How to change the read/write ratio of sysbench oltp_read_write script

Question

I'm using the sysbench(1.1.0) to test the performance of MySQL, and I want to test the scene that read:write is 95%:5%. Are there any parameters to change the read/write ratio?

Answer 1

You can have a look at the oltp_read_write script:

function event()
   if not sysbench.opt.skip_trx then
      begin()
   end

   execute_point_selects()

   if sysbench.opt.range_selects then
      execute_simple_ranges()
      execute_sum_ranges()
      execute_order_ranges()
      execute_distinct_ranges()
   end

   execute_index_updates()
   execute_non_index_updates()
   execute_delete_inserts()

   if not sysbench.opt.skip_trx then
      commit()
   end

   check_reconnect()
end

This script define the query in a transaction, and the options are below(sysbench oltp_read_write.lua help):

oltp_read_write.lua options:
  --auto_inc[=on|off]           Use AUTO_INCREMENT column as Primary Key (for MySQL), or its alternatives in other DBMS. When disabled, use client-generated IDs [on]
  --create_secondary[=on|off]   Create a secondary index in addition to the PRIMARY KEY [on]
  --create_table_options=STRING Extra CREATE TABLE options []
  --delete_inserts=N            Number of DELETE/INSERT combinations per transaction [1]
  --distinct_ranges=N           Number of SELECT DISTINCT queries per transaction [1]
  --index_updates=N             Number of UPDATE index queries per transaction [1]
  --mysql_storage_engine=STRING Storage engine, if MySQL is used [innodb]
  --non_index_updates=N         Number of UPDATE non-index queries per transaction [1]
  --order_ranges=N              Number of SELECT ORDER BY queries per transaction [1]
  --pgsql_variant=STRING        Use this PostgreSQL variant when running with the PostgreSQL driver. The only currently supported variant is 'redshift'. When enabled, create_secondary is automatically disabled, and delete_inserts is set to 0
  --point_selects=N             Number of point SELECT queries per transaction [10]
  --range_selects[=on|off]      Enable/disable all range SELECT queries [on]
  --range_size=N                Range size for range SELECT queries [100]
  --reconnect=N                 Reconnect after every N events. The default (0) is to not reconnect [0]
  --secondary[=on|off]          Use a secondary index in place of the PRIMARY KEY [off]
  --simple_ranges=N             Number of simple range SELECT queries per transaction [1]
  --skip_trx[=on|off]           Don't start explicit transactions and execute all queries in the AUTOCOMMIT mode [off]
  --sum_ranges=N                Number of SELECT SUM() queries per transaction [1]
  --table_size=N                Number of rows per table [10000]
  --tables=N                    Number of tables [1]

So, the default read/write ratio is 10+4/1+1+2+2, and you can change the read/write ratio just by changing the option number. For example:

sysbench oltp_read_write.lua --range_selects=off --point_selects=100 xxx

Then the read/write ratio is 100+4/1+1+2+2.