# Scaling Sourcegraph on Kubernetes

Sourcegraph can scale to accommodate large codebases and many users.

Increase resources according to the [Scaling Overview per Service](/self-hosted/deploy/scale) if you notice slower search or navigation.

## Cluster resource guidelines

For production environments, we recommend allocate resources based on your [instance size](/self-hosted/deploy/instance-size). See our [resource estimator](/self-hosted/deploy/resource-estimator) for estimates.

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## Improving performance with a large number of repositories

Here is a simplified list of the key parameters to tune when scaling Sourcegraph to many repositories:

-   `sourcegraph-frontend` CPU/memory resource allocations
-   `searcher` replica count and CPU/memory resource allocations
-   `indexedSearch` replica count and CPU/memory resource allocations
-   `gitserver` replica count
-   `gitMaxConcurrentClones`, because `git clone` and `git fetch` operations are IO and CPU-intensive
-   `repoListUpdateInterval` (in minutes), because each interval triggers `git fetch` operations for all repositories

Notes:

-   If your change requires restarting `gitserver` pods and they are rescheduled to other nodes, they may go offline briefly (showing a `Multi-Attach` error). This is due to volume detach/reattach. [Contact us](https://about.sourcegraph.com/contact/) for mitigation steps depending on your cloud provider.
-   See the docs to understand each service's role:
    -   [Sourcegraph Architecture Overview](https://docs-legacy.sourcegraph.com/dev/background-information/architecture)
    -   [Scaling Overview per Service](/self-hosted/deploy/scale)

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## Improving performance with large monorepos

Here is a simplified list of key parameters to tune when scaling Sourcegraph to large monorepos:

-   `sourcegraph-frontend` CPU/memory resource allocations
-   `searcher` CPU/memory resource allocations (allocate enough memory to hold all non-binary files in your repositories)
-   `indexedSearch` CPU/memory resource allocations (for the `zoekt-indexserver` pod, allocate enough memory to hold all non-binary files in your largest repository; for the `zoekt-webserver` pod, allocate enough memory to hold ~2.7x the size of all non-binary files in your repositories)
-   `gitserver` CPU/memory resource allocations (allocate enough memory to hold your Git packed bare repositories)

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## Configuring faster disk I/O for caches

Many parts of Sourcegraph's infrastructure benefit from using SSDs for caches. This is especially
important for search performance. By default, disk caches will use the
Kubernetes [hostPath](https://kubernetes.io/docs/concepts/storage/volumes/#hostpath) and will be the
same IO speed as the underlying node's disk. Even if the node's default disk is a SSD, however, it
is likely network-mounted rather than local.