This chapter describes how to create and manage origin servers. It contains the following sections:
You can add an origin server to an origin-server pool by specifying the host name, IP address and the proportion of the total request load to be distributed to the origin server.
When you add an origin server to a pool, you are, in effect, modifying a configuration. So for the updated configuration to take effect in the Oracle Traffic Director instances, you should redeploy the configuration as described in Activating Configuration Changes.
Before You Begin
Before you begin adding an origin server to a pool, decide the following:
The origin-server pool to which you want to add the origin server.
The host name or IP address of the origin server. It is recommended that the IP address that you provide is the InfiniBand interface IP address (IPoIB) or Socket Director Protocol (SDP) address.
Note:
SDP is a native Infiniband protocol. With SDP, performance is very specific to work load. Hence, it is important to evaluate and compare the performance with SDP and IPoIB, and then select the one that meets your requirement.
The port number at which the origin server listens for requests.
Whether the server is a backup origin server.
Oracle Traffic Director forwards requests to a backup origin server only when the health check indicates that none of the primary origin servers is available.
The proportion of the total request load that Oracle Traffic Director should distribute to the origin server. You define this proportion as a weight number that is relative to the weights assigned to the other origin servers in the pool.
You can use weights to get Oracle Traffic Director to distribute the request load based on the relative capacities of the origin servers in a pool.
Consider a pool consisting of three origin servers—os1
, os2
, and os3
, with the weights 1, 2, and 2 respectively. The total of the weights assigned to all the servers in the pool is 1+2+2=5. Oracle Traffic Director distributes a fifth (1/5) of the total load to os1
, and two-fifths (2/5) of the load to each of os2
and os3
.
You can add an origin server to an origin-server by using either Fusion Middleware Control or WLST as described in the following topics:
To add an origin server to a pool by using the Fusion Middleware Control, do the following:
To add an origin server to a pool, run the otd_createOriginServer
command.
For example, the following command adds host www.example.com
and port 12345 as the origin server in the pool origin-server-pool-1
of the configuration foo
.
props = {} props['configuration'] = 'foo' props['origin-server-pool'] = 'origin-server-pool-1' props['host'] = 'www.example.com' props['port'] = '12345' otd_createOriginServer(props)
After adding an origin server to an origin-server pool, you can view the current list of each origin server. To view a list of origin servers, run the otd_listOriginServers
command.
Topics
You can view a list of origin servers by using either Fusion Middleware Control or the WLST as described in the following topics:
To view a list of origin servers by using the Fusion Middleware Control, do the following:
To view a list of origin servers defined in a pool, run the otd_listOriginServers
command as shown in the following example:
props = {} props['configuration'] = 'foo' props['origin-server-pool'] = 'origin-server-pool-1' otd_listOriginServers(props)
You can view the properties of an origin server in detail by running the otd_getOriginServerProperties
command.
After you add an origin server to a pool, you might need to change some of the settings such as host, port, or enable/disable the origin server. To modify the properties of an origin server, run the otd_setOriginServerProperties
command.
This section describes how you can do the following:
Change the properties–host, port, weight, and so on–that you defined while creating the origin server.
Enable or disable the origin server.
Specify the maximum number of connections that the origin server can handle concurrently.
Specify the duration (ramp-up time) over which Oracle Traffic Director should increase the request-sending rate to the origin server. You can use this parameter to ensure that the request load, on origin servers that have just come up after being offline, is increased gradually up to the capacity of the server.
Note:
When you change the properties of an origin server in a pool, you are modifying a configuration. To see the updated configuration in the Oracle Traffic Director instances, you should redeploy the configuration as described in Activating Configuration Changes.Topics
You can modify the properties of an origin server by using either Fusion Middleware Control or the WLST as described in the following topics:
To change the properties of an origin server by using the Fusion Middleware Control, do the following:
To change the properties of an origin server, run the otd_setOriginServerProperties
command.
For example, the following command changes the ramp up time to 1200 for the origin server www.example.com
in the pool origin-server-pool-1
of the configuration foo
.
props = {} props['configuration'] = 'foo' props['origin-server-pool'] = 'origin-server-pool-1' props['host'] = 'www.example.com' props['port'] = '12345' props['ramp-up-time'] = '1200' otd_setOriginServerProperties(props)
In a topology that includes a client, OTD and Oracle WebLogic Server (WLS), OTD receives external requests at the configured HTTP listener port. OTD then opens up another connection while communicating and proxying the request to the WLS/origin server.
As part of this connection, OTD leverages ephemeral ports so that WLS/origin server can send data back to OTD. An ephemeral port is a short-lived transport protocol port for Internet Protocol (IP) communications allocated automatically from a predefined range by the IP software. In Linux, you can limit or restrict these ephemeral ports.
Note:
OTD relies on having sufficient ephemeral ports available so that it can have sufficient pool of connections established with WLS/origin server. Not having enough ephemeral ports will cause delays processing the requests.
You can remove an origin server from a pool that is no longer required. To delete origin server, run the otd_deleteOriginServer
command.
Topics
Note:
When dynamic discovery is enabled (see Configuring an Oracle WebLogic Server Cluster as an Origin-Server Pool), if you delete an origin server that is an Oracle WebLogic Server instance in a cluster, and then re-configure the Oracle Traffic Director instance. The instance might not start if no valid origin servers remain in the pool.
You can remove an origin server by using either Fusion Middleware Control or the WLST as described in the following topics:
To remove an origin server from a pool by using the Fusion Middleware Control, do the following:
To remove the origin server with the specified host and port from a pool, run the otd_deleteOriginServer
command, as shown in the following example:
props = {} props['configuration'] = 'foo' props['origin-server-pool'] = 'origin-server-pool-1' props['host'] = 'www.example.com' props['port'] = '12345' otd_deleteOriginServer(props)