HDR_TXN_SCOPE configuration parameter

The HDR_TXN_SCOPE configuration parameter is used with the DRINTERVAL configuration parameter to specify the synchronization mode for HDR replication in a high-availability cluster.

onconfig.std value
HDR_TXN_SCOPE NEAR_SYNC
values
FULL_SYNC = HDR replication if fully synchronous. Transactions require acknowledgement of completion on the HDR secondary server before they can complete.

NEAR_SYNC = HDR replication if nearly synchronous. Transactions require acknowledgement of being received on the HDR secondary server before they can complete. If used with unbuffered logging, SYNC mode, which is turned on when DRINTERVAL is set to -1, is the same as nearly synchronous mode.

ASYNC = HDR replication if fully asynchronous. Transactions do not require acknowledgement of being received or completed on the HDR secondary server before they can complete.

takes effect
After you edit your onconfig file and restart the database server.
When you reset the value dynamically in your onconfig file by running the onmode -wf command.
When you reset the value in memory by running the onmode -wm command.
After you run the SQL administration API task() or admin() function with the "onmode","-wf HDR_TXN_SCOPE=value" or "onmode","-wm HDR_TXN_SCOPE=value" argument.

Usage

When the DRINTERVAL configuration parameter is set to 0, the value of the HDR_TXN_SCOPE parameter determines the synchronization mode for HDR replication.

If unbuffered logging is used, HDR SYNC mode is the same as the nearly synchronous mode that is set through the HDR_TXN_SCOPE configuration parameter.

Table 1. Matrix of DRINTERVAL, HDR_TXN_SCOPE, and logging settings, and their resulting HDR replication modes.
DRINTERVAL HDR_TXN_SCOPE Logging Result
-1 n/a buffered Asynchronous replication
-1 n/a unbuffered Nearly synchronous replication
0 FULL_SYNC buffered Fully synchronous replication
0 FULL_SYNC unbuffered Fully synchronous replication
0 ASYNC buffered Asynchronous replication
0 ASYNC unbuffered Asynchronous replication
0 NEAR_SYNC buffered Nearly synchronous replication
0 NEAR_SYNC unbuffered Nearly synchronous replication
positive integer n/a buffered Asynchronous replication
positive integer n/a unbuffered Asynchronous replication

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