2.185 DUMP 104004

Code

104004

Symbol

EnableAdaptiveSpinning

Kernel Block

THRMAN

Description.  DUMP 104004 enable, where enable is 1 or 0. Using 0 disables adaptive spinning; that is, it causes spinning without checking use of CPU resources, which is the same static spinning used by NDB in the past.

Enabling adaptive spinning means that settings of spin timers are checked only to see whether the spin timer is set to 0. Setting the spin timer to 0 (using SchedulerSpinTimer or the spintime component of ThreadConfig) means that spinning is deactivated entirely.

Adaptive spinning begins with no spinning and checks for spinning after 60 microseconds, stepping up or down, or shutting off the spin timer, for each block thread independently of any others.

In most cases, rather than to enable or disable adaptive spinning directly using this DUMP command, it is sufficient (and more convenient) to do so by setting the SpinMethod data node configuration parameter in the config.ini file.

Additional Information.  Added in NDB 8.0.20.