How to control storage that is used by the optimizer

SUPEROPT lets you control the use of virtual storage that is required by the Optimizer. The following options are provided for controlling storage:

• Imaging and SCS Storage (1.6.1)
• Storage Compression (1.6.1)
• Work Area Storage (1.6.2)
• Dynamic Terminal and Transid Areas (1.6.3)

Imaging and SCS storage option

Imaging and SCS Printers optimization techniques use virtual storage to save data. The Optimizer uses the Imaging and the SCS Printer optimization techniques to optimize as many data streams as possible, by using the amount of storage that is allocated to the Optimizer. If the amount of allocated storage is insufficient, the Optimizer uses Conventional optimization for any additional data streams (except those for SCS printers) when storage is exhausted. The Imaging panel displays the number of data streams that are excluded from Imaging and SCS Printer optimization because of insufficient storage.

You can change the amount of allocated storage at any time. There is no need to stop the Optimizer. If you are using the extended architecture (XA) option of CICS 1.7 or later in an MVS/ESA, OS/390, or z/OS environment, the storage that you allocate is obtained from extended private storage (above the 16 MB line). If you are using CICS 3.0 or later, storage is obtained from Extended DSA (EDSA).

Allocating imaging storage

The amount of Imaging storage that you allocate to the Optimizer must be a multiple of four (for example, 16, 32, 64, 1024). The maximum amount that you can allocate depends on the operating system environment. Following Table shows the maximum amount of storage for each environment.

For each terminal that is optimized, the Optimizer requires approximately the amount of storage that is listed in Following table.

If your terminal buffers are significantly larger than average, you might need more storage. For example, you could be using 3270 displays with a screen size of 43 by 80, or you could make extensive use of extended attributes.

If you are using the XA option of CICS 1.7 or later in an MVS/ESA, OS/390, or z/OS environment, the storage that you allocate is obtained above the 16 MB line. If you are using CICS 3.0 or later, storage is obtained from EDSA.

Imaging and SCS storage management considerations

Observe the following considerations when using the Imaging and SCS Storage optimization techniques:

• If no storage is allocated or it is not available, Imaging and SCS Storage optimization techniques are not used to optimize your data streams.
• If you are using Imaging optimization, 8 KB of the storage that you allocated is reserved by the Optimizer.
• To reduce the amount of virtual storage that is required by Imaging, the data can be reduced in size (compressed) before it is stored. Use the Imaging and SCS Storage panel to select the amount of storage compression that you want to use for stored images. For more information about this feature, see Selecting the Amount of Storage Compression.

Changing the amount of imaging storage

To change the amount of storage allocated to the Optimizer, type the storage amount that you want to use in the Allocation Size field and press Enter.

The amount of storage that is allocated to the Optimizer is changed.

Displaying the active images by termid list

To display a list of active images by Termid, type a non-blank character in the List Active Images by Termid field and press Enter.

The Active Images List panel is displayed.

Following block shows a sample Active Image List panel. This panel lists active images by Termid.

Selecting the amount of storage compression

The Storage Compression option reduces the amount of virtual storage that is used by Imaging optimization. This option compresses the data that is saved in the Imaging and SCS storage area. If you have a limited amount of virtual storage and can tolerate an increase in the amount of CPU time that is used by the Optimizer, use Storage Compression to take full advantage of Imaging optimization.

To help you determine how much storage compression to use for a storage-constrained environment, see the example .

Select the amount of storage compression to use for Imaging optimization on the Imaging and SCS Storage panel.

Allocating data stream work areas

The Optimizer uses the data stream work area to hold a copy of the data stream that is being optimized. This feature lets you increase or decrease the amount of virtual storage that the Optimizer uses for its data stream work areas. Two data stream work areas are required. The size of each area should be the size of the largest data stream that you want optimized.

If the work area is insufficient to hold a data stream, the data stream is not optimized. Review the statistics that are displayed on the Work Area Storage panel to determine whether any data streams are not being optimized because the data stream work area is too small. If data streams are not being optimized, increase the amount of storage that is allocated for the data stream work area.

You can determine the amount of storage that is required by starting the Optimizer and letting it run for a while. Then check the Work Area Storage panel to determine the size of the largest data stream that the Optimizer processed. This number is shown in bytes. Round the number up to the nearest kilobyte. For example, if the largest data stream processed was 1,452 bytes, round this number to 2 KB.

Changing the amount of data stream storage

To change the amount of storage that is allocated to the Optimizer for data stream storage, type the storage amount you want to use (any number from 1 to 31) in the Data stream storage size field and press Enter.

Allocating 3270 buffer storage areas

The Optimizer uses 3270 buffer storage areas to hold the 3270 buffer that is associated with the data stream that is being optimized. This feature lets you increase or decrease the amount of virtual storage that the Optimizer uses for its 3270 buffer storage areas. Three 3270 buffer storage areas are required. The size of each area should be the size of the largest 3270 terminal size that you want optimized.

If the 3270 buffer storage area is insufficient to hold the 3270 buffer, the data stream is not optimized. Review the statistics that are displayed on the Work Area Storage panel to determine whether any data streams are not being optimized because the 3270 buffer storage area is too small. If data streams are not being optimized, increase the amount of storage that is allocated for 3270 buffer storage.

You can determine the amount of required storage by starting the Optimizer and letting it run for a while. Then check the Work Area Storage panel to determine the size of the largest 3270 buffer that is required by the Optimizer. This number is shown in bytes. Round the number up to the nearest kilobyte. For example, if the largest 3270 buffer required was 1,952 bytes, round this number to 2 KB.

To calculate the amount of required storage, multiply the largest number of required rows by the largest number of columns, multiply by three, then round the product to the next highest kilobyte:

(largest number of required rows) × (largest number of columns) × 3 = amount of required storage in bytes

Round product to next highest kilobyte. 

Changing the amount of allocated 3270 buffer storage

To change the amount of storage that is allocated to the Optimizer for 3270 buffer storage, type the storage amount that you want to use (use any number from 1 to 31) in the 3270 Buffer Storage Size field and press Enter.

Using the dynamic terminal and transid areas option

You can use the Dynamic Terminal and Transid Areas option to perform the following actions:

• Turn the REUSE option on and off
• Control the allocation of Dynamic Terminal Areas
• Control the allocation of Transid Statistic Areas

The Dynamic Terminal and Transid Area panel also displays statistics on the Optimizer’s use of the Dynamic Terminal Areas and Transid Statistic Areas.

If you are using the XA option of CICS 1.7 or later in an MVS/ESA, OS/390, or z/OS environment, the storage that you allocate is obtained above the 16 MB line. If you are using CICS 3.0 or later, storage is obtained from EDSA.

Using the REUSE option

The Optimizer uses each Dynamic Terminal Area for a single terminal only. When the REUSE option is set to YES, each area can be reused by another terminal after a CLSDST is received from the terminal that is assigned the area. If REUSE=YES, the Optimizer uses more CPU time but less storage for Dynamic Terminal Areas.

BMC Software recommends that you specify REUSE=NO. If your Autoinstall program uses arbitrary or sequential Termids such that a terminal is assigned a different Termid each time it logs on, optimize by Netname. If optimizing by Netname is not possible, specify REUSE=YES so that the DTA can be used by another terminal.

Allocating dynamic terminal areas

The Optimizer allocates 100 bytes of storage for each terminal that logs on through the Autoinstall (automatic installation of terminals) feature of CICS/VS 1.7 or later. This 100-byte dynamic terminal area (DTA) is for the exclusive use of the autoinstalled terminal.

The number of DTAs is set with the Dynamic Terminal Areas Number allocated field on the Dynamic Terminal and Transid Areas panel. If this number is insufficient for the number of terminals that are logged on, data streams for terminals that could not allocate a DTA will not be optimized. Review the statistics for Data streams not optimized and Too few dynamic terminals on the Dynamic Terminal and Transid Areas panel to determine how many DTAs are lacking. Increase the number of DTAs that are allocated to reflect the maximum number of terminals to be signed on at a time.

If your Autoinstall program uses arbitrary or sequential Termids such that a terminal is assigned a different Termid each time it logs on, see Using the REUSE option.

Terminals that are defined in the TCT have terminal areas allocated for them internally when the Optimizer is initialized. These areas are not part of the DTA.

Changing the number of allocated dynamic terminal areas

To change the number of DTAs that are allocated to the Optimizer, type the number of DTAs that you want to use (any number from 1 to 32,767—each area is 92 bytes) in the Dynamic Terminal Areas Number allocated field and press Enter.

The number of DTAs that are allocated to the Optimizer is changed.

Allocating transid statistic areas

The Optimizer saves 48 bytes of information for every unique transaction ID that is processed. Each 48-byte area is called a Transid area. When the Optimizer is initially started, the Monitor allocates no Transid statistic areas.

To display or print data stream statistics by Transid, you must use the Transid Statistics Areas option.

The Optimizer collects statistics for as many Transids as there are Transid statistic areas. If all Transid areas are used, the Optimizer will not collect statistics for any new Transids. Review the statistics that are displayed on the Dynamic Terminal and Transid Areas panel to determine whether you need to increase the number of Transid statistic areas that are allocated.

To change the number of Transid statistic areas that are allocated to the Optimizer, type the number of Transid statistic areas that you want to use (any number from 1 to 32,767) in the Transid Statistic Areas Number allocated field and press Enter.

The number of Transid Statistic Areas that are allocated to the Optimizer is changed.

Displaying the imaging and SCS storage panel

Summary: In this task, you will display the Imaging and SCS Storage panel.

To display the Imaging and SCS Storage panel, perform the following steps:

1. Select option 1 on the Monitor Primary Menu.
2. Press Enter.
   The Optimization Control Menu is displayed.
3. Select option 1.6.1.

4. Press Enter.
   The Imaging and SCS Storage panel is displayed.

   (1.6.1)                        3270 SUPEROPTIMIZER/CICS                     March 30, 2001
   Option. . ______              Imaging and SCS Storage                      21:26:27
                                 CICSID:CICSJXE
   
   Allocation Size . . . . . . . . . . . . . . .    2048 K
   List Active Images by Termid. . . . . . . . . _
   
   Select a storage compression percentage from below.
   _ * . 0%              Status. . . : 0 %
   2 . 20-50%
   3 . 40-80%
   
   Compression Percentage. . . . . . . . . . . : 0.0 %
   Termid currently active . . . . . . . . . . : L3ABE3
   Number of terminals active. . . . . . . . . : 1
   Current storage used. . . . . . . . . . . . : 3 K
   Peak Storage Used . . . . . . . . . . . . . : 3 K
   
   F1=Help F2=Keys F3=End F4=Return F6=Case F9=Print F10=Table List

Following table lists the fields that are displayed on the Imaging and SCS Storage panel.

Using the work area storage panel

Summary: You can use the Work Area Storage panel to increase or decrease the amount of virtual storage that the Optimizer needs for data streams and 3270 buffers. The Work Area Storage panel also displays statistics on the Optimizer’s use of the data stream storage and the 3270 buffer storage.

You can change the amount of allocated storage at any time. You do not need to stop the Optimizer. To display the Work Area Storage panel, perform the following steps:

1. Select option 1 on the Monitor Primary Menu.
2. Press Enter.
   The Optimization Control Menu is displayed.
3. Select option 1.6.2.
4. Press Enter.
   The Work Area Storage panel is displayed.

Following block shows the Work Area Storage panel:

Following table describes the fields on the Work Area Storage panel:

Displaying the dynamic terminal and transid areas panel

Summary: You can change the number of allocated areas at any time. There is no need to stop the Optimizer.

To display the Dynamic Terminal and Transid Areas panel, perform the following steps:

1. Select option 1 on the Monitor Primary Menu.
2. Press Enter.
   The Optimization Control Menu is displayed.
3. Select option 1.6.3.

4. Press Enter.
   The Dynamic Terminal and Transid Areas panel is displayed.

   (1.6.3)                          3270 SUPEROPTIMIZER/CICS                      March 30, 2001
   Option. . ______                Dynamic Terminal and Transid Areas            21:28:25
                                   CICSID:CICSJXE
   
   Dynamic Terminal Areas.
             Reuse . . . . . . . . . . . . . _ 1. Yes                  Status. . . : No
                                               *. No
   
   Number allocated. . . . . . . . 100
       Number currently used . . . : 0
       Maximum number used . . . . : 0
   
   Data streams not optimized.
       Too few dynamic terminals . : 0
   
   Transid Statistic Areas.
   Number allocated. . . . . . . . 100
       Number currently used . . . : 2
       Maximum number used . . . . : 2
   
   F1=Help F2=Keys F3=End F4=Return F9=Print 

Following table describes the fields on the Dynamic Terminal and Transid Areas panel: