Object cache: high mysql cpu usage

  • Hi,

    Since many days (I don’t know when exactly), there is a problem with object cache setting.

    When I enable object cache (with disk or memcached), mysql processes CPU usage explode, all cores are 100% usage.

    Formerly, it works fine but today, I cannot enable object cache anymore because the website become unusable.

    Have you got an idea?

    Configuration:
    – WordPress 5.0.2
    – PHP 7.3.0
    – MySQL 15.1 Distrib 10.3.11-MariaDB
    – Nginx 1.15.7

    Thanks.

Viewing 3 replies - 1 through 3 (of 3 total)
  • Plugin Contributor Marko Vasiljevic

    (@vmarko)

    Hello @dreamon11,

    Can you please check and share which queries are causing this?

    Thread Starter DreamOn11

    (@dreamon11)

    Hello @vmarko,

    Thanks for help.

    No much info about it: :/

    MariaDB [(none)]> show processlist;
+--------+-----------------+-----------+----------------------------+---------+------+----------------+-------------------------------------------------------------------------+----------+
| Id     | User            | Host      | db                         | Command | Time | State          | Info                                                                    | Progress |
+--------+-----------------+-----------+----------------------------+---------+------+----------------+-------------------------------------------------------------------------+----------+
| 237015 | xxx | localhost | xxx_production | Sleep   |   12 |                | NULL                                                                    |    0.000 |
| 237024 | xxx | localhost | xxx_production | Sleep   |    6 |                | NULL                                                                    |    0.000 |
| 237030 | xxx | localhost | xxx_production | Sleep   |   37 |                | NULL                                                                    |    0.000 |
| 237039 | xxx | localhost | xxx_production | Sleep   |    1 |                | NULL                                                                    |    0.000 |
| 237059 | xxx | localhost | xxx_production | Sleep   |   37 |                | NULL                                                                    |    0.000 |
| 237070 | xxx | localhost | xxx_production | Sleep   |   32 |                | NULL                                                                    |    0.000 |
| 237076 | xxx | localhost | xxx_production | Sleep   |   24 |                | NULL                                                                    |    0.000 |
| 237079 | xxx | localhost | xxx_production | Sleep   |   22 |                | NULL                                                                    |    0.000 |
| 237083 | xxx | localhost | xxx_production | Sleep   |   20 |                | NULL                                                                    |    0.000 |
| 237102 | xxx | localhost | xxx_production | Sleep   |   12 |                | NULL                                                                    |    0.000 |
| 237105 | xxx | localhost | xxx_production | Sleep   |    6 |                | NULL                                                                    |    0.000 |
| 237109 | xxx | localhost | xxx_production | Sleep   |    8 |                | NULL                                                                    |    0.000 |
| 237111 | xxx | localhost | xxx_production | Sleep   |    5 |                | NULL                                                                    |    0.000 |
| 237115 | xxx | localhost | xxx_production | Query   |    1 | Writing to net | SELECT option_name, option_value FROM wp_options WHERE autoload = 'yes' |    0.000 |
| 237116 | xxx | localhost | NULL                       | Query   |    0 | Init           | show processlist                                                        |    0.000 |
+--------+-----------------+-----------+----------------------------+---------+------+----------------+-------------------------------------------------------------------------+----------+
    Thread Starter DreamOn11

    (@dreamon11)

    Also, many of these errors with memcached:

    Dec 20 23:28:27 xxx memcached[17894]: Failed to write, and not due to blocking: Broken pipe

Viewing 3 replies - 1 through 3 (of 3 total)
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