VTL - What is the limit for concurrent Console users?

Asset ID:	1-71-1015321.1
Update Date:	2011-08-11
Keywords:

Solution Type Technical Instruction Sure

Solution 1015321.1 : VTL - What is the limit for concurrent Console users?

Applies to:

Sun StorageTek VTL Storage Appliance - Version: 4.0 - Build 1221 and later   [Release: 4.0 and later ]
Sun StorageTek VTL Plus Storage Appliance - Version: 1.0 - Build 1323 to 2.0 - Build 1656   [Release: 1.0 to 2.0]
Sun StorageTek VTL Value System - Version: 1.0 - Build 1323 and later    [Release: 1.0 and later]
Sun StorageTek VTL Prime System - Version: 1.0 - Build 1813 to 1.1 - Build 2076   [Release: 1.0 to 1.0]
All Platforms
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***Checked for relevance on 05-08-2011*** (dd-mm-yyyy)

Goal

To answer the following:

Is there a limit of number of users that can access the Console at one time?
What is the limit for concurrent Console users?
Is the two concurrent users limit a bug?

Solution

1. The limit of 2 concurrent users is not a bug, this is by design.
From VTL users Guide:

"Running VTL console software on a remote host"

For routine operations, using the VTL console application from a remote host machine is usually more convenient than running it on the appliance itself. So, in most cases, your Sun service representative will have installed at least one additional instance of the application for you. You can then install as many additional instances as you require on other machines. Note, however, that no more than two (2) instances of the console can access the same VTL server at the same time."

2. Issues that may arise with >2 users logged into Console concurrently:
    a. Resource/device contention. VTL uses first come first serve, so this should not be a big issue and normally is understood with shared device environments, and is true with only 2 users.
    b. VTL does not keep track of how many users are logged in concurrently, so a users display may become stale and not display the current data or events. VTL will refresh two Consoles periodically, but with >2 Consoles, unexpected results will occur. It does not matter if they are R/W or R/O. However, short term monitoring (e.g., support logging in for 5 minutes and logging out), should not cause issues.
    c. During engineering testing, no issues were seen until 9 concurrent connections were made. The issue that was encountered was that some users Consoles hung and a restart of the communication module on the VTL server had to be restarted ('vtl comm restart'). However, engineering warns that unpredictable results can occur with >2 concurrent users.

3. Recommendation is to make sure the Console inactivity timeout is set (default setting is 10 minutes, but can be changed via "Console Options" under the "Tools" pull down).

4. There is no message or any indication of how many users are logged in via the Console. An enhancement has been requested to address this issue.

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