MongoRepository(T, TKey).RequestStart Method

public virtual IDisposable RequestStart()

Public Overridable Function RequestStart As IDisposable

public:
virtual IDisposable^ RequestStart()

abstract RequestStart : unit -> IDisposable 
override RequestStart : unit -> IDisposable 

Return Value

Implements

Sometimes a series of operations needs to be performed on the same connection in order to guarantee correct results. This is rarely the case, and most of the time there is no need to call RequestStart/RequestDone. An example of when this might be necessary is when a series of Inserts are called in rapid succession with SafeMode off, and you want to query that data in a consistent manner immediately thereafter (with SafeMode off the writes can queue up at the server and might not be immediately visible to other connections). Using RequestStart you can force a query to be on the same connection as the writes, so the query won't execute until the server has caught up with the writes.

A thread can temporarily reserve a connection from the connection pool by using RequestStart and RequestDone. You are free to use any other databases as well during the request. RequestStart increments a counter (for this thread) and RequestDone decrements the counter. The connection that was reserved is not actually returned to the connection pool until the count reaches zero again. This means that calls to RequestStart/RequestDone can be nested and the right thing will happen.

Use the connectionstring to specify the readpreference; add "readPreference=X" where X is one of the following values: primary, primaryPreferred, secondary, secondaryPreferred, nearest. See http://docs.mongodb.org/manual/applications/replication/#read-preference

Reference