Peter wrote a post a while ago about choosing a good InnoDB log file size.Â Not to pick on Peter, but the post actually kind of talks about a lot of things and then doesn’t tell you how to choose a good log file size!Â So I thought I’d clarify it a little. The basic […]
Search Results for: innodb log file size
Now that InnoDB is the default storage engine in MySQL, is it time to update the default configuration for the InnoDB log file size (innodb_log_file_size) setting? In general, there are two settings that simply can’t be left at their historical defaults for a production installation. MySQL 5.5 increased the default buffer pool size to something […]
If you need to change MySQL’s innodb_log_file_size parameter (see How to calculate a good InnoDB log file size), you can’t just change the parameter in the my.cnf file and restart the server. If you do, InnoDB will refuse to start because the existing log files don’t match the configured size. You need to shut the […]
If you’re doing significant amount of writes to Innodb tables decent size of innodb_log_file_size is important for MySQL Performance. However setting it too large will increase recovery time, so in case of MySQL crash or power failure it may take long time before MySQL Server is operational again. So how to find the optimal combination […]
In a post, written a few months ago, I found that using EXT4 transactions with the “data=journal” mount option, improves the write performance significantly, by 55%, without putting data at risk. Many people commented on the post mentioning they were not able to reproduce the results and thus, I decided to further investigate in order […]
It seems these days if anyone knows anything about tuning InnoDB, it’s that you MUST tune your innodb_buffer_pool_size to 80% of your physical memory. This is such prolific tuning advice, it seems engrained in many a DBA’s mind. The MySQL manual to this day refers to this rule, so who can blame the DBA? The […]
On a recent engagement I worked with a customer who makes extensive use of UUID() values for their Primary Key and stores it as char(36), and their row count on this example table has grown to over 1 billion rows. The table is INSERT-only (no UPDATEs or DELETEs), and the bulk of their retrieval are PK […]
If you use Percona Server 5.5 and you have configured it to use multiple buffer pool instances than sooner or later you’ll see the following lines on the server’s error log and chances are you’ll be worried about them:
InnoDB: detected cycle in LRU for buffer pool 5, skipping to next buffer pool.
InnoDB: detected cycle in LRU for buffer pool 3, skipping to next buffer pool.
InnoDB: detected cycle in LRU for buffer pool 7, skipping to next buffer pool.
Worry not as this is mostly harmless. It’s becoming a February tradition for me (Fernando) […]
A few days ago I wrote about MySQL performance implications of InnoDB isolation modes and I touched briefly upon the bizarre performance regression I found with InnoDB handling a large amount of versions for a single row. Today I wanted to look a bit deeper into the problem, which I also filed as a bug. First […]
Some time ago, Peter Zaitsev posted a blog titled “How well does your table fits in innodb buffer pool?” He used some special INFORMATION_SCHEMA tables developed for Percona Server 5.1 to report how much of each InnoDB table and index resides in your buffer pool. As Peter pointed out, you can use this view into […]