slow inserts mysql

Question

I have very slow insert to my InnoDb table (2 500 000 notes). But why? Here is debug information:

Server: Intel® Core™ i7-920 24 GB DDR3 RAMFestplatten2 x 750 GB SATA 3 Gb/s HDD 168.02 query/sec

CREATE TABLE IF NOT EXISTS `bysr_customers` (
  `customerID` int(11) NOT NULL AUTO_INCREMENT,
  `OdnoklasID` varchar(255) NOT NULL,
  `Login` varchar(32) DEFAULT NULL,
  `cust_password` varchar(255) NOT NULL,
  `Email` varchar(255) DEFAULT NULL,
  `first_name` varchar(255) DEFAULT NULL,
  `last_name` varchar(255) DEFAULT NULL,
  `kopilka` int(110) NOT NULL DEFAULT '0',
  `subscribed4news` int(11) DEFAULT NULL,
  `custgroupID` int(11) DEFAULT NULL,
  `addressID` int(11) DEFAULT NULL,
  `reg_datetime` datetime DEFAULT NULL,
  `ActivationCode` varchar(16) NOT NULL DEFAULT '',
  `CID` int(11) DEFAULT NULL,
  `affiliateID` int(11) NOT NULL,
  `affiliateEmailOrders` int(11) NOT NULL DEFAULT '1',
  `affiliateEmailPayments` int(11) NOT NULL DEFAULT '1',
  `actions` text NOT NULL,
  `area` text NOT NULL,
  `city` text NOT NULL,
  `street` text NOT NULL,
  `house` text NOT NULL,
  `build` text NOT NULL,
  `room` text NOT NULL,
  `phone` text NOT NULL,
  `fake` int(10) NOT NULL,
  PRIMARY KEY (`customerID`),
  UNIQUE KEY `ok_index` (`OdnoklasID`),
  KEY `AFFILIATEID` (`affiliateID`)
) ENGINE=InnoDB  DEFAULT CHARSET=cp1251 AUTO_INCREMENT=3504023 ;



INSERT INTO bysr_customers (OdnoklasID, first_name, last_name, custgroupID, reg_datetime, CID, affiliateEmailOrders, affiliateEmailPayments, fake)  VALUES ('fake_4', '2', '3', '1', '2012-02-22 16:42:54', '1', '1', '1', '0');


mysql> SHOW profile FOR QUERY 7;
+----------------------+----------+
| Status               | Duration |
+----------------------+----------+
| starting             | 0.000043 |
| checking permissions | 0.000007 |
| Opening tables       | 0.000044 |
| System lock          | 0.000004 |
| Table lock           | 0.000004 |
| init                 | 0.000018 |
| update               | 7.521551 |
| end                  | 0.000011 |
| query end            | 0.000006 |
| freeing items        | 2.573892 |
| logging slow query   | 0.000013 |
| logging slow query   | 0.000035 |
| cleaning up          | 0.000006 |
+----------------------+----------+
13 rows in set (0.00 sec)
auto_increment_increment    1
auto_increment_offset   1
autocommit  ON
automatic_sp_privileges ON
back_log    50
basedir /usr/
big_tables  OFF
binlog_cache_size   32768
binlog_direct_non_transactional_updates OFF
binlog_format   STATEMENT
bulk_insert_buffer_size 8388608
character_set_client    utf8
character_set_connection    utf8
character_set_database  cp1251
character_set_filesystem    binary
character_set_results   utf8
character_set_server    cp1251
character_set_system    utf8
character_sets_dir  /usr/share/mysql/charsets/
collation_connection    utf8_general_ci
collation_database  cp1251_general_ci
collation_server    cp1251_general_ci
completion_type 0
concurrent_insert   1
connect_timeout 10
datadir /var/lib/mysql/
date_format %Y-%m-%d
datetime_format %Y-%m-%d %H:%i:%s
default_week_format 0
delay_key_write ON
delayed_insert_limit    100
delayed_insert_timeout  300
delayed_queue_size  1000
div_precision_increment 4
engine_condition_pushdown   ON
error_count 0
event_scheduler OFF
expire_logs_days    10
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    /var/lib/mysql/Ubuntu-1104-natty-64-minimal.log
group_concat_max_len    1024
have_community_features YES
have_compress   YES
have_crypt  YES
have_csv    YES
have_dynamic_loading    YES
have_geometry   YES
have_innodb YES
have_ndbcluster NO
have_openssl    DISABLED
have_partitioning   YES
have_query_cache    YES
have_rtree_keys YES
have_ssl    DISABLED
have_symlink    YES
hostname    Ubuntu-1104-natty-64-minimal
identity    0
ignore_builtin_innodb   OFF
init_connect     
init_file    
init_slave   
innodb_adaptive_hash_index  ON
innodb_additional_mem_pool_size 1048576
innodb_autoextend_increment 8
innodb_autoinc_lock_mode    1
innodb_buffer_pool_size 10737418240
innodb_checksums    ON
innodb_commit_concurrency   0
innodb_concurrency_tickets  500
innodb_data_file_path   ibdata1:10M:autoextend
innodb_data_home_dir     
innodb_doublewrite  ON
innodb_fast_shutdown    1
innodb_file_io_threads  4
innodb_file_per_table   OFF
innodb_flush_log_at_trx_commit  1
innodb_flush_method  
innodb_force_recovery   0
innodb_lock_wait_timeout    50
innodb_locks_unsafe_for_binlog  OFF
innodb_log_buffer_size  1048576
innodb_log_file_size    5242880
innodb_log_files_in_group   2
innodb_log_group_home_dir   ./
innodb_max_dirty_pages_pct  90
innodb_max_purge_lag    0
innodb_mirrored_log_groups  1
innodb_open_files   300
innodb_rollback_on_timeout  OFF
innodb_stats_on_metadata    ON
innodb_support_xa   ON
innodb_sync_spin_loops  20
Variable_name    Value
innodb_table_locks  ON
innodb_thread_concurrency   8
innodb_thread_sleep_delay   10000
innodb_use_legacy_cardinality_algorithm ON
insert_id   0
interactive_timeout 28800
join_buffer_size    131072
keep_files_on_create    OFF
key_buffer_size 2147483648
key_cache_age_threshold 300
key_cache_block_size    1024
key_cache_division_limit    100
language    /usr/share/mysql/english/
large_files_support ON
large_page_size 0
large_pages OFF
last_insert_id  0
lc_time_names   en_US
license GPL
local_infile    ON
locked_in_memory    OFF
log OFF
log_bin OFF
log_bin_trust_function_creators OFF
log_bin_trust_routine_creators  OFF
log_error   /var/log/mysql/error.log
log_output  FILE
log_queries_not_using_indexes   OFF
log_slave_updates   OFF
log_slow_queries    ON
log_warnings    1
long_query_time 2.000000
low_priority_updates    OFF
lower_case_file_system  OFF
lower_case_table_names  0
max_allowed_packet  16777216
max_binlog_cache_size   18446744073709547520
max_binlog_size 104857600
max_connect_errors  10
max_connections 151
max_delayed_threads 20
max_error_count 64
max_heap_table_size 1073741824
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
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  BACKUP
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   OFF
open_files_limit    1024
optimizer_prune_level   1
optimizer_search_depth  62
optimizer_switch    index_merge=on,index_merge_union=on,index_merge_so...
pid_file    /var/lib/mysql/Ubuntu-1104-natty-64-minimal.pid
plugin_dir  /usr/lib/mysql/plugin
port    3306
preload_buffer_size 32768
profiling   ON
profiling_history_size  15
protocol_version    10
pseudo_thread_id    79658
query_alloc_block_size  8192
query_cache_limit   10485760
query_cache_min_res_unit    4096
query_cache_size    314572800
query_cache_type    ON
query_cache_wlock_invalidate    OFF
query_prealloc_size 8192
rand_seed1   
rand_seed2   
range_alloc_block_size  4096
read_buffer_size    131072
read_only   OFF
read_rnd_buffer_size    262144
relay_log    
relay_log_index  
relay_log_info_file relay-log.info
Variable_name    Value
relay_log_purge ON
relay_log_space_limit   0
report_host  
report_password  
report_port 3306
report_user  
rpl_recovery_rank   0
secure_auth OFF
secure_file_priv     
server_id   0
skip_external_locking   ON
skip_name_resolve   OFF
skip_networking OFF
skip_show_database  OFF
slave_compressed_protocol   OFF
slave_exec_mode STRICT
slave_load_tmpdir   /tmp
slave_net_timeout   3600
slave_skip_errors   OFF
slave_transaction_retries   10
slow_launch_time    2
slow_query_log  ON
slow_query_log_file /var/log/mysql/mysql-slow.log
socket  /var/run/mysqld/mysqld.sock
sort_buffer_size    268435456
sql_auto_is_null    ON
sql_big_selects ON
sql_big_tables  OFF
sql_buffer_result   OFF
sql_log_bin ON
sql_log_off OFF
sql_log_update  ON
sql_low_priority_updates    OFF
sql_max_join_size   18446744073709551615
sql_mode     
sql_notes   ON
sql_quote_show_create   ON
sql_safe_updates    OFF
sql_select_limit    18446744073709551615
sql_slave_skip_counter   
sql_warnings    OFF
ssl_ca   
ssl_capath   
ssl_cert     
ssl_cipher   
ssl_key  
storage_engine  MyISAM
sync_binlog 0
sync_frm    ON
system_time_zone    MSK
table_definition_cache  256
table_lock_wait_timeout 50
table_open_cache    64
table_type  MyISAM
thread_cache_size   8
thread_handling one-thread-per-connection
thread_stack    196608
time_format %H:%i:%s
time_zone   SYSTEM
timed_mutexes   OFF
timestamp   1329916096
tmp_table_size  1073741824
tmpdir  /tmp
transaction_alloc_block_size    8192
transaction_prealloc_size   4096
tx_isolation    REPEATABLE-READ
unique_checks   ON
updatable_views_with_limit  YES
version 5.1.54-1ubuntu4-log
version_comment (Ubuntu)
version_compile_machine x86_64
version_compile_os  debian-linux-gnu
wait_timeout    28800
warning_count   0

Answer 1

If this just started happening, I would guess IO contention (disk or memory). Check your system.

If it occurs intermittently, but often, I would suspect the large unique index on the VARCHAR(255) OdnoklasID column. Try temporarily removing the index to see if inserts improve, then see if you can improve (shorten) or do without the index.

If you are doing multiple inserts, combine them into one statement because the indexes are updated after each statement.

Your VARCHAR(255) field, with 4 bytes for the Integer primary key added, is 259 bytes per index entry. MySQL InnoDB page size for indexes is 16KB, so you'll get at most 63 index entries per page, which will often cause page splits on insertion.

Answer 2

I'd suggest removing the UNIQUE KEY constraint and see how it runs.