Jenkins, a leading continuous integration and continuous delivery tool, is widely used to automate build, testing, and deployment processes. Especially for teams that rely on automation, Jenkins significantly improves development efficiency and release frequency. However, Jenkins instances running on Singapore VPS servers can sometimes experience excessive resource usage, severely impacting server performance and overall business stability. This article will focus on the practical issue of high Jenkins resource usage on Singapore VPS servers, analyze the causes in detail, and share practical optimization solutions.

　　Understanding the phenomenon of high Jenkins resource usage:

　　High Jenkins resource usage is typically manifested by soaring CPU utilization, memory usage, significant disk I/O bottlenecks, and network bandwidth issues. Due to limited hardware resources on Singapore VPS servers, running Jenkins under prolonged high load can not only cause build task delays, but can also lead to system lags, build failures, and even impact the normal operation of other services.

　　High resource usage is not a single occurrence; it is the result of a combination of factors. These include, but are not limited to, a large and complex number of build tasks, an inappropriate number of plugins, continuously expanding build logs, inadequate build history cleanup, outdated or improperly configured Jenkins versions, server hardware bottlenecks, or uneven allocation of virtualization resources.

　　Analysis of the specific causes of high Jenkins resource usage and optimization solutions:

　　1. Improper build task design. Build tasks are numerous and frequently triggered, especially when the number of concurrent builds exceeds the server's capacity. The build process is not optimized, such as inappropriate build scripts, duplicate dependency downloads, and ineffective testing.

　　Optimization Solution: Limit the number of concurrent builds. Configure the number of Jenkins "executors" to limit the number of concurrently executing build tasks to avoid excessive CPU and memory usage. Effectively arrange build triggering strategies, utilizing "scheduled triggering," "manual triggering," or "change-based triggering" to avoid unnecessary repetitive builds. Streamline build scripts, remove redundant steps, merge similar tasks, and utilize caching mechanisms to avoid duplicate dependency downloads. Separate resource-intensive build tasks, moving them to nodes with more resources, or adopt a distributed Jenkins build architecture.

　　2. Issues with the number and quality of plugins. Excessive number of plugins and incompatible versions can cause memory leaks or abnormal CPU usage. Some plugin background processes continue to run, leading to resource consumption.

　　Optimization Solution: Regularly review plugins, remove unnecessary or unused plugins, and maintain a reasonable number of plugins. Upgrade plugins to avoid memory leaks and performance issues caused by older plugins. Disable or uninstall high-consumption plugins, and replace or disable plugins found to be consuming unusual resources.

　　3. Log file and build history expansion. Build logs are not cleaned up promptly, consuming large amounts of disk space and memory. Excessive build history can slow the Jenkins management interface.

　　Optimization Solution: Configure log rotation and cleanup policies. Jenkins has a built-in "log rotation" feature that automatically cleans up expired logs by configuring the retention period and maximum number of builds. Manually clear disk space, regularly check build directories, and delete unused files to prevent disk occupancy. Use external log management to transfer build logs to a dedicated log management system to reduce pressure on Jenkins nodes.

　　4. Improper Jenkins JVM configuration. The JVM heap memory is set too high or too low, leading to frequent garbage collection (GC) or memory overflows. Appropriate JVM performance tuning parameters are not enabled.

　　Optimization Solution: Set the heap memory size appropriately. Adjust the -Xms and -Xmx parameters in the Jenkins startup parameters based on the VPS memory configuration to avoid excessive heap memory. Enable garbage collection logging and tune GC to observe GC behavior. If necessary, use G1 GC or Parallel GC to improve performance. Adjust Jenkins system parameters, such as -Djava.awt.headless=true, to reduce unnecessary UI overhead.

　　5. Insufficient server hardware resource allocation. The VPS configuration is low, and resources don't match business growth. VPS resources are being competed for by other applications, resulting in degraded Jenkins performance.

　　Optimization Solution: Upgrade the VPS configuration and, based on business needs, increase the number of CPU cores and memory capacity as appropriate. Use resource monitoring tools such as top, htop, jstat, and VisualVM to monitor the CPU and memory usage of the Jenkins process and provide timely alerts. Isolate resources and use containerization or virtualization to limit resource usage of the Jenkins process to avoid impacting other services.

　　6. Network and I/O bottlenecks. The build process frequently accesses external resources, resulting in insufficient network latency and bandwidth. Poor disk I/O performance impacts log writing and reading speeds.

　　Optimization Solution: Use a local caching proxy, such as Nexus or Artifactory, as a dependency cache to reduce network request latency. Optimize disk performance by choosing an SSD VPS to avoid I/O bottlenecks. Separate log and build data storage, storing them on independent high-speed storage devices.

　　The high resource usage of Jenkins on a Singapore VPS server presents both a technical challenge and an opportunity for optimization. Only by synergizing multiple aspects, including task design, plugin management, log maintenance, JVM tuning, server configuration, and resource monitoring, can resource bottlenecks be effectively alleviated and Jenkins' efficient and stable operation be ensured. By leveraging the unique characteristics of a Singapore VPS, rational planning, and dynamic adjustments, Jenkins can truly realize its core value in continuous integration.