Description

Error logs are seen when more than 32 concurrent Netconf sessions are connected to a router and trying to execute commands simultaneously.
 

Symptoms

The following errors are seen when more than 32 concurrent Netconf sessions are connected to router and trying to execute commands simultaneously. 
Aug 13 18:23:21.941  jtac-mx480-r2017-re0 mgd[92909]: UI_DBASE_LOGIN_FAILED: could not login to database: maximum edit sessions limit
Aug 13 18:23:21.942  jtac-mx480-r2017-re0 mgd[92956]: UI_DBASE_LOGIN_FAILED: could not login to database: maximum edit sessions limit
Aug 13 18:23:21.945  jtac-mx480-r2017-re0 mgd[92911]: UI_DBASE_LOGIN_FAILED: could not login to database: maximum edit sessions limit
Aug 13 18:23:21.945  jtac-mx480-r2017-re0 mgd[92908]: UI_DBASE_LOGIN_FAILED: could not login to database: maximum edit sessions limit
Aug 13 18:23:21.948  jtac-mx480-r2017-re0 mgd[92933]: UI_DBASE_LOGIN_FAILED: could not login to database: maximum edit sessions limit
Aug 13 18:23:22.038  jtac-mx480-r2017-re0 mgd[92942]: UI_DBASE_LOGIN_FAILED: could not login to database: maximum edit sessions limit
 
Aug 13 18:23:21.112  jtac-mx480-r2017-re0 sshd[92954]: error: do_exec_no_pty: fork: Resource temporarily unavailable
Aug 13 18:23:21.112  jtac-mx480-r2017-re0 sshd[92954]: subsystem request for netconf by user labroot failed, subsystem not found
Aug 13 18:23:21.132  jtac-mx480-r2017-re0 sshd[92961]: error: do_exec_no_pty: fork: Resource temporarily unavailable
Aug 13 18:23:21.135  jtac-mx480-r2017-re0 sshd[92961]: subsystem request for netconf by user labroot failed, subsystem not found

Solution

  1. The knob “set system services ssh connection-limit <number-of-connection-limit>” used to set the maximum SSH sessions can be allowed on the device.
  2. Among the login sessions confined by "connection-limit",  the system allows limited sessions at most to do operations simultaneously. That's DDL_MAX_USERS for CLI session which is hard-coded as 32.

Modification History

2022-09-16: Publish