To analyze some more, we ran the command SHOW GLOBAL STATUS was repeatedly at about once a minute. We ran this on the Active Affected System, the Passive of the affected system, on the Active Affected System where the Passive was not running, and a Normal Healthy Active System. Here are the average results: ============================= Active Affected System ============================= Bytes_received 151332 Bytes_sent 58153877 Com_begin 0 Com_delete 5 Com_insert 340 Com_select 83 Com_set_option 21 Com_show_create_table 1 Com_show_fields 0 Com_show_status 1 Com_show_triggers 0 Com_update 0 Connections 1 Created_tmp_disk_tables 1 Created_tmp_tables 19 Handler_commit 665 Handler_read_first 61 Handler_read_key 1448598 Handler_read_next 3414755 Handler_read_rnd_next 5907007 Handler_write 910 Innodb_buffer_pool_pages_data 7 Innodb_buffer_pool_pages_dirty -11 Innodb_buffer_pool_pages_flushed 1433 Innodb_buffer_pool_pages_free -1 Innodb_buffer_pool_pages_misc -8 Innodb_buffer_pool_pages_total 0 Innodb_buffer_pool_read_ahead_rnd 1 Innodb_buffer_pool_read_ahead_seq 58 Innodb_buffer_pool_read_requests 19006814 Innodb_buffer_pool_reads 164 Innodb_buffer_pool_write_requests 68340 Innodb_data_fsyncs 126 Innodb_data_read 64918025 Innodb_data_reads 248 Innodb_data_writes 1482 Innodb_data_written 48884843 Innodb_dblwr_pages_written 1433 Innodb_dblwr_writes 19 Innodb_log_write_requests 3790 Innodb_log_writes 369 Innodb_os_log_fsyncs 62 Innodb_os_log_written 1895289 Innodb_page_size 0 Innodb_pages_created 7 Innodb_pages_read 3962 Innodb_pages_written 1433 Innodb_rows_deleted 5475 Innodb_rows_inserted 631 Innodb_rows_read 9318468 Innodb_rows_updated 0 Key_blocks_unused 0 Key_blocks_used 0 Key_read_requests 0 Key_reads 0 Last_query_cost 0 Open_files -1 Open_tables 0 Opened_tables 2 Queries 649 Questions 649 Select_scan 59 Table_locks_immediate 443 Threads_created 1 ============================= Passive of affected system ============================= Bytes_received 168483 Bytes_sent 84930801 Com_begin 161 Com_delete 5 Com_insert 337 Com_select 1 Com_set_option 2 Com_show_create_table 1 Com_show_fields 0 Com_show_status 1 Com_show_triggers 0 Com_update 0 Connections 1 Created_tmp_disk_tables 1 Created_tmp_tables 4 Handler_commit 505 Handler_read_first 6 Handler_read_key 12 Handler_read_next 5392 Handler_read_rnd_next 529438 Handler_write 596 Innodb_buffer_pool_pages_data 81 Innodb_buffer_pool_pages_dirty -12 Innodb_buffer_pool_pages_flushed 1412 Innodb_buffer_pool_pages_free -74 Innodb_buffer_pool_pages_misc -8 Innodb_buffer_pool_pages_total 0 Innodb_buffer_pool_read_ahead_rnd 0 Innodb_buffer_pool_read_ahead_seq 86 Innodb_buffer_pool_read_requests 712983 Innodb_buffer_pool_reads 52 Innodb_buffer_pool_write_requests 66784 Innodb_data_fsyncs 121 Innodb_data_read 92506903 Innodb_data_reads 172 Innodb_data_writes 1404 Innodb_data_written 48008451 Innodb_dblwr_pages_written 1412 Innodb_dblwr_writes 18 Innodb_log_write_requests 3527 Innodb_log_writes 210 Innodb_os_log_fsyncs 61 Innodb_os_log_written 1706359 Innodb_page_size 0 Innodb_pages_created 5 Innodb_pages_read 5646 Innodb_pages_written 1412 Innodb_rows_deleted 5386 Innodb_rows_inserted 337 Innodb_rows_read 534549 Innodb_rows_updated 0 Key_blocks_unused 0 Key_blocks_used 0 Key_read_requests 0 Key_reads 0 Last_query_cost 0 Open_files -1 Open_tables 0 Opened_tables 2 Queries 516 Questions 12 Select_scan 4 Table_locks_immediate 344 Threads_created 1 ============================= Active affected system with Passive off ============================= Bytes_received 153328 Bytes_sent 82262 Com_begin 0 Com_delete 5 Com_insert 346 Com_select 83 Com_set_option 18 Com_show_create_table 0 Com_show_fields 0 Com_show_status 1 Com_show_triggers 0 Com_update 0 Connections 1 Created_tmp_disk_tables 0 Created_tmp_tables 17 Handler_commit 713 Handler_read_first 61 Handler_read_key 1360680 Handler_read_next 2791659 Handler_read_rnd_next 5469683 Handler_write 618 Innodb_buffer_pool_pages_data 7 Innodb_buffer_pool_pages_dirty -10 Innodb_buffer_pool_pages_flushed 1916 Innodb_buffer_pool_pages_free 0 Innodb_buffer_pool_pages_misc -8 Innodb_buffer_pool_pages_total 0 Innodb_buffer_pool_read_ahead_rnd 0 Innodb_buffer_pool_read_ahead_seq 1 Innodb_buffer_pool_read_requests 16870799 Innodb_buffer_pool_reads 1 Innodb_buffer_pool_write_requests 73727 Innodb_data_fsyncs 139 Innodb_data_read 1997718 Innodb_data_reads 5 Innodb_data_writes 2027 Innodb_data_written 64808765 Innodb_dblwr_pages_written 1916 Innodb_dblwr_writes 24 Innodb_log_write_requests 3907 Innodb_log_writes 410 Innodb_os_log_fsyncs 65 Innodb_os_log_written 1994584 Innodb_page_size 0 Innodb_pages_created 5 Innodb_pages_read 121 Innodb_pages_written 1916 Innodb_rows_deleted 5982 Innodb_rows_inserted 346 Innodb_rows_read 8261033 Innodb_rows_updated 0 Key_blocks_unused 0 Key_blocks_used 0 Key_read_requests 0 Key_reads 0 Last_query_cost 0 Open_files 0 Open_tables 0 Opened_tables 0 Queries 669 Questions 669 Select_scan 57 Table_locks_immediate 448 Threads_created 1 ============================= Normal Healthy Active System ============================= Bytes_received 2478049 Bytes_sent 2471080 Com_begin 0 Com_delete 0 Com_insert 6281 Com_select 98 Com_set_option 48 Com_show_create_table 0 Com_show_fields 0 Com_show_status 1 Com_show_triggers 0 Com_update 20 Connections 1 Created_tmp_disk_tables 0 Created_tmp_tables 33 Handler_commit 6888 Handler_read_first 29 Handler_read_key 73239 Handler_read_next 1980419 Handler_read_rnd_next 103149 Handler_write 109339 Innodb_buffer_pool_pages_data 0 Innodb_buffer_pool_pages_dirty 6 Innodb_buffer_pool_pages_flushed 1800 Innodb_buffer_pool_pages_free 0 Innodb_buffer_pool_pages_misc -1 Innodb_buffer_pool_pages_total 0 Innodb_buffer_pool_read_ahead_rnd 11 Innodb_buffer_pool_read_ahead_seq 2 Innodb_buffer_pool_read_requests 2749712 Innodb_buffer_pool_reads 193 Innodb_buffer_pool_write_requests 80085 Innodb_data_fsyncs 178 Innodb_data_read 7802790 Innodb_data_reads 313 Innodb_data_writes 1685 Innodb_data_written 63058184 Innodb_dblwr_pages_written 1800 Innodb_dblwr_writes 26 Innodb_log_write_requests 9118 Innodb_log_writes 663 Innodb_os_log_fsyncs 80 Innodb_os_log_written 4071493 Innodb_page_size 0 Innodb_pages_created 93 Innodb_pages_read 476 Innodb_pages_written 1800 Innodb_rows_deleted 6453 Innodb_rows_inserted 6304 Innodb_rows_read 2044924 Innodb_rows_updated 24 Key_blocks_unused 0 Key_blocks_used 0 Key_read_requests 0 Key_reads 0 Last_query_cost 0 Open_files 0 Open_tables 0 Opened_tables 1 Queries 6784 Questions 6784 Select_scan 29 Table_locks_immediate 6421 Threads_created 1