Viewing details for an alert

If one of the members or cluster caching facilities reports an alert, you can view more information about the alert using the DB2_INSTANCE_ALERTS administrative view. Alternatively, as an instance owner, you can use the db2cluster command with the [-cm] -list -alert parameters. Similarly, as a root, use the db2cluster command with the [-cm] -list -alert <instance> with <instance> as the instance of interest.

About this task

This task assumes that you already determined an alert was raised on one of the hosts in your Db2® pureScale® instance. For example, the LIST INSTANCE command might have shown an alert for one of your members:


ID     TYPE    STATE   HOME_HOST CURRENT_HOST ALERT
------ ------- ------- --------- ------------ -----
     0 MEMBER  STARTED hostA     hostA        YES
     1 MEMBER  STARTED hostB     hostB        NO   
     2 MEMBER  STARTED hostC     hostC        NO   
     3 MEMBER  STARTED hostD     hostD        NO   
   128 CF      PRIMARY hostE     -            NO   
   129 CF      PEER    hostF     -            NO   

HOSTNAME  STATE  INSTANCE_STOPPED ALERT
--------- ------ ---------------- -----
hostA     ACTIVE NO               NO
hostB     ACTIVE NO               NO
hostC     ACTIVE NO               NO
hostD     ACTIVE NO               NO
hostE     ACTIVE NO               NO
hostF     ACTIVE NO               NO

In this case, member 0 is showing an alert.

Procedure

To find more information about the alerts in your instance:

Formulate an SQL statement that uses the DB2_INSTANCE_ALERTS administrative view:
```
SELECT * FROM SYSIBMADM.DB2_INSTANCE_ALERTS
```
Run the SQL statement.

Results

Depending on the nature of the problem on member 0, the information that the DB2_INSTANCE_ALERTS administrative view returns varies. You might, for example, receive a message like the one that follows:

MESSAGE           
--------------------------------------------------------------------------------------------------------
Could not restart light Db2 member '0' on hosts 'hostA'. Check the db2diag.log for messages concerning a restart light or database crash recovery failure on the indicated hosts for Db2 member '0'.

ALERT_ACTION
-----------------------------------------------------------------------------------------
This alert must be cleared manually with the command: 'db2cluster -clear -alert -member 0'

IMPACT
---------------------------------------------------------------------------------------------------
Db2 member '0' will not be able to restart light on host 'hostC' until this alert has been cleared.

Example

Example 1: Using the db2cluster command to view alert information

In this example, the db2instance -list command returns the following information:

$ db2instance -list
ID        TYPE             STATE           HOME_HOST               CURRENT_HOST            ALERT   PARTITION_NUMBER        LOGICAL_PORT    NETNAME
--        ----             -----           ---------               ------------            -----   ----------------        ------------    -------
0       MEMBER           ERROR                 HostA                      HostA              YES                  0                   0          -
1       MEMBER           STARTED               HostB                      HostB               NO                  0                   1          -
2       MEMBER           STARTED               HostC                      HostC               NO                  0                   2          -
128     CF               PRIMARY               HostD                      HostD               NO                  -                   0          -
129     CF               PEER                  HostE                      HostE               NO                  -                   0          -

HOSTNAME                   STATE                INSTANCE_STOPPED        ALERT
--------                   -----                ----------------        -----
   HostA                  ACTIVE                              NO          YES
   HostB                  ACTIVE                              NO           NO
   HostC                  ACTIVE                              NO           NO
   HostD                  ACTIVE                              NO           NO
   HostE                  ACTIVE                              NO           NO

There is currently an alert for a member, CF, or host in the data-sharing instance. For more information on the alert, its impact,
and how to clear it, run the following command: 'db2cluster [-cm] -list -alert'

From the information contained in Table 2, you can see that the output of db2instance -list is showing that member 0 was not able to start on any host. (If it had started on guest host, then the status would be STARTED, and the current host would show the name of the host it was running on.)

Using the db2cluster -cm -list -alert command shows the following message:

$ db2cluster -cm -list -alert

Alert: Db2 member '0' failed to start on its home host 'Host A'. The cluster manager will 
attempt to restart the Db2 member
in restart light mode on another host. Check the db2diag.log for messages concerning failures 
on hosts 'HostA' for member '0'.

Action: This alert must be cleared manually with the command: 'db2cluster [-cm] -clear -alert'.

Impact: Db2 member '0' will not be able to service requests until this alert has been cleared 
and the Db2 member returns to its home host.

What to do next

Perform the investigation or action specified in the information returned by the DB2_INSTANCE_ALERTS administrative view or the db2cluster command.