There are four communication methods between the database server and client provided by ALTIBASE HDB. Among these, this document describes the ALTIBASE HDB and OS configurations required for IPC communication.

For a description of each communication method, please refer to the "12. Server/Client Communication" section from the Administrator's manual.

Manual Page: 


All the ALTIBASE HDB versions


ALTIBASE HDB Server Configurations

By default, the Altibase server does not allow IPC access. So, in order to connect to the Altibase server with the IPC connection type, the Altibase server properties must be changed.

Related properties cannot be changed while the Altibase server is running. Therefore, the Altibase server needs to be restarted in order to change the property value.


This property is required when running an Altibase server on a Windows system.

Unix and Linux use the 'Unix domain socket' in the form of a file for IPC connection, but Windows does not support this, so a TCP port is required for IPC connection.

In Windows, IPC connections communicate using shared memory, semaphores, and mutexes over TCP connections.


This property configures the maximum number of IPC sessions that can be connected to the Altibase server. The default value is 0, and the Altibase server is configured not to allow IPC access.


IPC communicates with the ALTIBASE HDB server with the 'Unix domain socket' in the form of a file.
If the 'Unix domain socket' file does not exist or the path is set incorrectly, the connection will fail.
Starting from ALTIBASE HDB server version, the user can change this path arbitrarily with the IPC_FILEPATH property, and the setting value can be checked in the performance view.

ALTIBASE HDB server versions prior to cannot change the default path and do not provide a separate verification method.

How to change properties

  1. Changing altibase.properties file
    Change the required values among the properties described above in the $ALTIBASE_HOME/conf/altibase.properties file and save the altibase.properties file.

    $ cd $ALTIBASE_HOME/conf
    $ vi altibase.properties
  2. Restarting ALTIBASE HDB
    Restart the Altibase server to reflect the changed property values to the Altibase server.

    $ server restart
  3. Checking properties
    Check that the values have been properly reflected.

    $ is
  4. Testing IPC connection
    Try to test the iSQL connection with the IPC type.

    $ export ISQL_CONNECTION=IPC                                                # Change the environment variable that sets the iSQL connection type.
    $ is
         Altibase Client Query utility.
         Release Version
         Copyright 2000, ALTIBASE Corporation or its subsidiaries.
         All Rights Reserved.
    ISQL_CONNECTION = IPC, SERVER = localhost, PORT_NO = 20300                  # IPC connection is successful only when ISQL_CONNECTION = IPC appears and the iSQL prompt appears.

OS Configurations

Shared memory and semaphore resources are used for IPC communication. Therefore, to use the IPC type, the related kernel parameters must be set.

Please refer to the documents below depending on the OS. There is no recommended configurations for AIX and Windows.

How the application communicates

Please refer to each manual for how to set the connection properties in the application program.