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

StateDescription
NONENode state is unset when the worker starts, expected to be set quickly to the current known state.
CREATEDbdr.create_node() has been executed, but the node isn't a member of any EDB Postgres Distributed cluster yet.
JOIN_STARTbdr.join_node_group() begins to join the local node to an existing EDB Postgres Distributed cluster.
JOININGThe node join has started and is currently at the initial sync phase, creating the schema and data on the node.
CATCHUPInitial 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.
STANDBYNode 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.
PROMOTENode 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.
PROMOTINGPromotion from logical standby to full BDR node is in progress.
ACTIVEThe node is a full BDR node and is currently ACTIVE. This is the most common node status.
PART_STARTNode was ACTIVE or STANDBY and we just called bdr.part_node to remove the node from the EDB Postgres Distributed cluster.
PARTINGNode disconnects from other nodes and plays no further part in consensus or replication.
PART_CATCHUPNon-parting nodes synchronize any missing data from the recently parted node.
PARTEDNode 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