Replication

WAL Senders Overview

The WAL Senders section contains a table that displays one WAL sender per row with configuration and current status information.

WAL Sender Status

  • Streaming – Indicates the number of WAL sender processes actively streaming WAL data to replicas in real time.
  • Startup – Represents WAL sender processes in the startup phase, preparing to establish a connection or begin streaming.
  • Catchup – Refers to WAL sender processes working to catch up replicas with the latest data after a delay.
  • Backup – Denotes WAL sender processes engaged in sending WAL data as part of a backup operation.
  • Stopping – Represents WAL sender processes that are in the process of shutting down.

Data

  • PID – The process ID of the WAL sender.
  • App Name – Name of the application connected to the WAL sender process.
  • Slot Name: Name of the replication slot, if used.
  • Slot Type: Type of the replication slot (e.g., physical or logical).
  • Host – Host of the connected WAL receiver client.
  • IP – IP address of the connected WAL receiver client.
  • Port – Port of the connected WAL receiver client.
  • State – Current WAL sender state.
  • Synch State – Synchronous state of the standby server.
  • Sync Priority – Priority of the current standby server client being chosen as the synchronous standby.
  • Standby Lag – Number of WAL segments the standby server is behind as compared to the primary server. If this number increases, it means that the standby server is not able to keep up and replication may eventually be broken.
  • Write Location - Last transaction log position written to disk by this standby server.
  • Sent Location - Last transaction log position sent on this connection.
  • Flush Location - Last transaction log position flushed to disk by this standby server.
  • Replay Location - Last transaction log position replayed into the database on this standby server.

Admin Actions

Click the icon in the Delete table column to perform the following action:

  • Delete – Delete the WAL Sender topology object if it becomes unnecessary. This will not affect the PostgreSQL server. Because the topology objects are persisted on the FMS, an object may become redundant or unnecessary if the WAL sender is no longer in use. You can manually delete it with this action. If it is still in use, the object will just be recreated.

WAL Senders

Replication Slots Overview

This dashboard provides insights into the replication slots configured for the PostgreSQL instance. It is divided into sections for logical and physical replication slots, displaying details about their status and metrics.

WAL Status

  • Reserved: Count of reserved slots.
  • Extended: Count of extended slots.
  • Unreserved: Count of unreserved slots.
  • Lost: Count of replication slots marked as lost.

Data

  • Slot Name: The name of the logical replication slot.
  • Database: The database associated with the slot.
  • Plugin: The plugin used for logical replication.
  • Active: Indicates whether the slot is currently active.
  • Active PID: The process ID (PID) associated with the active slot, if applicable.
  • WAL Status: Status of the Write-Ahead Log (e.g., active, lost).
  • Safe WAL Size: The size of the WAL that is considered safe for the slot.
  • Status:
    • Xmin: Transaction ID of the oldest transaction.
    • Catalog Xmin: The catalog transaction ID.
    • Restart LSN: The Log Sequence Number (LSN) where streaming can restart.
    • Confirmed Flush LSN: The last LSN flushed and confirmed by the slot.
    • Conflicting: Indicates if there are conflicts with this replication slot.
  • Configuration:
    • Two Phase: Whether two-phase commit is enabled for the slot.
  • Period Total:
    • Txns: Total number of transactions during the period.
    • Size: Total size of WAL data during the period.
  • Period Spilled:
    • Txns: Number of transactions spilled to disk during the period.
    • Count: Number of WAL entries spilled during the period.
    • Size: Size of WAL data spilled to disk during the period.
  • Period Streamed:
    • Txns: Number of transactions streamed during the period.
    • Count: Number of WAL entries streamed during the period.
    • Size: Size of WAL data streamed during the period.

Admin Actions

Click the icon in the Delete table column to perform the following action:

  • Delete – Delete the Replication Slot topology object if it becomes unnecessary. This will not affect the PostgreSQL server. Because the topology objects are persisted on the FMS, an object may become redundant or unnecessary if the WAL sender is no longer in use. You can manually delete it with this action. If it is still in use, the object will just be recreated.

Replication Slots

Publications

Overview

This table provides an overview of the replication publications set up in the PostgreSQL instance

Data

  • Name: The name of the publication.
  • Database: The name of the database where the publication is defined.
  • Owner: The role or user who owns the publication.
  • AllTables: Indicates whether the publication includes all tables in the database.
  • Insert: Specifies if the publication includes INSERT operations.
  • Update: Specifies if the publication includes UPDATE operations.
  • Delete: Specifies if the publication includes DELETE operations.
  • Truncate: Specifies if the publication includes TRUNCATE operations.
  • ViaRoot: Indicates whether the publication is applied via a root role.

Publications

Subscriptions

Overview

This table provides an overview of the replication subscriptions set up in the PostgreSQL instance

Data

  • Name: The name of the subscription.
  • Database: The name of the database where the subscription is defined.
  • Owner: The user or role that owns the subscription.
  • Slot: The replication slot used by the subscription to keep track of the WAL (Write-Ahead Log) positions.
  • Enabled: Indicates whether the subscription is enabled.
  • TwoPhaseState: Shows the state of the two-phase commit.
  • Publications: Lists the publications the subscription is subscribing to.
  • Workers: The number of workers assigned to this subscription.
  • SkipLSN: The Log Sequence Number (LSN) position to skip during replication.
  • Error Counts:
    1. Apply: Errors during applying changes.
    2. Sync: Errors during synchronization.
  • Binary: Indicates whether the subscription transfers data in binary format.
  • Stream: Specifies if streaming replication is enabled.
  • DisableOnErr: Indicates if the subscription should be disabled on error.
  • Configuration
    1. PasswordRequired: Specifies whether a password is required for the subscription.
    2. RunAsOwner: Indicates if the subscription runs with the owner’s permissions.
    3. SyncCommit: The synchronization commit setting.
    4. Origin: The origin of the replication data.

Subscriptions