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Displaying posts with tag: TokuDB (reset)

How Tokutek uses the Random Query Generator framework to test TokuDB
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During a typical release cycle for TokuDB at Tokutek, we spend time qualifying and hardening the product using numerous tools.  For example, we run stress and unit tests directly on the Fractal Tree indexes, MySQL Test Runner (MTR) tests on the storage engine as well as numerous performance benchmarks to prevent regressions. In addition, we have recently been implementing the …

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MariaDB 10.0.10 Overview and Highlights
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MariaDB 10.0.10 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.0.10/

This is the first GA ("Generally Availability", aka "recommended for production systems") release of MariaDB 10.0, and 11th overall release of MariaDB 10.0.

Since this is the initial 10.0 GA release, this is primarily a bug-fix and polishing release.

Here are the main items of note:

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Why TokuDB does not use the ‘uint3korr’ function
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The ‘uint3korr’ function inside of the mysqld server extracts a 3 byte unsigned integer from a memory buffer. One use is for ‘mediumint’ columns which encode their value in 3 bytes. MySQL 5.6 and MariaDB 10.0 claims to have optimized this function for x86 and x86_64 processors. There is a big comment that says:

Attention: Please, note, uint3korr reads 4 bytes (not 3)!
It means, that you have to provide enough allocated space.

The ‘uint3korr’ optimization may be fast, but it is not valgrind safe. Here is an example where valgrind detects TokuDB reading beyond the end of a buffer when it uses the ‘uint3korr’ function. …

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Percona Live 2014 Recap
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The MySQL community continues to amaze me, everyone is friendly and always willing to answer questions and help others. It’s always nice to meet people in-person that I’ve met virtually in the last 12 months. Percona Live 2014 MySQL Conference and Expo in Santa Clara just wrapped up and I wanted to share my highlights of the event before I unplug for the weekend.

  • I heard several stories of people’s experiences with TokuDB, open sourcing 12 months ago has been a huge success for Tokutek. We have a growing community in our tokudb-user Google Group, please share your …
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Uninitialized data in the TokuDB recovery log
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A TokuDB MySQL test run with valgrind reported an uninitialized data error when writing into the TokuDB recovery log.

==1032== Syscall param write(buf) points to uninitialised byte(s)
==1032== at 0x3EFA60E4ED: ??? (in /lib64/libpthread-2.12.so)
==1032== by 0xB894038: toku_os_full_write(int, void const*, unsigned long) (file.cc:249)
==1032== by 0xB83248A: write_outbuf_to_logfile(tokulogger*, __toku_lsn*) (logger.cc:513)
==1032== by 0xB83326C: toku_logger_maybe_fsync(tokulogger*, __toku_lsn, int, bool) (logger.cc:836)
==1032== by 0xB8327DE: toku_logger_fsync_if_lsn_not_fsynced(tokulogger*, __toku_lsn) (logger.cc:586)
==1032== by 0xB8493E6: …
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Lock Escalation and Big Transactions in TokuDB and TokuMX
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We have seen TokuDB lock escalation stall the execution of SQL operations for tens of seconds. To address this problem, we changed the lock escalation algorithm used by TokuDB and TokuMX so that the cost of lock escalation only affects big transactions. We also eliminated a serialization point when running lock escalation.

Transactions in TokuDB and TokuMX accumulate locks on key ranges while they execute. These locks allow multiple transactions to run concurrently. The locks are released when the transaction commits or aborts.

The locks are stored in an in memory data structure that contains a set of key range and …

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Percona Server with TokuDB: Packing 15TB into local SSDs
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Two weeks ago we released an Alpha release of Percona Server with TokuDB. Right now I am on a final stage of evaluation of TokuDB for using in our project Percona Cloud Tools and it looks promising.

What is the most attractive in TokuDB? For me it is compression, but not just compression: TokuDB provides great performance over compressed data.

In my synthetic tests I saw a compression ratio of 10:1 (TokuDB LZMA …


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My Favorite MongoDB Replication Feature: Crash Safety
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At an extremely high level, replication in MongoDB and MySQL are similar. Both databases have exactly one machine, the primary (or master), that accepts writes from clients. With a single transaction (or atomic operation, in MongoDB’s case), the tables and oplog (or binary log in MySQL) are modified to reflect the change. The log captures what the change is so other secondaries (or slaves) can read the changes and process them, making the slaves identical to the master. (Note that I …

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Big trouble with zero-length character columns in TokuDB
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What good is a zero-length character column in a MySQL table? A zero-length character column has type of ‘char(0)’. If it is nullable, then it can at least store one bit. If it is not nullable, then the value for this column in all rows is a null string. IMO, not very useful. However, the MySQL Reference Manual says that there are valid uses for such a column, so TokuDB should support it. Unfortunately, we recently found and fixed a bug related to zero length character columns in …

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March 20 Webinar: How to Scale MySQL for Big Data Applications
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You may think that you have to buy, install, and get up to speed on a new database if you want to work with large amounts of data, but you can do more than you think with the MySQL you already have.
Register Now!

SPEAKER: Jon Tobin, Tokutek
DATE: Thursday, March 20th
TIME: 1pm ET

Without having to change your application or do special tuning you can increase performance and save significant time and money when you need to scale.

Join …




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10 Newer Entries Showing entries 31 to 40 of 262 10 Older Entries

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