Replication Agents Overview

Replication Agents Overview

Replication uses many stand-alone programs, which are named "agents" to perform the tasks associated with tracking changes and distributing data. 
 
Replication Distribution Agent
In the replication Distribution Agent is moves the snapshot and the transactions held in the distribution database tables to the destination tables at the Subscribers. 


Replication Log Reader Agent
In the replication Log Reader Agent is monitors the transaction log of each database configured for transactional replication and copies the transactions marked for replication from the transaction log into the distribution database. 


Replication Merge Agent
In the replication Merge Agent is an applies the initial snapshot held in the database tables to the Subscribers. It also merges incremental data changes that occurred at the Publisher after the initial snapshot was created, and reconciles conflicts either according to the rules. 


Replication Queue Reader Agent
In the replication Queue Reader Agent is reads messages stored in a Microsoft SQL Server queue or a Microsoft Message Queue and then applies those messages to the Publisher. Queue Reader Agent is used with snapshot and transactional publications that allow queued updating. 


Replication Snapshot Agent
In the replication Snapshot Agent is a file that prepares snapshot files containing schema and data of published tables and database objects, stores the files in the snapshot folder, and records synchronization jobs in the distribution database.
What is Publisher. What is Subscriber. What is Article. What is Publication. What is Distributor. What is Pull Subscription. What is Push Subscription. What is Snapshot Agent. What is Log Reader Agent. What is Distribution Agent. What is Merge Agent. What is Queue Reader Agent.