Adding Multiplex Servers with Interactive SQL

Follow these steps to add multiplex servers from Interactive SQL.

Check server status. The coordinator must be running in order to add secondary servers.
In Interactive SQL, run the CREATE MULTIPLEX SERVER command.
For example:
```
CREATE MULTIPLEX SERVER mpxnode_w2 DATABASE 'host1/mpx/mpxtest.db' HOST 'host1' PORT 2957 ROLE WRITER STATUS INCLUDED
```
For command reference details, see Multiplex Reference > SQL Statements > CREATE MULTIPLEX SERVER Statement.

This command creates the definition for a secondary writer server mpxnode_w2.
Follow steps 7 through 12 in Multiplex Creation > Converting Databases to Multiplex > Converting Databases to Multiplex with Interactive SQL.

The first time you start the multiplex after adding a secondary server, the coordinator may return an error similar to:

I. 12/11 12:50:08. Trying to start TCPIP link ...
I. 12/11 12:50:08. Multiplex environment incorrect for this server
I. 12/11 12:50:08. Please connect and run procedure sp_iqmpxvalidate for help

This error occurs because the secondary server has no temporary file in IQ_SYSTEM_TEMP. You must add a temporary dbfile to IQ_SYSTEM_TEMP on the newly added server. See Multiplex Server Administration > Multiplex Server Administration with Interactive SQL > Converting databases to multiplex with Interactive SQL, steps 11 and 12. After adding this file, run sp_iqmpxvalidate to make sure that no errors are reported on this server.