Natural hangs during ET Sync

Introduction

This guide aims to provide step-by-step instructions to troubleshoot and resolve the “Natural hangs during ET Sync” issue. This issue typically manifests as a freeze or delay during the synchronization process, which can be frustrating and hinder productivity.

Pre-reqesuite

Problem

The problem may emerge after a migration to Linux. At the start of the day with only a few users logged on Natural stops working during an Online Backup using Utility ADABCK.

Cause

Client is doing an Online Backup with adabck db=<db_id> dump=*.

There was one parameter failing ET_SYNC_WAIT = number.

After adding the ET_SYNC_WAIT to ADABCK there were no hang-ups adabck db=<db_id> dump=* et_sync_wait=20.

Resolution

ET_SYNC_WAIT = number 

This parameter defines the time (in seconds) that ADABCK waits for ET-logic users to come to ET status at the end of the DUMP function: if a transaction is already active for the number of seconds (or longer) specified by ET_SYNC_WAIT when the ET synchronization begins, its wait time is 0.

Otherwise, the wait time for a transaction, in seconds, is the value specified for the parameter minus the number of seconds that the transaction is already active when the ET synchronization begins.

Transactions not yet terminated at the end of their wait times are rolled back.

If this parameter is omitted, the ET synchronization waits until all open transactions are terminated using the normal Adabas timeout logic (ADANUC parameter TT).

The minimum value is 1 and the maximum value is 32767.

Notes:

1. If you forgot to specify the ET_SYNC_WAIT parameter for ADABCK, and ADABCK is hanging because of open transactions, you can do one of the following to let ADABCK continue: temporarily set TT to a small value -after ADABCK terminates, you can set the value back to its original value or stop the user(s) that have open transactions (with ADAOPR STOP).
2. If updates were performed in the database during the ET synchronization, all modified blocks must be written to the database containers and to the backup copy when all open transactions have been committed or rolled back. Therefore, the total time for the ET synchronization, which can be displayed via the IOSTAT parameter, may be longer than the time specified with the ET_SYNC_WAIT parameter.

Useful links | Relevant resources

This is also described in the Documentation:

https://documentation.softwareag.com/adabas/ada711os/webhelp/adaos-webhelp/utils/bck.htm#bckdump

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