Collect Processlist info from P_S
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Escalation
General
Escalation
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AFFECTED CS IDs
CS0038557
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Naresh August 5, 2023 at 6:35 PM
Juan Arruti, But in MariaDB it's not implemented so we have to think about MariaDB perspective,
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Juan ArrutiPriority
MediumLabels
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Yes
Needs Doc
Yes
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Created August 4, 2023 at 10:44 PM
Updated October 9, 2024 at 8:38 AM
PMM collects information from the I_S.processlist table. Below you can find the related query:
https://github.com/percona/mysqld_exporter/blob/main/collector/info_schema_processlist.go#L39
Unfortuantely, this implementation iterates across active threads from within the thread manager while holding a global mutex, it has negative performance consequences, particularly on busy systems.
Starting with MySQL 5.7.39 and 8.0.22, an alternative implementation is available in the performance_schema.processlist table.
In order to prevent PMM from holding the mutex and affecting database performance, if the P_S is enabled on the system, the performance_schema.processlist should be queried instead.
https://dev.mysql.com/doc/refman/8.0/en/performance-schema-processlist-table.html