MOT Server Optimization – ARM Huawei Taishan 2P/4P

The following are optional settings for optimizing MOT database performance running on an ARM/Kunpeng-based Huawei Taishan 2280 v2 server powered by 2-sockets with a total of 256 Cores^[^{Comparison – Disk vs. MOT}^] and Taishan 2480 v2 server powered by 4-sockets with a total of 256 Cores^[Comparison – Disk vs. MOT^].

Unless indicated otherwise, the following settings are for both client and server machines –

BIOS

Modify related BIOS settings, as follows –

Select BIOS è Advanced è MISC Config. Set Support Smmu to Disabled.
Select BIOS è Advanced è MISC Config. Set CPU Prefetching Configuration to Disabled.
Select BIOS è Advanced è Memory Config. Set Die Interleaving to Disabled.
Select BIOS è Advanced è Performance Config. Set Power Policy to Performance.

OS – Kernel and Boot

The following operating system kernel and boot parameters are usually configured by a sysadmin.

Configure the kernel parameters, as follows –

net.ipv4.ip_local_port_range = 9000 65535
kernel.sysrq = 1
kernel.panic_on_oops = 1
kernel.panic = 5
kernel.hung_task_timeout_secs = 3600
kernel.hung_task_panic = 1
vm.oom_dump_tasks = 1
kernel.softlockup_panic = 1
fs.file-max = 640000
kernel.msgmnb = 7000000
kernel.sched_min_granularity_ns = 10000000
kernel.sched_wakeup_granularity_ns = 15000000
kernel.numa_balancing=0
vm.max_map_count = 1048576
net.ipv4.tcp_max_tw_buckets = 10000
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_keepalive_time = 30
net.ipv4.tcp_keepalive_probes = 9
net.ipv4.tcp_keepalive_intvl = 30
net.ipv4.tcp_retries2 = 80
kernel.sem = 32000 1024000000      500     32000
kernel.shmall = 52805669
kernel.shmmax = 18446744073692774399
sys.fs.file-max = 6536438
net.core.wmem_max = 21299200
net.core.rmem_max = 21299200
net.core.wmem_default = 21299200
net.core.rmem_default = 21299200
net.ipv4.tcp_rmem = 8192 250000 16777216
net.ipv4.tcp_wmem = 8192 250000 16777216
net.core.somaxconn = 65535
vm.min_free_kbytes = 5270325
net.core.netdev_max_backlog = 65535
net.ipv4.tcp_max_syn_backlog = 65535
net.ipv4.tcp_syncookies = 1
vm.overcommit_memory = 0
net.ipv4.tcp_retries1 = 5
net.ipv4.tcp_syn_retries = 5
##NEW
kernel.sched_autogroup_enabled=0
kernel.sched_min_granularity_ns=2000000
kernel.sched_latency_ns=10000000
kernel.sched_wakeup_granularity_ns=5000000
kernel.sched_migration_cost_ns=500000
vm.dirty_background_bytes=33554432
kernel.shmmax=21474836480
net.ipv4.tcp_timestamps = 0
net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1
net.ipv4.tcp_keepalive_time=600
net.ipv4.tcp_keepalive_probes=3
kernel.core_uses_pid=1

Tuned Service
The following section is mandatory.
The server must run a throughput-performance profile –
```
[...]$ tuned-adm profile throughput-performance
```
The throughput-performance profile is broadly applicable tuning that provides excellent performance across a variety of common server workloads.
Other less suitable profiles for openGauss and MOT server that may affect MOT's overall performance are – balanced, desktop, latency-performance, network-latency, network-throughput and powersave.
Boot Tuning
Add iommu.passthrough=1 to the kernel boot arguments.
When operating in pass-through mode, the adapter does require DMA translation to the memory, which improves performance.