Re: Mysql 5.6: Are these calculations for innodb_buffer_pool_size and instances correct?

[Cesar Murilo Cesar]

Why would 70% be safer? In the case, 11.2 out of 16GB, so then 11 started. I have never seen any problem logs related to this, I just want to make everything OK. When starting Mysql the messages below appear, see that it recommends to increase the innodb_buffer_pool_size, even having 12 of 16GB of RAM. I think there is already a lot, it must be because there are only 8 instances.


191223 14:42:39 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
191223 14:42:39 [Note] /usr/libexec/mysqld (mysqld 10.0.38-MariaDB) starting as process 20259 ...
191223 14:42:39 [Note] InnoDB: Using mutexes to ref count buffer pool pages
191223 14:42:39 [Note] InnoDB: The InnoDB memory heap is disabled
191223 14:42:39 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
191223 14:42:39 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
191223 14:42:39 [Note] InnoDB: Compressed tables use zlib 1.2.11
191223 14:42:39 [Note] InnoDB: Using Linux native AIO
191223 14:42:39 [Note] InnoDB: Using CPU crc32 instructions
191223 14:42:39 [Note] InnoDB: Initializing buffer pool, size = 12.0G
191223 14:42:40 [Note] InnoDB: Completed initialization of buffer pool
191223 14:42:40 [Note] InnoDB: Highest supported file format is Barracuda.
191223 14:42:40 [Note] InnoDB: 128 rollback segment(s) are active.
191223 14:42:40 [Note] InnoDB: Waiting for purge to start
191223 14:42:40 [Note] InnoDB: Percona XtraDB (http://www.percona.com) 5.6.42-84.2 started; log sequence number 1087485363986
191223 14:42:40 [Note] Plugin 'FEEDBACK' is disabled.
191223 14:42:40 [Note] /usr/libexec/mysqld: ready for connections.
Version: '10.0.38-MariaDB' socket: '/var/run/mysql/mysql.sock' port: 0 MariaDB Server
2020-10-02 18:13:34 7f58c9b63700 InnoDB: Warning: difficult to find free blocks in
InnoDB: the buffer pool (338 search iterations)!
InnoDB: 0 failed attempts to flush a page! Consider
InnoDB: increasing the buffer pool size.
InnoDB: It is also possible that in your Unix version
InnoDB: fsync is very slow, or completely frozen inside
InnoDB: the OS kernel. Then upgrading to a newer version
InnoDB: of your operating system may help. Look at the
InnoDB: number of fsyncs in diagnostic info below.
InnoDB: Pending flushes (fsync) log: 0; buffer pool: 0
InnoDB: 300056782 OS file reads, 860652373 OS file writes, 235885516 OS fsyncs
InnoDB: Starting InnoDB Monitor to print further
InnoDB: diagnostics to the standard output.