8.4.17 The QMGR Block

This is the logical cluster management block, and handles node membership in the cluster using a heartbeat mechanism. QMGR is responsible for polling the data nodes when a data node failure occurs and determining that the node has actually failed and should be dropped from the cluster. This block contains the following files, found in storage/ndb/src/kernel/blocks/qmgr:

This block also assists in the early phases of data node startup.

The QMGR block is implemented by the Qmgr class, whose definition is found in the file storage/ndb/src/kernel/blocks/qmgr/Qmgr.hpp.