Checking HotStandby status

High Availability Guide : Administering and configuring HotStandby : Administering HotStandby with ADMIN COMMANDs (HotStandby API) : Checking HotStandby status

You can request information about the HotStandby status from both the Primary and Secondary servers.

Procedure

To check status, issue the following command in the Primary or Secondary server:

ADMIN COMMAND 'hotstandby status option';

where option can be one of the following:

Option	Description
catchup	Indicates whether the server is doing catchup. Catchup occurs after the Primary server connects to the Secondary. During catchup, the Primary sends accumulated transaction logs so that the Secondary can apply the changes. Possible values are: 'ACTIVE' and 'NOT ACTIVE'.
connect	Shows whether the last attempt to connect the servers was successful.
copy	Shows whether the last attempt to copy/netcopy was successful.
switch	Shows whether the last attempt to switch the server into PRIMARY ACTIVE or SECONDARY ACTIVE state was successful.

Example

ADMIN COMMAND 'hotstandby status catchup';

Displaying switch status information

You can use the ADMIN COMMAND 'hotstandby status switch' command to verify whether a state switch occurred between two HotStandby servers.

About this task

To check HotStandby switch status information:

Procedure

Issue the following command in the Primary or Secondary server:

ADMIN COMMAND 'hotstandby status switch';

▪When no prior switch has occurred between the two servers, the following message is displayed: NO SERVER SWITCH OCCURRED BEFORE.

▪When the switch process is still active, the following message is displayed: ACTIVE.

▪When the most recent prior switch process has completed successfully, the following message is displayed: SUCCESS.

▪When the most recent attempt to switch has failed, the following message is displayed: ERROR number, where number identifies the type of error that occurred during the switch.

Displaying connect status information

You can query connect status information between the Primary and Secondary servers. This capability is equivalent to the SQL function HOTSTANDBY_CONNECTSTATUS, which you can use in the application code.

Procedure

To check connect status, issue the following command in the Primary or Secondary server:

ADMIN COMMAND 'hotstandby status connect';

The possible return values are:

Error Code	Text	Description
0	CONNECTED	Connect active. Returned from both the Primary and Secondary server.
14007	CONNECTING	Primary server is connecting to the Secondary server. Returned from both the Primary and Secondary servers.
14008	CATCHUP	Primary server is connected to the Secondary server, but the transaction log is not yet fully copied. Returned from both the Primary and Secondary server.
14010	DISCONNECTING	The servers are in the process of disconnecting.
14537	BROKEN	Connection is broken. Returned from both the Primary and Secondary servers.

Displaying connection information

You can query the connection information that the HotStandby server uses to connect to the other server by using the ADMIN COMMAND 'hotstandby cominfo' command.

Procedure

To display connection information, issue the following command in the Primary or

Secondary server:

ADMIN COMMAND 'hotstandby cominfo';

The command returns the connection information that is defined with the HotStandby.Connect parameter.

Displaying role start time

Sometimes it is important to know when the server entered the current role of Primary or Secondary.

You can retrieve information about the start time of the Primary or Secondary role by using the ADMIN COMMAND 'info' command with the options primarystarttime and secondarystarttime.

For example:

admin command 'info primarystarttime';
       RC TEXT
       -- ----
       0 2005-06-09 14:22:18

admin command 'info secondarystarttime';
       RC TEXT
       -- ----
       0 2005-06-09 18:24:44

The reported time is the time the server role became Primary or Secondary. The STANDALONE state is considered to be a state of the Primary role.

The primary start time is set when the following transitions occur:

▪SECONDARY ALONE => PRIMARY ALONE

▪SECONDARY ALONE => STANDALONE

▪SECONDARY ACTIVE => PRIMARY ACTIVE

The secondary start time is set when the following transitions occur:

▪The server is started in the SECONDARY ALONE state

▪OFFLINE (started with -x backupserver) => SECONDARY ALONE

▪PRIMARY ALONE => SECONDARY ALONE

▪STANDALONE => SECONDARY ALONE

▪PRIMARY ACTIVE => SECONDARY ACTIVE

If the current role contradicts the query, the query returns an empty string. For example, if the role is SECONDARY and the command info primarystarttime is issued, it returns an empty string.