2.2.2. Work execution
The indexing work (done by the back end) can be executed synchronously with the transaction commit (or update operation if out of transaction), or asynchronously.
2.2.2.1. Synchronous
This is the safe mode where the back end work is executed in concert with the transaction commit. Under highly concurrent environment, this can lead to throughput limitations (due to the Apache Lucene lock mechanism) and it can increase the system response time if the backend is significantly slower than the transactional process and if a lot of IO operations are involved.
