Hollie's Hub for Good Supporting each other to make an impact. Write for DigitalOcean You get paid, we donate to tech non-profits. This guide is intended to serve as a troubleshooting resource and starting point as you diagnose your MySQL setup. We will also include links to DigitalOcean tutorials and the official MySQL documentation that may be useful in certain cases. Oftentimes, the root cause of slowdowns, crashes, or other unexpected behavior in MySQL can be determined by analyzing its error logs.
The error log contains a record of mysqld startup and shutdown times. It also contains diagnostic messages such as errors, warnings, and notes that occur during server startup and shutdown, and while the server is running. For example, if mysqld notices that a table needs to be automatically checked or repaired, it writes a message to the error log.
On some operating systems, the error log contains a stack trace if mysqld exits abnormally. The trace can be used to determine where mysqld exited. See Section 5. The following sections discuss aspects of configuring error logging. This is your terminal or console window unless the standard error output has been redirected to a different destination.
The server interprets options that determine where to write error messages somewhat differently for Windows and Unix systems. Be sure to configure error logging using the information appropriate to your platform. Server Configuration Defaults. OTOH, the General Log is quite a disk hog, so it is generally good to turn it off right after getting the information you need.
Other logs can probably be left ON. Jon Jon 1 1 bronze badge. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Explaining the semiconductor shortage, and how it might end. Does ES6 make JavaScript frameworks obsolete?
Featured on Meta. Now live: A fully responsive profile. Linked 1. If you need better performance when you start using MySQL in a production environment, you can remove the -l option from mysql. The entries in this log are written as mysqld receives the questions. This may be different from the order in which the statements are executed.
This is in contrast to the update log and the binary log which are written after the query is executed, but before any locks are released. Note : the update log is replaced by the binary log. With this you can do anything that you can do with the update log.
If no filename is given, it defaults to the name of the host machine. If you use the --log or -l options, mysqld writes a general log with a filename of hostname. Restarts and refreshes do not cause a new log file to be generated although it is closed and reopened. In this case you can copy it on Unix by doing:. Update logging is smart because it logs only statements that really update data.
The update logging is done immediately after a query completes but before any locks are released or any commit is done. This ensures that the log will be logged in the execution order.
This can be useful if you have to revert to backup files after a crash and you want to redo the updates that occurred between the time of the backup and the crash. The intention is that the binary log should replace the update log, so we recommend you switch to this log format as soon as possible! The binary log contains all information that is available in the update log in a more efficient format. It also contains information about how long every query that updated the database took.
The binary log is also used when you are replicating a slave from a master. If no filename is given, it defaults to the name of the host machine followed by -bin.
0コメント