service-passthrough (Sun Java System Web Server 6.1 SP12 Reverse Proxy Plug-in Release Notes)

Sun Java System Web Server 6.1 SP12 Reverse Proxy Plug-in Release Notes

service-passthrough

The service-passthrough Service SAF forwards a request to another server for processing.

<Object name="passthrough">
ObjectType fn="force-type" type="magnus-internal/passthrough"
Service type="magnus-internal/passthrough" fn="service-passthrough"
servers="http://xxx:8084/" poll-timeout="18000" retries="0"
Error reason="Bad Gateway" fn="send-error"
uri="/opt/iplanet/web41sp8/docs/badgateway.html"
</Object>

The service-passthrough SAF accepts the following parameters:

servers - A quoted, space-delimited list of the servers that receive the forwarded requests. Individual server names may optionally be prefixed with http:// or https:// to indicate the protocol and suffixed with a colon and integer to indicate the port.
poll-timeout - Indicates the maximum time interval between two successive data for a single request. It is the waiting period for data to arrive from the client or the server. Reverse proxy plug-in waits for data to arrive from the client or the server. If there is no data written by either client or server, for poll-timeout interval, then the server logs an error and closes the connection. By default, the poll-timeout value is set to 5 minutes but can range between 1 second to 6 hours. poll-timeout does not represent maximum response time, as it could be much higher than poll-timeout value. The value of poll-timeout needs to be specified in milliseconds. For example, To set poll-timeout to 31 seconds, specify poll-timeout="31000".
retries - The number of times the service-passthrough directive tries to get a content from the web server before sending an error to the client can be configured by modifying the retries attribute in obj.conf. By default, retries is set to 2. It won't retry if the request (GET/POST) has body in it. The behavior of the retries for different values is described below:
1. When retries>0 and the request (GET / POST) has a message body then the retry will not happen.
2. When retries>0 and request is without a message body then it tries [maximum number of tries as per retries attribute in obj.conf] to get a content from the web server before sending an error to the client.
3. When retries is set to 0 (retries=0) then it won't retry if the request is timed out or due to other server errors.
sticky-cookie - (Optional) The name of a cookie that will cause requests from a given client to stick to a particular server. Once a request containing a cookie with this name is forwarded to a given server, service-passthrough attempts to forward subsequent requests from that client to the same server by sending a JROUTE header back to the client. If not specified, sticky-cookie defaults to JSESSIONID.
user - (Optional) The username that service-passthrough uses to authenticate to the remote server through Basic-Auth.

Note –
‘user&rsquo' requires that ‘password’ also be specified.
password - (Optional) The password that service-passthrough uses to authenticate to the remote server via Basic-Auth.

Note –
‘password’ requires that ‘user’ also be specified.
client-cert-nickname - (Optional) Nickname of the client certificate that service-passthrough uses to authenticate to the remote server.
validate-server-cert - (Optional) Indicates whether service-passthrough should validate the certificate presented by the remote server. If not specified, validate-server-cert defaults to true.
rewrite-host - (Optional) Indicates whether service-passthrough should rewrite the Host header sent to remote servers, replacing the local server’s hostname with the remote server’s hostname. If not specified, rewrite-host defaults to false.
rewrite-location - (Optional) Indicates whether service-passthrough should rewrite the Location headers returned by a remote server, replacing the remote server’s scheme and hostname with the local server’s scheme and hostname. If not specified, rewrite-location defaults to true.
ip-header - (Optional) Name of the header that contains the client’s IP address, or “” if the IP address should not be forwarded. If not specified, ip-header defaults to Proxy-ip.
cipher-header - (Optional) Name of the header that contains the symmetric cipher used to communicate with the client (when SSL/TLS is used), or “” if the symmetric cipher name should not be forwarded. If not specified, cipher-header defaults to Proxy-cipher.
keysize-header - (Optional) Name of the header that contains the symmetric key size used to communicate with the client (when SSL/TLS is used), or “” if the symmetric key size name should not be forwarded. If not specified, keysize-header defaults to Proxy-keysize.
secret-keysize-header - (Optional) Name of the header that contains the effective symmetric key size used to communicate with the client (when SSL/TLS is used), or “” if the effective symmetric key size name should not be forwarded. If not specified, secret-keysize-header defaults to Proxy-secret-keysize.
ssl-id-header - (Optional) Name of the header that contains the client’s SSL/TLS session ID (when SSL/TLS is used), or “” if the SSL/TLS session ID should not be forwarded. If not specified, ssl-id-header defaults to Proxy-ssl-id.
issuer-dn-header - (Optional) Name of the header that contains the client certificate issuer DN (when SSL/TLS is used), or “” if the client certificate issuer DN should not be forwarded. If not specified, issuer-dn-header defaults to Proxy-issuer-dn.
user-dn-header - (Optional) Name of the header that contains the client certificate user DN (when SSL/TLS is used), or “” if the client certificate user DN should not be forwarded. If not specified, user-dn-header defaults to Proxy-user-dn.
auth-cert-header - (Optional) Name of the header that contains the DER-encoded client certificate in Base64 encoding (when SSL/TLS is used), or “” if the client certificate should not be forwarded. If not specified, auth-cert-header defaults to Proxy-auth-cert.

When multiple remote servers are configured, service-passthrough chooses a single remote server from the list on a request-by-request basis. If a remote server cannot be contacted or returns an invalid response, service-passthrough sets the status code to 502 Bad Gateway and returns REQ_ABORTED. This will return an error to the browser. This error can be customized in the Web Server by configuring a customized response for the 502 error code.

When user and password are specified, service-passthrough will use these credentials to authenticate to the remote server using HTTP basic authentication. When one or more of the servers in the servers parameter are configured with a https:// prefix, client-cert-nickname specifies the nickname of the client certificate service-passthrough will use to authenticate to the remote server.

Note –

service-passthrough generally uses HTTP/1.1 and persistent connections for outbound requests with the following exceptions:

When forwarding a request with a Range header that arrived through HTTP/1.0, service-passthrough issues an HTTP/1.0 request. This is done because the experimental Range semantics expected by Netscape HTTP/1.0 clients differ from the Range semantics defined by the HTTP/1.1 specification.
When forwarding a request with a request body (For example POST request), service-passthrough will not reuse an existing persistent connection. This is done because the remote server is free to close a persistent connection at any time, and service-passthrough will not retry requests with a request body.

In addition, service-passthrough encodes information about the originating client in the headers named by the ip-header, cipher-header, keysize-header, secret-keysize-header, ssl-id-header, issuer-dn-header, user-dn-header, and auth-cert-header parameters (removing any client-supplied headers with the same name) before forwarding the request. Applications running on the remote server may examine these headers to extract information about the originating client.