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Displaying posts with tag: helgrind (reset)
Fun with Bugs #66 - On MySQL Bug Reports I am Subscribed to, Part VI

I have some free time today, but I am still lazy enough to work on numerous planned and pending "ToDo" kind of posts, so why not to continue review of older MySQL bugs I am subscribed to. Today I am going to list 15 more bugs reported more than a year ago and still not fixed:

  • Bug #85805 - "Incorrect ER_BAD_NULL_ERROR after LOAD DATA LOCAL INFILE". This detailed bug report by Tsubasa Tanaka stays "Verified" for more than a year already. It's a great example of gdb use for MySQL troubleshooting. Setting a couple of breakpoints may really help to understand how MySQL works and why some …
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mysql_real_connect is not thread safe

The "mysql_real_connect" function is used by MySQL clients, including multi-threaded clients,  to connect to a MySQL server.  The "mysql_real_connect" function is allowed to be run by concurrent threads without application level serialization.  Unfortunately, the thread sanitizer found a data race in the "mysql_real_connect" function when processing the …

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MySQL 5.7 Initialization Versus the Thread Sanitizer

The MySQL server is a large multi-threaded program primarily written in the C++ programming language.  Unfortunately,  data races and deadlocks in concurrent C++ programs are common.  Fortunately, the Thread Sanitizer can be used to find data races and deadlocks.  MySQL 5.7 does not support the Thread Sanitizer, but is is easy to add to the MySQL configuration using a simple build procedure.  When MySQL 5.7 is built with the Thread Sanitizer and database …

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TokuBackup Versus the Sanitizers

Percona recently open sourced TokuBackup, a library that may be used to take a snapshot of a set of files while these files are being changed by a running application like MySQL or MongoDB.  Making TokuBackup open source allows a larger set of users to improve and extend the software.  This blog describes how the Address Sanitizer and Thread Sanitizer found bugs in the TokuBackup library.

The TokuBackup library is used by Percona Server for MySQL and …

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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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Helgrind and MySQL 5.7

Valgrind's helgrind tool identifies data races and lock deadlocks in multi-threaded programs.  Since the MySQL server is a multi-threaded program, can helgrind find any issues in the MySQL server?

A simple test that does nothing except start up the MySQL server and shut it down is run on the MySQL test suite with memcheck and with helgrind.  For this simple test on MySQL 5.7.7, the memcheck run is nice and clean but the …

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Showing entries 1 to 6