show-nodes v5.6
Shows all nodes in the EDB Postgres Distributed cluster and their summary.
Synopsis
Shows all nodes in the EDB Postgres Distributed cluster and their summary, including name, node id, group, and current/target state.
Node States
| State | Description |
|---|---|
| NONE | Node state is unset when the worker starts, expected to be set quickly to the current known state. |
| CREATED | bdr.create_node() has been executed, but the node isn't a member of any EDB Postgres Distributed cluster yet. |
| JOIN_START | bdr.join_node_group() begins to join the local node to an existing EDB Postgres Distributed cluster. |
| JOINING | The node join has started and is currently at the initial sync phase, creating the schema and data on the node. |
| CATCHUP | Initial sync phase is complete; now the join is at the last step of retrieving and applying transactions that were performed on the upstream peer node since the join started. |
| STANDBY | Node join has finished, but not yet started to broadcast changes. All joins spend some time in this state, but if defined as a Logical Standby, the node will continue in this state. |
| PROMOTE | Node was a logical standby and we just called bdr.promote_node to move the node state to ACTIVE. These two PROMOTE states have to be coherent to the fact, that only one node can be with a state higher than STANDBY but lower than ACTIVE. |
| PROMOTING | Promotion from logical standby to full BDR node is in progress. |
| ACTIVE | The node is a full BDR node and is currently ACTIVE. This is the most common node status. |
| PART_START | Node was ACTIVE or STANDBY and we just called bdr.part_node to remove the node from the EDB Postgres Distributed cluster. |
| PARTING | Node disconnects from other nodes and plays no further part in consensus or replication. |
| PART_CATCHUP | Non-parting nodes synchronize any missing data from the recently parted node. |
| PARTED | Node parting operation is now complete on all nodes. |
Only one node at a time can be in either of the states PROMOTE or PROMOTING. STANDBY, in the Current State or Target State columns, indicates that the node is or will be in a read-only state.
pgd show-nodes [flags]
Options
No specific command options. See global options for global options.
Examples
Show all nodes in the cluster with a node down
In this example, there is a multi-node cluster with a data node down.
$ pgd show-nodes
Output
Node Node ID Group Type Current State Target State Status Seq ID ---- ------- ----- ---- ------------- ------------ ------ ------ bdr-a1 3136956818 group_a data ACTIVE ACTIVE Up 1 bdr-a2 2133699692 group_a data ACTIVE ACTIVE Unreachable 2 witness-a 3889635963 group_a witness ACTIVE ACTIVE Up 3
Show all nodes in the cluster with different node types
In this example, there is a multi-node cluster with logical standby, witness and subscriber-only nodes. Note that, unlike logical standby nodes, the subscriber-only nodes are fully joined node to the cluster.
$ pgd show-nodes
Output
Node Node ID Group Type Current State Target State Status Seq ID ---- ------- ----- ---- ------------- ------------ ------ ------ bdr-a1 3136956818 group_a data ACTIVE ACTIVE Up 6 bdr-a2 2133699692 group_a data ACTIVE ACTIVE Up 3 logical-standby-a1 1140256918 group_a standby STANDBY STANDBY Up 9 witness-a 3889635963 group_a witness ACTIVE ACTIVE Up 7 bdr-b1 2380210996 group_b data ACTIVE ACTIVE Up 1 bdr-b2 2244996162 group_b data ACTIVE ACTIVE Up 2 logical-standby-b1 3541792022 group_b standby STANDBY STANDBY Up 10 witness-b 661050297 group_b witness ACTIVE ACTIVE Up 5 witness-c 1954444188 group_c witness ACTIVE ACTIVE Up 4 subscriber-only-c1 2448841809 group_so subscriber-only ACTIVE ACTIVE Up 8