Obtaining Process Requirements Status

Database process requirements status indicates whether both of the following are true:

This status is MET or UNMET. For example, if two storage managers are required for the database and only one is running, then the database's process requirements status is UNMET regardless of whether the database's host tag constraints are fulfilled.

Database processes that are running but do not fulfill current host tag constraints are not counted when NuoDB determines the database's process requirements status. For example, suppose your database requires two storage managers and two storage managers are running. However, you have changed a host tag constraint such that if one SM were to become unavailable the enforcer would not be able to restart that SM. In this situation, the database's process requirements status is UNMET.

You can obtain the most helpful information by running the NuoDB Manager show database config command. If a running process does not meet host tag constraints then NuoDB Manager reports this. In the following example, NuoDB Manager indicates that the TE processes specified by process IDs 57926 and 57256 do not fulfill the newly created host tag constraint TE_TAG=ex:.

nuodb [test] > show database config database bar2
...
  Multi Host UNMET
    Region [us-west]:
      process requirement "TEs" (#1): only 0 running TEs but 1 are required.
        Tag constraints {TE_TAG=ex:} do not match PID 57926 running on Peer ec2-23-20-165-172:48114 (broker)
        Tag constraints {TE_TAG=ex:} do not match PID 57256 running on Peer ec2-21-20-22-171:48004 (local)

Note: The enforcer will start a maximum of one TE and one SM per database per host.

ACTIVE database status and UNMET process requirements status means that a client can connect to the database, but not all process requirements and host tag constraints for the database are currently fulfilled. Alternatively, the UNMET status might mean that the process requirements and host tag constraints are fulfilled but the enforcer would not be able to successfully restart processes in the database.