Connect MySQL

Connect MySQL by creating a monitoring user, confirming that performance_schema captures statement digests, and running the QueryComment collector.

Prepare MySQL

Create the monitoring user

Connect as a MySQL user with grant privileges and run:

CREATE USER 'querycomment'@'%' IDENTIFIED BY 'replace-with-strong-password';
GRANT SELECT, PROCESS, REPLICATION CLIENT ON *.* TO 'querycomment'@'%';
FLUSH PRIVILEGES;

PROCESS lets the collector inspect thread state and InnoDB status. REPLICATION CLIENT lets it read replication status when replicas are present.

Replace '%' with the collector host or subnet when you want to restrict where the monitoring user can connect from.

Enable statement digests

QueryComment uses performance_schema.events_statements_summary_by_digest for normalized query statistics.Confirm that performance_schema is enabled:

SHOW VARIABLES LIKE 'performance_schema';

Confirm that statement digests are being collected:

SELECT NAME, ENABLED
FROM performance_schema.setup_consumers
WHERE NAME = 'statements_digest';

If the consumer is disabled, enable it as an administrator:

UPDATE performance_schema.setup_consumers
SET ENABLED = 'YES'
WHERE NAME = 'statements_digest';

Verify access

Confirm the monitoring user has the required grants and that digest rows exist:

SHOW GRANTS FOR 'querycomment'@'%';

SELECT COUNT(*)
FROM performance_schema.events_statements_summary_by_digest;

If the digest table is empty, run a representative workload against the database and check again.

Collector connection values

Use the QueryComment collector with the bundled MySQL receiver. The collector is available as the ghcr.io/querycomment/collector:0.1.2 Docker image or as a release package for your operating system. Set these environment variables before starting the collector:

Variable	Description
`MYSQL_HOST`	MySQL host name or IP address.
`MYSQL_PORT`	MySQL port. Defaults to `3306` if omitted.
`MYSQL_USER`	Monitoring user name.
`MYSQL_PASSWORD`	Monitoring user password.
`MYSQL_DATABASE`	Database to connect to.
`MYSQL_TLS_INSECURE`	Optional. Set to `true` only when the connection should skip TLS. Defaults to `false`.
`MYSQL_TLS_SKIP_VERIFY`	Optional. Set to `true` only when TLS certificate verification should be skipped. Defaults to `false`.
`QC_ENDPOINT`	Optional QueryComment ingest endpoint. Defaults to `ingest.querycomment.com:443`.
`QC_INGEST_TOKEN`	QueryComment ingest token from your dashboard.
`QC_DATABASE_NAME`	Database or cluster name to attach to exported metrics.
`OTEL_ENVIRONMENT`	Deployment environment. Defaults to `production` if omitted.

Example .env file:

MYSQL_HOST=db.example.com
MYSQL_PORT=3306
MYSQL_USER=querycomment
MYSQL_PASSWORD=replace-with-strong-password
MYSQL_DATABASE=app

QC_INGEST_TOKEN=replace-with-querycomment-ingest-token
QC_DATABASE_NAME=production-mysql
OTEL_ENVIRONMENT=production

Run the collector with Docker:

docker run --rm \
  --env-file .env \
  ghcr.io/querycomment/collector:0.1.2 \
  --config /etc/querycommentcol/mysql.yaml

Or choose the release package for your operating system and architecture. This example uses Linux amd64:

curl -L -o querycommentcol_0.1.2_linux_amd64.tar.gz \
  https://github.com/querycomment/collector/releases/download/v0.1.2/querycommentcol_0.1.2_linux_amd64.tar.gz
tar -xzf querycommentcol_0.1.2_linux_amd64.tar.gz
cd querycommentcol_0.1.2_linux_amd64
set -a
. ../.env
set +a
./querycommentcol --config config/mysql.yaml

Get started

Databases

Prepare MySQL

Collector connection values

​Prepare MySQL

​Collector connection values

Prepare MySQL

Collector connection values