Host On-Demand Client Cache allows Web-based clients to connect to SNA host applications using a Java(TM)-based terminal emulation program, which connects the client to the host using TN3270. A less typical application of the Host On-Demand function is Telnet for emulation of non TN3270 terminals. It supports 3270, 5250, VT (VT52, VT100, VT220_7_BIT, VT220_8_BIT), and CICS gateway sessions.
The IP address of the Telnet servers is defaulted to the address of the Host On-Demand Server. This means that in the simplest configuration, the TN3270E server will be located external to the router.
In a more sophisticated setup, the Host On-Demand administrator will set up the Host On-Demand server specially so that it's common session Telnet server address is the same as the Host On-Demand Client Cache cluster address (that is, the router(s) are employed as the TN3270E servers). This is the standard usage of Host On-Demand Client Cache as envisioned by the creators. In this configuration, the Network Dispatcher cluster address will have several associated ports: some for the Host On-Demand function and one (typically port 23) for the TN3270E function. See "Using the Network Dispatcher Feature" for details about configuration of TN3270E with Network Dispatcher. From the point of view of the Host On-Demand Server, it is programmed with an arbitrary Telnet server address. An HOD session may be programmed to use an arbitrary Telnet server, provided that signed applets are supported by the browser (generally this is true, but refer to eNetwork Host On-Demand Version 3.0 Administrator's Guide, IBM document number SC31-8627, for provisions required for OS/2). The Host On-Demand server used to provide terminal capabilities to clients is independent of the Telnet servers, which are directly related to the computers with which clients wish to communicate.
On the other hand, for a large configuration a number of TN3270E servers can be added to the Telnet port (port 23) under the Network Dispatcher configuration. For an extremely large configuration, additional ports can be set up as Telnet ports, since both the IP address and port (default 23) of a Telnet server can be configured in Host On-Demand sessions. Only one Host On-Demand server is required for these multi-Telnet server configurations that support tens of thousands of users.
This support allows a IBM 2212 acting as a TN3270E server to cache the terminal emulation applet and serve it to client browsers upon request. The applet is retrieved from a Web server the first time a client requests it and is stored in the Host On-Demand cache memory. Future client requests for the applet will be served directly from the cache, eliminating the need to do additional retrieves from the Web server.
For detailed information about using Host On-Demand from a client browser, refer to the chapter entitled "Understanding the Host On-Demand Clients" in eNetwork Host On-Demand Version 3.0 Administrator's Guide, IBM document number SC31-8627.
Notes:
This chapter describes how to configure the Host On-Demand Client Cache feature and use the Host On-Demand Client Cache monitoring commands. It contains the following sections:
Host On-Demand Client Cache must be used with Network Dispatcher. Before you use Host On-Demand Client Cache the first time you must:
Then you can use the configuration and monitoring commands to alter the Host On-Demand Client Cache environment.
| Note: | While the Network Dispatcher changes done via Talk 6 change the current running configuration, the changes for the Host On-Demand Client Cache do not change the current running configuration unless explicitly activated via the activate command in Talk 6 or via the Talk 5 feature HOD Client Cache. The exception to this is if the cluster/port for an HTTP Proxy is removed via Talk 6 feature NDR it will cause the HTTP proxy for the Host On-Demand Client Cache to also be removed from the current running configuration. |
Example:
Config>f ndr
NDR Config>enable executor
NDR Config>add cluster
Cluster Address [0.0.0.0]? 113.3.1.10
FIN count [4000]?
FIN time out [30]?
Stale timer [1500]?
Cluster 113.3.1.10 has been added.
Fincount has been set to 4000 for cluster 113.3.1.10
Fintimeout has been set to 30 for cluster 113.3.1.10
Staletimer has been set to 1500 for cluster 113.3.1.10
NDR Config>add port
Cluster Address [0.0.0.0]? 113.3.1.10
Port number [80]? 80
Port type(tcp=1, udp=2, both=3) [3]?
Max. weight (0-100) [20]?
Only one pftp port per cluster allowed
Port mode (none=0, sticky=1 pftp=2 extcache=4 hod client cache=5) [0]? 5
Default server TCP connection timeout (Range 5-240 seconds) [120]?
Default client TCP connection timeout (Range 5-240 seconds) [120]?
Maximum partition size (1-4095 megabytes or 0 for no limit) [0]?
URL mask to identify Java applet [*.jar]?
Default expiration time for Java applet
(1-10080 minutes or 0 for no expiration) [60]?
Do you want to add a URL mask? [No]:
The Host On-Demand Client Cache partition has been successfully created.
Requested port has been added to cluster 113.3.1.10
Port Mode has been set to hod for port 80 in cluster 113.3.1.10
Maxweight has been set to 20 for port 80 in cluster 113.3.1.10
Port Type has been set to Both for port 80 in cluster 113.3.1.10
NDR Config>exit
| Note: | This example is partial and only shows the adding of the HOD Client Cache port (80) with its unique port mode and console menu. The remainder of the configuration follows examples seen in "Using the Network Dispatcher Feature". |
The following lists the example parameters and their descriptions.
| Note: | Cluster IP Addresses are assumed to be on the same logical subnet as the previous hop router (IP router). |
Valid values: Any valid IP address
Default value: 0.0.0.0
Valid Values: 0 to 65535
Default value: 4000
Valid Values: 0 to 65535
Default value: 30
Valid Values: 0 to 65535
Default value: 1500
Valid Values: 1 to 65535
Default value: 80
Valid Values: 1, 2, 3
Default value: 3
Valid Values: 0 to 100
Default value: 20
Valid Values: 0,1,2,4,5, where:
Default value: 0
Valid Values: 5 to 240 seconds
Default Value: 120 seconds
Valid Values: 5 to 240 seconds
Default Value: 120 seconds
Valid Values: Yes or No
Default Value: No
Valid Values: 1 to 4095 Megabytes or 0 (no maximum)
Default Value: 0 (no maximum)
Valid Values: any URL mask
Default Value: *.jar*
Valid Values: 1 - 10080 minutes, or 0 for no expiration
Default Value: 60
| Note: | This feature is not normally used with Host On-Demand, but it is explained here for completeness. There is one URL mask which is of interest; it is the Java applet mask which is configured as part of the partition. That mask is typically the only one which should be configured; thus it is recommended you do not use the add, delete, list, modify urlmask commands. |
Valid Values: Yes or No
Default Value: No
Wildcard characters can be used when specifying a URL mask. Wildcards can be used when configuring Network Dispatcher for Host On-Demand Client Cache or when using the add or modify url command from the HOD Client Cache prompt. The characters used as wildcards are an * (asterisk) or a # (number sign). Wildcards can be used in any position as a part of the URL.
The * represents no characters or all characters as a part of that URL:
Example: *abc.html would filter the following URL masks.
abc.html finabc.html defchtjqsprabc.html
The # represents any single character.
Example: ab#.html would filter the follow URL masks.
abc.html abf.html abo.html
You must use Network Dispatcher to configure the initial cluster and port for the Host On-Demand Client Cache feature. Once you have added the cluster and port, configuring the port mode as a Host On-Demand Client Cache port, you can then modify and display Host On-Demand Client Cache configuration parameters at the HOD Client Cache Config> prompt.
See *** for information about Network Dispatcher.
To access the Host On-Demand Client Cache configuration environment, enter the f hod client cache command at the Config> prompt.
Config> f h HOD Client Cache Config>
This section describes the Host On-Demand Client Cache Configuration
commands. Table 16 lists the Host On-Demand Client Cache configuration
commands. These commands specify the Host On-Demand Client Cache
feature parameters. To activate these changes, restart the router or
use the activate command.
Table 16. Host On-Demand Client Cache Configuration Commands Summary
| Command | Function |
|---|---|
| ? (Help) | Displays all the commands available for this command level or lists the options for specific commands (if available). See "Getting Help". |
| Activate | Activates the Host On-Demand Client Cache partition, using the latest configuration. |
| Add | Adds a URL mask. |
| Delete | Deletes a URL mask or a partition. |
| List | Lists the Host On-Demand Client Cache information. |
| Modify | Modifies the Host On-Demand Client Cache information. |
| Exit | Returns you to the previous command level. See "Exiting a Lower Level Environment". |
Use the activate command to initialize the Host On-Demand Client Cache partition, using the latest configuration.
Syntax:
Example:
HOD Client Cache Config>act ? ACTIVATE ALL initializes the Host On-Demand Client Cache partition, using the latest configuration.
Use the add command to add a URL mask.
| Note: | This feature is not normally used with Host On-Demand.. |
Syntax:
| Note: | To add proxies and the partition, you must use Network Dispatcher and go through the add port or set port commands. |
Use the delete command to delete a URL mask or the partition.
Syntax:
| Note: | URL masks are not normally added or deleted with HOD Client Cache. |
Example:
HOD Client Cache Config>del part The HOD Client Cache partition number has been deleted.
| Note: | To delete a proxy you must use the Network Dispatcher feature and remove the associated port and/or cluster, or change the port mode of the port to something other than Host On-Demand Client Cache. |
Use the list command to list the Host On-Demand Client Cache information.
Syntax:
| Note: | The ECCM is typically not used with Host On-Demand Client Cache. |
Example: list all
HOD Client Cache Config>list all
Host On-Demand Client Cache Partition
Cluster address 113.3.1.10, Port 80
1 Host On-Demand Client Cache partition defined.
Example: list partition
HOD Client Cache Config>list pa
Host On-Demand Client Cache Partition
Maximum partition size : Unlimited
URL mask to identify Java applets: '*.jar'
Default expiration time for Java applet: 60
Associated proxies (cluster port): (113.3.1.10 80)
1 Host On-Demand Client Cache partition defined.
Example: list proxy
HOD Client Cache Config>li pro
1) Cluster address 113.3.1.10, Port 80, HOD Client Cache partition
HTTP proxy number [1]? 1
HTTP Proxy 1
HOD Client Cache Partition
Cluster Address : 113.3.1.10
Port Number : 80
Server Connection Timeout : 120 seconds
Client Connection Timeout : 120 seconds
Use the modify command to modify the Host On-Demand Client Cache configuration information.
Syntax:
| Note: | This feature is not normally used with Host On-Demand.. |
| Note: | This feature is not normally used with Host On-Demand.. |
Example: modify partition
HOD Client Cache Config>modify partition
Maximum partition size (1-4095 megabytes or 0 for no limit) [0]? 2000
URL mask to identify Java applet [*.jar]?
Default expiration time for Java applet
(1-10080 minutes or 0 for no expiration) [60]?
The Host On-Demand Client Cache partition has been modified.
Example: modify proxy
HOD Client Cache Config>mod proxy
1) Cluster address 113.3.1.10, Port 80, HOD Client Cache partition
HTTP proxy number [1]? 1
Default server TCP connection timeout (Range 5-240 seconds) [120]? 200
Default client TCP connection timeout (Range 5-240 seconds) [120]?
The HTTP proxy has been modified.
To access the Host On-Demand Client Cache monitoring environment enter the f hod client cachecommand at the t 5 config prompt.
+f h
Table 17 lists the Host On-Demand Client
Cache monitoring commands.
Table 17. Host On-Demand Client Cache Monitoring Commands Summary
| Command | Function |
|---|---|
| ? (Help) | Displays all the commands available for this command level or lists the options for specific commands (if available). See "Getting Help". |
| Activate | Activates the Host On-Demand Client Cache information, using the latest configuration. |
| Clear | Clears all objects from the Host On-Demand Client Cache partition or clears Host On-Demand Client Cache statistics. |
| Enable | Enables the Host On-Demand Client Cache partition. |
| Delete | Deletes the Host On-Demand Client Cache partition, proxy or URL mask. |
| Disable | Disables the Host On-Demand Client Cache partition. |
| List | Lists the Host On-Demand Client Cache information. |
| Modify | Modifies the Host On-Demand Client Cache information. |
| Exit | Returns you to the previous command level. See "Exiting a Lower Level Environment". |
Use the activate command to activate the Host On-Demand Client Cache partition or proxies, or a specific proxy.
Syntax:
Example: activate all
HOD Client Cache>act all The Host On-Demand Client Cache partition must be disabled to reactivate it. Do you wish to continue? [No]: y
Example: activate partition
HOD Client Cache>act pa The Host On-Demand Client Cache partition must be disabled to reactivate it. Do you wish to continue? [No]: y Do you wish clear this partition? [No]: y Do you wish to enable this partition? [Yes]: y
Example: activate proxy
HOD Client Cache>activate pr
1) Cluster address 113.3.1.10, Port 80, HOD Client Cache partition
Enter proxy number: [1]? 1
You are trying to activate an existing proxy.
Doing this will cause the proxy to be terminated before
being reactivated.
Do you wish to continue? [No]: y
Use the clear command to clear all objects from the Host On-Demand Client Cache partition or to clear statistics.
| Note: | Clearing the objects from the partition does not clear the statistics for the partition. |
Syntax:
Example: clear partition
HOD Client Cache>clear pa HOD Client Cache partition must be disabled to clear its contents. Do you wish to continue? [No]: y Do you wish to enable this partition? [Yes]: y
Use the enable command to enable the Host On-Demand Client Cache partition.
Syntax:
Example:
HOD Client Cache>enable partition
Use the delete command to delete the Host On-Demand Client Cache partition.
Syntax:
Example: delete partition
HOD Client Cache>delete partition WARNING: This will delete partition and free all memory! Do you wish to continue? [No] : yes HOD Client Cache>
Use the disable command to disable the Host On-Demand Client Cache partition.
Syntax:
Example:
HOD Client Cache>disable partition
Use the list command to display the information for the Host On-Demand Client Cache partition, all policies and proxies, or a specified policy or proxy.
Syntax:
Example: list all
HOD Client Cache>list all
HOD Client Cache Partition Status: Enabled
Cluster address: 113.3.1.10 Port 80
1 partition(s) active.
External Cache Manager Port: 83
Connection timeout: 120 seconds
Example: list delete
HOD Client Cache>list delete Delete Table URL string -- hit count ======================= '/abc.html' -- 4 '/soccer.html' -- 2 '/tennis.html' -- 1 '/curling.html' -- 3
Example: list item
HOD Client Cache>list item Current number of items: 5 URL String -- hit count ======================= '/' -- 2 '/file5k.html' -- 1 '/file4k.html' -- 1 '/file2k.html' -- 3 '/file1k.html' -- 1
Example: list partition
HOD Client Cache>list partition
HOD Client Cache Partition Status: Enabled
Cluster address: 113.3.1.10, Port 80
Partition size: Current - 0 bytes Highest - 0 bytes Maximum - Unlimited
Number of objects: Current - 0 Highest - 0 Maximum - Unlimited
Maximum object size: Unlimited
HOD Client Cache purge interval: 600 minute(s)
Hit ratio: 0%
Total number of hits: 0
Cache Hit Bytes Served: 0
Breakdown of responses for the Cache Hits
(note: this is based on whether the HTTP Proxy considered it a hit.
So these count may not add up to the hit count above)
Response 200(OK): 0
Response 203(Non-Authoriative): 0
Response 206(Partial Content): 0
Response 300(Multiple Choices): 0
Response 301(Moved Permanently): 0
Response 304(Not Modified): 0
Response 410(Gone): 0
Total number of misses: 0
Cache Miss Bytes Served: 0
Breakdown of responses for the Cache Misses
Response 100 Range(Information): 0
Response 200(OK): 0
Response 200 Range(Successful-not 200): 0
Response 304(Not Modified): 0
Response 300 Range(Redirection-not 304): 0
Response 400 Range(Client Error): 0
Response 500 Range(Server Error): 0
Response other (not in the above): 0
Object Excluded (Object too large): 0
(Object expired): 0
(DONT CACHE header): 0
(URL Mask excluded): 0
(Image excluded): 0
(Static object excluded): 0
(Dynamic object excluded): 0
(Cache disabled): 0
Total number of objects added via ECCM Interface: 0
Total number of objects not added via ECCM Interface but was attempted: 0
Total number of objects replaced via ECCM Interface: 0
Example: list policy
HOD Client Cache>list policy
URL mask to identify Java Applets: *.jar
Default lifetime: 60 minute(s)
Example: list proxy
HOD Client Cache>list proxy
1) Cluster address 113.3.1.10, Port 80, HOD Client Cache Partition
Enter proxy number: [1]? 1
Proxy 1: assigned to the HOD Client Cache partition
Cluster address: 113.3.1.10 Port number: 80
Server Connection Timeout: 120 seconds
Client Connection Timeout: 120 seconds
Client connections: 0 current / 0 at highest point
Server connections: 0 current / 0 at highest point
Total cache hits: 0
Total cache misses: 0
Cache misses (object not in cache): 0
(unsupported method): 0
(can't send response): 0
(non-cached request): 0
Use the modify command to modify the External Cache Control Manager.
Syntax:
This section describes dynamic reconfiguration (DR) as it affects Talk 6 and Talk 5 commands.
Host On-Demand Client Cache does not support the CONFIG (Talk 6) delete interface command.
The GWCON (Talk 5) activate interface command is not applicable for Host On-Demand Client Cache. The Host On-Demand Client Cache is a feature, not an interface.
The GWCON (Talk 5) reset interface command is not applicable for Host On-Demand Client Cache. The Host On-Demand Client Cache is a feature, not an interface.
Host On-Demand Client Cache (HOD) supports the following Host On-Demand Client Cache (HOD)-specific GWCON (Talk 5) reset commands:
All Host On-Demand Client Cache commands are supported by the GWCON, feature HOD, activate all command.
The Host On-Demand Client Cache must already have been activated (see CONFIG, feature HOD, activate).
The following table summarizes the Host On-Demand Client Cache
configuration changes that are activated when the GWCON, feature HOD,
activate partition command is invoked:
| Commands whose changes are activated by the GWCON, feature HOD, activate partition command |
| CONFIG, feature HOD, add URLMASK |
| CONFIG, feature HOD, delete PARTITION |
| CONFIG, feature HOD, delete URLMASK |
| CONFIG, feature HOD, modify PARTITION |
| CONFIG, feature HOD, modify PROXY |
| CONFIG, feature HOD, modify URLMASK |
The following table summarizes the Host On-Demand Client Cache
configuration changes that are activated when the GWCON, feature HOD,
activate proxy command is invoked:
| Commands whose changes are activated by the GWCON, feature HOD, activate proxy command |
| CONFIG, feature HOD, modify PROXY |
The following table summarizes the Host On-Demand Client Cache (HOD)
configuration changes that are not activated when the GWCON, feature HOD,
activate external port command is invoked:
| Commands whose changes are activated by the GWCON, feature HOD, activate external port command |
| CONFIG, feature HOD, modify EXTERNAL |
Host On-Demand Client Cache (HOD) supports the following CONFIG (Talk 6) activate commands:
All Host On-Demand Client Cache commands are supported by the CONFIG, feature HOD, activate command.
Host On-Demand Client Cache (HOD) supports the following GWCON commands
that temporarily change the operational state of the device. These
changes are lost whenever the device is reloaded, restarted, or you execute
any dynamically reconfigurable command.
| Commands | ||
GWCON, feature HOD, modify external
| ||
GWCON, feature HOD, delete partition
|