Question & Answer
Question
How can I manually clear alerts in a DB2 pureScale system?
Cause
When there is a host alert or alerts specifying a host name the alert will need to be cleared manually from the host in question.
Answer
Take for example the following "db2instance -list" output:
$ db2instance -list
ID TYPE STATE HOME_HOST CURRENT_HOST ALERT PARTITION_NUMBER LOGICAL_PORT NETNAME
-- ------- --------- ---------------- ------------ --------- -------------------------------- --------------------- --------------
0 MEMBER STARTED mhost23 mhost23 NO 0 0 mhost23-ib0
1 MEMBER STARTED mhost20 mhost20 YES 0 0 mhost20-ib0
2 MEMBER STARTED mhost21 mhost21 NO 0 0 mhost21-ib0
3 MEMBER STARTED mhost22 mhost22 YES 0 0 mhost22-ib0
128 CF PRIMARY cfhost1 cfhost1 NO - 0 cfhost1-ib0,cfhost1-ib1
129 CF PEER cfhost2 cfhost2 NO - 0 cfhost2-ib0,cfhost2-ib1
HOSTNAME STATE INSTANCE_STOPPED ALERT
-------- ----- ---------------- ------
cf002 ACTIVE NO NO
cf001 ACTIVE NO NO
host22 ACTIVE NO YES
host21 ACTIVE NO YES
host20 ACTIVE NO NO
host23 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'.
Running the "db2cluster -cm -list -alert" command displays the following three alerts:
$ db2cluster -cm -list -alert
1.
Alert: The DB2 member '3' could not be started in restart light mode on
host 'mhost21'. Check the db2diag.log for messages concerning a
restart light or database crash recovery failure on the indicated host
for DB2 member '3'.
Action: Check the cluster caching facility cfdiag log files for
messages about CF failures on the host. If there are alerts about
network adapters not responding, this alert cannot be cleared manually.
It will be cleared when a network adapter becomes available. If it is
not a problem with network adapters, this alert needs to be manually
cleared after other alerts are handled. To clear this alert run the
following command: 'db2cluster -cm -clear -alert -member 3'. For more
information, see the 'Troubleshooting options for the db2cluster
command' topic in the DB2 Information Center.
Impact: DB2 member '3' will not be able to restart light on host
'mhost21' until this alert has been cleared.
------------------------------------------------------------------------
2.
Alert: The DB2 member '1' could not be started in restart light mode on
host 'mhost22'. Check the db2diag.log for messages concerning a
restart light or database crash recovery failure on the indicated host
for DB2 member '1'.
Action: Check the cluster caching facility cfdiag log files for
messages about CF failures on the host. If there are alerts about
network adapters not responding, this alert cannot be cleared manually.
It will be cleared when a network adapter becomes available. If it is
not a problem with network adapters, this alert needs to be manually
cleared after other alerts are handled. To clear this alert run the
following command: 'db2cluster -cm -clear -alert -member 1'. For more
information, see the 'Troubleshooting options for the db2cluster
command' topic in the DB2 Information Center.
Impact: DB2 member '1' will not be able to restart light on host
'mhost22' until this alert has been cleared.
------------------------------------------------------------------------
3.
Alert: The DB2 member '1' could not be started in restart light mode on
host 'mhost21'. Check the db2diag.log for messages concerning a
restart light or database crash recovery failure on the indicated host
for DB2 member '1'.
Action: Check the cluster caching facility cfdiag log files for
messages about CF failures on the host. If there are alerts about
network adapters not responding, this alert cannot be cleared manually.
It will be cleared when a network adapter becomes available. If it is
not a problem with network adapters, this alert needs to be manually
cleared after other alerts are handled. To clear this alert run the
following command: 'db2cluster -cm -clear -alert -member 1'. For more
information, see the 'Troubleshooting options for the db2cluster
command' topic in the DB2 Information Center.
Impact: DB2 member '1' will not be able to restart light on host
'mhost21' until this alert has been cleared.
If there are no problems with any of the network adapters and the lssam output looks normal apart from the following "Failed Offline" member resources:
Online IBM.ResourceGroup:db2_db2dsg01_1-rg Control=MemberInProblemState Nominal=Online
'- Online IBM.Application:db2_db2dsg01_1-rs Control=MemberInProblemState
|- Online IBM.Application:db2_db2dsg01_1-rs:mhost20
|- Failed offline IBM.Application:db2_db2dsg01_1-rs:mhost21
|- Failed offline IBM.Application:db2_db2dsg01_1-rs:mhost22
'- Offline IBM.Application:db2_db2dsg01_1-rs:mhost23
(...)
Online IBM.ResourceGroup:db2_db2dsg01_3-rg Control=MemberInProblemState Nominal=Online
'- Online IBM.Application:db2_db2dsg01_3-rs Control=MemberInProblemState
|- Offline IBM.Application:db2_db2dsg01_3-rs:mhost20
|- Failed offline IBM.Application:db2_db2dsg01_3-rs:mhost21
|- Online IBM.Application:db2_db2dsg01_3-rs:mhost22
'- Offline IBM.Application:db2_db2dsg01_3-rs:mhost23
then this is a situation where the alerts will need to be manually cleared by running the following commands as the instance owner:
Issue the "db2cluster -cm -clear -alert -member 3" command from mhost21
Issue the "db2cluster -cm -clear -alert -member 1" command from mhost22
Issue the "db2cluster -cm -clear -alert -member 1" command from mhost21
This is just one example, but as a general rule of thumb the "db2cluster -cm -clear -alert -member X" command will need to be run from the host which displays the alert.
This Technote is not applicable for the similar alerts in CF.
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Document Information
Modified date:
16 June 2018
UID
swg21688089