vb.org Archive - View Single Post - Session Table / race condition is always causing vBulletin to lockup/freeze

evannn · #1 06-18-2009, 03:46 AM

Our vB server is experiencing some hiccups recently. We are using already using the latest 3.8.3

The server will freeze and lockup when it happened. To resolve it, mysql daemon has to be killed and restarted.

There seems to be some kind of race conditions which fights to update the SESSION table and this causes the mysql daemon to lock up. (On average, we have close to 1,000 users logged on concurrently)

The freeze/lockups are getting too frequent and it is always the same condition.

We are now using mysql 5.1.35.

While we aren't 100% sure what is causing this lock up, I thought its better to share this information here; hopefully there is some light.

Some background on our infrastructure: We have a dedicated Web Server and a dedicated Database server.

X vBulletin 3.8.12 by vBS Debug Information
Page Generation 0.03342 seconds Memory Usage 1,766KB Queries Executed 11 (?)
More Information
Template Usage: (1)SHOWTHREAD_SHOWPOST (1)ad_footer_end (1)ad_footer_start (1)ad_header_end (1)ad_header_logo (1)ad_navbar_below (1)footer (1)gobutton (1)header (1)headinclude (6)option (1)post_thanks_box (1)post_thanks_button (1)post_thanks_javascript (1)post_thanks_navbar_search (1)post_thanks_postbit_info (1)postbit (1)postbit_onlinestatus (1)postbit_wrapper (1)spacer_close (1)spacer_open Phrase Groups Available: global postbit reputationlevel showthread	Included Files: ./showpost.php ./global.php ./includes/init.php ./includes/class_core.php ./includes/config.php ./includes/functions.php ./includes/class_hook.php ./includes/modsystem_functions.php ./includes/functions_bigthree.php ./includes/class_postbit.php ./includes/class_bbcode.php ./includes/functions_reputation.php ./includes/functions_post_thanks.php Hooks Called: init_startup init_startup_session_setup_start init_startup_session_setup_complete cache_permissions fetch_postinfo_query fetch_postinfo fetch_threadinfo_query fetch_threadinfo fetch_foruminfo style_fetch cache_templates global_start parse_templates global_setup_complete showpost_start bbcode_fetch_tags bbcode_create postbit_factory showpost_post postbit_display_start post_thanks_function_post_thanks_off_start post_thanks_function_post_thanks_off_end post_thanks_function_fetch_thanks_start post_thanks_function_fetch_thanks_end post_thanks_function_thanked_already_start post_thanks_function_thanked_already_end fetch_musername postbit_imicons bbcode_parse_start bbcode_parse_complete_precache bbcode_parse_complete postbit_display_complete post_thanks_function_can_thank_this_post_start showpost_complete
Messages: