Avoiding XCOM for z/OS S878 Abends due to lack of Storage

Products

• XCOM Data Transport
• XCOM Data Transport - z/OS

Issue/Introduction

Avoiding XCOM Server Abends on the Mainframe due to lack of Storage (S878). Best practices for storage management.

Environment

Release: XCOM for z/OS
Component: 12.0 

Cause

An S878 Abend occurs if a request for storage cannot be resolved.

Resolution

Best practice for Managing Storage

• Fill out the storage usage worksheet. This worksheet will allow you to calculate the approximate storage usage that is required for the XCOM Data Transport for z/OS Server (XCOMXFER).  This will help to avoid storage abends and  getmain problems in production.
  
  Click here for RI71800 CA XCOM V12.0 SERVER STORAGE USAGE WORKSHEET
  
  
• Storage shortage can be a problem as number of transfers increase or scanning is implemented or new features implemented or size of files transferred increase.

Increasing Storage

1. If more storage is needed above the line, one way to resolve this is to increase the region size. If the abend happened because storage was needed below the 16MB increasing the region size does not help.
2. In this case you need to check the value for parameter MAXTASK in the Configuration Member of the XCOM server specified in PARM-Parameter CONFIG. This parameter specifies the maximum number of file transfers that the XCOM server can perform concurrently. Each transfer needs about 36k of storage below 16MB, so 28 concurrent transfers need about 1M of storage below the line. Considering setting a value for MAXTASK which does not allow the XCOM Server to abend due to the number of concurrent transfers.

 

 

You will need to log into Broadcom support to see these worksheets

NOTE: Below the line only the parameter MAXTASK is responsible for the storage consumption:

Part I: Below the 16m line.                                                     
  Working storage (executables etc.) ...................  __________276k        
  Work Blocks, VTAM/TCPIP Buffers                                               
    34k * MAXTASK ......................................  ______________        
  Security Work Area                                                            
    2k * MAXTASK .......................................  ______________        
  Total (Add lines in part I) ..........................  ______________  

 

Additional Information

Click here for RI52575 CA XCOM R116 SERVER STORAGE USAGE WORKSHEET  
Note: XCOM R11.6 is no longer supported