# Binlog
> - **Objective:** Learn to use Binlog to sync data between TiDB cluster on AWS (with Kubernetes)
> - **Prerequisites:**
> - Background knowledge of TiDB components
> - Background knowledge of Kubernetes and TiDB Operator
> - Background knowledge of [Binlog](https://pingcap.com/docs/stable/reference/tidb-binlog/overview/#tidb-binlog-cluster-overview)
> - AWS account
> - TiDB cluster on AWS
> - **Optionality:** Optional
> - **Estimated time:** 30 mins

## Deploy Downstream TiDB Cluster
> - **Optionality:** Optional

TODO: extract instructions on how to deploy a second TiDB cluster.

If you have a downstream cluster already deployed, you can skip this section.

## Provision Binlog Nodes

TODO: The provision script does not support this feature yet. We will modify provision script to provide this.

## Deploy Binglog

Currently we have two TiDB cluster with two namespace.

we need deploy Binlog components(pump & drainer) in first cluster.

### Deploy Pump

$ kubectl edit tc ${upstream} -n ${upstream_namespace}

add pump in spec:

spec
  pump:
    baseImage: pingcap/tidb-binlog
    replicas: 1
    storageClassName: ebs-gp2
    requests:
      storage: 30Gi
    schedulerName: default-scheduler
    config:
      addr: 0.0.0.0:8250
      gc: 7
      heartbeat-interval: 2

----
**NOTE**

The Pump version need to be the as same as the TiDB version.

---

Confirm that pump pod is running:

$ kubectl get pod -n ${namespace}

### Deploy Drainer

#### Configure Drainer

$ helm repo update

You can search for the available versions

$ helm search tidb-drainer -l

pingcap/tidb-drainer	v1.1.0       	           	A Helm chart for TiDB Binlog drainer.
pingcap/tidb-drainer	v1.0.6       	           	A Helm chart for TiDB Binlog drainer.
pingcap/tidb-drainer	v1.0.5       	           	A Helm chart for TiDB Binlog drainer.
pingcap/tidb-drainer	v1.0.4       	           	A Helm chart for TiDB Binlog drainer.
pingcap/tidb-drainer	latest       	           	A Helm chart for TiDB Binlog drainer.
pingcap/tidb-drainer	dev          	           	A Helm chart for TiDB Binlog drainer.

$ helm inspect values pingcap/tidb-drainer --version=v1.1.0 > values-drainer.yaml

You need to configure

clusterName: basic
clusterVersion: v4.0.0
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 = 10.106.173.83
  user = "root"
  password = ""
  port = 4000

#### Install Drainer

$ helm install pingcap/tidb-drainer --name=${upstream} --namespace=${upstream_namespace} --version=v1.1.0 -f values-drainer.yaml

### Run Sysbench

1. Login to the bastion machine:

$ ssh -i credentials/${eks_name}.pem centos@${bastion_ip}

> - Note: Use `terraform output` to get bastion_ip

2. Create a database for sysbench

$ mysql -h ${first_cluster_tidb_ip} -P 4000 -u root
mysql> create database binlog;

3. Create a sysbench config file named `config`:

mysql-host=${first_cluster_tidb_ip}
mysql-port=4000
mysql-user=root
mysql-db=binlog
time=1200
threads=8
report-interval=10
db-driver=mysql

4. Prepare data:

$ sysbench --config-file=config oltp_point_select --tables=1 --table-size=1000 prepare

### Use admin checksum

#### check data is synced
1. Login to the bastion machine:

$ ssh -i credentials/${eks_name}.pem centos@${bastion_ip}

> - Note: Use `terraform output` to get bastion_ip
>

2. record upstream checksum

$ mysql -h ${first_cluster_tidb_ip} -P 4000 -u root
> admin checksum table binlog.sbtest1;

3. record downstream checksum

$ mysql -h ${first_cluster_tidb_ip} -P 4000 -u root
> admin checksum table binlog.sbtest1;