Summary:
FlashGrid Cluster software version 23.08 includes changes in network settings on Azure that provide substantial performance improvements. Customers are advised to update to the new software version and also to modify the network MTU setting on their systems.
Affected products:
- FlashGrid Cluster on Azure
Affected versions:
FlashGrid Cluster versions below 23.08
Changes in version 23.08:
- MTU setting for Azure NIC increased from 1500 to 3920.
- Higher bandwidth allocated for Oracle Private Network (a.k.a. cluster interconnect).
- Higher total network bandwidth on certain Azure VM types and sizes.
Main benefits:
- Reduced latency and increased bandwidth of Oracle Cache Fusion operations.
- Reduced probability of Cache Fusion packet loss because of packet fragmentation.
- Improved Oracle RAC database performance and stability.
Recommended actions:
- Update to FlashGrid Cluster software version 23.08 or later.
- Manually change network MTU setting on all cluster nodes, including quorum nodes (not required for clusters deployed with software version 23.08 or later)
How to
FlashGrid software update can be applied using the standard update procedure, one node at a time (a.k.a. "rolling update"). However, the MTU modification requires stopping Oracle services on all nodes. Please plan a maintenance window accordingly.
To reduce the total amount of time required for applying the software update and the MTU change, FlashGrid recommends applying both together:
- Follow the procedure for simultaneous software update on all nodes.
- On each node before reboot (step 9) run the following command to change the MTU setting:
# nmcli connection modify 'System eth0' 802-3-ethernet.mtu 3920 - On each node after reboot verify that the MTU setting is configured correctly. MTU must be set to 3920 for eth0 NIC (other NICs are expected to have different MTU):
# ip link show dev eth0