10.4.45. TimeDelay (delay) Filter

The TimeDelayFilter delays writing events to the THL and should be used only on Appliers in the remote-to-thl stage. This delays writing the transactions into the THL files, but allows the application of the data to the database to continue without further intervention.

From version 6.1.4 the delayInMs Filter was also added which allows delay prescion in milliseconds. See Section 10.4.46, “TimeDelayMsFilter (delayInMS) Filter” for more detail.

Pre-configured filter name delay
Classname com.continuent.tungsten.replicator.filter.TimeDelayFilter
Property prefix replicator.filter.delay
Stage compatibility remote-to-thl
tpm Option compatibility --repl-svc-thl-filters
Data compatibility Any event
Parameters
Parameter Type Default Description
delay numeric 300 Number of seconds to delay transaction processing row

The TimeDelayFilter delays the application of transactions recorded in the THL. The delay can be used to allow point-in-time recovery of DML operations before the transaction has been applied to the Target, or where data may need to be audited or checked before transactions are committed.

Note

For effective operation, Source and Targets should be synchronized using NTP or a similar protocol.

To enable the TimeDelayFilter, update the tungsten.ini configuration file to enable the filter. For example, to enable the delay for 600 seconds:

shell> vi /etc/tungsten/tungsten.ini
[serviceName]
...
svc-applier-filters=delay
property=replicator.filter.delay.delay=600
...

shel> tpm update

Time delay of transaction events should be performed with care, since the delay will prevent a Target from being up to date compared to the Source. In the event of a node failure, an up to date Target is required to ensure that data is safe.