1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
|
# GitLab.com settings
In this page you will find information about the settings that are used on
[GitLab.com](https://about.gitlab.com/pricing).
## SSH host keys fingerprints
Below are the fingerprints for GitLab.com's SSH host keys.
| Algorithm | MD5 | SHA256 |
| --------- | --- | ------- |
| DSA | `7a:47:81:3a:ee:89:89:64:33:ca:44:52:3d:30:d4:87` | `p8vZBUOR0XQz6sYiaWSMLmh0t9i8srqYKool/Xfdfqw` |
| ECDSA | `f1:d0:fb:46:73:7a:70:92:5a:ab:5d:ef:43:e2:1c:35` | `HbW3g8zUjNSksFbqTiUWPWg2Bq1x8xdGUrliXFzSnUw` |
| ED25519 | `2e:65:6a:c8:cf:bf:b2:8b:9a:bd:6d:9f:11:5c:12:16` | `eUXGGm1YGsMAS7vkcx6JOJdOGHPem5gQp4taiCfCLB8` |
| RSA | `b6:03:0e:39:97:9e:d0:e7:24:ce:a3:77:3e:01:42:09` | `ROQFvPThGrW4RuWLoL9tq9I9zJ42fK4XywyRtbOz/EQ` |
## Mail configuration
GitLab.com sends emails from the `mg.gitlab.com` domain via [Mailgun] and has
its own dedicated IP address (`198.61.254.240`).
## Alternative SSH port
GitLab.com can be reached via a [different SSH port][altssh] for `git+ssh`.
| Setting | Value |
| --------- | ------------------- |
| `Hostname` | `altssh.gitlab.com` |
| `Port` | `443` |
An example `~/.ssh/config` is the following:
```
Host gitlab.com
Hostname altssh.gitlab.com
User git
Port 443
PreferredAuthentications publickey
IdentityFile ~/.ssh/gitlab
```
## GitLab Pages
Below are the settings for [GitLab Pages].
| Setting | GitLab.com | Default |
| ----------------------- | ---------------- | ------------- |
| Domain name | `gitlab.io` | - |
| IP address | `52.167.214.135` | - |
| Custom domains support | yes | no |
| TLS certificates support| yes | no |
The maximum size of your Pages site is regulated by the artifacts maximum size
which is part of [GitLab CI/CD](#gitlab-ci-cd).
## GitLab CI/CD
Below are the current settings regarding [GitLab CI/CD](../../ci/README.md).
| Setting | GitLab.com | Default |
| ----------- | ----------------- | ------------- |
| Artifacts maximum size | 1G | 100M |
## Repository size limit
The maximum size your Git repository is allowed to be including LFS.
| Setting | GitLab.com | Default |
| ----------- | ----------------- | ------------- |
| Repository size including LFS | 10G | Unlimited |
## Shared Runners
Shared Runners on GitLab.com run in [autoscale mode] and powered by
DigitalOcean. Autoscaling means reduced waiting times to spin up builds,
and isolated VMs for each project, thus maximizing security.
They're free to use for public open source projects and limited to 2000 CI
minutes per month per group for private projects. Read about all
[GitLab.com plans](https://about.gitlab.com/pricing/).
All your builds run on 2GB (RAM) ephemeral instances, with CoreOS and the latest
Docker Engine installed. The default region of the VMs is NYC.
Below are the shared Runners settings.
| Setting | GitLab.com | Default |
| ----------- | ----------------- | ---------- |
| [GitLab Runner] | [Runner versions dashboard][ci_version_dashboard] | - |
| Executor | `docker+machine` | - |
| Default Docker image | `ruby:2.1` | - |
| `privileged` (run [Docker in Docker]) | `true` | `false` |
[ci_version_dashboard]: https://monitor.gitlab.net/dashboard/db/ci?refresh=5m&orgId=1&panelId=12&fullscreen&from=now-1h&to=now&var-runner_type=All&var-cache_server=All&var-gl_monitor_fqdn=postgres-01.db.prd.gitlab.com&var-has_minutes=yes&var-hanging_droplets_cleaner=All&var-droplet_zero_machines_cleaner=All&var-runner_job_failure_reason=All&theme=light
### `config.toml`
The full contents of our `config.toml` are:
```toml
[[runners]]
name = "docker-auto-scale"
limit = X
request_concurrency = X
url = "https://gitlab.com/ci"
token = "SHARED_RUNNER_TOKEN"
executor = "docker+machine"
environment = [
"DOCKER_DRIVER=overlay2"
]
[runners.docker]
image = "ruby:2.1"
privileged = true
[runners.machine]
IdleCount = 40
IdleTime = 1800
MaxBuilds = 1
MachineDriver = "digitalocean"
MachineName = "machine-%s-digital-ocean-2gb"
MachineOptions = [
"digitalocean-image=coreos-stable",
"digitalocean-ssh-user=core",
"digitalocean-access-token=DIGITAL_OCEAN_ACCESS_TOKEN",
"digitalocean-region=nyc1",
"digitalocean-size=2gb",
"digitalocean-private-networking",
"digitalocean-userdata=/etc/gitlab-runner/cloudinit.sh",
"engine-registry-mirror=http://IP_TO_OUR_REGISTRY_MIRROR"
]
[runners.cache]
Type = "s3"
ServerAddress = "IP_TO_OUR_CACHE_SERVER"
AccessKey = "ACCESS_KEY"
SecretKey = "ACCESS_SECRET_KEY"
BucketName = "runner"
Shared = true
```
## Sidekiq
GitLab.com runs [Sidekiq][sidekiq] with arguments `--timeout=4 --concurrency=4`
and the following environment variables:
| Setting | GitLab.com | Default |
|-------- |----------- |-------- |
| `SIDEKIQ_MEMORY_KILLER_MAX_RSS` | `1000000` | `1000000` |
| `SIDEKIQ_MEMORY_KILLER_SHUTDOWN_SIGNAL` | `SIGKILL` | - |
| `SIDEKIQ_LOG_ARGUMENTS` | `1` | - |
## Cron jobs
Periodically executed jobs by Sidekiq, to self-heal Gitlab, do external
synchronizations, run scheduled pipelines, etc.:
| Setting | GitLab.com | Default |
|-------- |------------- |------------- |
| `pipeline_schedule_worker` | `19 * * * *` | `19 * * * *` |
## PostgreSQL
GitLab.com being a fairly large installation of GitLab means we have changed
various PostgreSQL settings to better suit our needs. For example, we use
streaming replication and servers in hot-standby mode to balance queries across
different database servers.
The list of GitLab.com specific settings (and their defaults) is as follows:
| Setting | GitLab.com | Default |
|:------------------------------------|:--------------------------------------------------------------------|:--------------------------------------|
| archive_command | `/usr/bin/envdir /etc/wal-e.d/env /opt/wal-e/bin/wal-e wal-push %p` | empty |
| archive_mode | on | off |
| autovacuum_analyze_scale_factor | 0.01 | 0.01 |
| autovacuum_max_workers | 6 | 3 |
| autovacuum_vacuum_cost_limit | 1000 | -1 |
| autovacuum_vacuum_scale_factor | 0.01 | 0.02 |
| checkpoint_completion_target | 0.7 | 0.9 |
| checkpoint_segments | 32 | 10 |
| effective_cache_size | 338688MB | Based on how much memory is available |
| hot_standby | on | off |
| hot_standby_feedback | on | off |
| log_autovacuum_min_duration | 0 | -1 |
| log_checkpoints | on | off |
| log_line_prefix | `%t [%p]: [%l-1] ` | empty |
| log_min_duration_statement | 1000 | -1 |
| log_temp_files | 0 | -1 |
| maintenance_work_mem | 2048MB | 16 MB |
| max_replication_slots | 5 | 0 |
| max_wal_senders | 32 | 0 |
| max_wal_size | 5GB | 1GB |
| shared_buffers | 112896MB | Based on how much memory is available |
| shared_preload_libraries | pg_stat_statements | empty |
| shmall | 30146560 | Based on the server's capabilities |
| shmmax | 123480309760 | Based on the server's capabilities |
| wal_buffers | 16MB | -1 |
| wal_keep_segments | 512 | 10 |
| wal_level | replica | minimal |
| statement_timeout | 15s | 60s |
| idle_in_transaction_session_timeout | 60s | 60s |
Some of these settings are in the process being adjusted. For example, the value
for `shared_buffers` is quite high and as such we are looking into adjusting it.
More information on this particular change can be found at
<https://gitlab.com/gitlab-com/infrastructure/issues/1555>. An up to date list
of proposed changes can be found at
<https://gitlab.com/gitlab-com/infrastructure/issues?scope=all&utf8=%E2%9C%93&state=opened&label_name[]=database&label_name[]=change>.
## Unicorn
GitLab.com adjusts the memory limits for the [unicorn-worker-killer][unicorn-worker-killer] gem.
Base default:
* `memory_limit_min` = 750MiB
* `memory_limit_max` = 1024MiB
Web front-ends:
* `memory_limit_min` = 1024MiB
* `memory_limit_max` = 1280MiB
## GitLab.com at scale
In addition to the GitLab Enterprise Edition Omnibus install, GitLab.com uses
the following applications and settings to achieve scale. All settings are
located publicly available [chef cookbooks](https://gitlab.com/gitlab-cookbooks).
### ELK
We use Elasticsearch, logstash, and Kibana for part of our monitoring solution:
- [gitlab-cookbooks / gitlab-elk · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab-elk)
- [gitlab-cookbooks / gitlab_elasticsearch · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab_elasticsearch)
### Prometheus
Prometheus complete our monitoring stack:
- [gitlab-cookbooks / gitlab-prometheus · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab-prometheus)
### Grafana
For the visualization of monitoring data:
- [gitlab-cookbooks / gitlab-grafana · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab-grafana)
### Sentry
Open source error tracking:
- [gitlab-cookbooks / gitlab-sentry · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab-sentry)
### Consul
Service discovery:
- [gitlab-cookbooks / gitlab_consul · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab_consul)
### Haproxy
High Performance TCP/HTTP Load Balancer:
- [gitlab-cookbooks / gitlab-haproxy · GitLab](https://gitlab.com/gitlab-cookbooks/gitlab-haproxy)
[autoscale mode]: https://docs.gitlab.com/runner/configuration/autoscale.html "How Autoscale works"
[runners-post]: https://about.gitlab.com/2016/04/05/shared-runners/ "Shared Runners on GitLab.com"
[GitLab Runner]: https://gitlab.com/gitlab-org/gitlab-runner
[altssh]: https://about.gitlab.com/2016/02/18/gitlab-dot-com-now-supports-an-alternate-git-plus-ssh-port/ "GitLab.com now supports an alternate git+ssh port"
[GitLab Pages]: https://about.gitlab.com/features/pages "GitLab Pages"
[docker in docker]: https://hub.docker.com/_/docker/ "Docker in Docker at DockerHub"
[mailgun]: https://www.mailgun.com/ "Mailgun website"
[sidekiq]: http://sidekiq.org/ "Sidekiq website"
[unicorn-worker-killer]: https://rubygems.org/gems/unicorn-worker-killer "unicorn-worker-killer"
|
