MySQL Bugs: #75220: Need to add option of 10 or 20 LDM threads and LQH log parts as config options

Bug #75220	Need to add option of 10 or 20 LDM threads and LQH log parts as config options
Submitted:	15 Dec 2014 17:50	Modified:	12 Jan 2015 12:48
Reporter:	Mikael Ronström	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Cluster: Cluster (NDB) storage engine	Severity:	S3 (Non-critical)
Version:	7.4.3	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
New machines with 7/14 cores makes it perfect use of the HW to have 10/20 LDM threads
for a balanced use of the HW resources.

How to repeat:
New config options to better support new HW

Suggested fix:
Add option to use 10 and 20 LDM threads and 10 and 20 log parts.
This also means that we update the usage of the MaxNoOfExecutionThreads
parameter since we can now use 10 and 20 LDM threads.

Upgrade note:
-------------
This requires caution when previously using MaxNoOfExecutionThreads between 20 and 23
and between 40 and 47 since we will here change the number of LDM threads. So if one
has previously used those configs, one need to change to use ThreadConfig instead
with the parameters previously used in mapping table.

Thank you for your bug report. This issue has already been fixed in the latest released version of that product, which you can download at

  http://www.mysql.com/downloads/

  Documented feature change in the NDB 7.4.3 changelog as follows:

    The matrix of values used for thread configuration when applying
    the setting of the MaxNoOfExecutionThreads configuration
    parameter has been improved to align with support for greater
    numbers of LDM threads. See Multi-Threading Configuration 
    Parameters (ndbmtd)", for more information about the changes.

  Updated the documentation for this parameter in the MySQL Cluster 7.4 documentation (MySQL 5.6 Manual).

  Closed.