Troubleshooting a reference architecture setup

This page serves as the troubleshooting documentation if you followed one of the reference architectures.

Troubleshooting object storage

S3 API compatibility issues

Not all S3 providers are fully compatible with the Fog library that GitLab uses. Symptoms include:

411 Length Required

GitLab Pages requires NFS

If you intend to use GitLab Pages, this currently requires NFS. There is work in progress to remove this dependency. In the future, GitLab Pages will use object storage.

The dependency on disk storage also prevents Pages being deployed using the GitLab Helm chart.

Incremental logging is required for CI to use object storage

If you configure GitLab to use object storage for CI logs and artifacts, you must also enable incremental logging.

Proxy Download

A number of the use cases for object storage allow client traffic to be redirected to the object storage back end, like when Git clients request large files via LFS or when downloading CI artifacts and logs.

When the files are stored on local block storage or NFS, GitLab has to act as a proxy. With object storage, the default behavior is for GitLab to redirect to the object storage device rather than proxy the request.

The proxy_download setting controls this behavior: the default is generally false. Verify this in the documentation for each use case. Set it to true to make GitLab proxy the files rather than redirect.

When not proxying files, GitLab returns an HTTP 302 redirect with a pre-signed, time-limited object storage URL. This can result in some of the following problems:

  • If GitLab is using non-secure HTTP to access the object storage, clients may generate https->http downgrade errors and refuse to process the redirect. The solution to this is for GitLab to use HTTPS. LFS, for example, will generate this error:

     LFS: lfsapi/client: refusing insecure redirect, https->http
    
  • Clients will need to trust the certificate authority that issued the object storage certificate, or may return common TLS errors such as:

     x509: certificate signed by unknown authority
    
  • Clients will need network access to the object storage. Errors that might result if this access is not in place include:

     Received status code 403 from server: Forbidden
    

ETag mismatch

Using the default GitLab settings, some object storage back-ends such as MinIO and Alibaba might generate ETag mismatch errors.

When using GitLab direct upload, the workaround for MinIO is to use the --compat parameter on the server.

We are working on a fix to GitLab component Workhorse, and also a workaround, in the mean time, to allow ETag verification to be disabled.

Troubleshooting Redis

There are a lot of moving parts that needs to be taken care carefully in order for the HA setup to work as expected.

Before proceeding with the troubleshooting below, check your firewall rules:

  • Redis machines
    • Accept TCP connection in 6379
    • Connect to the other Redis machines via TCP in 6379
  • Sentinel machines
    • Accept TCP connection in 26379
    • Connect to other Sentinel machines via TCP in 26379
    • Connect to the Redis machines via TCP in 6379

Troubleshooting Redis replication

You can check if everything is correct by connecting to each server using redis-cli application, and sending the info replication command as below.

/opt/gitlab/embedded/bin/redis-cli -h <redis-host-or-ip> -a '<redis-password>' info replication

When connected to a Primary Redis, you will see the number of connected replicas, and a list of each with connection details:

# Replication
role:master
connected_replicas:1
replica0:ip=10.133.5.21,port=6379,state=online,offset=208037514,lag=1
master_repl_offset:208037658
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:206989083
repl_backlog_histlen:1048576

When it’s a replica, you will see details of the primary connection and if its up or down:

# Replication
role:replica
master_host:10.133.1.58
master_port:6379
master_link_status:up
master_last_io_seconds_ago:1
master_sync_in_progress:0
replica_repl_offset:208096498
replica_priority:100
replica_read_only:1
connected_replicas:0
master_repl_offset:0
repl_backlog_active:0
repl_backlog_size:1048576
repl_backlog_first_byte_offset:0
repl_backlog_histlen:0

Troubleshooting Sentinel

If you get an error like: Redis::CannotConnectError: No sentinels available., there may be something wrong with your configuration files or it can be related to this issue.

You must make sure you are defining the same value in redis['master_name'] and redis['master_password'] as you defined for your sentinel node.

The way the Redis connector redis-rb works with sentinel is a bit non-intuitive. We try to hide the complexity in omnibus, but it still requires a few extra configurations.


To make sure your configuration is correct:

  1. SSH into your GitLab application server
  2. Enter the Rails console:

    # For Omnibus installations
    sudo gitlab-rails console
    
    # For source installations
    sudo -u git rails console -e production
    
  3. Run in the console:

    redis = Redis.new(Gitlab::Redis::SharedState.params)
    redis.info
    

    Keep this screen open and try to simulate a failover below.

  4. To simulate a failover on primary Redis, SSH into the Redis server and run:

    # port must match your primary redis port, and the sleep time must be a few seconds bigger than defined one
     redis-cli -h localhost -p 6379 DEBUG sleep 20
    
  5. Then back in the Rails console from the first step, run:

    redis.info
    

    You should see a different port after a few seconds delay (the failover/reconnect time).

Troubleshooting Gitaly

For troubleshooting information, see Gitaly and Gitaly Cluster troubleshooting information.

Troubleshooting the GitLab Rails application

  • mount: wrong fs type, bad option, bad superblock on

You have not installed the necessary NFS client utilities. See step 1 above.

  • mount: mount point /var/opt/gitlab/... does not exist

This particular directory does not exist on the NFS server. Ensure the share is exported and exists on the NFS server and try to remount.

Troubleshooting Monitoring

If the monitoring node is not receiving any data, check that the exporters are capturing data.

curl "http[s]://localhost:<EXPORTER LISTENING PORT>/metric"

or

curl "http[s]://localhost:<EXPORTER LISTENING PORT>/-/metric"

Troubleshooting PgBouncer

In case you are experiencing any issues connecting through PgBouncer, the first place to check is always the logs:

sudo gitlab-ctl tail pgbouncer

Additionally, you can check the output from show databases in the administrative console. In the output, you would expect to see values in the host field for the gitlabhq_production database. Additionally, current_connections should be greater than 1.

PgBouncer administrative console

As part of Omnibus GitLab, the gitlab-ctl pgb-console command is provided to automatically connect to the PgBouncer administrative console. See the PgBouncer documentation for detailed instructions on how to interact with the console.

To start a session:

sudo gitlab-ctl pgb-console

The password you will be prompted for is the pgbouncer_user_password

To get some basic information about the instance, run

pgbouncer=# show databases; show clients; show servers;
        name         |   host    | port |      database       | force_user | pool_size | reserve_pool | pool_mode | max_connections | current_connections
---------------------+-----------+------+---------------------+------------+-----------+--------------+-----------+-----------------+---------------------
 gitlabhq_production | 127.0.0.1 | 5432 | gitlabhq_production |            |       100 |            5 |           |               0 |                   1
 pgbouncer           |           | 6432 | pgbouncer           | pgbouncer  |         2 |            0 | statement |               0 |                   0
(2 rows)

 type |   user    |      database       | state  |   addr    | port  | local_addr | local_port |    connect_time     |    request_time     |    ptr    | link
| remote_pid | tls
------+-----------+---------------------+--------+-----------+-------+------------+------------+---------------------+---------------------+-----------+------
+------------+-----
 C    | gitlab    | gitlabhq_production | active | 127.0.0.1 | 44590 | 127.0.0.1  |       6432 | 2018-04-24 22:13:10 | 2018-04-24 22:17:10 | 0x12444c0 |
|          0 |
 C    | gitlab    | gitlabhq_production | active | 127.0.0.1 | 44592 | 127.0.0.1  |       6432 | 2018-04-24 22:13:10 | 2018-04-24 22:17:10 | 0x12447c0 |
|          0 |
 C    | gitlab    | gitlabhq_production | active | 127.0.0.1 | 44594 | 127.0.0.1  |       6432 | 2018-04-24 22:13:10 | 2018-04-24 22:17:10 | 0x1244940 |
|          0 |
 C    | gitlab    | gitlabhq_production | active | 127.0.0.1 | 44706 | 127.0.0.1  |       6432 | 2018-04-24 22:14:22 | 2018-04-24 22:16:31 | 0x1244ac0 |
|          0 |
 C    | gitlab    | gitlabhq_production | active | 127.0.0.1 | 44708 | 127.0.0.1  |       6432 | 2018-04-24 22:14:22 | 2018-04-24 22:15:15 | 0x1244c40 |
|          0 |
 C    | gitlab    | gitlabhq_production | active | 127.0.0.1 | 44794 | 127.0.0.1  |       6432 | 2018-04-24 22:15:15 | 2018-04-24 22:15:15 | 0x1244dc0 |
|          0 |
 C    | gitlab    | gitlabhq_production | active | 127.0.0.1 | 44798 | 127.0.0.1  |       6432 | 2018-04-24 22:15:15 | 2018-04-24 22:16:31 | 0x1244f40 |
|          0 |
 C    | pgbouncer | pgbouncer           | active | 127.0.0.1 | 44660 | 127.0.0.1  |       6432 | 2018-04-24 22:13:51 | 2018-04-24 22:17:12 | 0x1244640 |
|          0 |
(8 rows)

 type |  user  |      database       | state |   addr    | port | local_addr | local_port |    connect_time     |    request_time     |    ptr    | link | rem
ote_pid | tls
------+--------+---------------------+-------+-----------+------+------------+------------+---------------------+---------------------+-----------+------+----
--------+-----
 S    | gitlab | gitlabhq_production | idle  | 127.0.0.1 | 5432 | 127.0.0.1  |      35646 | 2018-04-24 22:15:15 | 2018-04-24 22:17:10 | 0x124dca0 |      |
  19980 |
(1 row)

Message: LOG: invalid CIDR mask in address

See the suggested fix in Geo documentation.

Message: LOG: invalid IP mask "md5": Name or service not known

See the suggested fix in Geo documentation.

Troubleshooting PostgreSQL with Patroni

In case you are experiencing any issues connecting through PgBouncer, the first place to check is always the logs for PostgreSQL (which is run through Patroni):

sudo gitlab-ctl tail patroni

Consul and PostgreSQL with Patroni changes not taking effect

Due to the potential impacts, gitlab-ctl reconfigure only reloads Consul and PostgreSQL, it will not restart the services. However, not all changes can be activated by reloading.

To restart either service, run gitlab-ctl restart consul or gitlab-ctl restart patroni respectively.

For PostgreSQL with Patroni, to prevent the primary node from being failed over automatically, it’s safest to stop all secondaries first, then restart the primary and finally restart the secondaries again.

On the Consul server nodes, it is important to restart the Consul service in a controlled fashion. Read our Consul documentation for instructions on how to restart the service.

PgBouncer error ERROR: pgbouncer cannot connect to server

You may get this error when running gitlab-rake gitlab:db:configure or you may see the error in the PgBouncer log file.

PG::ConnectionBad: ERROR:  pgbouncer cannot connect to server

The problem may be that your PgBouncer node’s IP address is not included in the trust_auth_cidr_addresses setting in /etc/gitlab/gitlab.rb on the database nodes.

You can confirm that this is the issue by checking the PostgreSQL log on the master database node. If you see the following error then trust_auth_cidr_addresses is the problem.

2018-03-29_13:59:12.11776 FATAL:  no pg_hba.conf entry for host "123.123.123.123", user "pgbouncer", database "gitlabhq_production", SSL off

To fix the problem, add the IP address to /etc/gitlab/gitlab.rb.

postgresql['trust_auth_cidr_addresses'] = %w(123.123.123.123/32 <other_cidrs>)

Reconfigure GitLab for the changes to take effect.