topic Re: After cBR reload SmartPHY started multiple SSH sessions and locked me out of the box: in NSO Developer Hub Discussions

After cBR reload SmartPHY started multiple SSH sessions and locked me out of the box:

yuanliu2 — Fri, 01 Mar 2019 12:11:44 GMT

Hi, Expers

We met a issue that NSO started multiple SSH sessions and locked me out of the box after cBR reload:

SVS.RPCC01#show users

Line User Host(s) Idle Location

* 0 con 0 cisco idle 00:00:00

2 vty 0 sereno idle 00:01:48 9.13.100.89

3 vty 1 sereno idle 00:01:42 9.13.100.89

4 vty 2 epnm idle 00:00:31 9.13.100.231

5 vty 3 sereno idle 00:01:33 9.13.100.89

6 vty 4 sereno idle 00:01:53 9.13.100.89

7 vty 5 sereno idle 00:01:47 9.13.100.89

8 vty 6 sereno idle 00:01:35 9.13.100.89

9 vty 7 sereno idle 00:01:30 9.13.100.89

10 vty 8 sereno idle 00:01:24 9.13.100.89

11 vty 9 sereno idle 00:01:18 9.13.100.89

12 vty 10 sereno idle 00:01:12 9.13.100.89

13 vty 11 sereno idle 00:01:06 9.13.100.89

14 vty 12 sereno idle 00:00:59 9.13.100.89

15 vty 13 sereno idle 00:00:53 9.13.100.89

17 vty 15 epnm idle 00:00:09 9.13.100.231

These were the commands it was executing:

[ CmdAV=show configuration id ]
[ CmdAV=show configuration id ]
[ CmdAV=show version ]
[ CmdAV=terminal width 0 ]
[ CmdAV=terminal length 0 ]

Most of the sessions were terminated soon after; but this shouldn’t happen.

Re: After cBR reload SmartPHY started multiple SSH sessions and locked me out of the box:

haofan — Wed, 04 Jul 2018 07:37:12 GMT

I also hit this issue, whether have experts know why ?

Re: After cBR reload SmartPHY started multiple SSH sessions and locked me out of the box:

vleijon — Wed, 04 Jul 2018 12:14:05 GMT

There are some settings under devices device X session-pool that might be of interest, they allow you to limit the maximum number of sessions NSO will open towards a device.

Re: After cBR reload SmartPHY started multiple SSH sessions and locked me out of the box:

haofan — Wed, 04 Jul 2018 13:27:39 GMT

Hi Viktor,

Thanks for info. Two questions.

why NSO will connect device by multi sessions. Based on my idea, only need one ssh session connect to device.
what is default value of max-sessions and idle time ?

admin@ncs# show running-config devices device e8ba21ae-a0c8-344e-af08-32ec1dc79be8 session-pool max-sessions

% No entries found.

admin@ncs# show running-config devices device e8ba21ae-a0c8-344e-af08-32ec1dc79be8 session-pool idle-time

% No entries found.

Re: After cBR reload SmartPHY started multiple SSH sessions and locked me out of the box:

vleijon — Wed, 04 Jul 2018 13:39:14 GMT

Hi Hao Fan.

You can read more about session pooling in the user guide (Chapter: "Device Session Pooling").

1. There are several potential reasons, one reason is because you might be reading operational data, or you might be executing commands towards the device. NSO tries to run things in parallel towards the device where possible.

2. The default is unlimited (but the total pool is limited to 200 spread over all devices). You can control it either per device or globally under devices global-settings session-pool

Re: After cBR reload SmartPHY started multiple SSH sessions and locked me out of the box:

haofan — Wed, 04 Jul 2018 13:41:45 GMT

Thanks viktor, I will read more about "Device Session Pooling".

Re: After cBR reload SmartPHY started multiple SSH sessions and locked me out of the box:

yuanliu2 — Thu, 05 Jul 2018 01:44:46 GMT

Thanks viktor very much