SWS DNS Cache Test
The DNS cache caches IP addresses and DNS names. The Web Server uses DNS caching for logging and for access control by IP address.
Using this test, you can determine whether the DNS cache is enabled or not, and if so, how effectively the web server instance has been using it.
Target of the test : An Oracle iPlanet Web Server
Agent deploying the test : An internal agent
Outputs of the test : One set of results for the Oracle iPlanet web server instance being monitored.
Parameter | Description |
---|---|
Test period |
How often should the test be executed. |
Host |
The host for which the test is to be configured. |
Port |
The port number at which the specified Host listens to. |
User |
Specify the name of the administrator of the administration server to which the target web server is registered. |
PasswdFile |
The eG agent connects to the administration server to which the target web server is registered to extract the required metrics. To enable the eG agent to communicate with this administration server, you first need to create a password file containing the administrator password for accessing the server; this password file should be created in the install directory of the web server. Specify the name of this file in the PasswdFile text box; by default, this is admin.passwd. |
AdminServer |
Specify the IP address of the administration server to which the target web server is registered. |
AdminPort |
Indicate the port at which the administration server listens. |
Config |
In Web Server 7.0, all configurable elements of a server instance like web applications, configuration files, and search collection indexes are logically grouped and termed as a Configuration. To enable the test to locate the web server instance to be monitored, you need to mention the Configuration that applies to the instance. In the Config text box therefore, specify the name of the Configuration which the target web server instance uses. |
Node |
Node is a network resource, such as a server or a host. Instance refers to the environment of a web server daemon on a given node, including its configuration, log files and other runtime artifacts such as lock databases, caches and temporary files. To enable the test to identify the exact web server instance to be monitored, you need to specify the name of the Node on which the instance executes. The test will thus monitor only that web server instance that operates on the given Node and which uses the specified Config. |
SSL |
Set this flag to Yes if the administration server is SSL-enabled; if not, set it to No. |
WebServerDir |
Here, specify the Oracle iPlanet web server installation directory. |
Measurement | Description | Measurement Unit | Interpretation |
---|---|---|---|
No of cache hits |
Indicates the number of times the DNS cache was successfully looked up for an IP address. |
Number |
|
No. of cache misses |
Indicates the number of times an IP address was not found in the cache. |
Number |
This number includes newly-accepted connections and connections from the keep-alive system. |
Hit ratio |
Indicates the number of cache hits compared to the number of cache lookups. |
Percent |
Ideally, the value of this measure should be high. A low value is indicative of too many cache misses. This could be owing to a badly sized cache. Typically, the cache should be as large as the maximum number of clients that access your web site concurrently. Note that setting the cache size too high wastes memory and degrades performance. |
Async lookup enabled |
Indicates whether the server uses its own asynchronous DNS resolver instead of the operating system's synchronous resolver. |
Boolean |
|
Lookups in progress |
Indicates the current number of lookups in progress. |
Number |
|
Async name lookups |
Indicates the number of times during the last measurement period DNS names were looked up in the cache, so that the corresponding IP addresses could be resolved. |
Number |
|
Async address lookups |
Indicates the number of times IP addresses were looked up in the cache, so that the corresponding DNS name could be identified. |
Number |
|
DNS cache enabled |
Indicates whether the cache is enabled or not. |
Boolean |
|