Buffer Pool And Recovery Files

This document describes maintenance functions you can perform on the Editor buffer pool and user recovery files. These refer to the BPSTAT, BP FILES and BP RECS options on the Administrator Menu.

The following description is not intended to give full technical details on the buffer pool, but provides a rough outline of its function.

The buffer pool software enables you to allocate space to which users perform read and write operations.

The buffer pool consists of area in the memory and a container file. The area is divided into memory blocks of fixed length. The buffer pool manager reads blocks from the memory and writes blocks to it. If the buffer pool is full, it tries to release other blocks by writing them to the container file. In the normal case, however, most blocks in use will be in the memory.

This document covers the following topics:


Buffer Pool Maintenance

The BPSTAT option on the Administrator Menu (or the BPSTAT session command) invokes the Natural utility SYSEDT with the General Information function (SYSEDT Function Code G).

The General Information screen provides an overview of the current status of the editor buffer pool.

For further information, see the description of the SYSEDT utility in the Natural documentation.

Optimizing the Buffer Pool

Optimizing the buffer pool means modifying certain parameters to increase buffer pool efficiency. To modify a parameter, use the Natural utility SYSEDT or refer to the section Installing the Software AG Editor in the Natural Installation documentation.

Buffer Pool Files

The BP FILES option on the Administrator Menu invokes the Natural utility SYSEDT with the Logical Files function (SYSEDT Function Code F).

The Logical Files screen provides information such as file number, user ID, logical file type, pool blocks, file records, last access.

In addition, the first column contains an input field labeled M for Mark. If you enter a question mark (?) in this field, a window is displayed, which shows you the codes that are valid input for this field.

Enter the code in the Mark field to perform functions such as selecting the logical file of a user, deleting a logical file.

Note:
It is recommended that you delete only unused sessions. If you delete a buffer pool file for an Editor session that is in use, the results of the Editor session are unpredictable. (Typically, the user will receive the message: Session does not exist).

You can invoke the above display directly using a function command from a Natural ISPF session. You must address the object type BPF in the command syntax:

LIST BPF

For further information, see the description of the SYSEDT utility in the Natural documentation.

Recovery Files

Recovery files are checkpoints which are written during an edit session and deleted when the edit session is terminated normally. If the edit session is terminated abnormally, the checkpoint files are stored in the Editor work file indefinitely or until the user selects the file for recovery.

The BP RECS option on the Administrator Menu invokes the Natural utility SYSEDT with the Logical Files function (SYSEDT Function Code R).

The Recovery Files screen provides the information such as Natural user ID, library member name, library name, library type, number of recovery records per recovery file, creation date and time of the recovery file.

For each recovery file listed, you can execute a line command, for example, to select the recovery file of this user, or to delete the recovery file. You enter a line command in the C column, next to the user required.

To invoke a list of recovery files using a function command from a Natural ISPF session, address the object type BPR in the command syntax:

LIST BPR

Troubleshooting

This subsection lists messages that may appear in the message line of a Natural ISPF screen concerning the Editor buffer pool. Related messages are grouped together, and corrective action is suggested.

Installation Errors

Message:

SSIZE too small

Explanation / Action:

Modify your NATPARM module using SSIZE=64.

Message:

DBID of Natural PROCESS is missing

Explanation / Action:

The DBID of Entire System Server (formerly Natural Process) is missing in the Natural ISPF configuration. See the section System Configuration.

Messages:

Checkpoint file not active'
-caution-  profile changed to "recovery off" (from "recovery on") because checkpoint file not active' (in Editor session)

Explanation / Action:

The Editor work file was not formatted correctly, no space was reserved for the checkpoint file. Check your job that allocates the work file.

Message:

NSPF FAILURE IN OPEN BUFFERS

Explanation / Action:

The allocation of the Editor area failed or was not sufficient (SSIZE buffer). Check the SSIZE parameter. If the parameter has a value of at least 64, you can either increase the MSIZE parameter, or decrease the size value of other buffers you do not need, for example CSIZE, FSIZE or TSIZE (see the Natural Parameter Reference documentation). In some environments, you can use the Natural command SYSBUS to check the allocations in effect.

Message:

BP not active

Explanation / Action:

The buffer pool was not initialized correctly. See the section Installing the Software AG Editor in the Natural Installation documentation.

Editor Work File, Editor Auxiliary Buffer Pool and Timeout Parameters

Messages:

Checkpoint of file failed
No space for data block
No space for index block
Cannot allocate BP file
-caution-  profile changed to "recovery off" (from "recovery on") because checkpoint file is full (in Editor session)
-caution-  profile changed to "log off" (from "log on") because log file is full (undo command not active) (in Editor session)
Buffer pool is full 
Cannot allocate BP block
Cannot allocate checkpoint block
Suspending of a session failed

Explanation / Action:

If you get one of these messages your current activity might not be finished correctly. You should leave N-ISPF and finish the Natural session.

These messages indicate one of the following reasons:

  • The Software AG Editor work file is too small. You must increase the work file size.

    Note:
    The record length of data sets or PDS members, which will be edited with Natural ISPF, cannot be larger as the record length of this editor work file.

  • The Software AG Editor auxiliary buffer pool defined by the profile parameter EDPSIZE is too small. You must increase the EDPSIZE.

  • The timeout parameter values are too large, causing data to be kept in the buffer pool too long. You must decrease the timeout parameter values.

Message:

Activation of a session failed

Explanation / Action:

The session has been deleted due to a buffer pool timeout. Restart the session.

Internal ISPF/Editor Problems

The following messages are not usually displayed. They appear in the rare case of some internal problem.

Messages:

Some data may be ignored
Session does not exist
Cannot free BP block
Log error

Explanation / Action:

Contact your Software AG support representative.

I/O Problems on Editor Work File or Volume

Messages:

I/O ERROR
Cannot read index block
Write to BP failed
Read from BP failed
Read failed
Error reading log block
Cannot read checkpoint block
Cannot write checkpoint block
Recovery of file failed

Explanation / Action:

Check the work file. If the error persists, reallocate the file on another volume.

Other Inconsistencies

Message:

Error in getting lines

Explanation / Action:

The Natural source area is corrupted, for example if Natural ISPF is aborted by %% and the source area was modified.

Message:

Getting text failed

Explanation / Action:

The Editor message table is inconsistent.

Message:

Invalid printer reference number

Explanation / Action:

The requested printer has no corresponding definition in the NATPARM module. Note that with PRINTER=OFF in the NATPARM module, the WORKPOOL, BROWSE-VIEW and COMPARE functionality is disabled.