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How to know how much memory MySQL is using?
There are global buffers, per-connection buffers (which depend on the workload), and some uncontrolled memory allocations (i.e., inside Stored Procedures), all contributing to difficulties in computing how much memory MySQL will really use for your workload. It is better to check it by looking at the virtual memory size (VSZ) that MySQL uses.
Why does MySQL keep running out of memory?
MySQL tries to allocate more memory than available because we specifically told it to do so. For example: you did not set innodb_buffer_pool_size correctly. This is very easy to fix. There is some other process(es) on the server that allocates RAM.
What’s the best way to reduce MySQL memory usage?
The first rule of configuring MySQL memory usage is you never want your MySQL to cause the operating system to swap. Even minor swapping activity can dramatically reduce MySQL performance. Note the keyword “activity” here. It is fine to have some used space in your swap file,…
Where to start troubleshooting MySQL memory leaks?
Memory leaks in MySQL. This is a worst-case scenario, and we need to troubleshoot. Where to start troubleshooting MySQL memory leaks Here is what we can start with (assuming it is a Linux server):
What should MySQL buffer size be for 16GB?
Considering the 5-7% overhead that the InnodB Buffer Pool has, a sensible setting is innodb_buffer_pool_size=12G – what we very commonly see working well for systems with 16GB of memory. Now that we have configured MySQL memory usage, we also should look at the OS configuration.
Caveat: Some flavors of OS always claim to be using over 90%, even when there is really lots of free space. SHOW GLOBAL STATUS LIKE ‘Key%’; then calculate Key_read_requests / Key_reads If it is high (say, over 10), then the key_buffer is big enough.
Is the maximum memory usage in MySQL dangerously high?
I ran the MySQLTuner script, and followed the recommendations that they gave, but it’s still recommending increases, while telling me that MySQL’s maximum memory usage is dangerously high. My current config in my my.cnf file is:
How big should MySQL key buffer be in memory?
Set key_buffer_size no larger than that size, but not bigger than 20% of RAM. Add up Data_length + Index_length for all the InnoDB tables. Set innodb_buffer_pool_size to no more than 110% of that total, but not bigger than 70% of RAM. If that leads to swapping, cut both settings back. Suggest cutting them down proportionately.