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| author | GitLab Bot <gitlab-bot@gitlab.com> | 2023-05-18 09:08:32 +0300 |
|---|---|---|
| committer | GitLab Bot <gitlab-bot@gitlab.com> | 2023-05-18 09:08:32 +0300 |
| commit | 55e0080f9d6b971145ee95c62dbb65feacaa93f8 (patch) | |
| tree | 0d9db86b8745512327d1c35edc7375f7378199a8 /doc/ci | |
| parent | 962afb3da11a72c7fca322378886b2c0be9f3385 (diff) | |
Add latest changes from gitlab-org/gitlab@master
Diffstat (limited to 'doc/ci')
| -rw-r--r-- | doc/ci/runners/saas/linux_saas_runner.md | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/doc/ci/runners/saas/linux_saas_runner.md b/doc/ci/runners/saas/linux_saas_runner.md index a1864c59d47..e693c6ae5c1 100644 --- a/doc/ci/runners/saas/linux_saas_runner.md +++ b/doc/ci/runners/saas/linux_saas_runner.md @@ -101,6 +101,43 @@ SaaS runner instances are provisioned with a 25 GB storage volume. The underlyin is shared by the operating system, the Docker image, and a copy of your cloned repository. This means that the available free disk space that your jobs can use is **less than 25 GB**. +## RAM disk (tmpfs) + +If your workloads generate a lot of disk input/output, you can run them from a RAM disk instead. + +Add a `tmpfs` mount point as part of your CI job, and ensure that these operations run from that location: + +```yaml +myjob: + before_script: + - mkdir -p mount/point + - mount -t tmpfs -o size=1G tmpfs mount/point +``` + +`tmpfs` stores any data written in RAM, and is paged out to swap if necessary, which generates input/output. +To avoid this I/O, ensure that the combined memory needed by the workload plus the data written to `tmpfs` does not exceed +the amount of RAM in the [runner machine type](#machine-types-available-for-private-projects-x86-64) +selected for the job. + +The `free` command can be used to observe the state of memory use and potentially help explain why jobs +intermittently run slowly or fail. + +```yaml + script: + - run_tests --workdir mount/point/ + - free +``` + +If `buff/cache` is lower than normal or there is any swap used, this suggests that the server was under +memory pressure. In the following example, `Swap: used` is not zero, and additionally +compares `buff/cache` to a job which ran without any issues. + +```plaintext + total used free shared buff/cache available +Mem: 4396380 334028 3678404 3884 383948 3799128 +Swap: 1048572 69632 978940 +``` + ## Pre-clone script (deprecated) WARNING: |