Concurrency Control

NIM installations can become severely bogged down when they are being performed on a large number of clients at the same time. This can be caused by network bandwidth or workload on the NIM servers. Users can ease the severity of this situation by controlling the number of clients installing at the same time.

The "concurrent" and "time_limit" attributes can be used in conjunction with the bos_inst, cust, and alt_disk_install operations to control the number of client machines being operated on simultaneously from a client group. The "concurrent" attribute controls the number of clients in a group that are processing a particular operation at one time. Once a client finishes the operation, another client will initiate the operation one at a time. The "time_limit" attribute prohibits NIM from initiating an operation on any more clients of the group, after the specified time (in hours) has elapsed.

From Web-based System Manager

1. Select multiple targets from the main NIM object container.
2. Use the "Selected" pull down menu and select any of the following options:
   • Install Base Operating System
   • Install/Update Software
   • Alternate Disk Install
3. From any of those dialogs select the "NIM settings" or "Advanced" button.
4. In those dialogs a section containing the Concurrency Controls can be specified.

Note: Web-based System Manager does not provide support for continuing after a failure or the time limit expired. The user must reselect the clients that failed or were not attempted and then reissue the command.

From SMIT

The Concurrency Control attributes can be accessed from all SMIT panels under the Install and Update Software menu and the Alternate Disk Installation menu.

From the Command Line

The concurrent and time_limit attributes can be used in conjunction with the bos_inst, cust and alt_disk_install operations.

For example, to have the fileset bos.games installed on only 5 machines from the client group tmp_grp at one time, enter the following command:

nim -o cust -a lpp_source=lpp_source1 -a filesets=bos.games \ -a concurrent=5 tmp_grp

In this example, to have the fileset bos.games installed on only 10 clients from tmp_grp, with no other installs permitted after 3 hours have elapsed, enter the following command:

nim -o bos_inst -a lpp_source=lpp_source1 -a spot=spot1 \ -a concurrent=10 -a time_limit=3 tmp_grp

Note: The Concurrency Controlled operation can complete and leave the group in one of three states.

1. All machines install successfully.
2. Some machines may fail the install.
3. If the time_limit attribute was used, time may have expired before the install operation was complete.

In the first situation the group will get set back to the state prior to the operation. In the second and third situations, the group will be left in a state that indicates some machines have completed and some have not. Problems with failing machines should be investigated. At this point, the user can continue with the machines that did not complete by re-issuing the command on the group. Alternatively the user may wish to "reset" the group which will set the group back to its state prior to the Concurrency Controlled operation.