有一个基于java的cron，它做了一些处理，最后它将一些行插入InnoDB。
这个cron每小时运行24次，但每天都会在相同的特定时间运行，因为这几天都很少。 例外：
The last packet successfully received from the server was 465,902 milliseconds ago. The last packet sent successfully to the server was 8 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1038)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3434)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3334)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3774)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2447)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2594)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2541)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1604)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1535)
at DBConnection.QueryUpdate(DBConnection.java:41)
at Mailer.insertDetailstoDB(Mailer.java:203)
at Mailer.run(Mailer.java:64)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2926)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3344)
... 11 more
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
问题仅在插入时发生。在其他表上更新/选择查询工作正常。即使在同一（问题）表上选择查询也能正常工作。
JDBC网址：DB_URL=URL+DB+"?zeroDateTimeBehavior=convertToNull&autoReconnect=true&characterEncoding=UTF-8&characterSetResults=UTF-8&failOverReadOnly=true";
进行sql varibale转储，但即使没有问题，两者都是相同的。
Variable DUMP :
auto_increment_increment.........2
auto_increment_offset.........1
autocommit.........ON
automatic_sp_privileges.........ON
back_log.........150
basedir........./usr/local/mysql6
big_tables.........OFF
bind_address.........*
binlog_cache_size.........32768
binlog_checksum.........CRC32
binlog_direct_non_transactional_updates.........OFF
binlog_error_action.........IGNORE_ERROR
binlog_format.........MIXED
binlog_gtid_simple_recovery.........OFF
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........./usr/local/mysql-5.6.23-linux-glibc2.5-x86_64/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........./usr/local/mysql6/data_99acres06/
date_format.........%Y-%m-%d
datetime_format.........%Y-%m-%d %H:%i:%s
default_storage_engine.........MyISAM
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
event_scheduler.........OFF
expire_logs_days.........5
explicit_defaults_for_timestamp.........OFF
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........./usr/local/mysql6/data/npl9dba08.log
group_concat_max_len.........1073741824
gtid_executed.........
gtid_mode.........OFF
gtid_owned.........
gtid_purged.........
have_compress.........YES
have_crypt.........YES
have_dynamic_loading.........YES
have_geometry.........YES
have_openssl.........DISABLED
have_profiling.........YES
have_query_cache.........YES
have_rtree_keys.........YES
have_ssl.........DISABLED
have_symlink.........YES
host_cache_size.........628
hostname.........npl9dba08.ieil.net
ignore_builtin_innodb.........OFF
ignore_db_dirs.........
init_connect.........
init_file.........
init_slave.........
innodb_adaptive_flushing.........ON
innodb_adaptive_flushing_lwm.........10
innodb_adaptive_hash_index.........ON
innodb_adaptive_max_sleep_delay.........150000
innodb_additional_mem_pool_size.........8388608
innodb_api_bk_commit_interval.........5
innodb_api_disable_rowlock.........OFF
innodb_api_enable_binlog.........OFF
innodb_api_enable_mdl.........OFF
innodb_api_trx_level.........0
innodb_autoextend_increment.........64
innodb_autoinc_lock_mode.........1
innodb_buffer_pool_dump_at_shutdown.........OFF
innodb_buffer_pool_dump_now.........OFF
innodb_buffer_pool_filename.........ib_buffer_pool
innodb_buffer_pool_instances.........40
innodb_buffer_pool_load_abort.........OFF
innodb_buffer_pool_load_at_startup.........OFF
innodb_buffer_pool_load_now.........OFF
innodb_buffer_pool_size.........42949672960
innodb_change_buffer_max_size.........25
innodb_change_buffering.........all
innodb_checksum_algorithm.........innodb
innodb_checksums.........ON
innodb_cmp_per_index_enabled.........OFF
innodb_commit_concurrency.........0
innodb_compression_failure_threshold_pct.........5
innodb_compression_level.........6
innodb_compression_pad_pct_max.........50
innodb_concurrency_tickets.........5000
innodb_data_file_path.........ibdata1:100M:autoextend
innodb_data_home_dir........./usr/local/mysql6/data
innodb_disable_sort_file_cache.........OFF
innodb_doublewrite.........ON
innodb_fast_shutdown.........1
innodb_file_format.........Antelope
innodb_file_format_check.........ON
innodb_file_format_max.........Antelope
innodb_file_per_table.........ON
innodb_flush_log_at_timeout.........1
innodb_flush_log_at_trx_commit.........1
innodb_flush_method.........O_DIRECT
innodb_flush_neighbors.........1
innodb_flushing_avg_loops.........30
innodb_force_load_corrupted.........OFF
innodb_force_recovery.........0
innodb_ft_aux_table.........
innodb_ft_cache_size.........8000000
innodb_ft_enable_diag_print.........OFF
innodb_ft_enable_stopword.........ON
innodb_ft_max_token_size.........84
innodb_ft_min_token_size.........3
innodb_ft_num_word_optimize.........2000
innodb_ft_result_cache_limit.........2000000000
innodb_ft_server_stopword_table.........
innodb_ft_sort_pll_degree.........2
innodb_ft_total_cache_size.........640000000
innodb_ft_user_stopword_table.........
innodb_io_capacity.........200
innodb_io_capacity_max.........2000
innodb_large_prefix.........OFF
innodb_lock_wait_timeout.........100
innodb_locks_unsafe_for_binlog.........OFF
innodb_log_buffer_size.........16777216
innodb_log_compressed_pages.........ON
innodb_log_file_size.........536870912
innodb_log_files_in_group.........2
innodb_log_group_home_dir........../
innodb_lru_scan_depth.........1024
innodb_max_dirty_pages_pct.........75
innodb_max_dirty_pages_pct_lwm.........0
innodb_max_purge_lag.........0
innodb_max_purge_lag_delay.........0
innodb_mirrored_log_groups.........1
innodb_monitor_disable.........
innodb_monitor_enable.........
innodb_monitor_reset.........
innodb_monitor_reset_all.........
innodb_old_blocks_pct.........37
innodb_old_blocks_time.........1000
innodb_online_alter_log_max_size.........134217728
innodb_open_files.........400
innodb_optimize_fulltext_only.........OFF
innodb_page_size.........16384
innodb_print_all_deadlocks.........OFF
innodb_purge_batch_size.........300
innodb_purge_threads.........1
innodb_random_read_ahead.........OFF
innodb_read_ahead_threshold.........56
innodb_read_io_threads.........4
innodb_read_only.........OFF
innodb_replication_delay.........0
innodb_rollback_on_timeout.........OFF
innodb_rollback_segments.........128
innodb_sort_buffer_size.........1048576
innodb_spin_wait_delay.........6
innodb_stats_auto_recalc.........ON
innodb_stats_method.........nulls_equal
innodb_stats_on_metadata.........OFF
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.........5.6.23
innodb_write_io_threads.........4
interactive_timeout.........28800
join_buffer_size.........8388608
keep_files_on_create.........OFF
key_buffer_size.........12884901888
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
lc_messages.........en_US
lc_messages_dir........./usr/local/mysql-5.6.23-linux-glibc2.5-x86_64/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........./usr/local/mysql6/data/npl9dba08_99acres
log_bin_index........./usr/local/mysql6/data/npl9dba08_99acres.index
log_bin_trust_function_creators.........OFF
log_bin_use_v1_row_events.........OFF
log_error........./usr/local/mysql6/data/npl9dba08.ieil.net.err
log_output.........FILE
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.........1.000000
low_priority_updates.........OFF
lower_case_file_system.........OFF
lower_case_table_names.........0
master_info_repository.........FILE
master_verify_checksum.........OFF
max_allowed_packet.........33554432
max_binlog_cache_size.........18446744073709547520
max_binlog_size.........1073741824
max_binlog_stmt_cache_size.........18446744073709547520
max_connect_errors.........100
max_connections.........500
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.........12582912
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.........20000
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.........ON
performance_schema_accounts_size.........100
performance_schema_digests_size.........10000
performance_schema_events_stages_history_long_size.........10000
performance_schema_events_stages_history_size.........10
performance_schema_events_statements_history_long_size.........10000
performance_schema_events_statements_history_size.........10
performance_schema_events_waits_history_long_size.........10000
performance_schema_events_waits_history_size.........10
performance_schema_hosts_size.........100
performance_schema_max_cond_classes.........80
performance_schema_max_cond_instances.........3300
performance_schema_max_file_classes.........50
performance_schema_max_file_handles.........32768
performance_schema_max_file_instances.........30770
performance_schema_max_mutex_classes.........200
performance_schema_max_mutex_instances.........10000
performance_schema_max_rwlock_classes.........40
performance_schema_max_rwlock_instances.........5000
performance_schema_max_socket_classes.........10
performance_schema_max_socket_instances.........1020
performance_schema_max_stage_classes.........150
performance_schema_max_statement_classes.........168
performance_schema_max_table_handles.........800
performance_schema_max_table_instances.........12500
performance_schema_max_thread_classes.........50
performance_schema_max_thread_instances.........1100
performance_schema_session_connect_attrs_size.........512
performance_schema_setup_actors_size.........100
performance_schema_setup_objects_size.........100
performance_schema_users_size.........100
pid_file........./usr/local/mysql6/data/npl9dba08.ieil.net.pid
plugin_dir........./usr/local/mysql6/lib/plugin/
port.........3306
preload_buffer_size.........32768
profiling.........OFF
profiling_history_size.........15
protocol_version.........10
query_alloc_block_size.........8192
query_cache_limit.........1048576
query_cache_min_res_unit.........4096
query_cache_size.........268435456
query_cache_type.........ON
query_cache_wlock_invalidate.........OFF
query_prealloc_size.........8192
range_alloc_block_size.........4096
read_buffer_size.........16777216
read_only.........OFF
read_rnd_buffer_size.........262144
relay_log.........
relay_log_basename.........
relay_log_index.........
relay_log_info_file.........relay-log.info
relay_log_info_repository.........FILE
relay_log_purge.........ON
relay_log_recovery.........OFF
relay_log_space_limit.........0
report_host.........npl9dba0806
report_password.........
report_port.........3306
report_user.........
rpl_stop_slave_timeout.........31536000
secure_auth.........ON
secure_file_priv.........
server_id.........178806
server_id_bits.........32
server_uuid.........561d32a3-5544-11e5-b989-44a8423fc648
simplified_binlog_gtid_recovery.........OFF
skip_external_locking.........ON
skip_name_resolve.........ON
skip_networking.........OFF
skip_show_database.........OFF
slave_allow_batching.........OFF
slave_checkpoint_group.........512
slave_checkpoint_period.........300
slave_compressed_protocol.........ON
slave_exec_mode.........STRICT
slave_load_tmpdir........./usr/local/mysql6/data/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.........ON
slow_query_log_file.........npl9dba08.slow
socket........./tmp/mysql_06.sock
sort_buffer_size.........8388608
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.........
ssl_capath.........
ssl_cert.........
ssl_cipher.........
ssl_crl.........
ssl_crlpath.........
ssl_key.........
storage_engine.........MyISAM
stored_program_cache.........256
sync_binlog.........0
sync_frm.........ON
sync_master_info.........10000
sync_relay_log.........10000
sync_relay_log_info.........10000
system_time_zone.........IST
table_definition_cache.........600
table_open_cache.........400
table_open_cache_instances.........1
thread_cache_size.........400
thread_concurrency.........10
thread_handling.........one-thread-per-connection
thread_stack.........262144
time_format.........%H:%i:%s
time_zone.........Asia/Calcutta
timed_mutexes.........OFF
tmp_table_size.........3221225472
tmpdir........./usr/local/mysql6/data/tmp
transaction_alloc_block_size.........8192
transaction_prealloc_size.........4096
tx_isolation.........REPEATABLE-READ
tx_read_only.........OFF
unique_checks.........ON
updatable_views_with_limit.........YES
version.........5.6.23-log
version_comment.........MySQL Community Server (GPL)
version_compile_machine.........x86_64
version_compile_os.........linux-glibc2.5
wait_timeout.........200
答案 0 :(得分：0)
query_cache_size.........268435456 - 不超过约50M，否则修剪会在INSERTs和其他写入中导致性能问题。
INSERT看起来像？一排？很多行？ INSERT..SELECT？向我们展示INSERT。
你有至少64GB的RAM吗？
您只使用MyISAM？哎哟！
只有InnoDB使用的buffer_pool浪费了40GB。
group_concat_max_len.........1073741824 - 立即进行一些查询，你可能会用完RAM！
同上tmp_table_size.........3221225472。
FULLTEXT索引是否涉及顽皮的INSERT？