Replication Modes between Sites : HANA Replication

Here i am explaining different replication Modes between Sites in the HANA Replication setup. Synchronous (SYNC) : The secondary system sends an acknowledgment back to the primary system as soon as the data is received and persisted to the log volumes on disk. Asynchronous (ASYNC): Asynchronous replication, the primary does not wait until the secondary sends an acknowledgement. Synchronous in-memory (SYNCMEM):The secondary system sends an acknowledgment back to the primary system as soon as the data is received in memory. The disk I/O speed on the secondary system doesn’t influence the primary’s performance. Site Distance  Replication Mode  < 100 KM SYNC ……

memorymanager –> Parameter : allocationlimit

Parameter : allocationlimit  Key Highlights : This parameter is very useful in the Multi-tenant database container (MDC) system to set memory limit on each tenant system. Example : If we have 4 tenant systems in the landscape then we can set on indexsever.ini file –> allocationlimit for each tenant system to the accepted memory limit for each tenant system. Parameter: allocationlimit Description: Sets an upper limit of memory usable by individual processes in megabytes. When set to 0 or missing, the SAP HANA system implicitly calculates a default value based on global_allocation_limit. Multi-tenant database container (MDC) systems: In a tenant database, the parameter ……

inifile_checker –> Parameter : interval

Parameter: interval   Description: Sets a time interval in seconds between two checks for differences of ini file parameters between primary and secondary systems in a system replication scenario. To disable/enable those checks, set the parameter [inifile_checker] enable. Value: Positive integer   Default: 3600 (seconds = 1 hour)   Restart required: No     Ref: SAP HANA Admin Guide and Frequently Used Configuration Parameters in SAP HANA

inifile_checker–> exclusion_[|*][/]

Key Highlights: This parameter will help in the scenario where we don’t want to replicate few parameter from primary to secondary site. Scenario where we want to have different value of particular parameters in primary and secondary site. This parameter is helpful where replication on the primary site with [inifile_checker]/replicate = true is enables With parameter replication activated, any changes made on the primary are automatically replicated to the secondary sites; without this parameter replication activated changes should be manually duplicated on the other system.   Parameter: exclusion_[<inifilename>|*][/<LAYER>] Description: The ini file name can be replaced with an asterisk. The LAYER ……

[inifile_checker]/enable=true & [inifile_checker]/replicate = true

  inifile_checker –> enable = True  &  [inifile_checker]/replicate = true Key Highlights : [inifile_checker]/replicate = true- This parameter is very useful in the scenario where we have muli -tier and multi-target replication setup in the landscape . If we are changing any parameter in the primary site and [inifile_checker]/replicate = true- parameter is enabled then automatically it will be reflected in the secondary site . It helps to sync-up the parameters across all the HANA sites . If we don’t have [inifile_checker]/replicate = true : parameters set on HANA then there are chances that if we are changing any parameter in the primary site then ……

Hana table partitioning | re-partitioning | Improve Performance

Hana table partitioning is one of major problems for most of the customers to re partition of HANA tables due to the reason that a table partition cannot contain more than 2,147,483,648 (2 billion) rows. During the time customer need to perform table re partitioning due to 2 billion limit and For large tables – table partitioning takes lot of time and customer wants to optimize overall run-time of table partitioning . Here i am providing tips to improve total run-time of Hana table partitioning along with table partitioning steps: Run delta merge on table before re-partitioning . Command for delta merge “MERGE ……

How to Stop and Start SAP HANA Tenant Database

There are multiple way to stop and start SAP HANA Tenant Database . But i personally prefer to stop and start SAP HANA Tenant Database using SAP HANA Studio . Step 1- Launch SAP HANA Studio and open SQL console .     Once SQL Console is open then you can execute below mentioned sql commands for Stop and Start SAP HANA Tenant Database.   How to Stop SAP HANA Tenant Database: ( SMH is TENANT DATABASE SID): alter system stop database SMH   How to verify if Tenant database has been stopped: Execute SQL command: select * from m_databases; ACTIVE ……

How to Generate full system dump in hana

If You are experiencing high memory consumption / out of memory situations . SAP is asking you to generate full system dump for further analysis. This blog with help you to generate Generate full system dump in hana. Goto  /usr/sap/<SID>/HDBXX/exe/python_support directory Run python script fullSystemInfoDump.py as following:   <HOSTNAME>:/usr/sap/<SID>/HDB10/exe/python_support> python fullSystemInfoDump.py -t <TENANT SID> System Info Dump created 2019-07-22 11:09:20 (UTC) with script version 2.00 Called with command line options: -t <TENANT SID> Writing to file /usr/sap/<SID>/SYS/global/sapcontrol/snapshots/fullsysteminfodump_SMH_SM1_solman_2019_07_22_11_09_20.zip —– 2019-07-22 16:39:20 Generate esserver stack file —– SNo running esserver found for database <TENANT SID> —– 2019-07-22 16:39:23 Exporting xsenginetraces —– No files found matching ……

How to Generate a Runtime Dump on SAP HANA

If You are experiencing high memory consumption / out of memory situations . SAP is asking you to generate a runtime dump for further analysis. This blog with help you to generate a runtime dump in HANA database.   Easiest way to generate runtime dump is from OS Level:   1) Log into the HANA host as sidadm user 2) Run command ‘hdbcons’ 3) On the hdbcons console run command below > runtimedump dump This will create a runtimedump for the host . runtime dump file will be under traces directory with naming like ‘indexserver….rtedump.trc’.   Generate runtime dump from Python script ……