JMX Maintenance Operations

Available in Nexus Repository Pro

DatabaseMaintenanceBean

This JMX bean provides a set of attributes and operations to allow the user to inspect and manipulate the state of a node in Orient database cluster. The expectation is that these will be used mainly for troubleshooting and recovery operations.

Attributes

DatabaseRole

Only available in HA-C

Applies to all databases on the current node

Possible Values: MASTER, REPLICA

This attribute represents the role of the node in an Orient cluster. The role of MASTER represents a fully writable node in an Orient cluster which participates in the writeQuorum. The role of REPLICA represents a node in read-only mode which is accepting only idempotent commands, e.g. read and queries.

When setting a node's role to REPLICA an override is added to Orient's configuration so that node will always be a REPLICA, regardless of the cluster's default role. When the node is set back to MASTER that override is removed, so it will defer to the cluster's default role - which is MASTER unless it's been frozen.

References

Distributed-Architecture: Server Roles

DatabaseStatus

Only available in HA-C

Applies to all databases on the current node

Possible Values: ONLINE, OFFLINE, NOT_AVAILABLE

This attribute represents the status of the node in an Orient cluster. The status of ONLINE represents a node in a normal state which is fully participating in the cluster. The status of OFFLINE represents a node that is not currently participating in the cluster. The status of NOT_AVAILABLE represents a node that is not currently available for some reason.

Setting the database status to NOT_AVAILABLE triggers an automatic delta-sync with the rest of the cluster. If this is successful, it will move back to ONLINE.

Operations

checkDatabase

Possible Database Names: accesslog, component, config, security

Checks database pages for corruption and checks that indices cover all records (i.e. no duplicates).

repairDatabase

Possible Database Names: accesslog, component, config, security

Attempts to repair any corrupt database pages and rebuilds indices.

reinstallDatabase

Only available in HA-C

Possible Database Names: accesslog, component, config, security

Attempts to reinstall the full database from the rest of the cluster.

The user can't force a reinstall from a specific node, but typically Orient will choose the node that most recently took a backup or the oldest member (assuming that's not the node requesting the reinstall)