Advanced Options

Advanced options for Replicator Server include:

• Running Replicator Servers with server numbers greater than ten
• Scheduling servers using server parameters and database events
• Using commands and database events to affect server behavior from sources other than Visual DBA and the Replicator Manager

How You Assign Server Numbers Greater Than Ten

The Ingres Replicator setup script and the repcat utility support only server numbers 1 through 10. If you want to run a Replicator Server with a number greater than 10, you need to follow this process:

1. Assign the desired server number (N) in the Server field:

   In Visual DBA, use the Define Replicator Databases dialog.

   In Replicator Manager, use the CDDS Databases and Servers window.

   A row is added to the dd_servers catalog if N does not already exist.

2. Using the SQL Terminal Monitor, connect as the DBA of each replicated database with Full Peer or Protected Read-only targets and issue the following statements (replacing N with your server number):

   CREATE DBEVENT dd_set_serverN;

   CREATE DBEVENT dd_serverN;

   CREATE DBEVENT dd_go_serverN;

   CREATE DBEVENT dd_stop_serverN;

3. Create the server work directory from the command line. For example:

   Windows:

   md %II_SYSTEM%\ingres\rep\servers\serverN

   UNIX:

   mkdir $II_SYSTEM/ingres/rep/servers/serverN

   VMS:

   create /dir II_SYSTEM:[ingres.rep.servers.serverN]

Scheduling Servers

You can control when Ingres Replicator propagates changes to the target databases. If it is not critical to have the CDDS synchronized, you can turn on the servers at slow or no usage times. The main benefit of this strategy is that it conserves processing capacity at critical times; Ingres Replicator consumes resources.

You control replication timing through the servers. If the Replicator Server for a given CDDS is started and active, it is continually propagating changes to the target databases. If the Replicator Server is stopped or started but quiet, changes to the CDDS accumulate in the distribution queue until the Replicator Server is started or activated.

You can use the following methods to schedule Ingres Replicator by starting the replication cycle:

• At specific times using the -SGL flag
• At specific times using the -QIT flag and raising an event from an application
• At given intervals using the -QIT and -EVT flags

Note: To stop a server to perform maintenance on your system, see the online help topic Status Page [Performance Monitor window, Replication branch] for details. You can also stop servers in a terminal monitor or through your own customized shut down script by issuing the correct event to the server. For more information, see Database Events.

-SGL Flag—Run Replication Once

The -SGL flag configures the server to process its replication queues once before shutting down. You can schedule the replication with your operating system's job scheduling system—cron under UNIX, at on Windows, submit on VMS.

Place the -SGL flag in the server's runrepl.opt file.

-QIT Flag—Run Server in Quiet Mode

The -QIT flag starts the Replicator Server in quiet mode.

You can schedule Replicator Server activity with database events by using the -QIT flag setting, and use an Ingres application or script to raise a dd_go_server[n] database event at specific times, where n is the number of the Replicator Server you want to start.

-EVTn Flag—Use Event Timeout

You can use the event timeout flag, -EVTn, to affect server activity. The way the -EVTn flag affects server scheduling depends on several factors. The most common scenarios for using the -EVTn flag to schedule servers are:

• Replicator Server with the -NQT flag set

  The -EVTn flag controls the duration of the replication cycle in an idle database. On a relatively active database, -EVTn has little effect.

• Replicator Server with the -QIT flag set

  The -EVTn flag specifies that the Replicator Server reads the distribution queue only every n seconds.

Note: This configuration can cause significant backlogs because the Replicator Server does not take into account database activity or how large the backup is.

rpserver Command—Start a Replicator Server

The rpserver command starts an individual Replicator Server from the operating system prompt. The command reads in parameters from the configuration file, which must be present in the corresponding server directory.

This command has the following format:

rpserver n

• n

  Is the number of the server to be started.

Database Events

You can affect a server by using database events. Database events override the flag settings in the configuration file. An Ingres application must connect to the server's database to issue the event. You can affect a server in any mode: stopped, started and active, or started and quiet.

You can send events from the following sources:

• Visual DBA, Visual Performance Monitor, or SQL Scratchpad window

  For more information, see the online help topic Raising Events at the Server Level.

• Replication Monitor's Send Database Event Window.
• Terminal Monitor
• Ingres 4GL, embedded SQL, or OpenAPI application

The database events you can use to affect server behavior are:

• dd_stop_server[n]

  Stops the server, where n is the number of the server. If n is not specified, all started servers on that database are requested to shut down.

  For example:

  dd_stop_server7

  Note: Servers shut down only after they finish current processing activities.

• dd_go_server[n]

  Directs a quiet server to process pending replication transactions, where n is the number of the server. If n is not specified, all started servers on that database processes pending transactions.

  For example:

  dd_go_server7

  You can use the dd_go_server[n] event to schedule replication at specific times with a quiet server. For more information, see Scheduling Servers.

• dd_ping

  Sends a ping event to all servers.

  For more information, see Ping Servers.

• dd_set_server[n] '-flag'

  Overrides the server parameters set in the configuration file, where n is the number of the server and flag is a server parameter that can be set dynamically. For more information about server flags, see Server Parameters.

  For example:

  dd_set_server7 '-NQT'

  If n is not specified, all started servers connected to that database are altered.