Red Hat High Availability Clustering for SAP Solutions

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Guided Exercise: Setting up the SAP HSR

In this exercise, you access and use the lab environment, and install SAP HANA system replication on the previously installed SAP HANA servers.

Outcomes

You write a playbook that installs SAP HANA system replication from the hana1 to the hana2 server.

As the student user on the workstation machine, use the lab command to prepare your system for this exercise.

This command ensures that the environment is configured correctly for creating your Ansible Playbooks in the future.

[student@workstation ~]$ lab start sap-hana-hsr

Instructions

  1. Change to the ansible-files directory in your home directory:

    [student@workstation ~]$ cd ~/ansible-files

  2. Add the following content to the group_vars/hanas file:

    ## BEGIN sap_hana_hsr parameters
sap_hana_cluster_nodes:
  - node_name: hana1.lab.example.com
    node_ip: "172.25.250.22"
    node_role: primary
    hana_site: DC01

  - node_name: hana2.lab.example.com
    node_ip: "172.25.250.23"
    node_role: secondary
    hana_site: DC02
## END sap_hana_hsr parameters

    With this configuration, you achieve the following outcome:

    • You define the nodes for system replication. This variable is also used later in the cluster setup.

  3. Create the setup-hsr.yml playbook to install SAP HANA on the servers:

    - name: Step 3-C - Configure HANA System Replication
  hosts: hanas
  become: true

  tasks:

    - name: Configure System Replication
      include_role:
        name: community.sap_install.sap_ha_install_hana_hsr

  4. Execute the setup-hsr.yml playbook.

    [student@workstation ~]$ ansible-playbook setup-hsr.yml -v -K

  5. Log in to hana1 and verify that system replication is working.

    [student@workstation ansible-files]$ ssh hana1
Last login: Fri Jul 22 04:49:22 2022
[student@hana1 ~]$ sudo su - rheadm
[sudo] password for student: student
Last login: Fr Jul 22 04:49:35 EDT 2022 on pts/0
rheadm@hana1:/usr/sap/RHE/HDB00> cdpy
rheadm@hana1:/usr/[...]/python_support> python systemReplicationStatus.py
|Database |Host  |Port  |Service Name |Volume ID |Site ID |Site Name |Secon   ...
|         |      |      |             |          |        |          |Host    ...
|-------- |----- |----- |------------ |--------- |------- |--------- |------  ...
|SYSTEMDB |hana1 |30001 |nameserver   |        1 |      1 |DC01      |hana2   ...
|RHE      |hana1 |30007 |xsengine     |        2 |      1 |DC01      |hana2   ...
|RHE      |hana1 |30003 |indexserver  |        3 |      1 |DC01      |hana2   ...

status system replication site "2": ACTIVE
overall system replication status: ACTIVE

Local System Replication State
~~~~~~~~~~

mode: PRIMARY
site id: 1
site name: DC01

    Notice here that data is being replicated from hana1 to hana2, and the servers are fully in sync.

  6. Log in to hana2 and verify the replication state.

    [student@workstation ansible-files]$ ssh hana2
[student@hana2 ~]$ sudo su - rheadm
[sudo] password for student: student
rheadm@hana2:/usr/sap/RHE/HDB00> hdbnsutil -sr_state

System Replication State
~~~~~~~~

online: true

mode: sync
operation mode: logreplay
site id: 2
site name: DC02

is source system: false
is secondary/consumer system: true
has secondaries/consumers attached: false
is a takeover active: false
is primary suspended: false
is timetravel enabled: false
replay mode: auto
active primary site: 1

primary masters: hana1

Host Mappings:
~~~~~~

hana2 -> [DC02] hana2
hana2 -> [DC01] hana1


Site Mappings:
~~~~~~
DC01 (primary/primary)
    |---DC02 (sync/logreplay)

Tier of DC01: 1
Tier of DC02: 2

Replication mode of DC01: primary
Replication mode of DC02: sync

Operation mode of DC01: primary
Operation mode of DC02: logreplay

Mapping: DC01 -> DC02
done.

    Notice here that hana2 is the secondary site named DC02, and hana1 is the primary server.

  7. Now that both servers are in sync, take over the primary role on hana2:

    rheadm@hana2:/usr/sap/RHE/HDB00> hdbnsutil -sr_takeover
done.

    Running this command might take some time.

    Note

    After a takeover, both servers are acting as primary servers. Therefore, before initiating a takeover, you must ensure that no application is writing to hana1 any more, for example by shutting down hana1 first. In this case, no application exists yet, so it is not a concern.

  8. Now you register hana1 as a new secondary server.

    1. Log in to hana1 and assume rheadm:

      [student@workstation ansible-files]$ ssh hana1
[student@hana1 ~]$ sudo su - rheadm
[sudo] password for student: student

    2. Stop the HANA database:

      rheadm@hana1:/usr/sap/RHE/HDB00> HDB stop
hdbdaemon will wait maximal 300 seconds for NewDB services finishing.
Stopping instance using: /usr/sap/RHE/SYS/exe/hdb/sapcontrol -prot NI_HTTP
 -nr 00 -function Stop 400

07.09.2022 06:00:42
Stop
OK
Waiting for stopped instance using: /usr/sap/RHE/SYS/exe/hdb/sapcontrol
 -prot NI_HTTP -nr 00 -function WaitforStopped 600 2

07.09.2022 06:01:12
WaitforStopped
OK
hdbdaemon is stopped.

    3. Register hana1 as secondary host to hana2:

      rheadm@hana1:/usr/sap/RHE/HDB00>  hdbnsutil -sr_register --name=DC01 \
> --remoteHost=hana2 --remoteInstance='00' --replicationMode=sync
--operationMode not set; using default from global.ini/[system_replication]/
operation_mode: logreplay
adding site ...
collecting information ...
updating local ini files ...
done.

    4. Start database again on hana1:

      rheadm@hana1:/usr/sap/RHE/HDB00> HDB start


StartService
Impromptu CCC initialization by 'rscpCInit'.
  See SAP note 1266393.
OK
OK
Starting instance using: /usr/sap/RHE/SYS/exe/hdb/sapcontrol -prot NI_HTTP -nr 00 -function StartWait 2700 2


07.09.2022 06:08:13
Start
OK

07.09.2022 06:08:43
StartWait
OK

    5. On hana1, verify the replication state:

      rheadm@hana1:/usr/sap/RHE/HDB00> hdbnsutil  -sr_state
System Replication State
~~~~~~~~

online: true

mode: sync
operation mode: logreplay
site id: 1
site name: DC01

is source system: false
is secondary/consumer system: true
has secondaries/consumers attached: false
is a takeover active: false
is primary suspended: false
is timetravel enabled: false
replay mode: auto
active primary site: 2

primary masters: hana2

Host Mappings:
~~~~~~

hana1 -> [DC02] hana2
hana1 -> [DC01] hana1


Site Mappings:
~~~~~~
DC02 (primary/primary)
    |---DC01 (sync/logreplay)

Tier of DC02: 1
Tier of DC01: 2

Replication mode of DC02: primary
Replication mode of DC01: sync

Operation mode of DC02: primary
Operation mode of DC01: logreplay

Mapping: DC02 -> DC01
done.

  9. On hana2, verify the replication state:

    [student@workstation ansible-files]$ ssh hana2
Last login: Fri Jul 22 04:49:22 2022
[student@hana2 ~]$ sudo su - rheadm
[sudo] password for student: student
Last login: Fr Jul 22 04:49:35 EDT 2022 on pts/0
rheadm@hana2:/usr/sap/RHE/HDB00> cdpy
rheadm@hana2:/usr/[...]/python_support> python systemReplicationStatus.py
|Database |Host  |Port  |Service Name |Volume ID |Site ID |Site Name |Secon   ...
|         |      |      |             |          |        |          |Host    ...
|-------- |----- |----- |------------ |--------- |------- |--------- |-----   ...
|SYSTEMDB |hana2 |30001 |nameserver   |        1 |      2 |DC02      |hana1   ...
|RHE      |hana2 |30007 |xsengine     |        2 |      2 |DC02      |hana1   ...
|RHE      |hana2 |30003 |indexserver  |        3 |      2 |DC02      |hana1   ...

status system replication site "1": ACTIVE
overall system replication status: ACTIVE

Local System Replication State
~~~~~~~~~~

mode: PRIMARY
site id: 2
site name: DC02

    If the overall system replication status is ACTIVE, the system replication is configured correctly.

Finish

To complete this exercise, take these steps:

  • Run the lab command on the workstation machine, and use the lab command to create the files in this exercise.

  • Run the ansible-playbook command to configure HANA system replication if not successful previously, and complete the exercise.

These steps are important to ensure that resources from previous exercises do not impact upcoming exercises.

[student@workstation ~]$ lab finish sap-hana-hsr
[student@workstation ~]$ ansible-playbook setup-hsr.yml -v -K
BECOME password: student

This concludes the guided exercise.

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Revision: rh445-8.4-4e0c572