Red Hat Directory Server 8.0 Administrator's Guide
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
Chapter 3. Configuring Directory Databases
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