ClickHouse

The ClickHouse integration requires CXDOT Collector 1.4.0 or greater. ClickHouse is a column-oriented database for real-time analytics. Use the ClickHouse integration to collect query, connection, merge, and replication metrics from ClickHouse servers running in your environment. The ClickHouse integration supports ClickHouse 26.3 or greater.

​

Supported telemetry types

The ClickHouse integration supports these telemetry types:

​

Prerequisites

The ClickHouse integration has the following prerequisites:

• A ClickHouse HTTP interface that the Chronosphere XDOT Collector can reach.
• A ClickHouse account that can run SELECT 1 and read the system.metrics, system.events, system.asynchronous_metrics, system.parts, system.replicas, and system.dictionaries tables.

​

Configure

To configure the ClickHouse integration, follow these steps:

1. For discovered ClickHouse targets, provide the HTTP endpoint and credentials through autodiscovery annotations. For more information, see autodiscovery.
2. Optional: Manually configure ClickHouse servers as an alternative to autodiscovery. List each HTTP interface URL under instances, and provide the password through your deployment’s secret management. For example, the following Helm values reference the CLICKHOUSE_PASSWORD environment variable:
   config:
     integrations:
       clickhouse:
         instances:
           - endpoint: http://clickhouse.example.com:8123
         username: default
         password: "${env:CLICKHOUSE_PASSWORD}"
   

​

Validate

To validate the ClickHouse integration, follow these steps:

1. In Live Telemetry Analyzer, filter for cxdot.integration.name=clickhouse. Confirm that the ClickHouse metric names appear.
2. In Metrics Explorer, run the following query while the ClickHouse servers process queries:
   sum by ("server.address", "server.port") (rate({"clickhouse.query.count"}[$__rate_interval]))
   
   Confirm that the query returns the expected time series for each target.

​

Troubleshooting

• Some expected ClickHouse metrics are missing: Confirm that the ClickHouse account can read every system table listed in the prerequisites. The integration collects different metric groups from different system tables, so a permissions error can affect only part of the collected data.

For more information about diagnosing a failing integration, see Troubleshooting.

​

Configuration reference

Configure one ClickHouse integration instance with the following settings. In Helm values, place these settings under config.integrations.clickhouse. In a Collector configuration file, place them under cxdot.integrations.clickhouse.

​

Optional settings

• enabled Type: boolean. Optional. Default: true. Whether to enable this ClickHouse integration instance. If true, the Collector runs the instance. If false, the Collector doesn’t run it.
• username Type: string. Optional. Default: default. ClickHouse user name for static instance connections.
• password Type: string. Optional. ClickHouse password for static instance connections. The Collector masks this sensitive value in diagnostic output, logs, and errors.
• database Type: string. Optional. Default: default. Database to attach the connection to.
• collection_interval Type: duration. Optional. Default: 15s. How often the Collector collects metrics from each ClickHouse target.
• timeout Type: duration. Optional. Default: 15s. Maximum time allowed to collect metrics from one ClickHouse instance. The value must not exceed collection_interval.
• instances Type: array of object. Optional. Static ClickHouse instances. A nonempty list disables automatic discovery for this integration instance, and the Collector collects metrics from only the listed instances. Specify each endpoint as the full URL of the ClickHouse HTTP interface, such as http://clickhouse.default.svc:8123. Use an HTTPS URL and the tls settings for a connection that uses TLS.
• instances[].endpoint Type: string. Required. URL of the instance’s HTTP interface.
• tls Type: object. Optional. Transport layer security (TLS) settings for static HTTPS instances. Certificate verification is enabled unless insecure_skip_verify is true. These settings don’t apply to HTTP instances or targets configured through discovery annotations.
• tls.ca_file Type: string. Optional. Path to the CA cert. For a client this verifies the server certificate. For a server this verifies client certificates. If empty uses system root CA. (optional)
• tls.ca_pem Type: string. Optional. In memory PEM encoded cert. (optional)
• tls.cert_file Type: string. Optional. Path to the TLS cert to use for TLS required connections. (optional)
• tls.cert_pem Type: string. Optional. In memory PEM encoded TLS cert to use for TLS required connections. (optional)
• tls.cipher_suites Type: array of string. Optional. CipherSuites is a list of TLS cipher suites that the TLS transport can use. If left blank, a safe default list is used. See https://go.dev/src/crypto/tls/cipher_suites.go for a list of supported cipher suites.
• tls.curve_preferences Type: array of string. Optional. contains the elliptic curves that will be used in an ECDHE handshake, in preference order Defaults to empty list and “crypto/tls” defaults are used, internally.
• tls.include_system_ca_certs_pool Type: boolean. Optional. If true, load system CA certificates pool in addition to the certificates configured in this struct.
• tls.insecure Type: boolean. Optional. In gRPC and HTTP when set to true, this is used to disable the client transport security. See https://godoc.org/google.golang.org/grpc#WithInsecure for gRPC. Please refer to https://godoc.org/crypto/tls#Config for more information. (optional, default false)
• tls.insecure_skip_verify Type: boolean. Optional. InsecureSkipVerify will enable TLS but not verify the certificate.
• tls.key_file Type: string. Optional. Path to the TLS key to use for TLS required connections. (optional)
• tls.key_pem Type: string. Optional. In memory PEM encoded TLS key to use for TLS required connections. (optional)
• tls.max_version Type: string. Optional. MaxVersion sets the maximum TLS version that is acceptable. If not set, refer to crypto/tls for defaults. (optional)
• tls.min_version Type: string. Optional. MinVersion sets the minimum TLS version that is acceptable. If not set, TLS 1.2 will be used. (optional)
• tls.reload_interval Type: duration. Optional. ReloadInterval specifies the duration after which the certificate will be reloaded If not set, it will never be reloaded (optional)
• tls.server_name_override Type: string. Optional. ServerName requested by client for virtual hosting. This sets the ServerName in the TLSConfig. Please refer to https://godoc.org/crypto/tls#Config for more information. (optional)
• tls.tpm Type: object. Optional. Trusted platform module configuration
• tls.tpm.auth Type: string. Optional. Authorization value for the trusted platform module key.
• tls.tpm.enabled Type: boolean. Optional. Whether to use a trusted platform module for the TLS private key. If true, the Collector loads the key from the configured device or socket. If false, the Collector uses the configured key file or in-memory key.
• tls.tpm.owner_auth Type: string. Optional. Owner authorization value for the trusted platform module.
• tls.tpm.path Type: string. Optional. The path to the TPM device or Unix domain socket. For instance /dev/tpm0 or /dev/tpmrm0.