ERROR 1777 (HY000): Partition memsqldb:0 has no master instance

Question

I am using community edition of memsql. I got this error while i was running a query today. So i just restarted my cluster and got this error solved.

memsql-ops cluster-restart

But what happened and what should i do in future to avoid this error ?

NOTE

I donot want to buy the Enterprise edition.

Question

Is this problem of Availability ?

Answer 1

I got this error when experimenting with performance.

VM had 24 CPUs and 25 nodes: 1 Master Agg, 24 Leaf nodes Reduced VM to 4 CPUs and restarted cluster.

All the leaves did not recover. All except 4 recovered in < 5 minutes. 20 minutes later, 4 leaf nodes still were not connected.

From MySQL/MemSQL prompt:

use db;
show partitions;

I notice some partitions with ordinal from 0-71 for me have null instead Host, Port, Role defined for a given partition.

In memsql ops UI http://server:9000 > Settings > Config > Manual Cluster Control I checked "ENABLE MANUAL CONTROL" while I tried to run various commands with no real benefit.

Then 15 minutes later, I unchecked the box, Memsql-ops tried attaching all the leaf nodes again and was finally successful.

Perhaps a cluster restart would have done the same thing.