Documentation Home
MySQL 5.6 Reference Manual
Related Documentation Download this Manual
PDF (US Ltr) - 29.0Mb
PDF (A4) - 29.0Mb
PDF (RPM) - 28.0Mb
HTML Download (TGZ) - 7.0Mb
HTML Download (Zip) - 7.1Mb
HTML Download (RPM) - 6.1Mb
Man Pages (TGZ) - 180.5Kb
Man Pages (Zip) - 290.6Kb
Info (Gzip) - 2.8Mb
Info (Zip) - 2.8Mb
Excerpts from this Manual

18.5.14.10 The ndbinfo disk_write_speed_aggregate Table

The disk_write_speed_aggregate table provides aggregated information about the speed of disk writes during LCP, backup, and restore operations.

The disk_write_speed_aggregate table in NDB 7.4.3 and later contains the following columns:

  • node_id

    Node ID of this node

  • thr_no

    Thread ID of this LDM thread

  • backup_lcp_speed_last_sec

    Number of bytes written to disk by backup and LCP processes in the last second

  • redo_speed_last_sec

    Number of bytes written to REDO log in the last second

  • backup_lcp_speed_last_10sec

    Number of bytes written to disk by backup and LCP processes per second, averaged over the last 10 seconds

  • redo_speed_last_10sec

    Number of bytes written to REDO log per second, averaged over the last 10 seconds

  • std_dev_backup_lcp_speed_last_10sec

    Standard deviation in number of bytes written to disk by backup and LCP processes per second, averaged over the last 10 seconds

  • std_dev_redo_speed_last_10sec

    Standard deviation in number of bytes written to REDO log per second, averaged over the last 10 seconds

  • backup_lcp_speed_last_60sec

    Number of bytes written to disk by backup and LCP processes per second, averaged over the last 60 seconds

  • redo_speed_last_60sec

    Number of bytes written to REDO log per second, averaged over the last 10 seconds

  • std_dev_backup_lcp_speed_last_60sec

    Standard deviation in number of bytes written to disk by backup and LCP processes per second, averaged over the last 60 seconds

  • std_dev_redo_speed_last_60sec

    Standard deviation in number of bytes written to REDO log per second, averaged over the last 60 seconds

  • slowdowns_due_to_io_lag

    Number of seconds since last node start that disk writes were slowed due to REDO log I/O lag

  • slowdowns_due_to_high_cpu

    Number of seconds since last node start that disk writes were slowed due to high CPU usage

  • disk_write_speed_set_to_min

    Number of seconds since last node start that disk write speed was set to minimum

  • current_target_disk_write_speed

    Actual speed of disk writes per LDM thread (aggregated)

Notes

Prior to NDB 7.4.3, the standard deviation used in obtaining the values shown in the std_dev_backup_lcp_speed_last_10sec, std_dev_redo_speed_last_10sec, std_dev_backup_lcp_speed_last_60sec, and std_dev_redo_speed_last_60sec columns of this table was not calculated correctly. (Bug #74317, Bug #19795072)

Prior to NDB 7.4.3, some columns of this table showed values in kilobytes or other multiples of bytes. (In NDB 7.4.3 and later, all such columns display values in bytes, as shown previously.) (Bug #74317, Bug #19795072) In NDB 7.4.2 and earlier, this table contained the following columns:

  • node_id

    Node ID of this node

  • thr_no

    Thread ID of this LDM thread

  • backup_lcp_speed_last_sec

    Number of kilobytes written to disk by backup and LCP processes in the last second

  • redo_speed_last_sec

    Number of kilobytes written to REDO log in the last second

  • backup_lcp_speed_last_10sec

    Number of kilobytes written to disk by backup and LCP processes per second, averaged over the last 10 seconds

  • redo_speed_last_10sec

    Number of kilobytes written to REDO log per second, averaged over the last 10 seconds

  • std_dev_backup_lcp_speed_last_10sec

    Standard deviation in number of kilobytes written to disk by backup and LCP processes per second, averaged over the last 10 seconds

  • std_dev_redo_speed_last_10sec

    Standard deviation in number of kilobytes written to REDO log per second, averaged over the last 10 seconds

  • backup_lcp_speed_last_60sec

    Number of kilobytes written to disk by backup and LCP processes per second, averaged over the last 60 seconds

  • redo_speed_last_60sec

    Number of kilobytes written to REDO log per second, averaged over the last 10 seconds

  • std_dev_backup_lcp_speed_last_60sec

    Standard deviation in number of kilobytes written to disk by backup and LCP processes per second, averaged over the last 60 seconds

  • std_dev_redo_speed_last_60sec

    Standard deviation in number of kilobytes written to REDO log per second, averaged over the last 60 seconds

  • slowdowns_due_to_io_lag

    Number of seconds since last node start that disk writes were slowed due to REDO log I/O lag

  • slowdowns_due_to_high_cpu

    Number of seconds since last node start that disk writes were slowed due to high CPU usage

  • disk_write_speed_set_to_min

    Number of seconds since last node start that disk write speed was set to minimum

  • current_target_disk_write_speed

    Actual speed of disk writes per LDM thread (aggregated)

The disk_write_speed_aggregate table was added in NDB 7.4.1.