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View Full Version : New customer :) Server optimization request


andrerus
Tue 18th Sep '07, 12:33am
Hi

i need to tweak my server please help me to do that :)

1.
Dedicated server (only one website running)


2.

Switch port: 100Mbps (FE) :
OS: Linux (CentOS
CPU: 1 x Dual Core Xeon 3050
Memory: 1 GB
Harddisk: 1 x 160GB SATA
Directadmin panel

Apache Version Apache/1.3.37 (Unix) mod_gzip/1.3.26.1a mod_ssl/2.8.28 OpenSSL/0.9.7a mod_perl/1.29 FrontPage/5.0.2.2510
PHP Version 4.4.7
Mysql: 4.1.21

apc installed
memcache/d installed
mod_gzip installed

the website getting stuck . with low load.. very strange.

3.

VB 3.6.8

4. i think the directadmin using innodb , i'm not sure.

5.by directadmin

6.

top - 04:08:12 up 2 days, 6:59, 1 user, load average: 0.02, 0.18, 0.11
Tasks: 160 total, 1 running, 159 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.2% us, 0.2% sy, 0.0% ni, 99.7% id, 0.0% wa, 0.0% hi, 0.0% si
Mem: 1034396k total, 1012328k used, 22068k free, 134872k buffers
Swap: 1052248k total, 80316k used, 971932k free, 527036k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
25551 root 16 0 2468 1000 764 R 1 0.1 0:00.04 top
1 root 16 0 3184 476 448 S 0 0.0 0:00.49 init
2 root RT 0 0 0 0 S 0 0.0 0:00.04 migration/0
3 root 34 19 0 0 0 S 0 0.0 0:00.01 ksoftirqd/0
4 root RT 0 0 0 0 S 0 0.0 0:00.04 migration/1
5 root 34 19 0 0 0 S 0 0.0 0:00.02 ksoftirqd/1
6 root 5 -10 0 0 0 S 0 0.0 0:00.00 events/0
7 root 5 -10 0 0 0 S 0 0.0 0:00.00 events/1
8 root 5 -10 0 0 0 S 0 0.0 0:00.00 khelper
9 root 15 -10 0 0 0 S 0 0.0 0:00.00 kacpid
35 root 5 -10 0 0 0 S 0 0.0 0:00.00 kblockd/0
36 root 5 -10 0 0 0 S 0 0.0 0:00.00 kblockd/1
37 root 15 0 0 0 0 S 0 0.0 0:00.00 khubd
54 root 15 0 0 0 0 S 0 0.0 0:00.65 pdflush
56 root 15 0 0 0 0 S 0 0.0 1:31.63 kswapd0
57 root 13 -10 0 0 0 S 0 0.0 0:00.00 aio/0
58 root 13 -10 0 0 0 S 0 0.0 0:00.00 aio/1
202 root 25 0 0 0 0 S 0 0.0 0:00.00 kseriod


its a night right now so it's running fast just for the night.

7.


[mysqld]
back_log = 50
max_connections = 500
key_buffer = 48M
myisam_sort_buffer_size = 64M
join_buffer_size = 1M
read_buffer_size = 1M
sort_buffer_size = 2M
table_cache = 1800
thread_cache_size = 384
wait_timeout = 35
connect_timeout = 10
tmp_table_size = 64M
max_heap_table_size = 64M
max_allowed_packet = 64M
max_connect_errors = 10
thread_concurrency = 2
concurrent_insert = 2
read_rnd_buffer_size = 524288
bulk_insert_buffer_size = 8M
query_cache_limit = 2M
query_cache_size = 24M
query_cache_type = 1
query_prealloc_size = 131072
query_alloc_block_size = 65536
default-storage-engine = MyISAM
[mysqld_safe]
open_files_limit = 8192
[mysqldump]
quick
max_allowed_packet = 16M
[myisamchk]
key_buffer = 64M
sort_buffer = 64M
read_buffer = 16M
write_buffer = 16M


8.

+---------------------------------+------------------------------------------+
| Variable_name | Value |
+---------------------------------+------------------------------------------+
| back_log | 50 |
| basedir | / |
| binlog_cache_size | 32768 |
| bulk_insert_buffer_size | 8388608 |
| character_set_client | latin1 |
| character_set_connection | latin1 |
| character_set_database | latin1 |
| character_set_results | latin1 |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
| collation_connection | latin1_swedish_ci |
| collation_database | latin1_swedish_ci |
| collation_server | latin1_swedish_ci |
| concurrent_insert | OFF |
| 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 |
| expire_logs_days | 0 |
| flush | OFF |
| flush_time | 0 |
| ft_boolean_syntax | + -><()~*:""&| |
| ft_max_word_len | 84 |
| ft_min_word_len | 4 |
| ft_query_expansion_limit | 20 |
| ft_stopword_file | (built-in) |
| group_concat_max_len | 1024 |
| have_archive | NO |
| have_bdb | NO |
| have_blackhole_engine | NO |
| have_compress | YES |
| have_crypt | YES |
| have_csv | NO |
| have_example_engine | NO |
| have_geometry | YES |
| have_innodb | YES |
| have_isam | NO |
| have_ndbcluster | NO |
| have_merge_engine | YES |
| have_openssl | NO |
| have_query_cache | YES |
| have_raid | NO |
| have_rtree_keys | YES |
| have_symlink | YES |
| init_connect | |
| init_file | |
| init_slave | |
| innodb_additional_mem_pool_size | 1048576 |
| innodb_autoextend_increment | 8 |
| innodb_buffer_pool_awe_mem_mb | 0 |
| innodb_buffer_pool_size | 8388608 |
| innodb_data_file_path | ibdata1:10M:autoextend |
| innodb_data_home_dir | |
| innodb_fast_shutdown | ON |
| 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_arch_dir | |
| innodb_log_archive | 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_table_locks | ON |
| innodb_thread_concurrency | 8 |
| interactive_timeout | 28800 |
| join_buffer_size | 1044480 |
| key_buffer_size | 50331648 |
| key_cache_age_threshold | 300 |
| key_cache_block_size | 1024 |
| key_cache_division_limit | 100 |
| language | /usr/share/mysql/english/ |
| large_files_support | ON |
| lc_time_names | en_US |
| license | GPL |
| local_infile | ON |
| locked_in_memory | OFF |
| log | OFF |
| log_bin | OFF |
| log_error | |
| log_slave_updates | OFF |
| log_slow_queries | OFF |
| log_update | OFF |
| log_warnings | 1 |
| long_query_time | 10 |
| low_priority_updates | OFF |
| lower_case_file_system | OFF |
| lower_case_table_names | 0 |
| max_allowed_packet | 67107840 |
| max_binlog_cache_size | 4294967295 |
| max_binlog_size | 1073741824 |
| max_connect_errors | 10 |
| max_connections | 500 |
| max_delayed_threads | 20 |
| max_error_count | 64 |
| max_heap_table_size | 67107840 |
| max_insert_delayed_threads | 20 |
| max_join_size | 4294967295 |
| max_length_for_sort_data | 1024 |
| max_prepared_stmt_count | 16382 |
| max_relay_log_size | 0 |
| max_seeks_for_key | 4294967295 |
| max_sort_length | 1024 |
| max_tmp_tables | 32 |
| max_user_connections | 0 |
| max_write_lock_count | 4294967295 |
| myisam_data_pointer_size | 4 |
| myisam_max_extra_sort_file_size | 2147483648 |
| myisam_max_sort_file_size | 2147483647 |
| myisam_recover_options | OFF |
| myisam_repair_threads | 1 |
| myisam_sort_buffer_size | 67108864 |
| myisam_stats_method | nulls_unequal |
| net_buffer_length | 16384 |
| net_read_timeout | 30 |
| net_retry_count | 10 |
| net_write_timeout | 60 |
| new | OFF |
| old_passwords | OFF |
| open_files_limit | 4110 |
| pid_file | /var/lib/mysql/server.httpshare.com.pid |
| port | 3306 |
| preload_buffer_size | 32768 |
| prepared_stmt_count | 0 |
| protocol_version | 10 |
| query_alloc_block_size | 65536 |
| query_cache_limit | 2097152 |
| query_cache_min_res_unit | 4096 |
| query_cache_size | 25165824 |
| query_cache_type | ON |
| query_cache_wlock_invalidate | OFF |
| query_prealloc_size | 131072 |
| range_alloc_block_size | 2048 |
| read_buffer_size | 1044480 |
| read_only | OFF |
| read_rnd_buffer_size | 520192 |
| relay_log_purge | ON |
| relay_log_space_limit | 0 |
| rpl_recovery_rank | 0 |
| secure_auth | OFF |
| server_id | 0 |
| skip_external_locking | ON |
| skip_networking | OFF |
| skip_show_database | OFF |
| slave_net_timeout | 3600 |
| slave_transaction_retries | 0 |
| slow_launch_time | 2 |
| socket | /var/lib/mysql/mysql.sock |
| sort_buffer_size | 2097144 |
| sql_mode | |
| sql_notes | OFF |
| sql_warnings | OFF |
| storage_engine | MyISAM |
| sync_binlog | 0 |
| sync_frm | ON |
| sync_replication | 0 |
| sync_replication_slave_id | 0 |
| sync_replication_timeout | 0 |
| system_time_zone | CEST |
| table_cache | 1800 |
| table_type | MyISAM |
| thread_cache_size | 384 |
| thread_stack | 126976 |
| time_format | %H:%i:%s |
| time_zone | SYSTEM |
| tmp_table_size | 67108864 |
| tmpdir | |
| transaction_alloc_block_size | 8192 |
| transaction_prealloc_size | 4096 |
| tx_isolation | REPEATABLE-READ |
| version | 4.1.21-standard |
| version_comment | MySQL Community Edition - Standard (GPL) |
| version_compile_machine | i686 |
| version_compile_os | pc-linux-gnu |
| wait_timeout | 35 |
+---------------------------------+------------------------------------------+
+----------------------------+------------+
| Variable_name | Value |
+----------------------------+------------+
| Aborted_clients | 562 |
| Aborted_connects | 5 |
| Binlog_cache_disk_use | 0 |
| Binlog_cache_use | 0 |
| Bytes_received | 660472943 |
| Bytes_sent | 2700889566 |
| Com_admin_commands | 0 |
| Com_alter_db | 0 |
| Com_alter_table | 0 |
| Com_analyze | 0 |
| Com_backup_table | 0 |
| Com_begin | 0 |
| Com_change_db | 269442 |
| Com_change_master | 0 |
| Com_check | 191 |
| Com_checksum | 0 |
| Com_commit | 0 |
| Com_create_db | 0 |
| Com_create_function | 0 |
| Com_create_index | 0 |
| Com_create_table | 4 |
| Com_dealloc_sql | 0 |
| Com_delete | 6482 |
| Com_delete_multi | 0 |
| Com_do | 0 |
| Com_drop_db | 0 |
| Com_drop_function | 0 |
| Com_drop_index | 0 |
| Com_drop_table | 4 |
| Com_drop_user | 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 | 16471 |
| Com_insert_select | 4 |
| Com_kill | 0 |
| Com_load | 0 |
| Com_load_master_data | 0 |
| Com_load_master_table | 0 |
| Com_lock_tables | 11 |
| Com_optimize | 191 |
| Com_preload_keys | 0 |
| Com_prepare_sql | 0 |
| Com_purge | 0 |
| Com_purge_before_date | 0 |
| Com_rename_table | 0 |
| Com_repair | 0 |
| Com_replace | 6290 |
| Com_replace_select | 0 |
| Com_reset | 0 |
| Com_restore_table | 0 |
| Com_revoke | 0 |
| Com_revoke_all | 0 |
| Com_rollback | 0 |
| Com_savepoint | 0 |
| Com_select | 1165245 |
| Com_set_option | 434 |
| Com_show_binlog_events | 0 |
| Com_show_binlogs | 0 |
| Com_show_charsets | 0 |
| Com_show_collations | 0 |
| Com_show_column_types | 0 |
| Com_show_create_db | 0 |
| Com_show_create_table | 422 |
| Com_show_databases | 81 |
| Com_show_errors | 0 |
| Com_show_fields | 642 |
| Com_show_grants | 0 |
| Com_show_innodb_status | 0 |
| Com_show_keys | 2 |
| Com_show_logs | 0 |
| Com_show_master_status | 0 |
| Com_show_ndb_status | 0 |
| Com_show_new_master | 0 |
| Com_show_open_tables | 0 |
| Com_show_privileges | 0 |
| Com_show_processlist | 0 |
| Com_show_slave_hosts | 0 |
| Com_show_slave_status | 0 |
| Com_show_status | 1 |
| Com_show_storage_engines | 0 |
| Com_show_tables | 531 |
| Com_show_variables | 15 |
| Com_show_warnings | 0 |
| Com_slave_start | 0 |
| Com_slave_stop | 0 |
| Com_stmt_close | 0 |
| Com_stmt_execute | 0 |
| Com_stmt_prepare | 0 |
| Com_stmt_reset | 0 |
| Com_stmt_send_long_data | 0 |
| Com_truncate | 4 |
| Com_unlock_tables | 12 |
| Com_update | 127672 |
| Com_update_multi | 4 |
| Connections | 263979 |
| Created_tmp_disk_tables | 39811 |
| Created_tmp_files | 1199 |
| Created_tmp_tables | 69339 |
| Delayed_errors | 0 |
| Delayed_insert_threads | 0 |
| Delayed_writes | 0 |
| Flush_commands | 1 |
| Handler_commit | 0 |
| Handler_delete | 21499 |
| Handler_discover | 0 |
| Handler_read_first | 42700 |
| Handler_read_key | 30158747 |
| Handler_read_next | 185029469 |
| Handler_read_prev | 13666184 |
| Handler_read_rnd | 519570 |
| Handler_read_rnd_next | 336991870 |
| Handler_rollback | 0 |
| Handler_update | 1525937 |
| Handler_write | 5590631 |
| Key_blocks_not_flushed | 0 |
| Key_blocks_unused | 1 |
| Key_blocks_used | 43612 |
| Key_read_requests | 107858625 |
| Key_reads | 622766 |
| Key_write_requests | 360776 |
| Key_writes | 134925 |
| Max_used_connections | 59 |
| Not_flushed_delayed_rows | 0 |
| Open_files | 1166 |
| Open_streams | 0 |
| Open_tables | 776 |
| Opened_tables | 1070 |
| Qcache_free_blocks | 322 |
| Qcache_free_memory | 18643464 |
| Qcache_hits | 892795 |
| Qcache_inserts | 1146877 |
| Qcache_lowmem_prunes | 74071 |
| Qcache_not_cached | 18032 |
| Qcache_queries_in_cache | 574 |
| Qcache_total_blocks | 1732 |
| Questions | 2750699 |
| Rpl_status | NULL |
| Select_full_join | 29509 |
| Select_full_range_join | 0 |
| Select_range | 185310 |
| Select_range_check | 0 |
| Select_scan | 105911 |
| Slave_open_temp_tables | 0 |
| Slave_retried_transactions | 0 |
| Slave_running | OFF |
| Slow_launch_threads | 27 |
| Slow_queries | 184 |
| Sort_merge_passes | 596 |
| Sort_range | 260170 |
| Sort_rows | 22357885 |
| Sort_scan | 72606 |
| Table_locks_immediate | 2162996 |
| Table_locks_waited | 6477 |
| Threads_cached | 58 |
| Threads_connected | 1 |
| Threads_created | 59 |
| Threads_running | 1 |
| Uptime | 198239 |
+----------------------------+------------+
Uptime: 198239 Threads: 1 Questions: 2750700 Slow queries: 184 Opens: 1070
Flush tables: 1 Open tables: 776 Queries per second avg: 13.876
mysqladmin Ver 8.41 Distrib 4.1.21, for pc-linux-gnu on i686
Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL license
Server version 4.1.21-standard
Protocol version 10
Connection Localhost via UNIX socket
UNIX socket /var/lib/mysql/mysql.sock
Uptime: 2 days 7 hours 3 min 59 sec
Threads: 1 Questions: 2750700 Slow queries: 184 Opens: 1070 Flush tables: 1
Open tables: 776 Queries per second avg: 13.876


8

Can't locate DBI.pm in @INC (@INC contains: /usr/lib/perl5/5.8.5/i386-linux-thread-multi /usr/lib/perl5/5.8.5 /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.4/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.3/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.2/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.1/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.0/i386-linux-thread-multi /usr/lib/perl5/site_perl/5.8.5 /usr/lib/perl5/site_perl/5.8.4 /usr/lib/perl5/site_perl/5.8.3 /usr/lib/perl5/site_perl/5.8.2 /usr/lib/perl5/site_perl/5.8.1 /usr/lib/perl5/site_perl/5.8.0 /usr/lib/perl5/site_perl /usr/lib/perl5/vendor_perl/5.8.5/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.4/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.3/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.2/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.1/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.0/i386-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.5 /usr/lib/perl5/vendor_perl/5.8.4 /usr/lib/perl5/vendor_perl/5.8.3 /usr/lib/perl5/vendor_perl/5.8.2 /usr/lib/perl5/vendor_perl/5.8.1 /usr/lib/perl5/vendor_perl/5.8.0 /usr/lib/perl5/vendor_perl .) at ./mysqlreport line 24.
BEGIN failed--compilation aborted at ./mysqlreport line 24.


9. only vb running on my server

10.

10. 40-130 users

cookie time out : 900

11.

http://www.httpshare.com/d.php

12.

KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 4
MinSpareServers 10
MaxSpareServers 15
StartServers 10
MaxClients 850
MaxRequestsPerChild 1000

13.

[root@server ~]# find / -size +2000000k
find: /proc/26117/task/26117/fd/4: No such file or directory


14.

Linux server.httpshare.com 2.6.9-55.0.6.ELsmp #1 SMP Tue Sep 4 21:36:00 EDT 2007
i686 i686 i386 GNU/Linux

core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
file size (blocks, -f) unlimited
pending signals (-i) 1024
max locked memory (kbytes, -l) 32
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
stack size (kbytes, -s) unlimited
cpu time (seconds, -t) unlimited
max user processes (-u) 150
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited




processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Xeon(R) CPU 3050 @ 2.13GHz
stepping : 2
cpu MHz : 2133.440
cache size : 2048 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc pni
monitor ds_cpl est tm2 xtpr
bogomips : 4269.36
processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Xeon(R) CPU 3050 @ 2.13GHz
stepping : 2
cpu MHz : 2133.440
cache size : 2048 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc pni
monitor ds_cpl est tm2 xtpr
bogomips : 4266.87

andrerus
Tue 18th Sep '07, 8:32pm
anyone ?

Steve Machol
Tue 18th Sep '07, 11:15pm
Please be patient. This is not an official service we provide and eva2000 is not available every day.

andrerus
Wed 19th Sep '07, 9:44am
No problem :)

thank you! :)

eva2000
Thu 20th Sep '07, 9:01am
Try the following in this exact order. You can ignore any of the suggestions that you have already done.

1. Upgrade MySQL server to 4.1.22
2. Upgrade PHP to 5.2.4 if you're on 5.x or PHP 4.4.7 if you're on PHP 4.x after upgrading MySQL (ensure you install as ISAPI and NOT CGI)
3. Edit /etc/my.cnf and place the following mysql server settings in /etc/my.cnf and restart mysql server afterwards


[mysqld]
safe-show-database
#old_passwords
back_log = 75
skip-innodb
max_connections = 500
key_buffer = 64M
myisam_sort_buffer_size = 64M
join_buffer_size = 1M
read_buffer_size = 1M
sort_buffer_size = 3M
table_cache = 2500
thread_cache_size = 256
wait_timeout = 35
connect_timeout = 10
tmp_table_size = 64M
max_heap_table_size = 64M
max_allowed_packet = 64M
max_connect_errors = 10
thread_concurrency = 4
read_rnd_buffer_size = 524288
bulk_insert_buffer_size = 8M
query_cache_limit = 4M
query_cache_size = 64M
query_cache_type = 1
query_prealloc_size = 131072
query_alloc_block_size = 65536
default-storage-engine = MyISAM

[mysqld_safe]
nice = -5
open_files_limit = 8192

[mysqldump]
quick
max_allowed_packet = 16M

[myisamchk]
key_buffer = 64M
sort_buffer = 64M
read_buffer = 16M
write_buffer = 16M

[mysqlhotcopy]
interactive-timeout


4. Remove Eaccelerator or APC Cache if they're installed and instead install Xcache v1.2.1 final release which seems to be a bit faster than APC Cache - http://www.vbulletin.com/forum/showthread.php?t=213267. Xcache site http://xcache.lighttpd.net/, documentation http://trac.lighttpd.net/trac/wiki/Docs and forums http://forum.lighttpd.net/forum/4

5. Upgrade to vB 3.0.17 http://www.vbulletin.com/forum/showthread.php?t=209720 if you're on vB 3.0.xx or upgrade to vB 3.5.8 http://www.vbulletin.com/forum/showthread.php?t=221903 if you're on vB 3.5.x. Upgrade to vB 3.6.8 http://www.vbulletin.com/forum/showthread.php?t=237919 if you're on vB 3.6.x

6. If you just upgraded to vB 3.5.x/3.6.x try to disable these 4 options:

Admin CP -> vBulletin Options -> Forums Home Page Options -> Display Logged in Users?

Admin CP -> vBulletin Options -> Forum Display Options (forumdisplay) -> Show Users Browsing Forums

Admin CP -> vBulletin Options -> Thread Display Options -> Show Users Browsing Thread

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7. Edit httpd.conf values to following and restart apache

KeepAlive: On
MaxKeepAliveRequests: 100
KeepAliveTimeout: 1
MinSpareServers: 10
MaxSpareServers: 15
StartServers: 10
MaxClients: 150
MaxRequestsPerChild: 1000

8. Ensure vB admincp gzip is disabled since you already have Apache with mod_gzip which does the same thing