Stado

Why does stado need to checkConnections() before every commit()

Asked by chenbaiping

In the function commit() of MultinodeExecutor class, before sending the NodeMessage MSG_TRAN_COMMIT, Stado calls the function checkConnections(). But it seems that stado had never used the return values of the checkConnections().

What is its purpose ? Can I remove it?

In checkConnection(), it sends a PING msg to each node , and let each node to execute a 'select 1' command. In some cases it makes the low performance.

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chenbaiping (4bjwb) said : 		#1

I read the code carefully and now I know why.
When some nodes have lost their connections, checkConnections() will throw an XDBServerException, then stado will roll back the commit on each node.