Maximum sessions error when opening app in Parallels 2x client

Discussion in 'Parallels Remote Application Server' started by JamesL29, Apr 9, 2021.

  1. JamesL29

    JamesL29 Bit Poster

    Messages:
    6
    In the past few days, we've been getting an error when we open an application in the Parallels 2X client. It says Code [01/00000005] Maximum number of sessions reached.
    The Parallels knowledgebase says I should increase the number of sessions in Agent Settings tab of VDI Host Properties, but we don't have a VDI listed in our VDI tab as we're not using that config. On the RD Session Hosts there is the same tab, but the setting is inherited and the max sessions is 250. We're usually operating at about 5-10 sessions at a time.
    Whats really odd about the error is that it appears to clear itself, if I double click the shortcut for an app in the client window, the error may appear again. But if I keep trying to open the app, the error stops eventually and allows me access.
    Any ideas whats causing this and how to fix it please?
     
  2. JamesL29

    JamesL29 Bit Poster

    Messages:
    6
    Still getting this issue. It appears when you double a shortcut to an app in the Parallels client window, appears if you double click the app again, but eventually the error doesn't appear and the app opens. Its confusing our users and causing lots of helpdesk tickets for our IT department so needs sorting.
    Are there any Parallels support staff providing assistance on these forum posts or do I need to submit the issue another way to get support?

    Regards,
    James
     
  3. JustinW7

    JustinW7 Bit Poster

    Messages:
    2
    A little late to the party, but maybe this may help alleviate some confusion for you. The "Max sessions" configuration in Parallels is max sessions per RDSH, or VDI guest. So you have your max sessions set to 250, the default? meaning each RDSH will support up to 250 sessions. This isn't really ideal unless your servers are sufficiently provisioned, but I have ours set to about 30-34 Max sessions, with about 12-20 RDSH in the farm using VDI autoscaling based on user volume and load.

    A couple things you could check
    1. Server resourcing, verify they're not under provisioned and that you have enough servers in your RDSH group to serve your clients
    2. Make sure the app under publishing either doesn't have, or does have, concurrent license restrictions.
    3. Check to see if you have "Allow users to start only one instance of the application" enabled, as this will warn users that they've already launched the application and can't launch another.
    4. Make sure you have enough Microsoft RDP, and Parallels user CALs to support your user base.
    5. If you aren't, try using "Limit each user t one session per desktop" under loadbalancing. This will prevent users from launching apps on different servers, and keep them local to a single session instance on a single host.
     
  4. JamesL29

    JamesL29 Bit Poster

    Messages:
    6
    Apologies, should have been clearer. It was max sessions for RDSH. I opened a ticket with Parallels support and an engineer remoted in and had a look. The issue was being caused by a DDOS attack and once the Parallels settings were changed to only allow Parallels clients to connect in and not any HTTPS connection the issue was resolved.
     
  5. JestenC

    JestenC Bit Poster

    Messages:
    2
    Changing max connections value in vdi host properties will solve this problem. And you can do this in the agent settings. Just try it and let me know if it works!
     

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