 2)

Last time I wrote about memory allocators and how they can affect MySQL performance in general. This time I would like to explore this topic from a bit different angle: What impact does the number of processor cores have on different memory allocators and what difference we will see in MySQL performance in this scenario?

Let me share a conclusion first: If you have a server with more than 8 cores you should use something different than the default glibc memory allocator.
We recommend jemalloc or tcmalloc

In my test I will use Dell R720 box(spec), Centos 6.3, upcoming Percona Server 5.5.30 and 3 allocators – stock glibc 2.13, jemalloc-3.1.0, the latest tcmalloc from svn repo. …

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