In many systems, you will need to consider the effect of server outages. Server outages occur when a server is unable to perform its function because it is explicitly shut down or because a key network link is down. When the server is down, the application must be able to take some type of action, such as storing the messages to be forwarded when the server becomes active again. Queue sizing analysis should also be done for the case when the server is down, and for when it is restarting. The queuing load during restart operations is often significantly larger than during normal operation.
In the case where the service and arrival rates are not known, the
design and implementation work can still proceed by using the
trial-and-error method. If there is not enough of a particular
resource, add more and try again until the operation works.
1.3.3 Simulating Worst-Case Load Scenario
Another scheme to determine the resources that are required is to write input driver programs that simulate the worst-case load. Test drivers of this type are highly recommended, even when a complete systems design is available. Test drivers can be used in many phases of the project cycle, including design, modeling, implementation, and testing.
Servers can be also simulated, in a simple way, by programs coded as
simple loops that read from an input queue, then pause for some
interval before reading the next item. Using this methodology, you can
build a high-level simulation that runs on the hardware and network (or
a very similar network) on which the target application will run.
Examining the resources used by the model can be very helpful in
sucessfully sizing the production system.
1.3.4 Failover Provisions
Failover provisions must be taken into account early in the design process. Failover requires at least operational planning, and in most cases, requires application code to be written to support the failover process. If failover capability is required, it should be designed as an integral part of the application. It is difficult to back fit a failover process once an application is in production.
For example, recovery journals resides on physical media and this media must be accessible to both the primary node where the application is originally running and the backup node to which the application will fail over. In a VMScluster, the media is easily accessible because access to disks can span network nodes. Outside of a VMScluster, it is still possible to provide failover capability by physically moving or copying the media.
Refer to Chapter 15 for more information on failovers.
1.3.5 Design Summary
The following list summarizes basic questions you should consider when planning a distributed system that uses MessageQ:
The following topics are covered in this section:
Your MessageQ medit kit should contain the following:
MessageQ provides online release notes. We strongly recommend that you read the release notes before starting the installation. Refer to a copy of the release notes provided with your MessageQ software kit.
You can also access the release notes online as described in Section 2.2.6 .
Note:
Significant new features have been added to this MessageQ release that require the group initialization file format to be updated. Refer to Section 2.5 for instructions on upgrading your MessageQ for OpenVMS installation.
You must install one of the following operating system software prior to installing MessageQ :
If you plan to use MessageQ for OpenVMS software to communicate with UNIX systems, Windows NT systems, or other systems that support the Transmission Control Protocol/Internet Protocol (TCP/IP) and NFS protocol suites, install one of the following products on your system prior to installing MessageQ software:
For a complete list of networking products supported, refer to the
Read Before Installing BEA MessageQ for OpenVMS
1.4.5 Licensing
The MessageQ for OpenVMS installation procedure prompts you to enter
valid license information for your site. Refer to Chapter 2 of this
guide for complete instructions on how to install MessageQ software.
1.4.6 Checking System Parameter Values
To check the values of your system parameters, use the SYSGEN utility, as shown in the example below:
$ RUN SYS$SYSTEM:SYSGEN SYSGEN> SHOW GBLPAGFIL SYSGEN> EXIT
For MessageQ, the values displayed should equal or exceed the value of each system parameter listed in Table 1-1 . This table uses the symbol n to represent the current setting value. The number n plus the number listed in the Minimum Value column of the table is the minimum required system parameter values for the MessageQ installation. Depending on the kinds of programs and applications running at your site, you may need higher values for some settings.
| System Parameter | Minimum Value |
|---|---|
| GBLPAGES¹ | n + 2000 |
| GBLPAGFIL | n + 1000 |
| GBLSECTIONS¹ | n + 18 |
To install and run MessageQ, you must have sufficient free global pages and global sections. To find the number of free global pages and global sections, use the WRITE command with the F$GETSYI lexical function. The following example shows how to get this information at your terminal (the default for SYS$OUTPUT):
$ WRITE SYS$OUTPUT F$GETSYI("FREE_GBLPAGES")
15848
$ WRITE SYS$OUTPUT F$GETSYI("FREE_GBLSECTS")
24
If the values displayed by the system are greater than the values in
Section 1.4.6 , you need not increase the values for these parameters.
If the value of free global pages or global sections is less than the
value in Section 1.4.6 , you must increase the system parameter setting.
To increase the GBLPAGES and GBLSECTIONS system parameters, use the
AUTOGEN utility.
1.5 Installation Procedure Requirements
The following topics are covered in this section:
The following table includes the approximate times needed for installing MessageQ for OpenVMS. Note that actual times will vary depending on the type of media and system configuration. Times given in this table include installing the MessageQ development kit and running the Installation Verification Procedure (IVP). Both systems given as examples are standalone systems.
| Examples | |||
|---|---|---|---|
| Platform | Time (Approx.) | System | Time |
| Alpha | 25-60 minutes | DECstation 3000 Model 500 | 35 minutes |
| VAX | 30-90 minutes | VAXstation 4000 Model 90 | 50 minutes |
To install MessageQ, you must be logged on to an account that has SETPRV.
Note:
The VMSINSTAL command procedure turns off the BYPASS privilege at the start of the installation.
The following table summarizes MessageQ disk space requirements:
| Kit | Blocks Used During Installation | Blocks Required After Installation |
|---|---|---|
| Alpha Platform | ||
| OpenVMS Alpha Development (DEV) | 175,000 | 142,000 |
| OpenVMS Alpha Run-Time Only (RTO) | 175,000 | 97,000 |
| MessageQ online documentation (optional) | 10,000 | 10,000 |
| Client Library Kit Support (included in base DEV or RTO kit, but may be installed by itself) | 55,000 | 8,000 |
| LU6.2 support (include in base DEV kit, but optional on RTO kit install) | 32,500 | |
| VAX Platform | ||
| OpenVMS VAX Development | 80,000 | 56,000 |
| OpenVMS VAX Run-Time only | 80,000 | 42,000 |
| MessageQ online documentation (optional) | 10,000 | 10,000 |
| Client Library Kit Support (included in base DEV or RTO kit, but may be installed by itself) | 20,000 | 3,500 |
| LU6.2 support (include in base DEV kit, but optional on RTO kit install) | 6,000 | |
To determine the number of free disk blocks on the current system disk, enter the following command at the DCL prompt:
$ SHOW DEVICE SYS$SYSDEVICE
An alternate working device (AWD) may be specified as part of the VMSINSTAL procedure. This option may be used when the system disk does not have the device space needed to install MessageQ for OpenVMS. However, even with the AWD option the installation requires at least 1,000 blocks of space on the system disk.
@SYS$UPDATE:VMSINSTAL MQVAXA040 source_device: OPTIONS AWD=device:
The account you use to install MessageQ must have sufficient quotas to enable you to perform the installation. The following table lists the process quotas required for the installation account executing the VMSINSTAL command procedure.
| Account Quota | #Value |
|---|---|
| ASTLM | 24 |
| BIOLM | 18 |
| BYTLM | 18,000 |
| DIOLM | 18 |
Use the AUTHORIZE utility to verify and change user account quotas.
User account quotas are stored in the SYSUAF.DAT file.
1.5.5 VMSINSTAL Requirements
When you invoke VMSINSTAL, it checks the following:
If VMSINSTAL detects any problems during the installation, it notifies
you and asks if you want to continue the installation. To stop the
installation process and correct the situation, enter NO or press
Return. Correct the problem and restart the installation.
1.5.6 System Backup
At the beginning of the installation, VMSINSTAL asks if you have backed up your system disk. We recommend that you back up the system disk before installing any software. You should also back up the target disk where MessageQ will be installed.
Use the backup procedures that are established at your site. For details on performing a system disk backup, see the section on the Backup Utility (BACKUP) in the System Management Subkit.
This chapter provides a detailed description of the MessageQ installation procedure and related topics.
The following topics are covered in this chapter:
MessageQ for OpenVMS is installed by invoking the VMSINSTAL utility. This command procedure will prompt you for various installation options. When it is complete, the MessageQ for OpenVMS application is installed on your system. Then you can perform system configuration as described in Part II of this manual.
Note:
To end the installation procedure at any time, press Ctrl/Y. When you press Ctrl/Y, the installation procedure deletes all files it has created up to that point and exits. You can then restart the installation.
This section describes the installation procedure, as summarized in Table 2-1 :
| Step | Action |
|---|---|
| 1. | Invoking VMSINSTAL |
| 2. | Confirming Backup |
| 3. | Specify Where Distribution Media is Mounted |
| 4. | Specify the Product to Install |
| 5. | Enter VMSinstall Options |
| 6. | Installing MessageQ for OpenVMS Online Documentation |
| 7. | Selecting Kit Type |
| 8. | Confirming License Registration |
| 9. | Select Target Device for Installation |
| 10. | Running IVP |
| 11. | Purging Files |
| 12. | Viewing Informational Messages |
To invoke VMSINSTAL, use the following command:
@SYS$UPDATE:VMSINSTAL
To start the installation, invoke the VMSINSTAL command procedure from
a privileged account, such as the SYSTEM account. VMSINSTAL is in the
SYS$UPDATE directory.
2.2.2 Confirming Backup
The procedure requests that you confirm system backup:
* Are you satisfied with the backup of your system disk [YES]?
We recommend that you always back up your system disk before performing an installation.
If you are satisfied with the backup of your system disk, press Return . Otherwise, enter NO to discontinue the installation. After you back up your system disk, you can restart the installation.
Note:
MessageQ software can be installed on any disk. Be sure to backup the disk on which MessageQ is installed.
You are prompted to enter the location where the distribution CDROM is mounted. Insert the CDROM distribution media into the system's CDROM drive. Enter the file specification for the distribution media including the device name of the CDROM drive and the directory name from the software distribution medium as follows:
* Where will the distribution volumes be mounted:
and press Return.
2.2.4 Specify the Product to Install
The installation procedure then prompts for the name of the product that you want to install as follows:
* Enter the products to be processed from the first distribution volume set. * Products:
You can select to install MQAXPA040 for Digital Alpha systems
or MQVAXA040 for Digital VAX systems.
2.2.5 Enter VMSinstall Options
After you select the product to install, you can choose to enter one of the VMS INSTALL options. The most commonly used option is -N which enables users to view or print the release notes before the installation.
Next, VMSINSTAL displays the following question:
* Do you want to continue the installation [N]?: %VMSINSTAL-I-RELMOVED, Product's release notes have been moved to SYS$HELP.
To continue the installation, enter Y. Otherwise, press
Return. In either case, the release notes are copied to a
file in the SYS$HELP directory as SYS$HELP:MQAXPA040.RELEASE_NOTES or
SYS$HELP:MQVAXA040.RELEASE_NOTES.
2.2.6 Installing MessageQ for OpenVMS Online Documentation
MessageQ documentation includes online documentation in HTML format that can be read using a World Wide Web browser. Digital OpenVMS includes the Netscape Navigator Web browser for reading HTML-based documentation.
In addition, most PC environments now include a Web browser. Therefore, if your OpenVMS system is not licensed to use a Web browser, you can also view the documentation using a PC that is networked to an OpenVMS system running MessageQ .
To read the online user documentation, follow these steps:
* Install MessageQ online documentation files (9000 blks) [YES]?
drive:[dmq$v40.books]bookshelf.html
For those sites with a corporate Intranet, MessageQ documentation can
be copied to a single node and linked into the corporate information
base contained on an internal Web site. Copying the online
documentation to an Intranet server limits the use of disk space to a
single system while making it accessible to everyone on the corporate
Intranet. After the documentation is copied to the corporate Intranet
server, users must be given a URL to access the documentation or a
description of the page from which the documentation can be accessed.
2.2.7 Selecting Kit Type
Choose the development or the run-time only kit. The runtime only kit is the default kit if the development kit is not selected.
* Install the development kit (53500 blks) [NO]? * Install the runtime only kit (23500 blks) [YES]?
The installation procedure prompts you to enter you name and
organization name and then asks if you hold a valid license for the
system. Your MessageQ for OpenVMS software license agreement is
contained in your media distribution kit. Please read this information
and return the BEA license registration card contained in your
distribution kit.
2.2.9 Select Target Device for Installation
Next, enter the name of the device on which you want to install MessageQ software as follows:
* Device where MessageQ will reside [SYS$SYSDEVICE]:
Press return to install MessageQ on the default target device SYS$SYSDEVICE. Or, enter the name of the device on which you want to install MessageQ and press Return.
Note:
Installing MessageQ software on rooted directories will produce unpredictable results. Specify a device name or a logical name of a device.
The system automatically builds the TCP/IP link drivers. The DEC TCP/IP link driver is the default. You can choose other link drivers by editing the DMQ$BOOT.COM command procedure.
Note:
MessageQ links to all supported TCP/IP link drivers that it finds. Therefore, TCP/IP must be installed and started prior to this installation.
You may now choose to run the Installation Verification Procedure (IVP).
* Do you want to run the IVP after the installation [YES]?
The IVP for MessageQ verifies that the installation is successful. We recommend that you run the IVP.
After MessageQ is installed, you can run the IVP independently to
verify that the software is available on your system. You may need to
run the IVP after a system failure to make sure that users can access
MessageQ .
2.2.11 Purging Files
You now have the option to purge files from previous versions of MessageQ that are superseded by this installation.
* Do you want to purge files replaced by this installation [YES]?
Purging is recommended; however, if you need to keep files from a
previous installation of this version of MessageQ software, enter
NO in response to the question.
2.2.12 Viewing Informational Messages
The installation procedure now displays a number of informational messages that report on the progress of the installation. There are no further questions that require a user response.
If the installation procedure has been successful up to this point, VMSINSTAL moves the new or modified files to their target directories, updates help files, and updates DCL tables, if necessary. If you chose to have files purged, that work is done now.
If you chose to run the IVP, VMSINSTAL runs it now. When the IVP runs successfully, you see the following display:
%DMQ-S-SUCCESS, MessageQ for VMS IVP successfully completed.
Installation of MQAXP V4.0 completed at hh:mm
VMSINSTAL procedure done at hh:mm
These messages indicate that the entire installation procedure is complete.
Note:
VMSINSTAL deletes or changes entries in the process symbol tables during the installation. Therefore, if you are going to continue using the system manager's account and you want to restore these symbols, log out and log in again.
WARNING:
If you have been using a previous version of MessageQ and wish to continue to use your user areas, you MUST perform the upgrade conversion before you can run your applications using MessageQ for OpenVMS, Version 4.0A. Refer to Section 2.5 for more information.
The following topics are covered in this section:
If errors occur either during the installation or when the Installation Verification Procedure (IVP) is running, VMSINSTAL displays failure messages. If the installation fails, you see the following message:
%VMSINSTAL-E-INSFAIL, The installation of MessageQ Version 4.0A has failed.
If the IVP fails, you see these messages:
The MessageQ V4.0 Installation Verification Procedure failed. %VMSINSTAL-E-IVPFAIL, The IVP for MessageQ V4.0 has failed.
Any of the following error conditions may cause the installation to fail: