mysql innodb buffer pool size which dependencies

问题

I want to dimension RAM dependent on the innodb_buffer_pool_size. But all what I find is the dependence of the innodb_buffer_pool_size on RAM.

Can you tell me on which parameters on the innodb_buffer_pool_size depends? Number of queries? Number of transactions?

I want to find out the formula which calculates the RAM dependent on innodb_buffer_pool_size.

Can you help me? Thank you very much for your advice!

回答1:

Sizing innodb_buffer_pool_size:

If all the queries/transactions are touching tiny tables or tiny parts or big tables, then a tiny buffer_pool is sufficient.
If you have UUIDs, you need a big buffer pool -- because you can't touch only 'tiny' parts of the table/index via UUIDs; they are too 'random'.
Bigger than 70% of RAM is dangerous because it could lead to swapping, which is terrible for performance.
That's 70% of available RAM -- need to leave room for the OS, code, other caches, etc.
When you change RAM, change the buffer_pool_size. Or the other way around.
Bigger is better.
Much bigger than the total size of all data and indexes is unnecessary (wastes RAM).
Too small leads to inefficient operation of most operations involving InnoDB.
the buffer_pool is a cache. Computer Science discusses what that means and what the ramifications are.

So, the simple formula "set it to 70% of available RAM".

There are various metrics in SHOW GLOBAL STATUS that can say whether the buffer_pool is "big enough". But they are useful only after setting the size, then running for a while. And they only say "there are lots of reads/writes", they don't say whether or by how much to change the size.

If you would like me to analyze the STATUS (after it has been up at least a day), provide