WL#4980: Update InnoDB defaults

Affects: Server-5.4   —   Status: Complete   —   Priority: Medium

Updated InnoDB defaults.
In MySQL 5.4.0
  1) Buffer Pool size now defaults to 1GB and a minimum of 64MB
  2) Log files are 3 by default and each 128MB in size
  3) Removed innodb-file-io-threads config variable since no longer used
  4) Set read io and write io threads to 8 by default for better default performance
  5) Set log buffer size to 16 MB by default and minimum to 2MB
  6) Set additional memory buffer pool to 8 MB and minimum to 2MB
  7) Set max dirty percent to 75% and decreased to 99% to never allow a
completely dirty buffer pool
  8) Increased io capacity to 200 for a good default
In MySQL 5.4.0, change the following InnoDB defaults:
  1) innodb_buffer_pool_size: Increase default from 8MB to 1GB; 
increase minimum from 1MB to 64MB.
  2) innodb_log_files_in_group: Increase default from 2 to 3, with
each log file 128MB in size.
  3) Removed innodb_file_io_threads (no longer used); replaced by
innodb_read_io_threads and innodb_write_io_threads variables, each
with a default of 8 background I/O threads to use for read prefetch 
requests and for writing dirty pages from the buffer cache to disk.
  4) innodb_log_buffer_size: Increase default from 1MB to 16MB; 
increase minimum from 256KB to 2MB.
  5) innodb_additional_mem_pool_size: Increase default from 1MB to 
8MB; increase minimum from 512KB to 2MB.
  6) innodb_max_dirty_pages_pct: Decrease default from 90 to 75; 
decrease maximum from 100 to 99 to never allow a completely dirty 
buffer pool.
  7) innodb_autoextend_increment: Increase default from 8MB to 64MB.
  8) innodb_log_file_size: Increase default from 5MB to 128MB;
increase minimum from 1MB to 32MB.
  9) table_definition_cache: Increase default from 64 to 400.

These changes are made to provide better “out of box” configuration of default 
values for MySQL operation on up to 16-way x86 servers and 64-way CMT servers
with 4GB or more memory.
Default value of an existing variable changed; no
further LLD required.