This article will describe the configuration commit error seen after the code upgrade, it's workaround & fix.

This error may come with any type of configuration commit after the code upgrade or there are chances the initial commit might fail & you may lose the device access.

Example 1:

In this particular example, the initial commit failed & later the commit was failing.

Error Log:
 

# commit
error: Cannot read configuration: Database is already open
error: configuration check-out failed
 

Example 2:

In this particular example, we are trying to activate GRES, NSR & NSB.

# activate system switchover-on-routing-crash
# activate chassis redundancy graceful-switchover
# activate routing-options nonstop-routing
# activate protocols layer2-control nonstop-bridging
 

Error Log:
 

# commit

configuration check succeeds
re1:
error: Cannot read configuration: Database is already open
error: configuration check-out failed
re0:
error: remote commit-configuration failed on re1

The idea of the workaround here is to first do the "commit no-synchronize" first & later "commit" (If standalone) or "commit synchronize" (If VC or Dual-RE).
Later all the configuration commits will go fine.
 

Workaround:
 

# activate chassis redundancy graceful-switchover

# commit no-synchronize
# commit

OR

# commit synchronize
 

A few issues in this area have been resolved via https://prsearch.juniper.net/PR1663590.