Maintain TiDB Binlog

This document describes how to maintain TiDB Binlog of a TiDB cluster in Kubernetes.

Prerequisites

• Deploy TiDB Operator;
• Install Helm and configure it with the official PingCAP chart.

Enable TiDB Binlog of a TiDB cluster

TiDB Binlog is disabled in the TiDB cluster by default. To create a TiDB cluster with TiDB Binlog enabled, or enable TiDB Binlog in an existing TiDB cluster:

1. Modify the values.yaml file as described below:

   • Set binlog.pump.create to true.
   • Set binlog.drainer.create to true.
   • Set binlog.pump.storageClassName and binlog.drainer.storageClassName to an available storageClass in your Kubernetes cluster.

   • Set binlog.drainer.destDBType to your desired downstream storage as needed, which is explained in details below.

     TiDB Binlog supports three types of downstream storage:

     • PersistenceVolume: the default downstream storage. You can configure a large PV for drainer (by modifying binlog.drainer.storage) in this case.
     • MySQL compatible databases: enabled by setting binlog.drainer.destDBType to mysql. Meanwhile, you must configure the address and credential of the target database in binlog.drainer.mysql.
     • Apache Kafka: enabled by setting binlog.drainer.destDBType to kafka. Meanwhile, you must configure the zookeeper address and Kafka address of the target cluster in binlog.drainer.kafka.

2. Create a new TiDB cluster or update an existing cluster:

   • Create a new TiDB cluster with TiDB Binlog enabled:

     helm install pingcap/tidb-cluster --name=<release-name> --namespace=<namespace> --version=<chart-version> -f <values-file>

   • Update an existing TiDB cluster to enable TiDB Binlog:

     helm upgrade <release-name> pingcap/tidb-cluster --version=<chart-version> -f <values-file>

Deploy multiple drainers

By default, only one downstream drainer is created. You can install the tidb-drainer Helm chart to deploy more drainers for a TiDB cluster, as described below:

1. Make sure that the PingCAP Helm repository is up to date:

   helm repo update

   helm search tidb-drainer -l

2. Get the default values.yaml file to facilitate customization:

   helm inspect values pingcap/tidb-drainer --version=<chart-version> > values.yaml

3. Modify the values.yaml file to specify the source TiDB cluster and the downstream database of the drainer. Here is an example:

   clusterName: example-tidb
   clusterVersion: v3.0.0
   storageClassName: local-storage
   storage: 10Gi
   config: |
     detect-interval = 10
     [syncer]
     worker-count = 16
     txn-batch = 20
     disable-dispatch = false
     ignore-schemas = "INFORMATION_SCHEMA,PERFORMANCE_SCHEMA,mysql"
     safe-mode = false
     db-type = "tidb"
     [syncer.to]
     host = "slave-tidb"
     user = "root"
     password = ""
     port = 4000

   The clusterName and clusterVersion must match the desired source TiDB cluster.

   For complete configuration details, refer to TiDB Binlog Drainer Configurations in Kubernetes.

4. Deploy the drainer:

   helm install pingcap/tidb-drainer --name=<release-name> --namespace=<namespace> --version=<chart-version> -f values.yaml

   Note:

   This chart must be installed to the same namespace as the source TiDB cluster.