Strategies

The JDBC river plugin can be configured for different methods of data transport. Such methods of data transports are called a 'strategy'.

Be default, the JDBC River implements a oneshot strategy.

Simple strategy

This strategy contains the following steps of processing:

1. fetch data from the JDBC connection
2. build structured objects and move them to Elasticsearch for creation, indexing, or deleting
3. wait for a certain time before proceeding with step 1

The simple strategy can be refined.

• the sql command which is executed to fetch the data

• the poll time value can be adjusted to the interval how often data should be fetched.

• a digest can be added in order to detect different data transports. If the data of the previous run differs from the current, a housekeeper task is run to detect stale objects that must be deleted from the Elasticsearch index

• versioning can be added to refuse data from the source which is older than the current Elasticsearch documents

• a handshake SQL statement can be given in order to delete the fetched documents. The current documents can be marked with a _job column.

One-shot strategy

The oneshot strategy is like the simple strategy, but there is no loop. The poll parameter is ignored. After a single run, the river stops.

Column strategy

TODO