Note Check the solidDB Release Notes for any limitations that are associated with using a grid in the current release.
The statement ALTER GRID .. ADD NODE adds a new node to a solidDB grid as a synchronously replicated transaction that is started and coordinated by the grid leader, see Adding a node to a grid.
The node to be added must be started in ‘grid’ mode by using the -x gridnode command line argument, see solidDB (solid) command line syntax.
Note The node must not have a database or transaction log files.
In grid mode, the node only accepts a grid start request from the grid leader.
When the ALTER GRID .. ADD NODE statement is executed, the following steps are performed:
1 The grid leader connects the new grid node.
2 The grid leader checks the validity of the new grid node:
▪ The new grid node must not contain any data.
▪ The new grid node must have a solid.ini file where Grid.GridEnabled is set to Yes.
Note If the node already has data, or does not have the required parameter in the solid.ini file, the ADD NODE statement fails.
3 The grid leader requests that the new grid node replicates common data (schema, configuration, and other necessary metadata) from the grid leader.
4 The new grid node replicates the required data and starts all the routines that a grid node performs (for example, heartbeat messaging and subscription monitor).
5 The grid leader adds the new grid node to the grid configuration with the membership state set to MEMBER_BEING_ADDED.
6 The grid leader prepares the transaction, writes changes to the transaction log, and waits for acknowledgments that the transaction is prepared on other nodes (including the new grid node).
7 When a majority of grid nodes have prepared the transaction, the grid leader commits the transaction, and writes the commit to the transaction log.
8 All grid nodes commit the transaction and the new grid node state becomes MEMBER_ONLINE.
Note If the transaction execution fails, the transaction is rolled back and the transitory grid node state NOT_MEMBER is written to the message log.
After the node is added, the Grid Availability Manager (GAM) balances the workload of the grid, see New or reconnected node.