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Displaying posts with tag: TokuDB (reset)
The Address Sanitizer Finds Bugs in TokuFT

This blog describes how the Address Sanitizer found bugs in the TokuFT (now PerconaFT) storage library.  TokuFT is the storage library used by the TokuDB for MySQL and TokuMX for MongoDB products.  TokuFT is currently tested with valgrind's memcheck tool.  However, memcheck is very slow compared to native execution, so memcheck is not always used for large tests.  This leads to missed bugs.

The Address Sanitizer is a memory …

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Races in the TokuFT Race Detector

TokuFT (now called PerconaFT) is the write optimized storage component used by TokuDB for MySQL and TokuMX for MongoDB.  Since TokuFT is its own component, TokuFT can be tested independently of TokuDB and TokuMX.  Some of the TokuFT tests use valgrind's memcheck, helgrind, and DRD tools to identify bugs.

Helgrind and DRD find data races in multi-threaded programs at runtime rather than at compile time.  In my experience with these …

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Checkpoint strikes back

In my recent benchmarks for MongoDB, we can see that the two engines WiredTiger and TokuMX struggle from periodical drops in throughput, which is clearly related to a checkpoint interval – and therefore I correspond it to a checkpoint activity.

The funny thing is that I thought we solved checkpointing issues in InnoDB once and for good. There are bunch of posts on this issue in InnoDB, dated some 4 years ago.  We did a lot of research back then working on a fix for Percona Server

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InnoDB vs TokuDB in LinkBench benchmark

Previously I tested Tokutek’s Fractal Trees (TokuMX & TokuMXse) as MongoDB storage engines – today let’s look into the MySQL area.

I am going to use modified LinkBench in a heavy IO-load.

I compared InnoDB without compression, InnoDB with 8k compression, TokuDB with quicklz compression.
Uncompressed datasize is 115GiB, and cachesize is 12GiB for InnoDB and 8GiB + 4GiB OS cache for TokuDB.

Important to note is that I used tokudb_fanout=128, which is only available in our latest Percona Server release.
I …

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Percona Server 5.6.25-73.1 is now available

Percona is glad to announce the release of Percona Server 5.6.25-73.1 on July 9, 2015. Download the latest version from the Percona web site or from the Percona Software Repositories.

Based on MySQL 5.6.25, including all the bug fixes in it, Percona Server 5.6.25-73.1 is the current GA release in the Percona Server 5.6 series. Percona Server is open-source and free – and …

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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 interested to see how a database server will perform, say if only 16GB of memory is available.

And while InnoDB usually respects the setting of innodb_buffer_pool_size in O_DIRECT mode (OS cache is not being used in this case), more engines (TokuDB for MySQL, MMAP, WiredTiger, RocksDB for MongoDB) usually get benefits from OS cache, and Linux kernel by default is generous enough to allocate as much memory as available. There I should note that while TokuDB (and TokuMX for MongoDB) supports DIRECT mode (that is bypass OS cache), we found there is a performance gain if OS cache is used for compressed pages.

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TokuDB and Binlog Group Commit in MySQL 5.7

The MySQL 5.7.6 release notes describe a change to the binary log group commit algorithm that can improve the performance of write intensive applications when the binary log is enabled (noted with Bug #19424075).  This change is probably inspired by the experiment reported in MySQL bug #73202.

There is a long history of tweaking the binary log group commit algorithm and the InnoDB storage engine to scale performance.  Mark Callaghan describes the work done on this problem at Facebook. …

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TokuDB and JSON data in MySQL 5.7


MySQL recently added support for JSON data with MySQL 5.7.8.  It would be cool to store JSON data in TokuDB tables.

First, I had to get TokuDB running on MySQL 5.7.8.   TokuDB currently runs on Percona Server 5.6, and various flavors of MariaDB.  The only issues porting TokuDB to MySQL 5.7 were adopting the changes to various internal APIs that storage engines use.  Since I did not make any patches to the MySQL code,  some TokuDB features including clustered secondary keys and selection of various compression algorithms …

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Percona Acquires Tokutek : My Thoughts #3 : Fractal Tree Indexes

Last week I wrote up my thoughts about the Percona acquisition of Tokutek from the perspective of TokuDB and TokuMX[se]. In this third blog of the trilogy I'll cover the acquisition and the future of the Fractal Tree Index. The Fractal Tree Index is the foundational technology upon which all Tokutek products are built.



 So what is a Fractal Tree Index? To quote the Wikipedia page:
"a Fractal Tree index is a tree data structure that keeps data sorted and allows searches and …

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LinkBenchX: benchmark based on arrival request rate

An idea for a benchmark based on the “arrival request” rate that I wrote about in a post headlined “Introducing new type of benchmark” back in 2012 was implemented in Sysbench. However, Sysbench provides only a simple workload, so to be able to compare InnoDB with TokuDB, and later MongoDB with Percona TokuMX, I wanted to use more complicated scenarios. (Both TokuDB and TokuMX are part of Percona’s product line, in the case you missed Tokutek now part of the Percona family.)

Thanks to Facebook – they provide LinkBench, a benchmark that emulates the social graph …

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