Optimizing download performance

In order to optimize HTTP Gateway's download performance, complete the following procedures.

About this task

Set The Correct Buffer Download Size

Even though each environment and use case may benefit from different download buffer size values, Aspera in-lab testing shows that 128 kilobytes (131073 bytes) provide significant download performance improvements.

Procedure

Add the transferconfig.download_buffer_size=131073 parameter to the gatewayconfig.properties file, and restart the HTTP Gateway service.

Enable TCP BBR to Improve Linux Performance

To maximize the throughput of HTTP-Gateway based transfers, for the HTTP(S) leg which runs over TCP and improve its performance, we recommend using the BBR TCP congestion control algorithm instead of the default cubic one.

Important: When considering switching to the BBR TCP congestion control algorithm, you should be cautious with the impact on network utilization and congestion. In order to enable TCP BBR Your Linux machine must be running kernel 4.9 or later.

Run the following commands as root:

Determine if BBR is available:
```
sysctl net.ipv4.tcp_available_congestion_control
```
If BBR is available, the previous command should report:
```
net.ipv4.tcp_available_congestion_control = reno cubic bbr
```
If you don’t see BBR reported, load the BBR module:
```
modprobe tcp_bbr
```

Set BBR as default:

sysctl net.core.default_qdisc=fq

sysctl net.ipv4.tcp_congestion_control=bbr

Reload sysctl:
```
sysctl -p
```
Check which congestion control algorithm is in use:
```
sysctl net.ipv4.tcp_congestion_control
```
Expected output:
```
net.ipv4.tcp_congestion_control=bbr
```
You have successfully optimized your download performance.