Run-time Parameters

The server uses run-time parameters after it is started by tmboot. As indicated previously, tmboot uses the values found in the TUXDIR, APPDIR and ENVFILE parameters for the MACHINES section when booting the server. It also sets thePATH for the server to:

     “APPDIR:TUXDIR/bin:/bin:path

where path is the value of the last PATH= line appearing in the ENVFILE file. The following parameters are run-time parameters.

ENVFILE=string_value 

You can use the ENVFILE parameter for a server to add values to the environment established by tmboot during initialization of the server. You can optionally set variables specified in the file named in the SERVERS ENVFILE parameter after you set those in the MACHINES ENVFILE used by tmboot. These files cannot be used to override TUXDIR, APDIR, TUXCONFIG, or TUSOFFSET. The best policy is to include in the server’s ENVFILE only those variable assignments known to be needed to ensure proper running of the application.

On the server, the ENVFILE file is processed after the server starts. Therefore, it cannot be used to set the pathnames used to find executable or dynamically loaded files needed to execute the server. If you need to perform these tasks, use the machine ENVFILE instead.

Within ENVFILE only lines of the form VARIABLE =string are allowed. VARIABLE must start with an underscore or alphabetic character and can contain only underscore or alphanumeric characters. If the server is associated with a server group that can be migrated to a second machine, the ENVFILE must be in the same location on both machines.

CONV={Y | N}

CONV specifies whether the server is a conversational server.CONV takes a Y value if a conversational server is being defined. Connections can only be made to conversational servers. For a request/response server, you can either set CONV=N, which is the default, or omit the parameter.

RQADDR=string_value 

RQADDR assigns a symbolic name to the request queue of this server. MSSQ sets are established by using the same symbolic name for more than one server (or by specifying MIN greater than 1). All members of an MSSQ set must offer an identical set of services and must be in the same server group.

If RQADDR is not specified, the system assigns a unique key to serve as the queue address for this server. However,tmadmin commands that take a queue address as an argument are easier to use if queues are given symbolic names.

RQPERM =number 

Use the RQPERM parameter to assign UNIX-style permissions to the request queue for this server. The value of number can be between 0001 and 0777, inclusive. If no parameter is specified, the permissions value of the bulletin board, as specified by PERM in the RESOURCES section, is used. If no value is specified there, the default of 0666 is used (the default exposes your application to possible use by any login on the system, so consider this carefully).

REPLYQ={ Y | N }

The REPLYQ parameter specifies whether a reply queue, separate from the request queue, should be established for AOUT. If N is specified, the reply queue is created on the same LMID as the AOUT. If only one server is using the request queue, replies can be retrieved from the request queue without causing problems. However, if the server is a member of an MSSQ set and contains services programmed to receive reply messages, REPLYQ should be set to Y so that an individual reply queue is created for this server. If set toN, the reply is sent to the request queue shared by all servers for the MSSQ set, and you cannot ensure that the reply will be picked up by the server that is waiting for it.

It should be standard practice for all member servers of an MSSQ set to specify REPLYQ=Y if replies are anticipated. Servers in an MSSQ set are required to have identical offerings of services, so it is reasonable to expect that if one server in the set expects replies, any server in the set can also expect replies.

RPPERM=number 

Use the RPPERM parameter to assign permissions to the reply queue. number is specified in the usual UNIX fashion (for example, 0600); the value can be between 0001 and 0777, inclusive. If RPPERM is not specified, the default value 0666 is used. This parameter is useful only when REPLYQ=Y. If requests and replies are read from the same queue, only RQPERM is needed; RPPERM is ignored.

RESTART={ Y | N }

The RESTART parameter takes a Y or N to indicate whether AOUT is restartable. The default is N. If the server is in a group that can be migrated, RESTART must be Y. A server started with a SIGTERM signal cannot be restarted; it must be rebooted.

An application’s policy on restarting servers might vary according to whether the server is in production or not. During the test phase of application development it is reasonable to expect that a server might fail repeatedly, but server failures should be rare events once the application has been put into production. You might want to set more stringent parameters for restarting servers once the application is in production.