Troubleshooting

[Edit this page](https://github.com/ClickHouse/clickhouse-docs/blob/main/docs/guides/troubleshooting.md)

## Installation[​](#installation "Direct link to Installation")

### Can't import GPG keys from keyserver.ubuntu.com with apt-key[​](#cant-import-gpg-keys-from-keyserverubuntucom-with-apt-key "Direct link to Can't import GPG keys from keyserver.ubuntu.com with apt-key")

The `apt-key` feature with the [Advanced package tool (APT) has been deprecated](https://manpages.debian.org/bookworm/apt/apt-key.8.en.html). You should use the `gpg` command instead. Please refer the [install guide](/docs/install) article.

### Can't import GPG keys from keyserver.ubuntu.com with gpg[​](#cant-import-gpg-keys-from-keyserverubuntucom-with-gpg "Direct link to Can't import GPG keys from keyserver.ubuntu.com with gpg")

1. See if your `gpg` is installed:

```
sudo apt-get install gnupg
```

### Can't get deb packages from ClickHouse repository with apt-get[​](#cant-get-deb-packages-from-clickhouse-repository-with-apt-get "Direct link to Can't get deb packages from ClickHouse repository with apt-get")

1. Check firewall settings.
2. If you can't access the repository for any reason, download packages as described in the [install guide](/docs/install) article and install them manually using the `sudo dpkg -i <packages>` command. You will also need the `tzdata` package.

### Can't update deb packages from ClickHouse repository with apt-get[​](#cant-update-deb-packages-from-clickhouse-repository-with-apt-get "Direct link to Can't update deb packages from ClickHouse repository with apt-get")

The issue may be happened when the GPG key is changed.

Please use the manual from the [setup](/docs/install/debian_ubuntu) page to update the repository configuration.

### You get different warnings with `apt-get update`[​](#you-get-different-warnings-with-apt-get-update "Direct link to you-get-different-warnings-with-apt-get-update")

The completed warning messages are as one of following:

```
N: Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'https://packages.clickhouse.com/deb stable InRelease' doesn't support architecture 'i386'
```

```
E: Failed to fetch https://packages.clickhouse.com/deb/dists/stable/main/binary-amd64/Packages.gz  File has unexpected size (30451 != 28154). Mirror sync in progress?
```

```
E: Repository 'https://packages.clickhouse.com/deb stable InRelease' changed its 'Origin' value from 'Artifactory' to 'ClickHouse'
E: Repository 'https://packages.clickhouse.com/deb stable InRelease' changed its 'Label' value from 'Artifactory' to 'ClickHouse'
N: Repository 'https://packages.clickhouse.com/deb stable InRelease' changed its 'Suite' value from 'stable' to ''
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.
```

```
Err:11 https://packages.clickhouse.com/deb stable InRelease
400  Bad Request [IP: 172.66.40.249 443]
```

To resolve the above issue, please use the following script:

```
sudo rm /var/lib/apt/lists/packages.clickhouse.com_* /var/lib/dpkg/arch /var/lib/apt/lists/partial/packages.clickhouse.com_*
sudo apt-get clean
sudo apt-get autoclean
```

### Can't get packages with Yum because of wrong signature[​](#cant-get-packages-with-yum-because-of-wrong-signature "Direct link to Can't get packages with Yum because of wrong signature")

Possible issue: the cache is wrong, maybe it's broken after updated GPG key in 2022-09.

The solution is to clean out the cache and lib directory for Yum:

```
sudo find /var/lib/yum/repos/ /var/cache/yum/ -name 'clickhouse-*' -type d -exec rm -rf {} +
sudo rm -f /etc/yum.repos.d/clickhouse.repo
```

After that follow the [install guide](/docs/install/redhat)

## Connecting to the server[​](#connecting-to-the-server "Direct link to Connecting to the server")

Possible issues:

- The server isn't running.
- Unexpected or wrong configuration parameters.

### Server isn't running[​](#server-is-not-running "Direct link to Server isn't running")

#### Check if server is running[​](#check-if-server-is-running "Direct link to Check if server is running")

```
sudo service clickhouse-server status
```

If the server isn't running, start it with the command:

```
sudo service clickhouse-server start
```

#### Check the logs[​](#check-the-logs "Direct link to Check the logs")

The main log of `clickhouse-server` is in `/var/log/clickhouse-server/clickhouse-server.log` by default.

If the server started successfully, you should see the strings:

- `<Information> Application: starting up.` — Server started.
- `<Information> Application: Ready for connections.` — Server is running and ready for connections.

If `clickhouse-server` start failed with a configuration error, you should see the `<Error>` string with an error description. For example:

```
2019.01.11 15:23:25.549505 [ 45 ] {} <Error> ExternalDictionaries: Failed reloading 'event2id' external dictionary: Poco::Exception. Code: 1000, e.code() = 111, e.displayText() = Connection refused, e.what() = Connection refused
```

If you don't see an error at the end of the file, look through the entire file starting from the string:

```
<Information> Application: starting up.
```

If you try to start a second instance of `clickhouse-server` on the server, you see the following log:

```
2019.01.11 15:25:11.151730 [ 1 ] {} <Information> : Starting ClickHouse 19.1.0 with revision 54413
2019.01.11 15:25:11.154578 [ 1 ] {} <Information> Application: starting up
2019.01.11 15:25:11.156361 [ 1 ] {} <Information> StatusFile: Status file ./status already exists - unclean restart. Contents:
PID: 8510
Started at: 2019-01-11 15:24:23
Revision: 54413

2019.01.11 15:25:11.156673 [ 1 ] {} <Error> Application: DB::Exception: Cannot lock file ./status. Another server instance in same directory is already running.
2019.01.11 15:25:11.156682 [ 1 ] {} <Information> Application: shutting down
2019.01.11 15:25:11.156686 [ 1 ] {} <Debug> Application: Uninitializing subsystem: Logging Subsystem
2019.01.11 15:25:11.156716 [ 2 ] {} <Information> BaseDaemon: Stop SignalListener thread
```

#### See system.d logs[​](#see-systemd-logs "Direct link to See system.d logs")

If you don't find any useful information in `clickhouse-server` logs or there aren't any logs, you can view `system.d` logs using the command:

```
sudo journalctl -u clickhouse-server
```

#### Start clickhouse-server in interactive mode[​](#start-clickhouse-server-in-interactive-mode "Direct link to Start clickhouse-server in interactive mode")

```
sudo -u clickhouse /usr/bin/clickhouse-server --config-file /etc/clickhouse-server/config.xml
```

This command starts the server as an interactive app with standard parameters of the autostart script. In this mode `clickhouse-server` prints all the event messages in the console.

### Configuration parameters[​](#configuration-parameters "Direct link to Configuration parameters")

Check:

1. Docker settings:

   - If you run ClickHouse in Docker in an IPv6 network, make sure that `network=host` is set.
2. Endpoint settings.

   - Check [listen\_host](/docs/operations/server-configuration-parameters/settings#listen_host) and [tcp\_port](/docs/operations/server-configuration-parameters/settings#tcp_port) settings.
   - ClickHouse server accepts localhost connections only by default.
3. HTTP protocol settings:

   - Check protocol settings for the HTTP API.
4. Secure connection settings.

   - Check:
     - The [tcp\_port\_secure](/docs/operations/server-configuration-parameters/settings#tcp_port_secure) setting.
     - Settings for [SSL certificates](/docs/operations/server-configuration-parameters/settings#openssl).
   - Use proper parameters while connecting. For example, use the `port_secure` parameter with `clickhouse_client`.
5. User settings:

   - You might be using the wrong user name or password.

## Query processing[​](#query-processing "Direct link to Query processing")