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High SEMAPHORES from the time upgraded to 5.6

infdude666infdude666 ContributorCurrent User Role Beginner
Hi recently upgraded 5.5 to 5.6 and have noticed High SEMAPHORES round, waits, os waits.

Im unsure of why this is happening.


Please help

Comments

  • niljoshiniljoshi MySQL Sage Inactive User Role Beginner
    Hi,

    Can you provide some more information? like
    1. steps you have taken while upgrade your server from 5.5 to 5.6?
    2. Error log
    3. Give exact version of 5.5 and 5.6 (i.e 5.5.x to 5.6.x)
  • infdude666infdude666 Contributor Current User Role Beginner
    Also im seeing frequent stalls with queries taking more time than milliseconds, even commit's.

    Steps.
    Shutdown mysql;
    remove old version 5.5.29 via yum remove
    install new version 5.6.19 via yum install
    run mysql_upgrade
    change TEMPORAL Columns for Datatime with ALTER FORCE.


    I have RAID 10 with BBU, 2 CPU with 16cores, 32(virtual), 32 GB RAM

    my.cnf
    innodb_buffer_pool_instances=2
    innodb_buffer_pool_size=22G
    innodb_flush_log_at_trx_commit=2
    innodb_flush_method=O_DIRECT
    innodb_io_capacity=800
    innodb_log_file_size=1G
    innodb_log_files_in_group=2
    innodb_purge_threads=1
    innodb_read_io_threads=12
    innodb_write_io_threads=12
    innodb_thread_concurrency=0
    table_open_cache=2000
    table_definition_cache=4096
    query_cache_limit=64M
    query_cache_size=128M
    query_cache_type=1
    query_cache_strip_comments=1
    relay_log_info_repository=TABLE
    relay_log_recovery=ON
    master_info_repository=TABLE
    thread_stack = 256K


    The list was big and couldnt paste or attach:

    SHOW ENGINE MUTEX:
    http://pastebin.com/F8XfyL7r
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