ClickHouse Self-Managed component costs and maintenance requirements
Summary
ClickHouse requires additional cost and maintenance for self-managed customers:
- Resource allocation cost: ClickHouse requires a considerable amount of resources to run optimally.
- Minimum cost estimation shows that setting up ClickHouse can be applicable only for very large Reference Architectures: 25k and up.
- High availability: ClickHouse SaaS supports HA. No documented HA configuration for self-managed at the moment.
- Geo setups: Sync and replication complexity for GitLab Geo setups.
- Upgrades: An additional database to maintain and upgrade along with existing Postgres database. This also includes compatibility issues of mapping GitLab version to ClickHouse version and keeping them up-to-date.
- Backup and restore: Self-managed customers need to have an engineer who is familiar with backup strategies and disaster recovery process in ClickHouse or switch to ClickHouse SaaS.
- Monitoring: ClickHouse can use Prometheus, additional component to monitor and troubleshoot.
- Limitations: Azure object storage is not supported. GitLab does not have the documentation or support expertise to assist customers with deployment and operation of self-managed ClickHouse.
- ClickHouse SaaS: Customers using a self-managed GitLab instance with regulatory or compliance requirements, or latency concerns likely cannot use ClickHouse SaaS.
Minimum self-managed component costs
Based on ClickHouse spec requirements analysis and collaborating with ClickHouse team, we identified the following minimal configurations for ClickHouse self-managed:
- ClickHouse High Availability (HA)
- ClickHouse - 2 machines with >=16-cores, >=64 GB RAM, SSD, 10 GB Internet. Each machine also runs Keeper.
- Keeper - 1 machine with 2 CPU, 4 GB of RAM, SSD with high IOPS
- ClickHouse non-HA
- ClickHouse - 1 machine with >=16-cores, >=64 GB RAM, SSD, 10 GB Internet.
The following cost table was compiled using the machine CPU and memory requirements for ClickHouse, and comparing them to the GitLab Reference Architecture sizes and costs from the GCP calculator.
| Reference Architecture | ClickHouse type | ClickHouse cost / (GitLab cost + ClickHouse cost) |
|---|---|---|
| 20 RPS / 1k users - non HA | non-HA | 78.01% |
| 40 RPS / 2k users- non HA | non-HA | 44.50% |
| 60 RPS / 3k users - HA | HA | 37.87% |
| 100 RPS / 5k users - HA | HA | 30.92% |
| 200 RPS / 10k users - HA | HA | 20.47% |
| 500 RPS / 25k users - HA | HA | 14.30% |
| 1000 RPS / 50k users - HA | HA | 8.16% |
NOTE: The ClickHouse Self-Managed component evaluation is the minimum estimation for the costs with a simplified architecture.
The following components increase the cost, and were not considered in the minimum calculation:
- Disk size - depends on data size, hard to estimate.
- Disk types - ClickHouse recommends fast SSDs.
- Network usage - ClickHouse recommends using 10 GB network, if possible.
- For HA we sum minimum cost across all reference architectures from 60 RPS / 3k users to 1000 RPS / 50k users, but HA specs tend to increase with user count.
Resources
- Research and understand component costs and maintenance requirements of running a ClickHouse instance with GitLab
- ClickHouse for Error Tracking on GitLab.com
Last modified August 23, 2024: Ensure frontmatter is consistent (
e47101dc)
