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https://github.com/MariaDB/server.git
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e90f68c0ba
Clean up and improve the parallel implementation code, mainly related to scheduling of work to threads and handling of stop and errors. Fix a lot of bugs in various corner cases that could lead to crashes or corruption. Fix that a single replication domain could easily grab all worker threads and stall all other domains; now a configuration variable --slave-domain-parallel-threads allows to limit the number of workers. Allow next event group to start as soon as previous group begins the commit phase (as opposed to when it ends it); this allows multiple event groups on the slave to participate in group commit, even when no other opportunities for parallelism are available. Various fixes: - Fix some races in the rpl.rpl_parallel test case. - Fix an old incorrect assertion in Log_event iocache read. - Fix repeated malloc/free of wait_for_commit and rpl_group_info objects. - Simplify wait_for_commit wakeup logic. - Fix one case in queue_for_group_commit() where killing one thread would fail to correctly signal the error to the next, causing loss of the transaction after slave restart. - Fix leaking of pthreads (and their allocated stack) due to missing PTHREAD_CREATE_DETACHED attribute. - Fix how one batch of group-committed transactions wait for the previous batch before starting to execute themselves. The old code had a very complex scheduling where the first transaction was handled differently, with subtle bugs in corner cases. Now each event group is always scheduled for a new worker (in a round-robin fashion amongst available workers). Keep a count of how many transactions have started to commit, and wait for that counter to reach the appropriate value. - Fix slave stop to wait for all workers to actually complete processing; before, the wait was for update of last_committed_sub_id, which happens a bit earlier, and could leave worker threads potentially accessing bits of the replication state that is no longer valid after slave stop. - Fix a couple of places where the test suite would kill a thread waiting inside enter_cond() in connection with debug_sync; debug_sync + kill can crash in rare cases due to a race with mysys_var_current_mutex in this case. - Fix some corner cases where we had enter_cond() but no exit_cond(). - Fix that we could get failure in wait_for_prior_commit() but forget to flag the error with my_error(). - Fix slave stop (both for normal stop and stop due to error). Now, at stop we pick a specific safe point (in terms of event groups executed) and make sure that all event groups before that point are executed to completion, and that no event group after start executing; this ensures a safe place to restart replication, even for non-transactional stuff/DDL. In error stop, make sure that all prior event groups are allowed to execute to completion, and that any later event groups that have started are rolled back, if possible. The old code could leave eg. T1 and T3 committed but T2 not, or it could even leave half a transaction not rolled back in some random worker, which would cause big problems when that worker was later reused after slave restart. - Fix the accounting of amount of events queued for one worker. Before, the amount was reduced immediately as soon as the events were dequeued (which happens all at once); this allowed twice the amount of events to be queued in memory for each single worker, which is not what users would expect. - Fix that an error set during execution of one event was sometimes not cleared before executing the next, causing problems with the error reporting. - Fix incorrect handling of thd->killed in worker threads. |
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| .. | ||
| aggregate.result | ||
| all_instances.result | ||
| bad_option_1.result | ||
| bad_option_2.result | ||
| bad_option_3.result | ||
| bad_option_4.result | ||
| bad_option_5.result | ||
| binlog_mix.result | ||
| binlog_row.result | ||
| binlog_stmt.result | ||
| checksum.result | ||
| cnf_option.result | ||
| column_privilege.result | ||
| ddl_cond_instances.result | ||
| ddl_events_waits_current.result | ||
| ddl_events_waits_history.result | ||
| ddl_events_waits_history_long.result | ||
| ddl_ews_by_instance.result | ||
| ddl_ews_by_thread_by_event_name.result | ||
| ddl_ews_global_by_event_name.result | ||
| ddl_file_instances.result | ||
| ddl_fs_by_event_name.result | ||
| ddl_fs_by_instance.result | ||
| ddl_mutex_instances.result | ||
| ddl_performance_timers.result | ||
| ddl_rwlock_instances.result | ||
| ddl_setup_consumers.result | ||
| ddl_setup_instruments.result | ||
| ddl_setup_timers.result | ||
| ddl_threads.result | ||
| dml_cond_instances.result | ||
| dml_events_waits_current.result | ||
| dml_events_waits_history.result | ||
| dml_events_waits_history_long.result | ||
| dml_ews_by_instance.result | ||
| dml_ews_by_thread_by_event_name.result | ||
| dml_ews_global_by_event_name.result | ||
| dml_file_instances.result | ||
| dml_file_summary_by_event_name.result | ||
| dml_file_summary_by_instance.result | ||
| dml_mutex_instances.result | ||
| dml_performance_timers.result | ||
| dml_rwlock_instances.result | ||
| dml_setup_consumers.result | ||
| dml_setup_instruments.result | ||
| dml_setup_timers.result | ||
| dml_threads.result | ||
| func_file_io.result | ||
| func_mutex.result | ||
| global_read_lock.result | ||
| information_schema.result | ||
| misc.result | ||
| myisam_file_io.result | ||
| no_threads.result | ||
| one_thread_per_con.result | ||
| pfs_upgrade.result | ||
| privilege.result | ||
| query_cache.result | ||
| read_only.result | ||
| relaylog.result | ||
| schema.result | ||
| selects.result | ||
| server_init.result | ||
| short_option_1.result | ||
| short_option_2.result | ||
| start_server_no_cond_class.result | ||
| start_server_no_cond_inst.result | ||
| start_server_no_file_class.result | ||
| start_server_no_file_inst.result | ||
| start_server_no_mutex_class.result | ||
| start_server_no_mutex_inst.result | ||
| start_server_no_rwlock_class.result | ||
| start_server_no_rwlock_inst.result | ||
| start_server_no_thread_class.result | ||
| start_server_no_thread_inst.result | ||
| start_server_no_waits_history.result | ||
| start_server_no_waits_history_long.result | ||
| start_server_nothing.result | ||
| start_server_off.result | ||
| start_server_on.result | ||
| tampered_perfschema_table1.result | ||
| thread_cache.result | ||