[HANA] Network configuration 관련 Notes

2382421 - Optimizing the Network Configuration on HANA- and OS-Level

Version 36 from 2020.01.16

 

• On SAP HANA 1 Revisions <= 122.14 and on all SAP HANA 2 Revisions of SPS00 you additionally need to set the following parameter:

  net.ipv4.tcp_syn_retries = 8
  The default value for this parameter is 5, which translates to a timeout of about 24 seconds.
  If the system is under load, a timeout of 24 seconds can be too short and lead to avoidable errors.
  It also prevents processes to set a longer timeout. The recommended value is 8, which translates into a timeout of 190 seconds.

https://launchpad.support.sap.com/#/notes/2382421

https://launchpad.support.sap.com/#/notes/2382421

 

 

 

2696099 - Standby Node Failover Delay of SAP HANA Database in Network Down or Hardware failure Situation

Version 3 from 2018. 9. 20. in English

 

• Reduce the default value of the OS parameter for TCP retransmission in SAP HANA server. Execute following command as root user in OS shell.

  • sysctl -w net.ipv4.tcp_retries2=5

  To persist the OS parameter, add following line to /etc/sysctl.conf.

  • net.ipv4.tcp_retries2 = 5

  To reduce the failover duration in SAP HANA, following configurations in SAP HANA will be helpful. In case of multi-container system, need to configure in both SYSTEM DB and each Tenant DB

  • global.ini
  • [communication]
  • tcp_keepalive_idle = 60
  • tcp_keepalive_count = 5
  • tcp_keepalive_interval = 5

https://launchpad.support.sap.com/#/notes/2696099

https://launchpad.support.sap.com/#/notes/2696099