I have same problem in 5.1.54 (FreeBSD 9.0 amd64). After restart percona server works fast, but after some hours (about 24) it works very slow. There is some statistics:
query_response_time_stats when performance are degraded (resets each 2 min):
time count total
0.000001 0 0.000000
0.000010 165 0.000646
0.000100 9172 0.464741
0.001000 7510 2.384370
0.010000 2555 9.394653
0.100000 1447 67.788210
1.000000 2634 1040.339679
10.000000 210 336.660582
100.000000 0 0.000000
1000.000000 0 0.000000
10000.000000 0 0.000000
100000.000000 0 0.000000
1000000.00000 0 0.000000
After restart:
time count total
0.000001 1 0.000000
0.000010 354 0.001318
0.000100 22695 1.113743
0.001000 12765 3.382774
0.010000 4640 15.994595
0.100000 1821 97.915290
1.000000 901 178.562421
10.000000 1 1.671335
100.000000 0 0.000000
1000.000000 0 0.000000
10000.000000 0 0.000000
100000.000000 0 0.000000
1000000.00000 0 0.000000
Status when performance are degraded
Variable_name Value
Aborted_clients 56
Aborted_connects 154
Binlog_cache_disk_use 6130
Binlog_cache_use 2110517
Bytes_received 115
Bytes_sent 188
Com_admin_commands 0
Com_assign_to_keycache 0
Com_alter_db 0
Com_alter_db_upgrade 0
Com_alter_event 0
Com_alter_function 0
Com_alter_procedure 0
Com_alter_server 0
Com_alter_table 0
Com_alter_tablespace 0
Com_analyze 0
Com_backup_table 0
Com_begin 0
Com_binlog 0
Com_call_procedure 0
Com_change_db 0
Com_change_master 0
Com_check 0
Com_checksum 0
Com_commit 0
Com_create_db 0
Com_create_event 0
Com_create_function 0
Com_create_index 0
Com_create_procedure 0
Com_create_server 0
Com_create_table 0
Com_create_trigger 0
Com_create_udf 0
Com_create_user 0
Com_create_view 0
Com_dealloc_sql 0
Com_delete 0
Com_delete_multi 0
Com_do 0
Com_drop_db 0
Com_drop_event 0
Com_drop_function 0
Com_drop_index 0
Com_drop_procedure 0
Com_drop_server 0
Com_drop_table 0
Com_drop_trigger 0
Com_drop_user 0
Com_drop_view 0
Com_empty_query 0
Com_execute_sql 0
Com_flush 0
Com_grant 0
Com_ha_close 0
Com_ha_open 0
Com_ha_read 0
Com_help 0
Com_insert 0
Com_insert_select 0
Com_install_plugin 0
Com_kill 0
Com_load 0
Com_load_master_data 0
Com_load_master_table 0
Com_lock_tables 0
Com_optimize 0
Com_preload_keys 0
Com_prepare_sql 0
Com_purge 0
Com_purge_before_date 0
Com_release_savepoint 0
Com_rename_table 0
Com_rename_user 0
Com_repair 0
Com_replace 0
Com_replace_select 0
Com_reset 0
Com_restore_table 0
Com_revoke 0
Com_revoke_all 0
Com_rollback 0
Com_rollback_to_savepoint 0
Com_savepoint 0
Com_select 1
Com_set_option 0
Com_show_authors 0
Com_show_binlog_events 0
Com_show_binlogs 0
Com_show_charsets 0
Com_show_client_statistics 0
Com_show_collations 0
Com_show_column_types 0
Com_show_contributors 0
Com_show_create_db 0
Com_show_create_event 0
Com_show_create_func 0
Com_show_create_proc 0
Com_show_create_table 0
Com_show_create_trigger 0
Com_show_databases 0
Com_show_engine_logs 0
Com_show_engine_mutex 0
Com_show_engine_status 0
Com_show_events 0
Com_show_errors 0
Com_show_fields 0
Com_show_function_status 0
Com_show_grants 0
Com_show_index_statistics 0
Com_show_keys 0
Com_show_master_status 0
Com_show_new_master 0
Com_show_open_tables 0
Com_show_patches 0
Com_show_plugins 0
Com_show_privileges 0
Com_show_procedure_status 0
Com_show_processlist 0
Com_show_profile 0
Com_show_profiles 0
Com_show_slave_hosts 0
Com_show_slave_status 0
Com_show_slave_status_nolock 0
Com_show_status 1
Com_show_storage_engines 0
Com_show_table_statistics 0
Com_show_table_status 0
Com_show_tables 0
Com_show_thread_statistics 0
Com_show_temporary_tables 0
Com_show_triggers 0
Com_show_user_statistics 0
Com_show_variables 0
Com_show_warnings 0
Com_slave_start 0
Com_slave_stop 0
Com_stmt_close 0
Com_stmt_execute 0
Com_stmt_fetch 0
Com_stmt_prepare 0
Com_stmt_reprepare 0
Com_stmt_reset 0
Com_stmt_send_long_data 0
Com_truncate 0
Com_uninstall_plugin 0
Com_unlock_tables 0
Com_update 0
Com_update_multi 0
Com_xa_commit 0
Com_xa_end 0
Com_xa_prepare 0
Com_xa_recover 0
Com_xa_rollback 0
Com_xa_start 0
Compression OFF
Connections 259251
Created_tmp_disk_tables 0
Created_tmp_files 8883
Created_tmp_tables 0
Delayed_errors 0
Delayed_insert_threads 2
Delayed_writes 133198
Flashcache_enabled OFF
Flush_commands 1
Handler_commit 0
Handler_delete 0
Handler_discover 0
Handler_prepare 0
Handler_read_first 0
Handler_read_key 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_rnd 0
Handler_read_rnd_next 0
Handler_rollback 0
Handler_savepoint 0
Handler_savepoint_rollback 0
Handler_update 0
Handler_write 0
Innodb_buffer_pool_pages_data 852611
Innodb_buffer_pool_pages_dirty 312
Innodb_buffer_pool_pages_flushed 6580420
Innodb_buffer_pool_pages_free 919228
Innodb_buffer_pool_pages_misc 63169
Innodb_buffer_pool_pages_total 1835008
Innodb_buffer_pool_read_ahead 115089
Innodb_buffer_pool_read_ahead_evicted 0
Innodb_buffer_pool_read_requests 52557150083
Innodb_buffer_pool_reads 507097
Innodb_buffer_pool_wait_free 0
Innodb_buffer_pool_write_requests 493538656
Innodb_data_fsyncs 6401331
Innodb_data_pending_fsyncs 0
Innodb_data_pending_reads 0
Innodb_data_pending_writes 0
Innodb_data_read 10896773120
Innodb_data_reads 555665
Innodb_data_writes 9272785
Innodb_data_written 131561846784
Innodb_dblwr_pages_written 0
Innodb_deadlocks 0
Innodb_dblwr_writes 0
Innodb_dict_tables 382
Innodb_have_atomic_builtins ON
Innodb_log_waits 0
Innodb_log_write_requests 50662374
Innodb_log_writes 1933044
Innodb_os_log_fsyncs 1955611
Innodb_os_log_pending_fsyncs 0
Innodb_os_log_pending_writes 0
Innodb_os_log_written 23735574016
Innodb_page_size 16384
Innodb_pages_created 5485198
Innodb_pages_read 664953
Innodb_pages_written 6580420
Innodb_row_lock_current_waits 0
Innodb_row_lock_time 1024994
Innodb_row_lock_time_avg 10459
Innodb_row_lock_time_max 92585
Innodb_row_lock_waits 98
Innodb_rows_deleted 8180322
Innodb_rows_inserted 23039851
Innodb_rows_read 67296077907
Innodb_rows_updated 3001715
Key_blocks_not_flushed 0
Key_blocks_unused 800000
Key_blocks_used 57376
Key_read_requests 147480037
Key_reads 56872
Key_write_requests 5282504
Key_writes 742619
Last_query_cost 0.000000
Max_used_connections 39
Not_flushed_delayed_rows 0
Open_files 460
Open_streams 0
Open_table_definitions 431
Open_tables 1578
Opened_files 17114921
Opened_table_definitions 0
Opened_tables 0
Prepared_stmt_count 0
Qcache_free_blocks 28166
Qcache_free_memory 95901016
Qcache_hits 241166
Qcache_inserts 17846299
Qcache_lowmem_prunes 6041433
Qcache_not_cached 5724637
Qcache_queries_in_cache 81740
Qcache_total_blocks 196354
Queries 42349353
Questions 2
Rpl_status NULL
Select_full_join 0
Select_full_range_join 0
Select_range 0
Select_range_check 0
Select_scan 0
Slave_open_temp_tables 0
Slave_retried_transactions 0
Slave_running OFF
Slow_launch_threads 0
Slow_queries 0
Sort_merge_passes 0
Sort_range 0
Sort_rows 0
Sort_scan 0
Table_locks_immediate 65739338
Table_locks_waited 67201
Tc_log_max_pages_used 0
Tc_log_page_size 0
Tc_log_page_waits 1
Threads_cached 33
Threads_connected 8
Threads_created 39
Threads_running 5
Uptime 255146
Uptime_since_flush_status 255146
Status after restart (10 min ago)
Variable_name Value
Aborted_clients 0
Aborted_connects 0
Binlog_cache_disk_use 5
Binlog_cache_use 8139
Bytes_received 115
Bytes_sent 188
Com_admin_commands 0
Com_assign_to_keycache 0
Com_alter_db 0
Com_alter_db_upgrade 0
Com_alter_event 0
Com_alter_function 0
Com_alter_procedure 0
Com_alter_server 0
Com_alter_table 0
Com_alter_tablespace 0
Com_analyze 0
Com_backup_table 0
Com_begin 0
Com_binlog 0
Com_call_procedure 0
Com_change_db 0
Com_change_master 0
Com_check 0
Com_checksum 0
Com_commit 0
Com_create_db 0
Com_create_event 0
Com_create_function 0
Com_create_index 0
Com_create_procedure 0
Com_create_server 0
Com_create_table 0
Com_create_trigger 0
Com_create_udf 0
Com_create_user 0
Com_create_view 0
Com_dealloc_sql 0
Com_delete 0
Com_delete_multi 0
Com_do 0
Com_drop_db 0
Com_drop_event 0
Com_drop_function 0
Com_drop_index 0
Com_drop_procedure 0
Com_drop_server 0
Com_drop_table 0
Com_drop_trigger 0
Com_drop_user 0
Com_drop_view 0
Com_empty_query 0
Com_execute_sql 0
Com_flush 0
Com_grant 0
Com_ha_close 0
Com_ha_open 0
Com_ha_read 0
Com_help 0
Com_insert 0
Com_insert_select 0
Com_install_plugin 0
Com_kill 0
Com_load 0
Com_load_master_data 0
Com_load_master_table 0
Com_lock_tables 0
Com_optimize 0
Com_preload_keys 0
Com_prepare_sql 0
Com_purge 0
Com_purge_before_date 0
Com_release_savepoint 0
Com_rename_table 0
Com_rename_user 0
Com_repair 0
Com_replace 0
Com_replace_select 0
Com_reset 0
Com_restore_table 0
Com_revoke 0
Com_revoke_all 0
Com_rollback 0
Com_rollback_to_savepoint 0
Com_savepoint 0
Com_select 1
Com_set_option 0
Com_show_authors 0
Com_show_binlog_events 0
Com_show_binlogs 0
Com_show_charsets 0
Com_show_client_statistics 0
Com_show_collations 0
Com_show_column_types 0
Com_show_contributors 0
Com_show_create_db 0
Com_show_create_event 0
Com_show_create_func 0
Com_show_create_proc 0
Com_show_create_table 0
Com_show_create_trigger 0
Com_show_databases 0
Com_show_engine_logs 0
Com_show_engine_mutex 0
Com_show_engine_status 0
Com_show_events 0
Com_show_errors 0
Com_show_fields 0
Com_show_function_status 0
Com_show_grants 0
Com_show_index_statistics 0
Com_show_keys 0
Com_show_master_status 0
Com_show_new_master 0
Com_show_open_tables 0
Com_show_patches 0
Com_show_plugins 0
Com_show_privileges 0
Com_show_procedure_status 0
Com_show_processlist 0
Com_show_profile 0
Com_show_profiles 0
Com_show_slave_hosts 0
Com_show_slave_status 0
Com_show_slave_status_nolock 0
Com_show_status 1
Com_show_storage_engines 0
Com_show_table_statistics 0
Com_show_table_status 0
Com_show_tables 0
Com_show_thread_statistics 0
Com_show_temporary_tables 0
Com_show_triggers 0
Com_show_user_statistics 0
Com_show_variables 0
Com_show_warnings 0
Com_slave_start 0
Com_slave_stop 0
Com_stmt_close 0
Com_stmt_execute 0
Com_stmt_fetch 0
Com_stmt_prepare 0
Com_stmt_reprepare 0
Com_stmt_reset 0
Com_stmt_send_long_data 0
Com_truncate 0
Com_uninstall_plugin 0
Com_unlock_tables 0
Com_update 0
Com_update_multi 0
Com_xa_commit 0
Com_xa_end 0
Com_xa_prepare 0
Com_xa_recover 0
Com_xa_rollback 0
Com_xa_start 0
Compression OFF
Connections 964
Created_tmp_disk_tables 0
Created_tmp_files 14
Created_tmp_tables 0
Delayed_errors 0
Delayed_insert_threads 2
Delayed_writes 704
Flashcache_enabled OFF
Flush_commands 1
Handler_commit 0
Handler_delete 0
Handler_discover 0
Handler_prepare 0
Handler_read_first 0
Handler_read_key 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_rnd 0
Handler_read_rnd_next 0
Handler_rollback 0
Handler_savepoint 0
Handler_savepoint_rollback 0
Handler_update 0
Handler_write 0
Innodb_buffer_pool_pages_data 50879
Innodb_buffer_pool_pages_dirty 738
Innodb_buffer_pool_pages_flushed 10701
Innodb_buffer_pool_pages_free 1781756
Innodb_buffer_pool_pages_misc 2373
Innodb_buffer_pool_pages_total 1835008
Innodb_buffer_pool_read_ahead 2096
Innodb_buffer_pool_read_ahead_evicted 0
Innodb_buffer_pool_read_requests 197925577
Innodb_buffer_pool_reads 48141
Innodb_buffer_pool_wait_free 0
Innodb_buffer_pool_write_requests 1358955
Innodb_data_fsyncs 30687
Innodb_data_pending_fsyncs 0
Innodb_data_pending_reads 0
Innodb_data_pending_writes 0
Innodb_data_read 828493824
Innodb_data_reads 48501
Innodb_data_writes 34924
Innodb_data_written 253442048
Innodb_dblwr_pages_written 0
Innodb_deadlocks 0
Innodb_dblwr_writes 0
Innodb_dict_tables 124
Innodb_have_atomic_builtins ON
Innodb_log_waits 0
Innodb_log_write_requests 161961
Innodb_log_writes 9379
Innodb_os_log_fsyncs 9417
Innodb_os_log_pending_fsyncs 0
Innodb_os_log_pending_writes 0
Innodb_os_log_written 78097408
Innodb_page_size 16384
Innodb_pages_created 26039
Innodb_pages_read 50433
Innodb_pages_written 10701
Innodb_row_lock_current_waits 0
Innodb_row_lock_time 0
Innodb_row_lock_time_avg 0
Innodb_row_lock_time_max 0
Innodb_row_lock_waits 0
Innodb_rows_deleted 2251
Innodb_rows_inserted 47140
Innodb_rows_read 258897798
Innodb_rows_updated 6016
Key_blocks_not_flushed 1
Key_blocks_unused 855901
Key_blocks_used 1467
Key_read_requests 643025
Key_reads 1466
Key_write_requests 19259
Key_writes 2930
Last_query_cost 0.000000
Max_used_connections 12
Not_flushed_delayed_rows 1
Open_files 161
Open_streams 0
Open_table_definitions 130
Open_tables 424
Opened_files 82941
Opened_table_definitions 0
Opened_tables 0
Prepared_stmt_count 0
Qcache_free_blocks 1
Qcache_free_memory 178309504
Qcache_hits 73
Qcache_inserts 70702
Qcache_lowmem_prunes 0
Qcache_not_cached 23411
Qcache_queries_in_cache 39405
Qcache_total_blocks 78891
Queries 166623
Questions 2
Rpl_status NULL
Select_full_join 0
Select_full_range_join 0
Select_range 0
Select_range_check 0
Select_scan 0
Slave_open_temp_tables 0
Slave_retried_transactions 0
Slave_running OFF
Slow_launch_threads 0
Slow_queries 0
Sort_merge_passes 0
Sort_range 0
Sort_rows 0
Sort_scan 0
Table_locks_immediate 281388
Table_locks_waited 521
Tc_log_max_pages_used 0
Tc_log_page_size 0
Tc_log_page_waits 0
Threads_cached 4
Threads_connected 10
Threads_created 12
Threads_running 8
Uptime 376
Uptime_since_flush_status 376
There is no SWAP (48 GB RAM). Disks are not busy. CPU load about 2 (4 cores+hypertrading). What information may helps?