In Hong Kong VPS hosting, optimizing the number of network connections is a key factor in improving overall system performance. Many users prioritize bandwidth, CPU, and memory when configuring their servers. However, in reality, the core factor determining service response speed and stability under high-concurrency conditions also lies in how the system handles concurrent connections. If the number of connections is not configured properly, even with sufficient bandwidth, request delays, connection interruptions, or service denials can occur. Therefore, optimizing the number of connections at both the system and application levels can ensure that Hong Kong VPS hosting remains stable and efficient even under high load.

Understand the default connection limits of the operating system. To prevent unlimited system resource usage, the Linux kernel typically sets limits on file descriptors, semi-connected queues, and the maximum number of concurrent connections. After initialization, Hong Kong VPS hosting often uses low default values ​​for these parameters, making them suitable for standard websites or lightweight applications. However, they are not suitable for the high-concurrency demands of cross-border e-commerce, video streaming, or real-time communication services. Therefore, system administrators need to optimize these parameters.

File descriptors are the foundation of the system's network connection handling. Each connection requires a file descriptor. Insufficient file descriptors will result in connection rejection. You can check the current limit using the command:

ulimit -n

If the output value is low, for example, 1024, you can increase it by modifying the configuration file:

vi /etc/security/limits.conf

Add the following content to the file:

* soft nofile 65535
* hard nofile 65535

After making the changes, re-login to your user session for the settings to take effect. This adjustment ensures that the system does not terminate connections due to insufficient file descriptors in high-concurrency scenarios.

When tuning TCP connections, the parameters of the half-connection queue and the full-connection queue are crucial. When the client initiates the TCP three-way handshake, the server maintains a half-connection queue. If the length of this queue is insufficient, some requests will be dropped. The queue size can be increased by adjusting kernel parameters:

vi /etc/sysctl.conf
Add the following configuration:
net.core.somaxconn = 65535
net.ipv4.tcp_max_syn_backlog = 65535

Save and execute:

sysctl -p

This configuration improves the system's ability to handle new connections, preventing connections from being dropped due to a large number of requests in a short period of time.

Furthermore, excessive connections in the TIME_WAIT state can also affect VPS performance. By default, Linux maintains connections in the TIME_WAIT state for a period of time to ensure data transmission integrity. However, in high-concurrency, short-lived applications, excessive TIME_WAIT connections can consume system resources. This can be optimized by configuring the following:

net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1

This allows the system to recycle connections in the TIME_WAIT state more quickly, thereby increasing the number of available connections.

Regarding the performance of Hong Kong VPS hosting in cross-border applications, it's also worth considering the use of persistent and short-term connections. Persistent connections are suitable for applications with frequent communication, such as API calls, while short-term connections are suitable for business scenarios with longer request intervals. In web server configuration, the maximum number of connections can be adjusted based on business needs. For example, in Nginx:

worker_connections 65535;

Combined with an appropriate number of worker_processes, this can significantly improve concurrent processing capabilities.

Also, pay attention to the port range setting in kernel parameters. The system has a limited number of available ephemeral ports by default. If a large number of connections are initiated simultaneously, port exhaustion may occur. This can be increased using the following command:

net.ipv4.ip_local_port_range = 1024 65535

This setting allows the system to have a wider range of available ports, supporting more concurrent connections.

Connection optimization is also important for database services like MySQL and Redis. For example, MySQL's default maximum number of connections may be 151, which is far from sufficient for high-concurrency applications. This can be adjusted in the configuration file:

max_connections = 1000

In Redis, you can increase the maximum number of client connections by modifying the following parameter:

maxclients 10000

Combining persistence and memory optimization strategies can ensure stable database operation in high-concurrency scenarios.

In addition to adjusting system parameters and service configurations, stress testing is also necessary during actual operations and maintenance. Using tools such as ab, wrk, or JMeter, you can simulate high-concurrency access to test the effectiveness of connection number tuning. If connection loss or high latency persists during testing, further monitoring system logs and network stack status is necessary to identify bottlenecks.

In Hong Kong VPS hosting scenarios, cross-border business requires high network quality. While optimizing the connection number can significantly improve the server's ability to handle bursty traffic, it's also important to consider overall optimization, including bandwidth utilization, CPU usage, and memory consumption. Excessively increasing the connection limit may increase resource consumption, so it's important to find a reasonable balance based on stress testing results.

In Hong Kong VPS hosting, optimizing the connection number can significantly improve system performance. Key tuning steps include file descriptor limits, TCP queue parameters, TIME_WAIT recycling policies, port range expansion, and connection configuration for application-layer services. Combining stress testing with actual business needs ensures the system remains stable and fast even under high-concurrency access, providing more reliable technical support for cross-border businesses, video services, and e-commerce systems.