Continuous Integration and Continuous Delivery (CI/CD) have revolutionized the software development process. GitLab runners play a crucial role in this, automating the deployment pipeline by executing CI/CD jobs. However, many developers find that their self-hosted GitLab runners are not performing as efficiently as they should.
Let's explore the reasons behind this and how Cloud-Runner can help.
A common reason for slow performance in self-hosted GitLab runners is insufficient hardware resources. When your CI/CD jobs demand high CPU, RAM, or disk space, having inadequate resources can severely impact the runners' performance. Here are some practical steps to optimize your GitLab runners:
Before Optimization:
A runner configuration with minimal resources might look like this:
[[runners]]
name = "Minimal Runner"
url = "https://gitlab.example.com/"
token = "your-token"
executor = "shell"
limit = 1
[runners.custom_build_dir]
[runners.cache]
[runners.cache.s3]
[runners.cache.gcs]
After Optimization:
Upgrade your runner's hardware resources to better handle CI/CD workloads:
[[runners]]
name = "Optimized Runner"
url = "https://gitlab.example.com/"
token = "your-token"
executor = "shell"
limit = 4
[runners.custom_build_dir]
[runners.cache]
[runners.cache.s3]
[runners.cache.gcs]
[runners.machine]
IdleCount = 2
MachineDriver = "digitalocean"
MachineName = "gitlab-runner-%s"
MachineOptions = [
"digitalocean-access-token=your-do-token",
"digitalocean-size=s-2vcpu-4gb",
"digitalocean-image=ubuntu-20-04-x64"
]
Explanation:
Increasing the number of concurrent jobs (limit) and using a more powerful instance type (e.g., s-2vcpu-4gb) provides a considerable performance boost. This allows the runner to handle more tasks simultaneously and reduces the time taken for each CI/CD job.
Another frequent issue that affects the performance of GitLab runners is network bottlenecks. CI/CD jobs often require downloading dependencies, uploading artifacts, and communicating with other services—all of which rely on a stable and fast network connection. Here's how you can optimize your network infrastructure:
Before Optimization:
A runner struggling with network issues might show signs like slow downloads or uploads:
# Slow download example
curl -O https://example.com/largefile.zip
After Optimization:
Invest in a high-speed, stable internet connection, and, if possible, use a dedicated network line solely for CI/CD operations:
bashCopier le code
# Faster download example using parallel connections
aria2c -x 16 https://example.com/largefile.zip
Explanation:
Ensuring a reliable and fast network connection minimizes delays caused by network bottlenecks. Using tools like aria2 for parallel downloads can also help in optimizing network usage.
Misconfiguration can also contribute to slow performance in GitLab runners. Incorrectly set environment variables, suboptimal runner settings, or flawed cache configurations can all hinder efficiency. Here's how to review and optimize your runner configurations:
Before Optimization:
A misconfigured runner might have inefficient cache settings or incorrect environment variables:
variables:
GIT_STRATEGY: fetch
GIT_SUBMODULE_STRATEGY: recursive
cache:
paths:
- node_modules/
After Optimization:
Optimize cache settings and environment variables to enhance performance:
variables:
GIT_STRATEGY: clone
GIT_SUBMODULE_STRATEGY: none
cache:
key: "$CI_COMMIT_REF_SLUG"
paths:
- node_modules/
- .m2/repository
Explanation:
Using the clone strategy instead of fetch can be faster for certain repositories. Additionally, properly configuring cache paths and keys ensures that dependencies are reused efficiently, reducing build times.
Poorly optimized build scripts can significantly slow down your CI/CD pipeline. Refactoring your build scripts can improve this situation. Eliminate any unnecessary code, optimize your logic, and streamline your scripts to execute CI/CD jobs as swiftly as possible.
Before Optimization:
A build script with unnecessary steps and inefficient logic:
# build.sh
echo "Starting build..."
sleep 10
npm install
npm run build
After Optimization:
Streamline the build script to eliminate unnecessary delays:
# build.sh
echo "Starting build..."
npm ci
npm run build
Explanation:
Replacing npm install with npm ci (which is faster and more reliable for CI environments) can significantly speed up the build process by ensuring clean installs based on package-lock.json.
Running jobs sequentially instead of in parallel can lead to delays in your CI/CD pipeline. Parallelization allows multiple jobs to run simultaneously, maximizing server resource utilization and reducing pipeline completion time.
Before Optimization:
Sequential job execution in a CI/CD pipeline:
stages:
- build
- test
- deploy
build:
stage: build
script:
- ./build.sh
test:
stage: test
script:
- ./test.sh
deploy:
stage: deploy
script:
- ./deploy.sh
After Optimization:
Enable parallel job execution:
stages:
- build
- test
- deploy
build:
stage: build
script:
- ./build.sh
unit_test:
stage: test
script:
- ./unit_test.sh
integration_test:
stage: test
script:
- ./integration_test.sh
deploy:
stage: deploy
script:
- ./deploy.sh
Explanation:
By configuring multiple jobs within the same stage to run in parallel, you can reduce the total time taken for the pipeline to complete. This makes better use of the available runner resources and speeds up the CI/CD process.
Are you searching for a simpler solution to accelerate your GitLab runners? Cloud-Runner provides high-performance GitLab runners designed for CI/CD workloads. With dedicated resources, an optimized infrastructure, and expert support, Cloud-Runner ensures faster pipeline execution and shorter wait times. Plus, for those with self-hosted GitLab instances, Cloud-Runner can set up VPNs to your private network, enabling seamless communication between your instance and the runner.
In conclusion, optimizing your self-hosted GitLab runners can significantly enhance your CI/CD pipeline's performance. By identifying and addressing performance issues and implementing the suggested solutions, you can streamline your development process and achieve better results more quickly. Cloud-Runner offers a hassle-free, high-speed managed runner solution that can elevate your CI/CD experience.
