HP UX Red Hat Direry Server Software manual Managing Threaded Operations

Chapter 3. Configuring Directory Databases

The first attribute, nsMaxResponseDelay, sets a maximum duration for an LDAP operation to complete. If the operation takes more than the amount of time specified in this attribute, the database link's server suspects that the remote server is no longer online.

Once the nsMaxResponseDelay period has been met, the database link pings the remote server. During the ping, the database link issues another LDAP request, a simple search request for an object that does not exist in the remote server. The duration of the ping is set using the nsMaxTestResponseDelay.

If the remote server does not respond before the nsMaxTestResponseDelay period has passed, then an error is returned, and the connection is flagged as down. All connections between the database link and remote server will be blocked for 30 seconds, protecting the server from a performance degradation. After 30 seconds, operation requests made by the database link to the remote server continue as normal.

Both attributes are stored in the cn=config,cn=chaining database,cn=plugins,cn=config entry. The following table describes the attributes in more detail:

Attribute Name	Description
nsMaxResponseDelay	Maximum amount of time it can take a remote
	server to respond to an LDAP operation
	request made by a database link before an
	error is suspected. This period is given in
	seconds. The default delay period is 60
	seconds. Once this delay period has been
	met, the database link tests the connection
	with the remote server.
nsMaxTestResponseDelay	Duration of the test issued by the database
	link to check whether the remote server is
	responding. If a response from the remote
	server is not returned before this period has
	passed, the database link assumes the
	remote server is down, and the connection is
	not used for subsequent operations. This
	period is given in seconds. The default test
	response delay period is 15 seconds.

Table 3.6. Database Link Processing Error Detection Parameters

3.6.3. Managing Threaded Operations

Generally, Directory Server performs best using a limited number of threads for processing operations. A limited number of threads can generally process operations very quickly, preventing the queue of operations waiting for a free thread from growing too long.

However, the database link forwards operations to remote servers for processing. The database

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