MAMP Pro MySQL issue with changing database engine to InnoDB and migrating databases

Question

I have MAMP Pro on El Capitan running. It has been fine up until now, but I've run into a problem. I have a mixture of database, some using the MyISAM Engine and others using InnoDB. I don't really know how that works. I guess if some are InnoDB, the Engine is still MyISAM by default. The issue is with databases that I have for Atlassians Confluence and JIRA. In Confluence, all is good, but it says:

You should increase innodb_log_file_size to 256M

I tried playing around with the my.cnf, but ran into issues. I restored things, and these are the relevant sections from the config.

[mysqld]
#port       = 9999
socket      = /Applications/MAMP/tmp/mysql/mysql.sock
key_buffer_size = 64M
max_allowed_packet = 512M

# table_cache only works for MySQL 5.5.x
#table_cache = 64

# If you are running MySQL 5.6.x, use table_open_cache.
#table_open_cache = 64

sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 32M

#Uncomment the following if you are using InnoDB tables
#innodb_data_home_dir = /Applications/MAMP/db/mysql/
#innodb_data_file_path = ibdata1:10M:autoextend
#innodb_log_group_home_dir = /Applications/MAMP/db/mysql/
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
#innodb_buffer_pool_size = 128M
#innodb_additional_mem_pool_size = 2M
# Set .._log_file_size to 25 % of buffer pool size
#innodb_log_file_size = 512M
#innodb_log_buffer_size = 8M
#innodb_flush_log_at_trx_commit = 1
#innodb_lock_wait_timeout = 50

When I uncommented the InnoDB section the server crashes and the database got corrupted.

Just wondering how I can turn on InnoDB for MAMP, if that is recommended, and update my existing databases at the same time, the MyISAM ones and the InnoDB ones.

While I'm at it, I might want to upgrade MAMP to the newer MySQL version, maybe later.

Answer 1

How much RAM do you have?

Keep max_allowed_packet under 2% of RAM.

Since you are using both MyISAM and InnoDB, set innodb_buffer_pool_size to about 1/3 of RAM unless; less if you have a tiny system.

Do not change innodb_log_file_size without further instructions. That is, don't set it in my.cnf if it is not already set.

MyISAM and InnoDB can coexist.