Re: We use ndbd at data node(single thread mode), but found 34 threads of ndbd

[Mikael Ronström]

This is perfectly normal.
NDB has a large set of threads handling interaction with the
file system. In addition we have threads to handle TCP connection
setup, watchdog handling and some more stuff possibly. So it is
normal with these extra 33 threads, most of them are always idle
and waiting to be waken up to handle a file system interaction.
We handle file system interaction in separate threads since they
are blocking and the single execution thread should never block
other than when no work to do.

These extra threads exists in both ndbd and in ndbmtd.