We've got a MySQL database (on Amazon RDS) which occasionally gets a lot of INSERT traffic with large (~1MB) TEXT columns. We find that when this happens, this causes the database CPU to get quite high, with a "see-saw" pattern. This causes other queries that would ordinarily be very fast to slow down unacceptably.
I synthesised a benchmark where I did nothing except INSERT large TEXT columns, with no other work happening. The CPU usage profile ends up looking like this:
My best guess is that there is some sort of page allocation algorithm strategy that kicks in every couple of minutes as data is being added and runs in some critical single-threaded part of MySQL. Can anybody suggest how to tune this better?
More details:
The table we are inserting into:
mysql> show create table workItemContentVersion \G
*************************** 1. row ***************************
Table: workItemContentVersion
Create Table: CREATE TABLE `workItemContentVersion` (
`parentId` int(11) NOT NULL,
`serialNumber` int(11) NOT NULL,
`previousVersionSerialNumber` int(11) DEFAULT NULL,
`authorPrincipalName` varchar(256) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`textAnswer` longtext COLLATE utf8mb4_unicode_ci,
`textAnswerContentType` varchar(10) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`blobAnswer` longblob,
`contentSavedOn` datetime DEFAULT NULL,
PRIMARY KEY (`parentId`,`serialNumber`),
CONSTRAINT `fk_workItemContentVersion_workItem` FOREIGN KEY (`parentId`) REFERENCES `workItem` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
1 row in set (0.00 sec)
The INSERT statement being used for the benchmark (where the parameter for textAnswer is 1MB of the letter 'a':
INSERT IGNORE INTO workItemContentVersion (parentId, serialNumber, textAnswer)
VALUES (?, ?, ?), (?, ?, ?)
Hardware details: Amazon RDS on db.r3.xlarge instance (4 vCPU, 30GB RAM, 500 Mbps disk bandwidth)
Server config (output of SHOW GLOBAL STATUS):
Variable_name Value
Aborted_clients 6
Aborted_connects 0
Binlog_cache_disk_use 268012
Binlog_cache_use 268284
Binlog_stmt_cache_disk_use 0
Binlog_stmt_cache_use 0
Bytes_received 514070955062
Bytes_sent 41617844
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_alter_user 0
Com_analyze 0
Com_begin 0
Com_binlog 0
Com_call_procedure 0
Com_change_db 21994
Com_change_master 0
Com_check 0
Com_checksum 0
Com_commit 272
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 278
Com_get_diagnostics 0
Com_grant 0
Com_ha_close 0
Com_ha_open 0
Com_ha_read 0
Com_help 0
Com_insert 268288
Com_insert_select 0
Com_install_plugin 0
Com_kill 1
Com_load 0
Com_lock_tables 0
Com_optimize 0
Com_preload_keys 0
Com_prepare_sql 0
Com_purge 278
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_resignal 0
Com_revoke 0
Com_revoke_all 0
Com_rollback 0
Com_rollback_to_savepoint 0
Com_savepoint 0
Com_select 132852
Com_set_option 8
Com_signal 0
Com_show_binlog_events 0
Com_show_binlogs 0
Com_show_charsets 0
Com_show_collations 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 2
Com_show_create_trigger 0
Com_show_databases 2
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 81
Com_show_function_code 0
Com_show_function_status 0
Com_show_grants 0
Com_show_keys 0
Com_show_master_status 0
Com_show_open_tables 0
Com_show_plugins 0
Com_show_privileges 0
Com_show_procedure_code 0
Com_show_procedure_status 0
Com_show_processlist 5
Com_show_profile 0
Com_show_profiles 0
Com_show_relaylog_events 0
Com_show_slave_hosts 0
Com_show_slave_status 0
Com_show_status 267
Com_show_storage_engines 0
Com_show_table_status 0
Com_show_tables 2
Com_show_triggers 0
Com_show_variables 1
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Com_slave_start 0
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Com_stmt_execute 270641
Com_stmt_fetch 0
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Com_stmt_reprepare 0
Com_stmt_reset 0
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Com_truncate 0
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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
Connection_errors_accept 0
Connection_errors_internal 0
Connection_errors_max_connections 0
Connection_errors_peer_address 0
Connection_errors_select 0
Connection_errors_tcpwrap 0
Connections 22288
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Created_tmp_files 22009
Created_tmp_tables 55230
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Delayed_writes 0
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Handler_read_key 8936
Handler_read_last 20
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Handler_read_prev 594
Handler_read_rnd 0
Handler_read_rnd_next 125997
Handler_rollback 0
Handler_savepoint 0
Handler_savepoint_rollback 0
Handler_update 272
Handler_write 567816
Innodb_buffer_pool_dump_status not started
Innodb_buffer_pool_load_status not started
Innodb_buffer_pool_pages_data 1455843
Innodb_buffer_pool_bytes_data 23852531712
Innodb_buffer_pool_pages_dirty 11311
Innodb_buffer_pool_bytes_dirty 185319424
Innodb_buffer_pool_pages_flushed 32307952
Innodb_buffer_pool_pages_free 7324
Innodb_buffer_pool_pages_misc 1
Innodb_buffer_pool_pages_total 1463168
Innodb_buffer_pool_read_ahead_rnd 0
Innodb_buffer_pool_read_ahead 0Warning: Using a password on the command line interface can be insecure.
Innodb_buffer_pool_read_ahead_evicted 0
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Innodb_buffer_pool_reads 5484
Innodb_buffer_pool_wait_free 0
Innodb_buffer_pool_write_requests 226317402
Innodb_data_fsyncs 1881794
Innodb_data_pending_fsyncs 2
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Innodb_data_pending_writes 1
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Innodb_data_reads 5806
Innodb_data_writes 33848583
Innodb_data_written 1593306025984
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Innodb_dblwr_writes 645081
Innodb_have_atomic_builtins ON
Innodb_log_waits 413
Innodb_log_write_requests 1041108828
Innodb_log_writes 335941
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Innodb_os_log_pending_fsyncs 2
Innodb_os_log_pending_writes 0
Innodb_os_log_written 534630468096
Innodb_page_size 16384
Innodb_pages_created 31897395
Innodb_pages_read 5483
Innodb_pages_written 32308192
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Innodb_row_lock_time 1874
Innodb_row_lock_time_avg 93
Innodb_row_lock_time_max 425
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Innodb_rows_read 9521
Innodb_rows_updated 272
Innodb_num_open_files 42
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Innodb_available_undo_logs 128
Key_blocks_not_flushed 0
Key_blocks_unused 13384
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Key_read_requests 12
Key_reads 12
Key_write_requests 0
Key_writes 0
Last_query_cost 0.000000
Last_query_partial_plans 0
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Not_flushed_delayed_rows 0
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Open_streams 0
Open_table_definitions 114
Open_tables 176
Opened_files 54928
Opened_table_definitions 114
Opened_tables 6014
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Performance_schema_cond_classes_lost 0
Performance_schema_cond_instances_lost 0
Performance_schema_digest_lost 0
Performance_schema_file_classes_lost 0
Performance_schema_file_handles_lost 0
Performance_schema_file_instances_lost 0
Performance_schema_hosts_lost 0
Performance_schema_locker_lost 0
Performance_schema_mutex_classes_lost 0
Performance_schema_mutex_instances_lost 0
Performance_schema_rwlock_classes_lost 0
Performance_schema_rwlock_instances_lost 0
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Performance_schema_socket_classes_lost 0
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Performance_schema_thread_instances_lost 0
Performance_schema_users_lost 0
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Qcache_free_memory 1031352
Qcache_hits 0
Qcache_inserts 0
Qcache_lowmem_prunes 0
Qcache_not_cached 132851
Qcache_queries_in_cache 0
Qcache_total_blocks 1
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Questions 446338
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Select_range_check 0
Select_scan 61056
Slave_heartbeat_period 0.000
Slave_last_heartbeat
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Ssl_cipher
Ssl_cipher_list
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Ssl_version
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Tc_log_page_waits 0
Threads_cached 0
Threads_connected 12
Threads_created 12
Threads_running 6
Uptime 83387
Uptime_since_flush_status 83387
Output of SHOW VARIABLES:
Variable_name Value
auto_increment_increment 1
auto_increment_offset 1
autocommit ON
automatic_sp_privileges ON
back_log 558
basedir /rdsdbbin/mysql/
big_tables OFF
bind_address *
binlog_cache_size 32768
binlog_checksum CRC32
binlog_direct_non_transactional_updates OFF
binlog_format MIXED
binlog_max_flush_queue_time 0
binlog_order_commits ON
binlog_row_image FULL
binlog_rows_query_log_events OFF
binlog_stmt_cache_size 32768
binlogging_impossible_mode IGNORE_ERROR
block_encryption_mode aes-128-ecb
bulk_insert_buffer_size 8388608
character_set_client latin1
character_set_connection latin1
character_set_database latin1
character_set_filesystem binary
character_set_results latin1
character_set_server latin1
character_set_system utf8
character_sets_dir /rdsdbbin/mysql-5.6.21.R1/share/charsets/
collation_connection latin1_swedish_ci
collation_database latin1_swedish_ci
collation_server latin1_swedish_ci
completion_type NO_CHAIN
concurrent_insert AUTO
connect_timeout 10
core_file OFF
datadir /rdsdbdata/db/
date_format %Y-%m-%d
datetime_format %Y-%m-%d %H:%i:%s
default_storage_engine InnoDB
default_tmp_storage_engine InnoDB
default_week_format 0
delay_key_write ON
delayed_insert_limit 100
delayed_insert_timeout 300
delayed_queue_size 1000
disconnect_on_expired_password ON
div_precision_increment 4
end_markers_in_json OFF
enforce_gtid_consistency OFF
eq_range_index_dive_limit 10
error_count 0
event_scheduler OFF
expire_logs_days 0
explicit_defaults_for_timestamp ON
external_user
flush OFF
flush_time 0
foreign_key_checks ON
ft_boolean_syntax + -><()~*:""&|
ft_max_word_len 84
ft_min_word_len 4
ft_query_expansion_limit 20
ft_stopword_file (built-in)
general_log OFF
general_log_file /rdsdbdata/log/general/mysql-general.log
group_concat_max_len 1024
gtid_executed
gtid_mode OFF
gtid_next AUTOMATIC
gtid_owned
gtid_purged
have_compress YES
have_crypt YES
have_dynamic_loading YES
have_geometry YES
have_openssl YES
have_profiling YES
have_query_cache YES
have_rtree_keys YES
have_ssl YES
have_symlink YES
host_cache_size 730
hostname ip-172-22-1-13
identity 0
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ignore_db_dirs
init_connect
init_file
init_slave
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innodb_adaptive_flushing_lwm 10
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innodb_additional_mem_pool_size 8388608
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innodb_api_enable_binlog OFF
innodb_api_enable_mdl OFF
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innodb_buffer_pool_dump_now OFF
innodb_buffer_pool_filename ib_buffer_pool
innodb_buffer_pool_instances 8
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innodb_buffer_pool_load_now OFF
innodb_buffer_pool_size 23972544512
innodb_change_buffer_max_size 25
innodb_change_buffering all
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innodb_data_file_path ibdata1:12M:autoextend
innodb_data_home_dir /rdsdbdata/db/innodb
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innodb_doublewrite ON
innodb_fast_shutdown 1
innodb_file_format Antelope
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innodb_file_format_max Antelope
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innodb_flush_method
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innodb_ft_total_cache_size 640000000
innodb_ft_user_stopword_table
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innodb_log_group_home_dir /rdsdbdata/log/innodb
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innodb_max_dirty_pages_pct_lwm 0
innodb_max_purge_lag 0
innodb_max_purge_lag_delay 0
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innodb_monitor_disable
innodb_monitor_enable
innodb_monitor_reset
innodb_monitor_reset_all
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innodb_old_blocks_time 1000
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innodb_open_files 2000
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innodb_page_size 16384
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innodb_rollback_segments 128
innodb_sort_buffer_size 1048576
innodb_spin_wait_delay 6
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innodb_stats_method nulls_equal
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innodb_stats_persistent ON
innodb_stats_persistent_sample_pages 20
innodb_stats_sample_pages 8
innodb_stats_transient_sample_pages 8
innodb_status_output OFF
innodb_status_output_locks OFF
innodb_strict_mode OFF
innodb_support_xa ON
innodb_sync_array_size 1
innodb_sync_spin_loops 30
innodb_table_locks ON
innodb_thread_concurrency 0
innodb_thread_sleep_delay 10000
innodb_undo_directory .
innodb_undo_logs 128
innodb_undo_tablespaces 0
innodb_use_native_aio ON
innodb_use_sys_malloc ON
innodb_version 5.6.21
innodb_write_io_threads 4
insert_id 0
interactive_timeout 28800
join_buffer_size 262144
keep_files_on_create OFF
key_buffer_size 16777216
key_cache_age_threshold 300
key_cache_block_size 1024
key_cache_division_limit 100
large_files_support ON
large_page_size 0
large_pages OFF
last_insert_id 0
lc_messages en_US
lc_messages_dir /rdsdbbin/mysql-5.6.21.R1/share/
lc_time_names en_US
license GPL
local_infile ON
lock_wait_timeout 31536000
locked_in_memory OFF
log_bin ON
log_bin_basename /rdsdbdata/log/binlog/mysql-bin-changelog
log_bin_index /rdsdbdata/log/binlog/mysql-bin-changelog.index
log_bin_trust_function_creators OFF
log_bin_use_v1_row_events OFF
log_error /rdsdbdata/log/error/mysql-error.log
log_output TABLE
log_queries_not_using_indexes OFF
log_slave_updates ON
log_slow_admin_statements OFF
log_slow_slave_statements OFF
log_throttle_queries_not_using_indexes 0
log_warnings 1
long_query_time 10.000000
low_priority_updates OFF
lower_case_file_system OFF
lower_case_table_names 0
master_info_repository TABLE
master_verify_checksum OFF
max_allowed_packet 4194304
max_binlog_cache_size 18446744073709547520
max_binlog_size 134217728
max_binlog_stmt_cache_size 18446744073709547520
max_connect_errors 100
max_connections 2540
max_delayed_threads 20
max_error_count 64
max_heap_table_size 16777216
max_insert_delayed_threads 20
max_join_size 18446744073709551615
max_length_for_sort_data 1024
max_prepared_stmt_count 16382
max_relay_log_size 0
max_seeks_for_key 18446744073709551615
max_sort_length 1024
max_sp_recursion_depth 0
max_tmp_tables 32
max_user_connections 0
max_write_lock_count 18446744073709551615
metadata_locks_cache_size 1024
metadata_locks_hash_instances 8
min_examined_row_limit 0
multi_range_count 256
myisam_data_pointer_size 6
myisam_max_sort_file_size 9223372036853727232
myisam_mmap_size 18446744073709551615
myisam_recover_options OFF
myisam_repair_threads 1
myisam_sort_buffer_size 8388608
myisam_stats_method nulls_unequal
myisam_use_mmap OFF
net_buffer_length 16384
net_read_timeout 30
net_retry_count 10
net_write_timeout 60
new OFF
old OFF
old_alter_table OFF
old_passwords 0
open_files_limit 65535
optimizer_prune_level 1
optimizer_search_depth 62
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,mrr=on,mrr_cost_based=on,block_nested_loop=on,batched_key_access=off,materialization=on,semijoin=on,loosescan=on,firstmatch=on,subquery_materialization_cost_based=on,use_index_extensions=on
optimizer_trace enabled=off,one_line=off
optimizer_trace_features greedy_search=on,range_optimizer=on,dynamic_range=on,repeated_subselect=on
optimizer_trace_limit 1
optimizer_trace_max_mem_size 16384
optimizer_trace_offset -1
performance_schema OFF
performance_schema_accounts_size -1
performance_schema_digests_size -1
performance_schema_events_stages_history_long_size -1
performance_schema_events_stages_history_size -1
performance_schema_events_statements_history_long_size -1
performance_schema_events_statements_history_size -1
performance_schema_events_waits_history_long_size -1
performance_schema_events_waits_history_size -1
performance_schema_hosts_size -1
performance_schema_max_cond_classes 80
performance_schema_max_cond_instances -1
performance_schema_max_file_classes 50
performance_schema_max_file_handles 32768
performance_schema_max_file_instances -1
performance_schema_max_mutex_classes 200
performance_schema_max_mutex_instances -1
performance_schema_max_rwlock_classes 40
performance_schema_max_rwlock_instances -1
performance_schema_max_socket_classes 10
performance_schema_max_socket_instances -1
performance_schema_max_stage_classes 150
performance_schema_max_statement_classes 168
performance_schema_max_table_handles -1
performance_schema_max_table_instances -1
performance_schema_max_thread_classes 50
performance_schema_max_thread_instances -1
performance_schema_session_connect_attrs_size -1
performance_schema_setup_actors_size 100
performance_schema_setup_objects_size 100
performance_schema_users_size -1
pid_file /rdsdbdata/log/mysql-3306.pid
plugin_dir /rdsdbbin/mysql-5.6.21.R1/lib/plugin/
port 3306
preload_buffer_size 32768
profiling OFF
profiling_history_size 15
protocol_version 10
proxy_user
pseudo_slave_mode OFF
pseudo_thread_id 22310
query_alloc_block_size 8192
query_cache_limit 1048576
query_cache_min_res_unit 4096
query_cache_size 1048576
query_cache_type OFF
query_cache_wlock_invalidate OFF
query_prealloc_size 8192
rand_seed1 0
rand_seed2 0
range_alloc_block_size 4096
read_buffer_size 262144
read_only OFF
read_rnd_buffer_size 524288
relay_log /rdsdbdata/log/relaylog/relaylog
relay_log_basename /rdsdbdata/log/relaylog/relaylog
relay_log_index /rdsdbdata/log/relaylog/relaylog.index
relay_log_info_file relay-log.info
relay_log_info_repository TABLE
relay_log_purge ON
relay_log_recovery ON
relay_log_space_limit 0
report_host
report_password
report_port 3306
report_user
rpl_stop_slave_timeout 31536000
secure_auth ON
secure_file_priv /tmp/
server_id 507840347
server_id_bits 32
server_uuid 520896f1-1296-11e7-9164-0275a6150d51
simplified_binlog_gtid_recovery OFF
skip_external_locking ON
skip_name_resolve OFF
skip_networking OFF
skip_show_database OFF
slave_allow_batching OFF
slave_checkpoint_group 512
slave_checkpoint_period 300
slave_compressed_protocol OFF
slave_exec_mode STRICT
slave_load_tmpdir /rdsdbdata/tmp
slave_max_allowed_packet 1073741824
slave_net_timeout 3600
slave_parallel_workers 0
slave_pending_jobs_size_max 16777216
slave_rows_search_algorithms TABLE_SCAN,INDEX_SCAN
slave_skip_errors OFF
slave_sql_verify_checksum ON
slave_transaction_retries 10
slave_type_conversions
slow_launch_time 2
slow_query_log OFF
slow_query_log_file /rdsdbdata/log/slowquery/mysql-slowquery.log
socket /tmp/mysql.sock
sort_buffer_size 262144
sql_auto_is_null OFF
sql_big_selects ON
sql_buffer_result OFF
sql_log_bin ON
sql_log_off OFF
sql_mode NO_ENGINE_SUBSTITUTION
sql_notes ON
sql_quote_show_create ON
sql_safe_updates OFF
sql_select_limit 18446744073709551615
sql_slave_skip_counter 0
sql_warnings OFF
ssl_ca /rdsdbdata/rds-metadata/ca-cert.pem
ssl_capath
ssl_cert /rdsdbdata/rds-metadata/server-cert.pem
ssl_cipher EXP1024-RC4-SHA:EXP1024-DES-CBC-SHA:AES256-SHA:AES128-SHA:DES-CBC3-SHA:DES-CBC-SHA:EXP-DES-CBC-SHA:EXP-RC2-CBC-MD5:RC4-SHA:RC4-MD5:EXP-RC4-MD5:NULL-SHA:NULL-MD5:DES-CBC3-MD5:DES-CBC-MD5:EXP-RC2-CBC-MD5:RC2-CBC-MD5:EXP-RC4-MD5:RC4-MD5:KRB5-DES-CBC3-MD5:KRB5-DES-CBC3-SHA:ADH-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:EDH-DSS-DES-CBC3-SHA:ADH-AES256-SHA:DHE-RSA-AES256-SHA:DHE-DSS-AES256-SHA:ADH-AES128-SHA:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA:EXP-KRB5-RC4-MD5:EXP-KRB5-RC2-CBC-MD5:EXP-KRB5-DES-CBC-MD5:KRB5-RC4-MD5:KRB5-DES-CBC-MD5:ADH-RC4-MD5:EXP-ADH-RC4-MD5:DHE-DSS-RC4-SHA:EXP1024-DHE-DSS-RC4-SHA:EXP1024-DHE-DSS-DES-CBC-SHA:EXP-KRB5-RC4-SHA:EXP-KRB5-RC2-CBC-SHA:EXP-KRB5-DES-CBC-SHA:KRB5-RC4-SHA:KRB5-DES-CBC-SHA:ADH-DES-CBC-SHA:EXP-ADH-DES-CBC-SHA:EDH-RSA-DES-CBC-SHA:EXP-EDH-RSA-DES-CBC-SHA:EDH-DSS-DES-CBC-SHA:EXP-EDH-DSS-DES-CBC-SHA
ssl_crl
ssl_crlpath
ssl_key /rdsdbdata/rds-metadata/server-key.pem
storage_engine InnoDB
stored_program_cache 256
sync_binlog 1
sync_frm ON
sync_master_info 10000
sync_relay_log 10000
sync_relay_log_info 10000
system_time_zone UTC
table_definition_cache 1400
table_open_cache 2000
table_open_cache_instances 16
thread_cache_size 33
thread_concurrency 10
thread_handling one-thread-per-connection
thread_stack 262144
time_format %H:%i:%s
time_zone UTC
timed_mutexes OFF
timestamp 1490747772.419137
tmp_table_size 16777216
tmpdir /rdsdbdata/tmp
transaction_alloc_block_size 8192
transaction_allow_batching OFF
transaction_prealloc_size 4096
tx_isolation REPEATABLE-READ
tx_read_only OFF
unique_checks ON
updatable_views_with_limit YES
version 5.6.21-log
version_comment MySQL Community Server (GPL)
version_compile_machine x86_64
version_compile_os Linux
wait_timeout 28800
warning_count 0
Best Answer
Do you have Replication turned on? The first couple might be a cause for extra I/O (and CPU):
( Binlog_cache_disk_use ) = 268,012 / 83387 = 3.2 /sec-- Freq of binlog cache spilling to disk -- Increase binlog_cache_size.( Binlog_cache_disk_use / Binlog_cache_use ) = 268,012 / 268284 = 99.9%-- Spill to disk -- Increase binlog_cache_size( (Innodb_buffer_pool_reads + Innodb_buffer_pool_pages_flushed) ) = ((5484 + 32307952) ) / 83387 = 387 /sec-- InnoDB I/O -- Increase innodb_buffer_pool_size?( Innodb_log_waits / Innodb_log_writes ) = 413 / 335941 = 0.12%-- Frequency of needing to wait to write to log -- Increase innodb_log_buffer_size.( Uptime / 60 * innodb_log_file_size / Innodb_os_log_written ) = 83,387 / 60 * 128M / 534630468096 = 0.349-- Minutes between InnoDB log rotations Beginning with 5.6.8, this can be changed dynamically; be sure to also change my.cnf. -- (The recommendation of 60 minutes between rotations is somewhat arbitrary.) Adjust innodb_log_file_size.( ( Innodb_pages_read + Innodb_pages_written ) / Uptime / innodb_io_capacity ) = ( 5483 + 32308192 ) / 83387 / 200 = 193.8%-- If > 100%, need more io_capacity. -- Increase innodb_io_capacity if the drives can handle it. (AWS can probably handle it.)( Select_scan / Com_select ) = 61,056 / 132852 = 46.0%-- % of selects doing full table scan. (May be fooled by Stored Routines.) -- Add indexes / optimize queries( slave_pending_jobs_size_max / max_allowed_packet ) = 16M / 4M = 400.0%-- For parallel slave threads -- slave_pending_jobs_size_max must not be less than max_allowed_packet( long_query_time ) = 10.000000 = 10-- Cutoff (Seconds) for defining a "slow" query. -- Suggest 2You have the Query Cache half-off. You should set both query_cache_type = OFF and query_cache_size = 0 . There is (according to a rumor) a 'bug' in the QC code that leaves some code on unless you turn off both of those settings.
Uptime is 23 hours. Were you running nothing but the benchmark for that whole time? I would prefer to analyze your workload, not a benchmark. (I usually find that benchmarks do not mirror reality.)
You asked about CPU... Some of the above issues relate directly to CPU; some relate indirectly. That is, the CPU is sometimes involved in things that otherwise seem like I/O. Perhaps a main example is when the code "spins the cpu" in hopes that a Mutex will be released or I/O will finished. The presumption is that that is 'faster' than hitting the OS.
In any case, address whatever issues you can, then we can make another analysis pass.