Links (Standby)

The Standby branch of the Server Status Tool includes a Links category. The category provides status information about the synchronization of the standby server(s) with the main server. You can use the information to check that each standby server updates correctly.

The standby links status information is categorized as:

Id

The Server Label that uniquely identifies the server in the server standby arrangement. By default, the Server Label comprises the NetBIOS name of the machine on which the server is installed, however this can be replaced with a more meaningful label if required. The entry matches the Server Label that is defined for the server's Partners settings (see Server Label).

Node Name

The node name or IP address of the Standby or Permanent Standby server. This matches the node name or IP address that is defined for the primary connection (see Configure the Partners Settings of a Server).

IP Address

The Internet Protocol address of the standby server.

Port

The address for the port that is being used for data transfer between the Main server and the Standby server.

Link

This indicates the link that is servicing the standby server. The format is PLx:CLy where x is the number of the parent link and y is the number of the child link. The Ids match those shown in the Id columns in the Comms Parent Links and Comms Child Links categories of the Server Status Tool respectively.

Xfer Flags

Provides information about the phases of the transfer between the Main and Standby servers. The transfer phases are represented by letters (or a - if the phase has not completed correctly) and are shown in sequential order.

The possible entries for the transfer phases are:

Phase 1:
  • M—The link is a Main-Standby link.
  • D—The link is a Duty Duty link.

There is one entry for Phase 1, so M or D (or - if there if phase 1 cannot complete correctly).

Phase 2:
  • 0—The Main Connection and Back Up Connection are both unavailable.
  • 1—The Main Connection is available. The Main Connection is defined in the server configuration.
  • 2—The Back Up Connection is available. The Back Up Connection is defined in the server configuration.
  • 3—The Main Connection and the Back Up Connection are both available.

The Main and Back Up connections are defined in the server configuration (see Configure the Partners Settings of a Server).

Phase 3:
  • R—The link is running. While the link between the Main and Standby server is running, the Main server will try to update the Standby server continuously.
Phase 4:
Phase 5:
  • M—The transfer of metadata has been successful. Metadata is the term used to describe custom fields and tables.
Phase 6:
  • S—The transfer of the database structure has been successful. The database structure is the hierarchy of group names, item names and so on.
Phase 7:
  • C—The transfer of configuration has been successful. The configuration includes Mimic objects, field entries on Forms and so on.
Phase 8:
  • E—The transfer of 'live' event data has been successful. The 'live' event data includes the information that is shown in the Alarm Banner and in the ad hoc Events List. This does not include historic events.
Phase 9:
  • Q—The configuration transaction queue has been transferred from the Main to the Standby server. The configuration transaction queue is a list of pending updates relating to: Group Template changes being propagated to Group Instances, importing configuration, saving the database, and transferring the database to standby servers.

    Information on the pending transactions is available in Transactions.

Phase 10:
  • V—The Main server considers the Standby server to be valid. When a change is made, for example, a database item is renamed, the phase 8 status becomes invalid for a short time. The status should revert to V when the server is next updated.
Phase 11:
  • F—The Main server has queried and transferred the data files successfully.
Phase 12:
  • L—The Main server has queried the historic life of the Standby server to determine how much historic data is available.
Phase 13:
  • H—The historic data has been transferred successfully. Historic data includes historic data for points.
Phase 14:
  • J—The historic event journal data has been transferred successfully. The historic event journal data is the data that is shown on Events Lists.
Phase 15:
  • F—The historic files have been transferred successfully. The historic files are those that are generated for reports and so on.
Phase 16:
  • F—The configuration changes (if any) have been queried and transferred.
Phase 17:
  • * —There have been transfer errors. If there have been no errors and the transfers have completed successfully, a space is shown instead of an asterisk *.

For each of the phases, if a dash - is shown, the phase has not completed, but if a letter is shown, the phase has completed successfully. If the system is configured so that it does not support a feature, the letter is still shown as the phase has completed correctly. For example, on a system that has Historic disabled, H is still shown when phase 10 is complete (even though there is no Historic data to transfer).

State

Indicates the state of the link between the Main server and the Standby server. The possible states are:

Sync

Indicates whether the standby server is fully synchronized with the main server.

If the Sync status is Full, the standby server is synchronized with the main server.

If the Sync status is Data, the configuration has been synchronized and the servers are now synchronizing their data.

If the Sync status is No, both configuration and data are pending transfer from the main server to the standby server. The configuration is currently being synchronized.

The Sync column shows the last known synchronization status. If the link to the standby server is disconnected or the standby server has been shut down, this status will not update until the link is restored or the standby server is restarted.

Refer to the State column to determine the state of the connection to the standby server.

Flags

Indicates the pending synchronization phases (represented by four flags).

The possible flags are:

The letters are displayed in sequence (S first, and then C, followed by D and then Y).

% Cfg Sync

The percentage of configuration that has been copied and transferred to the standby server. This percentage increases as the synchronization takes place, and the Pend Cfg number decreases.

% Data Sync

The percentage of data that has been copied and transferred to the standby server. As the synchronization takes place, the % Data Sync percentage increases, and the Pend Data number decreases.

% Dyn Sync

The percentage of dynamic data that has been copied and transferred to the standby server. Dynamic data is data that is stored in the main server but is lost when the main server is shutdown, for example, statistical information such as counts.

As the synchronization takes place, the % Dyn Sync percentage increases, and the Pend Dyn number decreases.

Total Obj

The total number of database items in the main server's database.

Pend Cfg

The number of database items that have configuration updates awaiting transfer to the Standby server(s).

Pend Data

The number of database items that have data updates awaiting transfer to the Standby server(s).

Pend Dyn

The number of database items that have dynamic data updates awaiting transfer to the Standby server(s). Dynamic data is data that is stored in the main server but is lost when the main server is shutdown, for example, statistical information such as counts.

Pend GEvt

The number of global events (Alarm Banner updates, Events List updates and so on.) that have occurred at the same time as the synchronization process.

GEvt Max

The maximum number of global events (Alarm Banner updates, Events List updates and so on.) that can be stored on the Main server while the synchronization process is in progress.

% His Sync

The percentage of historic data that has been copied and transferred to the standby server. As this number increases, the Pend Record number decreases. As the synchronization takes place, the % His Sync percentage increases, and the Pend Record number decreases. If the % His Sync status appears to be stuck, the synchronization process may be unable to complete—see the Sync status for more information.

Total Record

Displays the total number of records in the Main server’s database. A record is a single event, historic value, annotation, modified value, suppressed alarm, or configuration change.

Total Bytes

The total size of the records.

Pend Record

The number of records that have changed in the main server's database since the last time the main server and standby server were synchronized. These records are waiting to be copied and transferred to the standby server.

Pend Bytes

The size of the records that are waiting to be copied and transferred to the standby server.

%His File Sync

The percentage of historic files that have been transferred.

Total His Files

The total number of historic files that are to be transferred.

Pend His Files

The number of historic files that are waiting to be transferred.

% Data File Sync

The percentage of non-historic files that have been transferred.

Total Data Files

The total number of non-historic files that are to be transferred.

Pend Data Files

The number of non-historic files that are waiting to be transferred.

Errors

The number of errors that have occurred during the transfer of data between the Main server and Standby server.

Last Error State

Indicates the state of the transfer when the last error was detected (if any). The Last Error State entries can be the same as any of the State entries.

Last Error Time

The time and date of the latest error.

Last Error

Provides technical information relating to the latest error. This information can be used by Schneider Electric engineers to determine the cause of the error.

Overruns

The number of times that the transfer was restarted due to it taking too long to complete. The amount of time permitted for a transfer is defined using the Server Configuration Tool’s Transfer Interval and Interleave settings (see Define the Transfer Interval and Transfer Timeouts).

Thread Exec Count

This provides a visual indication of standby thread activity and displays the number of times the thread has executed. It displays the same number as is shown for the standby thread’s exec count in the General System Status Information,Threads category.

Last Cold Sync Start

This shows when the synchronization was last reset to a cold sync.

Warm Sync Restarts Since Last Cold Sync

This shows how many times the link has restarted and attempted a warm sync because of a failure.

During the synchronization process, the % Cfg Sync, % Dyn Sync, % Data Sync, % Data File Sync, % His Sync, % His File Sync, and % His File Sync statuses increase. When these statuses reach 100%, the Sync status changes to Full. This indicates that the standby servers are synchronized with the main server.

If the % Cfg Sync, % Dyn Sync, % Data Sync, % Data File Sync, % His Sync, % His File Sync, and % His File Sync statuses appear to be stuck at a specific percentage below 100%, the servers may be unable to synchronize correctly. To resolve this, you could try and shutdown and restart the standby server(s). For more information, see Start and Stop the System Server.

The speed of the synchronization process varies according to the size of the database, the amount of time that the database has been down (for example, not running), and the communications path.

You can access a context-sensitive menu by right-clicking on an entry in the list.

The options that are available are:

At any point, if you suspect that the synchronization process has stalled or is not working correctly, you can use the Full Resync option.

If you intend to reset the recorded errors, or to analyze frequently occurring synchronization errors, you can use the the Reset Error Indicator option.


Disclaimer

Geo SCADA Expert 2022