What is a Collector?
The Collector is started by the manager process and is a process that runs in the background on the target system. It reassembles the transactional data into a target trail.
When the Manager receives a connection request from an Extract process, the Collector scans and binds to an available port and sends the port number to the Manager for assignment to the requesting Extract process. The Collector also receives the captured data that is sent by the Extract process and writes them to the remote trail file.
Collector is started automatically by the Manager when a network connection is required, so Oracle GoldenGate users do not interact with it. Collector can receive information from only one Extract process, so there is one Collector for each Extract that you use. Collector terminates when the associated Extract process terminates.
By default, Extract initiates TCP/IP connections from the source system to Collector on the target, but Oracle GoldenGate can be configured so that Collector initiates connections from the target. Initiating connections from the target might be required if, for example, the target is in a trusted network zone, but the source is in a less trusted zone.
Note:
Collector can be run manually, if needed. This is known as a static Collector (as opposed to the regular, dynamic Collector). Several Extract processes can share one static Collector; however, a one-to-one ratio is optimal. A static Collector can be used to ensure that the process runs on a specific port.