HSR question

[kalyan]

Site1 replicates to site2(HA - synb) and site3(DR - async) directly in a multi-target replication. Now Site1 is down, Takeover to Site2 is completed, Site3(DR) replication is disabled by using hook sr_unregister and now setup to replicate with Site2(new primary). Now replication is only from Site2(new primary) and Site3(DR). Site1 is still down meaning it still thinks its the primary site if it were to brought up. If we bring server up(not HANA) on Site1 and we want to set it up as new secondary to Site2(new primary), what is the best process to disable replication on site1(new secondary). Is it as simple as disabling it by using hook -sr_disable and starting HANA up once, Stopping it again and then registering to site1 as new secondary. Bear in mind the idea is not to disturb site2(new primary) and site3(DR) in anyway as they are supporting production currently. I guess my concern is does -sr_disable send any info to replicated sites or it only disables replication locally ?

[rajeshazmeera]

hdbnsutil -sr_disable will disable replication completely and once you start this server it is a stand alone server. It will not be in sync with any other servers HA or DR.

once server up(not HANA) Applications it will connect to running database if you use standard virtual hostname and correct HDB store mapping.

Best way to bring back site 1 which was went down

one site1 is up use this as HA server, no down time on primary (new site2) is required.

steps:-

1. disable replication hdbnsutil -sr_diable on site1

2. un register DR site3 hdbnsutil -sr_unregister and restart

2. register site1 as HA

hdbnsutil -sr_register --name=site1 --remoteHost=site2hostname --remoteInstance=$$ --replicationMode=syncmem --operationMode=logreplay

3. register DR site3

hdbnsutil -sr_register --name=site3 --remoteHost=site1hostname --remoteInstance=$$ --replicationMode=async --operationMode=logreplay

New feature available you can also set HA with active/active. Please refer below link.

Active/Active (Read Enabled) | SAP Help Portal