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Displaying posts with tag: logging (reset)
Track and Optimize Server Connection Methods

The MySQL server supports a variety of client connection methods. To summarize: you have TCP/IP (v4 and v6) on all OSes (with or without TLS/SSL encryption), Unix Domain Sockets on Unix/Linux, and Named Pipes and/or Shared Memory on Windows.

Each of these connection methods has its own set of pros and cons: speed, security, portability, and ease-of-use.…

What Makes the MySQL Audit Plugin API Special?

Why Should I Be Reading This?

To better understand how the MySQL Server functions, how to monitor the relevant server events, and find out what’s new in MySQL 5.7.8.

What’s Special About the Audit Plugin API?

Picking the right API for your new plugin is probably the most important design decision a plugin author will need to make.…

New Option to Stop the Server If Binlogging Fails in MySQL 5.6

In this post I will try to explain the new MySQL binlog_error_action server option. This new option is available from MySQL 5.6.22 and later.

As part of MySQL replication all data changes that happen on the master server are recorded into a binary log so that they can be sent to slave and replayed there. If an error occurs that prevents mysqld from writing to the binary log (disk full, readonly file system, etc.) then the logs are simply disabled and operations continue on the master. This error mainly occurs during rotation of the binary log or while opening a binary log file.

This problem creates a serious potential for data loss …

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Logging with MySQL: Error-Logging to Syslog & EventLog

You’ve already read it in What’s new in 5.7 (So Far) — the MySQL server now has new-and-improved supported for syslog (on unix-like systems) and EventLog (on Windows). In the next few paragraphs, we’ll take a look at what they are, what has changed, and how they can make your life easier.

The MySQL server supplies information in two main ways:

  1. The client will receive a reply to every statement. If everything goes right, then we’ll see a simple OK for success, or a result set for SELECT, SHOW, etc.; and even a successful statement may be qualified by a set of warnings or notices. If the statement fails for some reason then we’ll receive an error regarding the failure.
  2. On the server, we’ll see a variety of logs depending on the server configuration. Queries exceeding a certain execution …
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Redo Logging in InnoDB


InnoDB is a general-purpose storage engine that balances high reliability and high performance. It is a transactional storage engine and is fully ACID compliant, as would be expected from any relational database. The durability guarantee provided by InnoDB is made possible by the redo logs.

This article will provide an overview of the redo log subsystem or log subsystem of InnoDB. We will look at the following details:

  • The global log system object, which provides access to important data structures and information.
  • The mini-transaction (mtr), using which all redo log records are created.
  • The global in-memory log buffer (or just log buffer), into which the redo logs are written to from the mini transaction buffer. This log buffer will be periodically flushed to the log file on disk. …
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How MySQL 5.6 handles passwords more securely

There are many thing changed in MySQL 5.6 which are related to passwords:

  • There is a new password hash algorithm (SHA-256)
  • There is obfuscation for passwords with the .mylogin.cnf file.
  • The option to store slave passwords in a database table.
  • It's now possible to supply a password to START SLAVE.

But that's not what this blog post is about.

This blog post is a great new feature: Hiding passwords from your log files, automatically.

MySQL 5.6 will by default hide passwords from the general log. This is not just obfuscation as only the one-way hash will be put in the log files. By setting log-raw=OFF you can disable password hiding for the general log. The log-raw setting will only influence the general log, so the passwords in the slow query log and the binary logs will still be hidden.

With MySQL 5.5 this could be done manually by …

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Bash scripting: ElasticSearch and Kibana init.d scripts

As a follow up to the previous post about logstash, here are a couple of related init scripts for anyone implementing the OpenSource Log Analytics setup that is explained over at divisionbyzero. These have been tested on CentOS 6.3 and are based on generic RC functions from Redhat so they will work with Redhat, CentOS, Fedora, Scientific Linux, etc.

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MySQL Syslog Audit Plugin

This post shows the construction process of the Syslog Audit plugin that was presented at MySQL Connect 2012. It is based on an environment that has the appropriate development tools enabled including gcc,g++ and cmake. It also assumes you have downloaded the MySQL source code (5.5.16 or higher) and have compiled and installed the system into the /usr/local/mysql directory ready for use. 

The information provided below is designed to show the different components that make up a plugin, and specifically an audit type plugin, and how it comes together to be used within the MySQL service. The MySQL Reference Manual contains information regarding the plugin API and how it can be used, so please refer there for more detailed information. The code in this post is designed to …

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Why a statement can be unsafe when it uses LIMIT clause?

MySQL 5.1 or newer can sometimes start throwing a strange message into an error log. The message states that a query was unsafe for binary logging along with some additional information. What does it mean? Is it a problem?

From time to time you might spot MySQL error log filling with the following warning:

“[Warning] Unsafe statement written to the binary log using statement format since BINLOG_FORMAT = STATEMENT. The statement is unsafe because it uses a LIMIT clause. This is unsafe because the set of rows included cannot be predicted. Statement: DELETE FROM score WHERE user_id = 12345 AND created = ’2012-04-15′ LIMIT 1″

If binary logging is enabled and the log format is set to STATEMENT, MySQL generates such message when it considers that a query is ambiguous and could behave differently each time it executes against the same data set. Such situation could happen, for example, on a …

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Apache and MySQL Logging with Syslog-ng

Apache and syslog-ng

While logging to a database back-end has its benefits, the setup as it stands leaves us wanting. Some applications, such as Apache, do not log via syslog-ng by default. The good news is that this can be easily remedied, and there are a couple of different ways of doing this. First, the less good way:

Method #1: Changing the Apache configuration file.

First, we need to setup syslog-ng appropriately by creating a new source for apache, such as the following:

source s_apache {

log { source(s_apache); destination(d_pgsql); };

This recycles the original destination for …

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