I have a puzzle.. Frequently, about, weekly? our data server gets into a state where select distinct(keyfield) from table hangs in the 'sending data' phase, or the 'sorting result' phase, the client is left waiting for the result, no rows are returned, no errors are in the sql server error log. I've had to write a monitor to kill these off as they show up. otherwise they accumulate, use all CPU and never die. I used to think the fix was to take the server offline and isamchk them, or run 'optimize table' from mysql> but today I've found out that that is NOT the problem.. I found this because after it happened, I took a file copy of the problem table, to table_new then did an isamchk on it -- no errors! So then I did the same query on the new copy select distinct(keyfield) form table_new instant success! select distinct(keyfield) form table still hangs consistently! On disk, cmp table.ISD table_new.ISD cmp table.ISM table_new.ISM shows they are bit for bit identical! So the server has itself is confused, and the way to fix it is to restart mysqld (although that does not always work), the problem might occur with the same query on another table, or not go away until the table is 'alterd' in some no-op type way... file descriptor use is heavy but below 1024 limit: ls /proc/NNN/fd | wc 491 This is version 3.22.32 - the binary FROM MYSQL.COM .. max_connections 100 key_buffer=300m max_allowed_packet=1m table_cache=300 sort_buffer=4m record_buffer=2m tmp_table_size=2m thread_stack=128k -Justin --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
