Appendix: Running Multiple Instances of s-Server

You may install multiple instances of s-Server on a single host machine, in order for multiple developers to have their instances of s-Server on a multi-tenant deployment. You may also install multiple instances for testing, as well as for validation of federated/distributed deployment of Guavus SQLstream suite of products in a multinode cluster.

In order to run multiple instances of s-Server on the same system, you need to change the way you install a second instance of s-Server.

When you run the installer as root or with sudo privileges, the installer does several things that interfere with running a second instance with the same settings:

  • The installer creates a user with the default username of “sqlstream” and installs s-Server and s-Server clienttools as this user.
  • The installer installs s-Server as a linux service, s-serverd. The linux service starts up s-Server as the “sqlstream” user.
  • The installer uses the default installation directory /opt/sqlstream/ and default tracelog directory /var/log/sqlstream.

Only one instance of SQLstream s-Server can be set up to start/stop as a linux service. As a result, if you try to install a second instance with root privileges, the installer will overwrite earlier the installation of the linux service unless the installer is instructed not to install as a service.

So, to install a second instance using a super-user, you need to make changes in the steps below. You can also run this installer form the command line and pass in these properties. See Appendix: Command-line Installation for more details.

The Installation Directories page. Here, you need to change the installation directories. For example, you might change these to the following:

The Server Port Number page. By default, port is set to* 5570. You need to change it to something like 5670. Note: Make sure the new port is not in use.

The Service/Daemon page. Here, you need to deselect the Create the s-serverd Service option:

The Server User page. Here, you need to change the name of the user to be created by the installer, to something like sqlstream2:
The webAgent Service/Daemon page appears. Here, you need to deselect the Create the webAgentd Service option. In order to run webAgent with a second instance of s-Server, you will need to change its default port. See the topic webAgent in the SQLstream Integration Guide for more details.
The Create Dashboard Service page. Here, you need to deselect the Create the s-dashboardd Service option. In order to run s-Dashboard with a second instance of s-Server, you will need to change its default port. See the The s-Dashboard Guide for more details.
Once you install s-Server, you will need to manually start it. To do so:

  • Navigate to the second instance’s installation directory, such as /opt/sqlstream2/.
  • Navigate to s-Server/bin
  • Enter su , such as *su sqlstream2
  • Enter ./s-Server

To start this instance in the background, you will need to use a Linux command such as nohup. This command lets the instance continue to run in the background after the terminal is closed. See http://en.wikipedia.org/wiki/Nohup for more details.

Installing a Second Instance as a User Without Root Privileges

Installing as a user without root privileges avoids these problems. First, when the installer is run without superuser privileges, it cannot be installed as a linux service. When you install as a regular user, the default location for trace logs is set relative to “installation directory” rather than

/var/log/sqlstream.

Having said all that, the problem with installing as a regular user is that you will need to create that user on your system first. Since installing with root privileges creates a new user, it may be advantageous to take the steps described above.

When you install an instance as a regular user, you will need to start it in the foreground through a terminal. To start this instance in the background, you will need to use a Linux command such as nohup. This command lets the instance continue to run in the background after the terminal is closed. See http://en.wikipedia.org/wiki/Nohup for more details.

Parameters for Separate Instance

For all instances, you need to make sure the following definitions are unique:

  • First, each instance needs to have a unique installation directory.
  • Second, each new instance needs a unique port number. From the command line, you can change this number by changing the property “–serverPort ”. The s-Server, when started, uses that portNumber to accept JDBC connections.
  • Third, each instance needs to have a unique trace log directory.

See the topic Configuring SQLstream in the SQLstream Adminstrator Guide for more information.