Understanding the Configuration Parameters

This section describes the information you supply to the hadsconfig(1M) command to create configuration files for Sun Cluster HA for the Apache data service. The hadsconfig command uses templates to create these configuration files. The templates contain defaults; some are hard coded and others are unspecified parameters. You must provide values for the unspecified parameters.

The fault probe parameters, in particular, can affect the performance of Sun Cluster HA for Apache data services. Tuning the probe interval value too low (that is, increasing the frequency of fault probes) might encumber system performance and result in unnecessary takeovers or attempted restarts when the system is simply slow.

Fault monitor parameters are configurable for Sun Cluster HA for the Apache Web Server. One of the parameters is the takeover flag, which specifies how Sun Cluster handles partial failover. You have two options:

• y (yes) -- Sun Cluster attempts to switch over the logical host to another master. However, if the attempt fails, the logical host remains on the original master. This is the default setting.

• n (no) -- Sun Cluster does not move the logical host to another master even if it detects problems with the data server, nor does it take any action against the faulty data server or database on the logical host.

Configure the Sun Cluster HA for Apache Web Server parameters listed in the hadsconfig(1M) input form by supplying the options described in Table 1-1. The parameters are listed in the order they appear in the form.

Table 1-1 Configuration Parameters for Sun Cluster HA for Apache

Parameter	Description
NAME (name of the instance)	The name tag that serves as an identifier for the instance. The log messages generated by Sun Cluster refer to this name tag. The hadsconfig(1M) command prefixes the package name to the value you supply here. For example, if you specify apache_80, hadsconfig produces SUNWscapc_apache_80.
LOGICAL_HOST (logical host)	The name of the logical host that provides service for this instance of Sun Cluster HA for Apache Web Server.
PORT (server port number)	The unique port for this instance of Sun Cluster HA for Apache Web Server. This is the server port value you supplied to the httpd.conf file while configuring Apache Web Server.
INTERVAL (probe interval)	The time, in seconds, between fault probes. The default interval is 60 seconds.
TIMEOUT (probe timeout)	The time, in seconds, after which a fault probe times out. The default timeout value is 30 seconds.
TAKEOVER (takeover flag)	The flag that specifies whether a failure of this instance causes a takeover or failover of the logical host associated with the data service instance. Possible values are y (yes) and n (no).
BIN_DIR (binary directory)	The directory of the product installation that contains the httpd binary, for example, /hahost1/apache-home/bin.
CONF_DIR (configuration directory)	The directory of the product installation that contains the configuration file httpd.conf, for example, /hahost1/apache-home/conf.