The system runs extremely slowly

When Blueworx Voice Response slows down, check the following:

Is the AIX operating environment set up correctly?
Blueworx Voice Response requires two AIX resources to run quickly: page space (for swapping software into and out of memory) and processes. The parameters that control how much page space the system can use and how many processes it can start might not be set correctly. Use the information provided in Analyzing the problem to determine how much page space is defined and the maximum number of processes the system can start.

The system should have a minimum of 100 MB of page space. Use the information given in Blueworx Voice Response for AIX: Installation to increase the amount of page space.

The optimum value for the maximum number of user processes parameter differs from system to system. Generally, you should set the maxuproc parameter to a number equal to 150, +1 for every telephone channel to which Blueworx Voice Response is connected and +3 for each 3270 session that is defined. For example, if your system has 24 telephone channels and 24 3270 sessions, maxuproc must be set to at least 246. When you have determined the minimum acceptable number, round it up to the nearest hundred. Then use the information provided in Blueworx Voice Response for AIX: Installation to reset the maxuproc parameter.

Is enough disk space available?
Blueworx Voice Response requires a minimum amount of free disk space to avoid performance problems. Ensure that your system has enough disk space in /home for your applications, and that you have enough space in /var (see “Ensuring you have enough space for the new software” in Blueworx Voice Response for AIX: Installation.)

Use the information provided in Analyzing the problem to find out whether your system has enough free disk space. If there is not enough, clean up the file systems and recover disk space. If you still do not have enough space available, you might need to get additional disk space on the system.

For more information on managing disk space, see Blueworx Voice Response for AIX: Managing and Monitoring the System.

Is there enough real memory (RAM) available?
Without adequate available memory, Blueworx Voice Response runs very slowly. The more RAM that is available, the more quickly the system responds. For example, a system with 48 channels and no 3270 sessions needs at least 128 MB of RAM. A system with 72 channels and the same number of 3270 sessions should have at least 256 MB of RAM for optimum performance.

To find out how much RAM is on your system, log on as root, type lsdev -C | grep mem, and press Enter. If you do not have enough RAM, you may have to add more.

Always ensure that the amount of page space that is defined exceeds the amount of RAM fitted in the Power System. Otherwise, you might not be able to access all the RAM.

Are there enough buffers?
Blueworx Voice Response uses buffers for voice segments and other state table components. It also uses them to pass data backwards and forwards between internal processes and servers. You need enough buffers to handle the permitted number of simultaneous calls. The number of buffers is affected by the number of state tables, prompts, and servers that are in use and by the number and type of voice segments (compressed and uncompressed). Symptoms that indicate insufficient buffers include the system running slowly, and the system not handling or answering calls correctly.

Use the information provided in Blueworx Voice Response for AIX: Configuring the System to redefine the number of buffers.

Are buffers released quickly enough?
Blueworx Voice Response releases buffers that are holding voice segments according to how long the segment has been in memory since it was last requested. If the parameter that controls this timeout is set too high, Blueworx Voice Response might not be able to release the buffers quickly enough.

Use the Configuration —> System Configuration —> Application Server Interface menus to find out the value of the Time in Cache parameter and reset it.

Is the DB2® buffer large enough?
If the DB2 indexes have grown too large to be held in the DB2 buffer, Blueworx Voice Response has to access the hard disk every time it needs to look up information in the database. This is far slower than accessing the buffer directly, and can cause long delays. This problem is most likely to occur on voice messaging systems or systems that have large numbers of Blueworx Voice Response objects.
As dtuser, type the following commands to increase the size of the DB2 buffer pool:
db2 connect to dtdbv230
db2 alter bufferpool ibmdefaultbp size n
where n is the new size of the buffer pool in 4 KB units. The default is 1000 (4 MB).

Try increasing the buffer to 32 MB (n=8000) at first, or to 128 MB (n=32000) if more space is needed.

Is the database manager timing out too quickly?
When the process that retrieves information from the database times out too quickly, other processes that require the information (such as voice applications) cannot complete their tasks. However, they keep trying to access the database and failing, thus using system resources and slowing down the system.

You should set the database timeout parameter, DBIM Time Out, to a value of 240 seconds. Use the information provided in Blueworx Voice Response for AIX: Configuring the System to check the value of this performance parameter, and reset it if necessary.

Is there a deadlock between Blueworx Voice Response and DB2?
The following are common causes of deadlock problems:
  • Runstats are not being run regularly on the database server. If db2_runstats script is not run periodically, the database queries become slower, and eventually lead to deadlocks. The script should be set to run when 25% of the data in the database has been changed. It is particularly important to run it when a high number of subscribers are added to the database, or when a significant change is made.
  • Ensure that DB2_RR_TO_RS is set to ON. To check this, enter the following commands:
    1. Login as root
    2. su - dtdbbvr
    3. db2set
    If the value is not set to ON, enter DB2_RR_TO_RS=ON to set it. Then log in as dtuser and enter the following commands to get the value to take effect:
    1. db2stop force
    2. db2start
Are you using SSI?
If you are using single system image:
  • Use the monitoring tools to ensure that the network is not overloaded. See the section about monitoring the performance of a single system image in Blueworx Voice Response for AIX: Configuring the System.
  • Use the standard AIX monitoring tools to ensure that the server (the database server or the voice server) is not overloaded.
  • Use the DTmon -f command to check performance statistics. For information about the DTmon command, see Blueworx Voice Response for AIX: Managing and Monitoring the System.
Is the var file system filling up
By default, when the JVM experiences a problem, a javadump file is created in the /var/dirTalk/DTBE/native/aix directory. To stop the var file system filling, it may be necessary to configure the system so that the javadump files are generated in a different location. To do this, export the following environment variable:
IBM_JAVACOREDIR=path to javadump
where path to javadump is the new location.

For a Blueworx Voice Response installation, this variable should be set in $VAE/sw/environ/.vaeprofile.user