Multiple logons by a single userid

• From Developer for z/OS® Versions 7.5.1.1 and 7.6.0.1:

In Versions 7.5.1.1 and 7.6.0.1, there is a behavior change for multiple logons by a single userid. Until those release versions, Developer for z/OS did not check for multiple logons by the same user, because only the user-specific log files are affected. However, some customers have users who regularly lose the client-host connection (usually because they are tired of waiting for a huge download and shut down the client). When those users log on again, the time-outs of the first session have not yet expired, and the host thinks the first session is still active. This is not a problem, except that the first session still has the lock on all the files the user was editing, and the users are not willing to wait for the host to realize that the session is gone and free the locks.

Lowering the time-out values was a first attempt to resolve the problem (in Version 7.6 GA), but this is a delicate balance, as Developer for z/OS should not terminate a session just because there is a network slowdown.

As a solution, the single.logon option was created (activated with v7511 UK51499 or v7601 UK54177) that cleans up any existing session if a user ID logs on twice. This is now the default behavior, because the benefit of ensuring all locks are freed outweighs the problem for the few users that log on multiple times. You can change this behavior with the new single.logon directive in rsed.envvars, which is documented in the PTF hold information.

#_RSE_JAVAOPTS=“$_RSE_JAVAOPTS -Dsingle.logon=false”

The purpose is to allow a user ID to log on multiple times. The default value is false. Uncomment to allow a user ID to log on multiple times to a single RSE daemon.