Causes and solutions for MySQL Server "Connection dropped - lasts exactly 60 seconds" problem

MySQL queries used to run normally , but now it times out after 60 seconds and throws an error, even though the query is running slowly, but as part of a nightly job, this is not an issue (so please don't suggest optimizing the query).

I was able to reproduce the error by running "select SLEEP(120);" from PHP as shown below. However, running the same statement from the MySQL client succeeds (returns 0). I tried adjusting wait_timeout (set to 28800) with no success. I also restarted the database server and the machine itself.

The issue always times out at exactly 60 seconds, which makes me think it might be a setup issue rather than a constrained resource issue.

My running environment is as follows:

• Windows Server 2003
• MySQL 5.1.36 Community Edition
• PHP 5.3

The following is my test code, output and results of SHOW VARIABLES:

<code class="php">set_error_handler("sqlErrorHandler");
set_time_limit(12000);


$link = mysql_connect("$MYSQL_Host","$MYSQL_User","$MYSQL_Pass");
mysql_select_db($MYSQL_db, $link);

echo "mysql_ping = " . (mysql_ping($link) ? "LIVE" : "DEAD") . "<br /><br />"; 

$sql = "SELECT SLEEP(120);";

$start = microtime(true);
mysql_query($sql, $link);

echo "**query done**<br />";
allDone();

function allDone(){
 global $start, $sql;

 $end = microtime(true);
 echo "sql : $sql<br />";
 echo "elapsed : " . ($end - $start) . "<br />";
 echo "<br />";
}

function sqlErrorHandler($errno, $errstr, $errfile, $errline){
 global $link;
 echo "Error : $errno<br />$errstr<br />";
 echo "mysql_ping : " . (mysql_ping($link) ? "LIVE" : "DEAD") . "<br />"; 
 echo "<br />";

 allDone();
}</code>

OUTPUT :

mysql_ping = LIVE

Error : 2
mysql_query() [function.mysql-query]: MySQL server has gone away
mysql_ping : DEAD

sql : SELECT SLEEP(120);
elapsed : 60.051116943359

Error : 2
mysql_query() [function.mysql-query]: Error reading result set's header
mysql_ping : DEAD

sql : SELECT SLEEP(120);
elapsed : 60.0511469841

**query done**
sql : SELECT SLEEP(120);
elapsed : 60.051155090332

SHOW VARIABLES:

Variable_name=Value
auto_increment_increment=1
auto_increment_offset=1
autocommit=ON
automatic_sp_privileges=ON
back_log=50
basedir=C:\Program Files\MySQL\MySQL Server 5.1\
big_tables=OFF
binlog_cache_size=32768
binlog_format=STATEMENT
bulk_insert_buffer_size=8388608
character_set_client=utf8
character_set_connection=utf8
character_set_database=latin1
character_set_filesystem=binary
character_set_results=utf8
character_set_server=latin1
character_set_system=utf8
character_sets_dir=C:\Program Files\MySQL\MySQL Server 5.1\share\charsets\
collation_connection=utf8_general_ci
collation_database=latin1_swedish_ci
collation_server=latin1_swedish_ci
completion_type=0
concurrent_insert=1
connect_timeout=10
datadir=C:\Documents and Settings\All Users\Application Data\MySQL\MySQL Server 5.1\Data\
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=0
flush=OFF
flush_time=1800
foreign_key_checks=ON
ft_boolean_syntax=+ -><()~*:""&amp;|
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=C:\Documents and Settings\All Users\Application Data\MySQL\MySQL Server 5.1\Data\p1.log
group_concat_max_len=1024
have_community_features=YES
have_compress=YES
have_crypt=NO
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
identity=0
ignore_builtin_innodb=OFF
init_connect=
init_file=
init_slave=
innodb_adaptive_hash_index=ON
innodb_additional_mem_pool_size=2097152
innodb_autoextend_increment=8
innodb_autoinc_lock_mode=1
innodb_buffer_pool_size=96468992
innodb_checksums=ON
innodb_commit_concurrency=0
innodb_concurrency_tickets=500
innodb_data_file_path=ibdata1:10M:autoextend
innodb_data_home_dir=D:\MySQL Datafiles\
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=19922944
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
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=50331648
key_cache_age_threshold=300
key_cache_block_size=1024
key_cache_division_limit=100
language=C:\Program Files\MySQL\MySQL Server 5.1\share\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
log=OFF
log_bin=OFF
log_bin_trust_function_creators=OFF
log_bin_trust_routine_creators=OFF
log_error=C:\Documents and Settings\All Users\Application Data\MySQL\MySQL Server 5.1\Data\p1.err
log_output=FILE
log_queries_not_using_indexes=OFF
log_slave_updates=OFF

The above is the detailed content of Why Does My MySQL Server Time Out at Exactly 60 Seconds After Connecting?. For more information, please follow other related articles on the PHP Chinese website!