Question

我连续批量插入mysql innoDB表，插入每秒比率减慢。有些行为是 - 如果关闭数据插入器（java）应用程序，mysql做一些i / o操作一段时间。 - 添加一些插入然后关闭mysql服务器，关机操作持续时间太长。如果没有任何插入启动和停止mysql，启动和停止操作如此之快。 - 插入速度不是（那么多）取决于表格上的数据量。如果重启mysql服务器，则每秒插入类似于上次重启每秒插入值。

我在论坛上看了一些评论，不要连续添加，2次插入之间有差距。有意义吗？为什么sql会变慢？

查询 SHOW VARIABLES LIKE'inno％'结果低于

innodb_adaptive_flushing = ON
innodb_adaptive_hash_index = ON
innodb_additional_mem_pool_size = 20971520
innodb_autoextend_increment = 8
innodb_autoinc_lock_mode = 1
innodb_buffer_pool_instances = 1
innodb_buffer_pool_size = 268435456
innodb_change_buffering = all
innodb_checksums = ON
innodb_commit_concurrency = 0
innodb_concurrency_tickets = 500
innodb_data_file_path = ibdata1:50M:autoextend
innodb_data_home_dir = 
innodb_doublewrite = ON
innodb_fast_shutdown = 1
innodb_file_format = Barracuda
innodb_file_format_check = ON
innodb_file_format_max = Antelope
innodb_file_per_table = ON
innodb_flush_log_at_trx_commit = 2
innodb_flush_method = O_DSYNC
innodb_force_recovery = 0
innodb_io_capacity = 200
innodb_lock_wait_timeout = 50
innodb_locks_unsafe_for_binlog = OFF
innodb_log_buffer_size = 8388608
innodb_log_file_size = 268435456
innodb_log_files_in_group = 2
innodb_log_group_home_dir = ./
innodb_max_dirty_pages_pct = 75
innodb_max_purge_lag = 0
innodb_mirrored_log_groups = 1
innodb_old_blocks_pct = 37
innodb_old_blocks_time = 0
innodb_open_files = 300
innodb_purge_batch_size = 20
innodb_purge_threads = 0
innodb_read_ahead_threshold = 56
innodb_read_io_threads = 4
innodb_replication_delay = 0
innodb_rollback_on_timeout = OFF
innodb_spin_wait_delay = 6
innodb_stats_on_metadata = ON
innodb_stats_sample_pages = 8
innodb_strict_mode = ON
innodb_support_xa = ON
innodb_sync_spin_loops = 30
innodb_table_locks = ON
innodb_thread_concurrency = 0
innodb_thread_sleep_delay = 10000
innodb_use_native_aio = OFF
innodb_use_sys_malloc = ON
innodb_version = 1.1.1
innodb_write_io_threads = 4

由于

Answer 1

InnoDB默认在自动提交模式下工作，这意味着每个插入都需要两次写入磁盘。使用扩展插入（a.k.a.多行插入）并将多个连续插入包含在事务中可以提高性能。

Answer 2

减速原因是存储在缓存（脏页）上的插入操作和周期性写入的硬盘驱动器。在脏页内存已满之前，插入操作很快，然后缓存已满并且插入速度瓶颈盘写入（I / O）。您可以使用以下sql显示脏页大小“已修改的数据库页”

show engine innodb status

InnoDB插入计数减慢

2 个答案: