Week 5: Tune and Test the Cluster Unit 1: Designing the

Week 5: Tune and Test the Cluster

Unit 1: Designing the Cluster Tests

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Designing the cluster testsOverview of planning the cluster tests

• Designing test cases involves:o Gathering the requirementso Assessing the possible failure scenarioso Walking through the possible outcomes• In a complex, high availability environment, several types of

failures may occuro The types of failures range from software crashes up to a loss of

the whole network or SAN infrastructure• The cluster must be able to safely handle all possible failure

scenarios• Testing each scenario, comparing it with the requirements,

and documenting the recovery procedure will enable efficient handling of failures when they occur


Designing the cluster testsPlanning the tests to perform

• There will be several test to be performed• You must plan tests for every conceivable scenario• Below are some example tests to be performed on the SAP

HANA SR primary:o Stop Primary Database on node01o Stop Primary Database on node02o Crash Primary Database on node01o Crash Primary Database on node02o Crash node01o Crash node02• Below are some example tests to be performed on the SAP

HANA SR secondary:o Stop the Secondary Database on node02o Crash the Secondary Database on node02o Crash node02


Designing the cluster testsExample test procedure document

• A test procedure document should contain all the information required to perform the test and assess the outcome

• This includes:o Stating which component is being testedo Description of the testo The procedure for performing the testo The recovery procedureo The expected results


Designing the cluster testsWalk through an example test – establish the initial cluster state

• The following test is based on the settings:o PREFER_SITE_TAKEOVER=“true”o AUTOMATED_REGISTER=“false”o SBD_STARTMODE=clean• This test will walk through the primary SAP

HANA database suffering a complete failure• Check the current cluster statuso The cluster is healthyo All resources are runningo The primary SAP HANA database is active on

node01• You have now established the initial state

of the cluster and the configuration options• Have the documentation for this test

available


Designing the cluster testsWalk through an example test – execute the test procedure

• Create the failure by killing the primary databaseo In a terminal session on the node running the

SAP HANA primary, switch to the <SID>admuser

o Run: HDB kill-9o Monitor the progress


Designing the cluster testsWalk through an example test – monitor the failover process

• The primary SAP HANA database running on node01 has just been killedo The multi-state resource

msl_SAPHana_HA1_HDB00 is in an unknown state

o There is no master (primary) for this resourceo The IP address resource rsc_ip_HA1_HDB00

has moved to node02

• The cluster is in the process of re-configuring and the SAP HANA primary database is not located on either node01 or node02


Designing the cluster testsWalk through an example test – monitor the failover process

• The resource msl_SAPHana_HA1_HDB00 is starting the master (SAP HANA primary) on node02o The IP address resource

rsc_ip_HA1_HDB00 previously moved to node02 is active

• The resource msl_SAPHana_HA1_HDB00 is running on node02o The SAP HANA primary database is now active

on node02


Designing the cluster testsWhat next? Review the test

• The failover of the SAP HANA primary database to node02 is completeo From a client, test the connection to the SAP HANA database is

working• Check the documented expected outcome of the test• Compare the documented outcome with the actual outcome• Make any required updates:o Documentationo Cluster configurationo Operations Manual

Thank You!

Contact Information:[email protected]


Unit 2: Activating SAP HANA SR on the Cluster


Activating SAP HANA SR on the clusterDemonstration – activate SAP HANA SR on the cluster

• The cluster configuration is completeo The cluster has been in maintenance mode during the

configuration process• The SAP HANA status will be checked on both nodes to

ensure it is stopped• The cluster status will be checked• The cluster will be taken out of maintenance mode• Hawk will be used to monitor the cluster loading the

resources• The cluster status will be checked to ensure everything is

running as expected


Activating SAP HANA SR on the clusterDemonstration summary – activate SAP HANA SR on the cluster

• The cluster configuration is complete, and the cluster has been in maintenance mode during the configuration process

• SAP HANA was stopped on both nodes• The cluster status was checked

• The cluster was taken out of maintenance mode



• Hawk was used to watch the resources load

• The resources have started but there is a monitor error on the SAP HANA resource on node02



• The monitoring error on the SAP HANA resource on node02 was clearedo This is a temporary warning which occurred as the cluster came out of

maintenance mode

• All the resources have started and there are no warnings or errors



• SAP HANA with system replication is now active on the cluster

• The next stage is to perform tests on the cluster hosting SAP HANA to make sure it performs as the design specification states

Thank You!



Unit 3: Testing the Completed Cluster Configuration


Testing the completed cluster configurationDemonstration – perform an example test on the SAP HANA SR primary

• In this demonstration we will performed a single test on the cluster hosting SAP HANA SRo To fully test the cluster other tests must be performed• The cluster and configuration will be checked before

performing the test• The SAP HANA primary instance running on node01 will be

stopped using SAP tools and the cluster’s reaction to the SAP HANA failure will be monitored using Hawk

• The cluster will be monitored until the SAP HANA primary has been recovered

• The cluster status will be checked using the command line


Testing the completed cluster configurationDemonstration – perform an example test on the SAP HANA SR primary

• Once the failover has completed, the SAP HANA system replication configuration on node01 will be viewed

• The SAP HANA system replication status will be checked• The SAP HANA SR deployment will be returned back to

full HA, the SAP HANA primary will be running on node02 and the SR secondary on node01


Testing the completed cluster configurationDemonstration summary – perform an example test on the SAP HANA SR primary

• In this demonstration we performed a single test on the cluster hosting SAP HANAo To fully test the cluster other tests must be performed• The cluster status before performing the test was

established

• The SAP HANA primary instance running on node01 was stopped and monitored using Hawk



• After some time the IP address resource was running on node02 and the multi-state clone master SAP HANA resource was also running on node02o At this point the cluster has recovered the SAP HANA primary and

it is active on node02

• The cluster status was then checked using the command line



• The SAP HANA system replication configuration on node01 was checked

• The system replication status was checked from node01

• The next step is to return the SAP HANA SR deployment back to full HA



• The SAP HANA SR instance on node01 was configured to be an SR secondary with node02 as the primary

• To bring back full HA the SAP HANA cluster resource must be refreshed

Thank You!


Documents

Week 5: Tune and Test the Cluster Unit 1: Designing the