Project: ClickHouse (App Definition and Development / Database)
File: _troubleshooting.md

Check firewall settings. If you cannot access the repository for any reason, download packages as described in the article and install them manually using the `sudo dpkg -i <packages>` command. You will also need the `tzdata` package. The issue may be happened when the GPG key is changed. Please use the manual from the page to update the repository configuration. 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: ```bash 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 ``` 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 Possible issues: The server is not running. Unexpected or wrong configuration parameters. Check if server is running Command: ``` bash $ sudo service clickhouse-server status ``` If the server is not running, start it with the command: ``` bash $ sudo service clickhouse-server start ``` Check 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: ``` text 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 do not see an error at the end of the file, look through the entire file starting from the string: ``` text <Information> Application: starting up. ``` If you try to start a second instance of `clickhouse-server` on the server, you see the following log: ``` text 2019.01.11 15:25:11.151730 [ 1 ] {} <Information> : Starting ClickHouse

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 If you do not find any useful information in `clickhouse-server` logs or there arent any logs, you can view `system.d` logs using the command: ``` bash $ sudo journalctl -u clickhouse-server ``` Start clickhouse-server in interactive mode ``` bash $ 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. Check: Docker settings. If you run ClickHouse in Docker in an IPv6 network, make sure that `network=host` is set. Endpoint settings. Check and settings. ClickHouse server accepts localhost connections only by default. HTTP protocol settings. Check protocol settings for the HTTP API. Secure connection settings. Check: The setting. Settings for . Use proper parameters while connecting. For example, use the `portsecure` parameter with `clickhouseclient`. User settings. You might be using the wrong user name or password. If ClickHouse is not able to process the query, it sends an error description to the client. In the `clickhouse-client` you get a description of the error in the console. If you are using the HTTP interface, ClickHouse sends the error description in the response body. For example: ``` bash $ curl 'http://localhost:8123/' --data-binary "SELECT a" Code: 47, e.displayText() = DB::Exception: Unknown identifier: a. Note that there are no tables (FROM clause) in your query, context: requirednames: 'a' sourcetables: tablealiases: privatealiases: columnaliases: publiccolumns: 'a' maskedcolumns: arrayjoincolumns: sourcecolumns: , e.what() = DB::Exception ``` If you start `clickhouse-client` with the `stack-trace` parameter, ClickHouse returns the server stack trace with the description of an error. You might see a message about a broken connection. In this case, you can repeat the query. If the connection breaks every time you perform the query, check the server logs for errors. If you see that ClickHouse is working too slowly, you need to profile the load on the server resources and network for your queries. You can use the clickhouse-benchmark utility to profile queries. It shows the number of queries processed per second, the number of rows processed per second, and percentiles of query processing times.