# pt-online-schema-change

  • Please download and install percona-toolkit (v3.0.4 or other campatible version) first.
  • Please specific pt-osc dir by osc_bin_dir first,default /usr/local/bin.

# Options

you can check pt-osc options by inception show variables like 'osc%';

inception show variables like 'osc%';

Modify in two ways:

  • one at inception set
inception set osc_check_interval = 10;
  • another one at config.toml, and start by -config=config.toml

# process command

# check osc process
inception get osc processlist;

result return:

test_inc t1 alter table t1 add column c33 int *E53542EFF4E179BE267210114EC5EDBEF9DC5D8F 9 00:36 Copying test_inc.t1: 9% 00:36 remain
# check specific osc process
inception get osc_percent '*E53542EFF4E179BE267210114EC5EDBEF9DC5D8F';

result return:

test_inc t1 *E53542EFF4E179BE267210114EC5EDBEF9DC5D8F 49 00:14 Copying test_inc.t1: 49% 00:14 remain
# stop specific osc process

need to remove auxiliary tables manual

inception kill osc '*E53542EFF4E179BE267210114EC5EDBEF9DC5D8F';
-- or --
inception stop alter '*E53542EFF4E179BE267210114EC5EDBEF9DC5D8F';

# Option description

Options default type description
osc_on false bool OSC switch
osc_alter_foreign_keys_method none string correspond OSC option alter-foreign-keys-method
osc_bin_dir /usr/local/bin string pt-online-schema-change script path
osc_check_alter true bool correspond --[no]check-alter
osc_check_interval 5 int correspond --check-interval, means Sleep time between checks for --max-lag.
osc_check_replication_filters true bool correspond --[no]check-replication-filters
osc_chunk_size 1000 int correspond --chunk-size
osc_chunk_size_limit 4 int correspond --chunk-size-limit
osc_chunk_time 1 int correspond --chunk-time
osc_check_unique_key_change v1.0.5 true bool correspond --[no]check_unique_key_change, if check unique index.
osc_critical_thread_connected 1000 int correspond --critical-load中的thread_connected
osc_critical_thread_running 80 int correspond --critical-load中的thread_running
osc_drop_new_table true bool correspond --[no]drop-new-table
osc_drop_old_table true bool correspond --[no]drop-old-table
osc_max_lag 3 int correspond --max-lag
osc_max_thread_connected 1000 int correspond --max-load中的thread_connected
osc_max_thread_running 80 int correspond --max-load中的thread_running
osc_min_table_size 16 int Switch set,if value is 0, all ALTER will use OSC.if values is not 0, only the table size more than the values, use OSC. unit in MB,table size = select (DATA_LENGTH + INDEX_LENGTH)/1024/1024 from information_schema.tables where table_schema = "dbname" and table_name = "tablename"
osc_print_none false bool If value is 1, do not print. If values is 0, print osc output in inception result error sets.
osc_print_sql false bool correspond --print
osc_recursion_method processlist string correspond -ecursion_method